diff --git a/Cargo.toml b/Cargo.toml
index 9bbe5b833..2417a92eb 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -4,6 +4,9 @@ version = "0.1.0"
 authors = ["dignifiedquire <dignifiedquire@gmail.com>"]
 edition = "2018"
 
+[lib]
+name = "deltachat"
+crate-type = ["cdylib", "staticlib"]
 
 [build-dependencies]
 cc = "1.0.35"
diff --git a/build.rs b/build.rs
index 803d68b4f..cbe765768 100644
--- a/build.rs
+++ b/build.rs
@@ -2,6 +2,8 @@ extern crate cc;
 
 use std::env;
 
+const VERSION: &'static str = env!("CARGO_PKG_VERSION");
+
 fn main() {
     let mut config = cc::Build::new();
     config.file("misc.h");
@@ -31,10 +33,23 @@ fn main() {
     }
 
     let crate_dir = env::var("CARGO_MANIFEST_DIR").unwrap();
-
-    cbindgen::Builder::new()
+    let cfg = cbindgen::Config::from_root_or_default(std::path::Path::new(&crate_dir));
+    let c = cbindgen::Builder::new()
+        .with_config(cfg)
         .with_crate(crate_dir)
-        .generate()
-        .expect("Unable to generate bindings")
-        .write_to_file("deltachat.h");
+        .with_header(format!("/* deltachat Header Version {} */", VERSION))
+        // .with_language(cbindgen::Language::C)
+        .generate();
+
+    // This is needed to ensure we don't panic if there are errors in the crates code
+    // but rather just tell the rest of the system we can't proceed.
+    match c {
+        Ok(res) => {
+            res.write_to_file("deltachat.h");
+        }
+        Err(err) => {
+            eprintln!("unable to generate bindings: {:#?}", err);
+            std::process::exit(1);
+        }
+    }
 }
diff --git a/src/dc_aheader.rs b/src/dc_aheader.rs
index d537c741c..ea5b7c301 100644
--- a/src/dc_aheader.rs
+++ b/src/dc_aheader.rs
@@ -20,8 +20,7 @@ pub struct dc_aheader_t {
 }
 
 /* the returned pointer is ref'd and must be unref'd after usage */
-#[no_mangle]
-pub unsafe extern "C" fn dc_aheader_new() -> *mut dc_aheader_t {
+pub unsafe fn dc_aheader_new() -> *mut dc_aheader_t {
     let mut aheader: *mut dc_aheader_t = 0 as *mut dc_aheader_t;
     aheader = calloc(
         1i32 as libc::c_ulong,
@@ -33,8 +32,7 @@ pub unsafe extern "C" fn dc_aheader_new() -> *mut dc_aheader_t {
     (*aheader).public_key = dc_key_new();
     return aheader;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_aheader_new_from_imffields(
+pub unsafe fn dc_aheader_new_from_imffields(
     mut wanted_from: *const libc::c_char,
     mut header: *const mailimf_fields,
 ) -> *mut dc_aheader_t {
@@ -84,8 +82,7 @@ pub unsafe extern "C" fn dc_aheader_new_from_imffields(
     }
     return fine_header;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_aheader_unref(mut aheader: *mut dc_aheader_t) {
+pub unsafe fn dc_aheader_unref(mut aheader: *mut dc_aheader_t) {
     if aheader.is_null() {
         return;
     }
@@ -93,8 +90,7 @@ pub unsafe extern "C" fn dc_aheader_unref(mut aheader: *mut dc_aheader_t) {
     dc_key_unref((*aheader).public_key);
     free(aheader as *mut libc::c_void);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_aheader_set_from_string(
+pub unsafe fn dc_aheader_set_from_string(
     mut aheader: *mut dc_aheader_t,
     mut header_str__: *const libc::c_char,
 ) -> libc::c_int {
@@ -167,8 +163,7 @@ pub unsafe extern "C" fn dc_aheader_set_from_string(
     }
     return success;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_aheader_empty(mut aheader: *mut dc_aheader_t) {
+pub unsafe fn dc_aheader_empty(mut aheader: *mut dc_aheader_t) {
     if aheader.is_null() {
         return;
     }
@@ -183,7 +178,7 @@ pub unsafe extern "C" fn dc_aheader_empty(mut aheader: *mut dc_aheader_t) {
 /* ******************************************************************************
  * Parse Autocrypt Header
  ******************************************************************************/
-unsafe extern "C" fn add_attribute(
+unsafe fn add_attribute(
     mut aheader: *mut dc_aheader_t,
     mut name: *const libc::c_char,
     mut value: *const libc::c_char,
@@ -225,8 +220,7 @@ unsafe extern "C" fn add_attribute(
     }
     return 0i32;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_aheader_render(mut aheader: *const dc_aheader_t) -> *mut libc::c_char {
+pub unsafe fn dc_aheader_render(mut aheader: *const dc_aheader_t) -> *mut libc::c_char {
     let mut success: libc::c_int = 0i32;
     let mut keybase64_wrapped: *mut libc::c_char = 0 as *mut libc::c_char;
     let mut ret: dc_strbuilder_t = dc_strbuilder_t {
diff --git a/src/dc_apeerstate.rs b/src/dc_apeerstate.rs
index 8760727d3..32f695a2d 100644
--- a/src/dc_apeerstate.rs
+++ b/src/dc_apeerstate.rs
@@ -37,8 +37,7 @@ pub struct dc_apeerstate_t {
 }
 
 /* the returned pointer is ref'd and must be unref'd after usage */
-#[no_mangle]
-pub unsafe extern "C" fn dc_apeerstate_new(mut context: *mut dc_context_t) -> *mut dc_apeerstate_t {
+pub unsafe fn dc_apeerstate_new(mut context: *mut dc_context_t) -> *mut dc_apeerstate_t {
     let mut peerstate: *mut dc_apeerstate_t = 0 as *mut dc_apeerstate_t;
     peerstate = calloc(
         1i32 as libc::c_ulong,
@@ -50,15 +49,14 @@ pub unsafe extern "C" fn dc_apeerstate_new(mut context: *mut dc_context_t) -> *m
     (*peerstate).context = context;
     return peerstate;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_apeerstate_unref(mut peerstate: *mut dc_apeerstate_t) {
+pub unsafe fn dc_apeerstate_unref(mut peerstate: *mut dc_apeerstate_t) {
     dc_apeerstate_empty(peerstate);
     free(peerstate as *mut libc::c_void);
 }
 /* ******************************************************************************
  * dc_apeerstate_t represents the state of an Autocrypt peer - Load/save
  ******************************************************************************/
-unsafe extern "C" fn dc_apeerstate_empty(mut peerstate: *mut dc_apeerstate_t) {
+unsafe fn dc_apeerstate_empty(mut peerstate: *mut dc_apeerstate_t) {
     if peerstate.is_null() {
         return;
     }
@@ -83,8 +81,7 @@ unsafe extern "C" fn dc_apeerstate_empty(mut peerstate: *mut dc_apeerstate_t) {
     (*peerstate).verified_key = 0 as *mut dc_key_t;
     (*peerstate).degrade_event = 0i32;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_apeerstate_init_from_header(
+pub unsafe fn dc_apeerstate_init_from_header(
     mut peerstate: *mut dc_apeerstate_t,
     mut header: *const dc_aheader_t,
     mut message_time: time_t,
@@ -103,10 +100,7 @@ pub unsafe extern "C" fn dc_apeerstate_init_from_header(
     dc_apeerstate_recalc_fingerprint(peerstate);
     return 1i32;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_apeerstate_recalc_fingerprint(
-    mut peerstate: *mut dc_apeerstate_t,
-) -> libc::c_int {
+pub unsafe fn dc_apeerstate_recalc_fingerprint(mut peerstate: *mut dc_apeerstate_t) -> libc::c_int {
     let mut success: libc::c_int = 0i32;
     let mut old_public_fingerprint: *mut libc::c_char = 0 as *mut libc::c_char;
     let mut old_gossip_fingerprint: *mut libc::c_char = 0 as *mut libc::c_char;
@@ -151,7 +145,6 @@ pub unsafe extern "C" fn dc_apeerstate_recalc_fingerprint(
     free(old_gossip_fingerprint as *mut libc::c_void);
     return success;
 }
-#[no_mangle]
 pub unsafe extern "C" fn dc_apeerstate_init_from_gossip(
     mut peerstate: *mut dc_apeerstate_t,
     mut gossip_header: *const dc_aheader_t,
@@ -169,8 +162,7 @@ pub unsafe extern "C" fn dc_apeerstate_init_from_gossip(
     dc_apeerstate_recalc_fingerprint(peerstate);
     return 1i32;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_apeerstate_degrade_encryption(
+pub unsafe fn dc_apeerstate_degrade_encryption(
     mut peerstate: *mut dc_apeerstate_t,
     mut message_time: time_t,
 ) -> libc::c_int {
@@ -185,8 +177,7 @@ pub unsafe extern "C" fn dc_apeerstate_degrade_encryption(
     (*peerstate).to_save |= 0x2i32;
     return 1i32;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_apeerstate_apply_header(
+pub unsafe fn dc_apeerstate_apply_header(
     mut peerstate: *mut dc_apeerstate_t,
     mut header: *const dc_aheader_t,
     mut message_time: time_t,
@@ -223,8 +214,7 @@ pub unsafe extern "C" fn dc_apeerstate_apply_header(
         }
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_apeerstate_apply_gossip(
+pub unsafe fn dc_apeerstate_apply_gossip(
     mut peerstate: *mut dc_apeerstate_t,
     mut gossip_header: *const dc_aheader_t,
     mut message_time: time_t,
@@ -251,8 +241,7 @@ pub unsafe extern "C" fn dc_apeerstate_apply_gossip(
         }
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_apeerstate_render_gossip_header(
+pub unsafe fn dc_apeerstate_render_gossip_header(
     mut peerstate: *const dc_apeerstate_t,
     mut min_verified: libc::c_int,
 ) -> *mut libc::c_char {
@@ -267,8 +256,7 @@ pub unsafe extern "C" fn dc_apeerstate_render_gossip_header(
     dc_aheader_unref(autocryptheader);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_apeerstate_peek_key(
+pub unsafe fn dc_apeerstate_peek_key(
     mut peerstate: *const dc_apeerstate_t,
     mut min_verified: libc::c_int,
 ) -> *mut dc_key_t {
@@ -293,8 +281,7 @@ pub unsafe extern "C" fn dc_apeerstate_peek_key(
     }
     return (*peerstate).gossip_key;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_apeerstate_set_verified(
+pub unsafe fn dc_apeerstate_set_verified(
     mut peerstate: *mut dc_apeerstate_t,
     mut which_key: libc::c_int,
     mut fingerprint: *const libc::c_char,
@@ -327,8 +314,7 @@ pub unsafe extern "C" fn dc_apeerstate_set_verified(
     }
     return success;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_apeerstate_load_by_addr(
+pub unsafe fn dc_apeerstate_load_by_addr(
     mut peerstate: *mut dc_apeerstate_t,
     mut sql: *mut dc_sqlite3_t,
     mut addr: *const libc::c_char,
@@ -350,7 +336,7 @@ pub unsafe extern "C" fn dc_apeerstate_load_by_addr(
     sqlite3_finalize(stmt);
     return success;
 }
-unsafe extern "C" fn dc_apeerstate_set_from_stmt(
+unsafe fn dc_apeerstate_set_from_stmt(
     mut peerstate: *mut dc_apeerstate_t,
     mut stmt: *mut sqlite3_stmt,
 ) {
@@ -378,8 +364,7 @@ unsafe extern "C" fn dc_apeerstate_set_from_stmt(
         dc_key_set_from_stmt((*peerstate).verified_key, stmt, 9i32, 0i32);
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_apeerstate_load_by_fingerprint(
+pub unsafe fn dc_apeerstate_load_by_fingerprint(
     mut peerstate: *mut dc_apeerstate_t,
     mut sql: *mut dc_sqlite3_t,
     mut fingerprint: *const libc::c_char,
@@ -403,8 +388,7 @@ pub unsafe extern "C" fn dc_apeerstate_load_by_fingerprint(
     sqlite3_finalize(stmt);
     return success;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_apeerstate_save_to_db(
+pub unsafe fn dc_apeerstate_save_to_db(
     mut peerstate: *const dc_apeerstate_t,
     mut sql: *mut dc_sqlite3_t,
     mut create: libc::c_int,
@@ -535,8 +519,7 @@ pub unsafe extern "C" fn dc_apeerstate_save_to_db(
     sqlite3_finalize(stmt);
     return success;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_apeerstate_has_verified_key(
+pub unsafe fn dc_apeerstate_has_verified_key(
     mut peerstate: *const dc_apeerstate_t,
     mut fingerprints: *const dc_hash_t,
 ) -> libc::c_int {
diff --git a/src/dc_array.rs b/src/dc_array.rs
index f6f56d7fb..4390821db 100644
--- a/src/dc_array.rs
+++ b/src/dc_array.rs
@@ -43,8 +43,7 @@ pub struct _dc_location {
  * The items of the array are typically IDs.
  * To free an array object, use dc_array_unref().
  */
-#[no_mangle]
-pub unsafe extern "C" fn dc_array_unref(mut array: *mut dc_array_t) {
+pub unsafe fn dc_array_unref(mut array: *mut dc_array_t) {
     if array.is_null() || (*array).magic != 0xa11aai32 as libc::c_uint {
         return;
     }
@@ -55,8 +54,7 @@ pub unsafe extern "C" fn dc_array_unref(mut array: *mut dc_array_t) {
     (*array).magic = 0i32 as uint32_t;
     free(array as *mut libc::c_void);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_array_free_ptr(mut array: *mut dc_array_t) {
+pub unsafe fn dc_array_free_ptr(mut array: *mut dc_array_t) {
     if array.is_null() || (*array).magic != 0xa11aai32 as libc::c_uint {
         return;
     }
@@ -73,8 +71,7 @@ pub unsafe extern "C" fn dc_array_free_ptr(mut array: *mut dc_array_t) {
         i = i.wrapping_add(1)
     }
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_array_add_uint(mut array: *mut dc_array_t, mut item: uintptr_t) {
+pub unsafe fn dc_array_add_uint(mut array: *mut dc_array_t, mut item: uintptr_t) {
     if array.is_null() || (*array).magic != 0xa11aai32 as libc::c_uint {
         return;
     }
@@ -97,36 +94,25 @@ pub unsafe extern "C" fn dc_array_add_uint(mut array: *mut dc_array_t, mut item:
     *(*array).array.offset((*array).count as isize) = item;
     (*array).count = (*array).count.wrapping_add(1);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_array_add_id(mut array: *mut dc_array_t, mut item: uint32_t) {
+pub unsafe fn dc_array_add_id(mut array: *mut dc_array_t, mut item: uint32_t) {
     dc_array_add_uint(array, item as uintptr_t);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_array_add_ptr(mut array: *mut dc_array_t, mut item: *mut libc::c_void) {
+pub unsafe fn dc_array_add_ptr(mut array: *mut dc_array_t, mut item: *mut libc::c_void) {
     dc_array_add_uint(array, item as uintptr_t);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_array_get_cnt(mut array: *const dc_array_t) -> size_t {
+pub unsafe fn dc_array_get_cnt(mut array: *const dc_array_t) -> size_t {
     if array.is_null() || (*array).magic != 0xa11aai32 as libc::c_uint {
         return 0i32 as size_t;
     }
     return (*array).count;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_array_get_uint(
-    mut array: *const dc_array_t,
-    mut index: size_t,
-) -> uintptr_t {
+pub unsafe fn dc_array_get_uint(mut array: *const dc_array_t, mut index: size_t) -> uintptr_t {
     if array.is_null() || (*array).magic != 0xa11aai32 as libc::c_uint || index >= (*array).count {
         return 0i32 as uintptr_t;
     }
     return *(*array).array.offset(index as isize);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_array_get_id(
-    mut array: *const dc_array_t,
-    mut index: size_t,
-) -> uint32_t {
+pub unsafe fn dc_array_get_id(mut array: *const dc_array_t, mut index: size_t) -> uint32_t {
     if array.is_null() || (*array).magic != 0xa11aai32 as libc::c_uint || index >= (*array).count {
         return 0i32 as uint32_t;
     }
@@ -135,8 +121,7 @@ pub unsafe extern "C" fn dc_array_get_id(
     }
     return *(*array).array.offset(index as isize) as uint32_t;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_array_get_ptr(
+pub unsafe fn dc_array_get_ptr(
     mut array: *const dc_array_t,
     mut index: size_t,
 ) -> *mut libc::c_void {
@@ -145,8 +130,7 @@ pub unsafe extern "C" fn dc_array_get_ptr(
     }
     return *(*array).array.offset(index as isize) as *mut libc::c_void;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_array_get_latitude(
+pub unsafe fn dc_array_get_latitude(
     mut array: *const dc_array_t,
     mut index: size_t,
 ) -> libc::c_double {
@@ -160,8 +144,7 @@ pub unsafe extern "C" fn dc_array_get_latitude(
     }
     return (*(*(*array).array.offset(index as isize) as *mut _dc_location)).latitude;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_array_get_longitude(
+pub unsafe fn dc_array_get_longitude(
     mut array: *const dc_array_t,
     mut index: size_t,
 ) -> libc::c_double {
@@ -175,8 +158,7 @@ pub unsafe extern "C" fn dc_array_get_longitude(
     }
     return (*(*(*array).array.offset(index as isize) as *mut _dc_location)).longitude;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_array_get_accuracy(
+pub unsafe fn dc_array_get_accuracy(
     mut array: *const dc_array_t,
     mut index: size_t,
 ) -> libc::c_double {
@@ -190,11 +172,7 @@ pub unsafe extern "C" fn dc_array_get_accuracy(
     }
     return (*(*(*array).array.offset(index as isize) as *mut _dc_location)).accuracy;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_array_get_timestamp(
-    mut array: *const dc_array_t,
-    mut index: size_t,
-) -> time_t {
+pub unsafe fn dc_array_get_timestamp(mut array: *const dc_array_t, mut index: size_t) -> time_t {
     if array.is_null()
         || (*array).magic != 0xa11aai32 as libc::c_uint
         || index >= (*array).count
@@ -205,11 +183,7 @@ pub unsafe extern "C" fn dc_array_get_timestamp(
     }
     return (*(*(*array).array.offset(index as isize) as *mut _dc_location)).timestamp;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_array_get_chat_id(
-    mut array: *const dc_array_t,
-    mut index: size_t,
-) -> uint32_t {
+pub unsafe fn dc_array_get_chat_id(mut array: *const dc_array_t, mut index: size_t) -> uint32_t {
     if array.is_null()
         || (*array).magic != 0xa11aai32 as libc::c_uint
         || index >= (*array).count
@@ -220,11 +194,7 @@ pub unsafe extern "C" fn dc_array_get_chat_id(
     }
     return (*(*(*array).array.offset(index as isize) as *mut _dc_location)).chat_id;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_array_get_contact_id(
-    mut array: *const dc_array_t,
-    mut index: size_t,
-) -> uint32_t {
+pub unsafe fn dc_array_get_contact_id(mut array: *const dc_array_t, mut index: size_t) -> uint32_t {
     if array.is_null()
         || (*array).magic != 0xa11aai32 as libc::c_uint
         || index >= (*array).count
@@ -235,11 +205,7 @@ pub unsafe extern "C" fn dc_array_get_contact_id(
     }
     return (*(*(*array).array.offset(index as isize) as *mut _dc_location)).contact_id;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_array_get_msg_id(
-    mut array: *const dc_array_t,
-    mut index: size_t,
-) -> uint32_t {
+pub unsafe fn dc_array_get_msg_id(mut array: *const dc_array_t, mut index: size_t) -> uint32_t {
     if array.is_null()
         || (*array).magic != 0xa11aai32 as libc::c_uint
         || index >= (*array).count
@@ -250,8 +216,7 @@ pub unsafe extern "C" fn dc_array_get_msg_id(
     }
     return (*(*(*array).array.offset(index as isize) as *mut _dc_location)).msg_id;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_array_get_marker(
+pub unsafe fn dc_array_get_marker(
     mut array: *const dc_array_t,
     mut index: size_t,
 ) -> *mut libc::c_char {
@@ -267,8 +232,7 @@ pub unsafe extern "C" fn dc_array_get_marker(
         (*(*(*array).array.offset(index as isize) as *mut _dc_location)).marker,
     );
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_array_search_id(
+pub unsafe fn dc_array_search_id(
     mut array: *const dc_array_t,
     mut needle: uint32_t,
     mut ret_index: *mut size_t,
@@ -291,21 +255,18 @@ pub unsafe extern "C" fn dc_array_search_id(
     }
     return 0i32;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_array_get_raw(mut array: *const dc_array_t) -> *const uintptr_t {
+pub unsafe fn dc_array_get_raw(mut array: *const dc_array_t) -> *const uintptr_t {
     if array.is_null() || (*array).magic != 0xa11aai32 as libc::c_uint {
         return 0 as *const uintptr_t;
     }
     return (*array).array;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_array_new(
+pub unsafe fn dc_array_new(
     mut context: *mut dc_context_t,
     mut initsize: size_t,
 ) -> *mut dc_array_t {
     return dc_array_new_typed(context, 0i32, initsize);
 }
-#[no_mangle]
 pub unsafe extern "C" fn dc_array_new_typed(
     mut context: *mut dc_context_t,
     mut type_0: libc::c_int,
@@ -338,15 +299,13 @@ pub unsafe extern "C" fn dc_array_new_typed(
     }
     return array;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_array_empty(mut array: *mut dc_array_t) {
+pub unsafe fn dc_array_empty(mut array: *mut dc_array_t) {
     if array.is_null() || (*array).magic != 0xa11aai32 as libc::c_uint {
         return;
     }
     (*array).count = 0i32 as size_t;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_array_duplicate(mut array: *const dc_array_t) -> *mut dc_array_t {
+pub unsafe fn dc_array_duplicate(mut array: *const dc_array_t) -> *mut dc_array_t {
     let mut ret: *mut dc_array_t = 0 as *mut dc_array_t;
     if array.is_null() || (*array).magic != 0xa11aai32 as libc::c_uint {
         return 0 as *mut dc_array_t;
@@ -362,8 +321,7 @@ pub unsafe extern "C" fn dc_array_duplicate(mut array: *const dc_array_t) -> *mu
     );
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_array_sort_ids(mut array: *mut dc_array_t) {
+pub unsafe fn dc_array_sort_ids(mut array: *mut dc_array_t) {
     if array.is_null()
         || (*array).magic != 0xa11aai32 as libc::c_uint
         || (*array).count <= 1i32 as libc::c_ulong
@@ -391,8 +349,7 @@ unsafe extern "C" fn cmp_intptr_t(
         0i32
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_array_sort_strings(mut array: *mut dc_array_t) {
+pub unsafe fn dc_array_sort_strings(mut array: *mut dc_array_t) {
     if array.is_null()
         || (*array).magic != 0xa11aai32 as libc::c_uint
         || (*array).count <= 1i32 as libc::c_ulong
@@ -414,8 +371,7 @@ unsafe extern "C" fn cmp_strings_t(
     let mut v2: *const libc::c_char = *(p2 as *mut *const libc::c_char);
     return strcmp(v1, v2);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_array_get_string(
+pub unsafe fn dc_array_get_string(
     mut array: *const dc_array_t,
     mut sep: *const libc::c_char,
 ) -> *mut libc::c_char {
@@ -448,8 +404,7 @@ pub unsafe extern "C" fn dc_array_get_string(
     }
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_arr_to_string(
+pub unsafe fn dc_arr_to_string(
     mut arr: *const uint32_t,
     mut cnt: libc::c_int,
 ) -> *mut libc::c_char {
diff --git a/src/dc_chat.rs b/src/dc_chat.rs
index a7665a399..ca3666c19 100644
--- a/src/dc_chat.rs
+++ b/src/dc_chat.rs
@@ -35,8 +35,7 @@ pub struct dc_chat_t {
 }
 
 // handle chats
-#[no_mangle]
-pub unsafe extern "C" fn dc_create_chat_by_msg_id(
+pub unsafe fn dc_create_chat_by_msg_id(
     mut context: *mut dc_context_t,
     mut msg_id: uint32_t,
 ) -> uint32_t {
@@ -84,8 +83,7 @@ pub unsafe extern "C" fn dc_create_chat_by_msg_id(
 // only an indicator in a chatlist
 // only an indicator in a chatlist
 // larger chat IDs are "real" chats, their messages are "real" messages.
-#[no_mangle]
-pub unsafe extern "C" fn dc_chat_new(mut context: *mut dc_context_t) -> *mut dc_chat_t {
+pub unsafe fn dc_chat_new(mut context: *mut dc_context_t) -> *mut dc_chat_t {
     let mut chat: *mut dc_chat_t = 0 as *mut dc_chat_t;
     if context.is_null() || {
         chat = calloc(
@@ -102,8 +100,7 @@ pub unsafe extern "C" fn dc_chat_new(mut context: *mut dc_context_t) -> *mut dc_
     (*chat).param = dc_param_new();
     return chat;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_chat_unref(mut chat: *mut dc_chat_t) {
+pub unsafe fn dc_chat_unref(mut chat: *mut dc_chat_t) {
     if chat.is_null() || (*chat).magic != 0xc4a7c4a7u32 {
         return;
     }
@@ -112,8 +109,7 @@ pub unsafe extern "C" fn dc_chat_unref(mut chat: *mut dc_chat_t) {
     (*chat).magic = 0i32 as uint32_t;
     free(chat as *mut libc::c_void);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_chat_empty(mut chat: *mut dc_chat_t) {
+pub unsafe fn dc_chat_empty(mut chat: *mut dc_chat_t) {
     if chat.is_null() || (*chat).magic != 0xc4a7c4a7u32 {
         return;
     }
@@ -127,12 +123,10 @@ pub unsafe extern "C" fn dc_chat_empty(mut chat: *mut dc_chat_t) {
     (*chat).gossiped_timestamp = 0i32 as time_t;
     dc_param_set_packed((*chat).param, 0 as *const libc::c_char);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_unblock_chat(mut context: *mut dc_context_t, mut chat_id: uint32_t) {
+pub unsafe fn dc_unblock_chat(mut context: *mut dc_context_t, mut chat_id: uint32_t) {
     dc_block_chat(context, chat_id, 0i32);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_block_chat(
+pub unsafe fn dc_block_chat(
     mut context: *mut dc_context_t,
     mut chat_id: uint32_t,
     mut new_blocking: libc::c_int,
@@ -150,11 +144,7 @@ pub unsafe extern "C" fn dc_block_chat(
     sqlite3_step(stmt);
     sqlite3_finalize(stmt);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_chat_load_from_db(
-    mut chat: *mut dc_chat_t,
-    mut chat_id: uint32_t,
-) -> libc::c_int {
+pub unsafe fn dc_chat_load_from_db(mut chat: *mut dc_chat_t, mut chat_id: uint32_t) -> libc::c_int {
     let mut success: libc::c_int = 0i32;
     let mut stmt: *mut sqlite3_stmt = 0 as *mut sqlite3_stmt;
     if !(chat.is_null() || (*chat).magic != 0xc4a7c4a7u32) {
@@ -173,10 +163,7 @@ pub unsafe extern "C" fn dc_chat_load_from_db(
     sqlite3_finalize(stmt);
     return success;
 }
-unsafe extern "C" fn set_from_stmt(
-    mut chat: *mut dc_chat_t,
-    mut row: *mut sqlite3_stmt,
-) -> libc::c_int {
+unsafe fn set_from_stmt(mut chat: *mut dc_chat_t, mut row: *mut sqlite3_stmt) -> libc::c_int {
     let mut row_offset: libc::c_int = 0i32;
     if chat.is_null() || (*chat).magic != 0xc4a7c4a7u32 || row.is_null() {
         return 0i32;
@@ -235,8 +222,7 @@ unsafe extern "C" fn set_from_stmt(
     }
     return row_offset;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_create_chat_by_contact_id(
+pub unsafe fn dc_create_chat_by_contact_id(
     mut context: *mut dc_context_t,
     mut contact_id: uint32_t,
 ) -> uint32_t {
@@ -285,8 +271,7 @@ pub unsafe extern "C" fn dc_create_chat_by_contact_id(
     }
     return chat_id;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_create_or_lookup_nchat_by_contact_id(
+pub unsafe fn dc_create_or_lookup_nchat_by_contact_id(
     mut context: *mut dc_context_t,
     mut contact_id: uint32_t,
     mut create_blocked: libc::c_int,
@@ -396,8 +381,7 @@ pub unsafe extern "C" fn dc_create_or_lookup_nchat_by_contact_id(
         *ret_chat_blocked = create_blocked
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_lookup_real_nchat_by_contact_id(
+pub unsafe fn dc_lookup_real_nchat_by_contact_id(
     mut context: *mut dc_context_t,
     mut contact_id: uint32_t,
     mut ret_chat_id: *mut uint32_t,
@@ -432,8 +416,7 @@ pub unsafe extern "C" fn dc_lookup_real_nchat_by_contact_id(
     }
     sqlite3_finalize(stmt);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_chat_id_by_contact_id(
+pub unsafe fn dc_get_chat_id_by_contact_id(
     mut context: *mut dc_context_t,
     mut contact_id: uint32_t,
 ) -> uint32_t {
@@ -449,8 +432,7 @@ pub unsafe extern "C" fn dc_get_chat_id_by_contact_id(
         chat_id
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_prepare_msg(
+pub unsafe fn dc_prepare_msg(
     mut context: *mut dc_context_t,
     mut chat_id: uint32_t,
     mut msg: *mut dc_msg_t,
@@ -472,7 +454,7 @@ pub unsafe extern "C" fn dc_prepare_msg(
     );
     return msg_id;
 }
-unsafe extern "C" fn prepare_msg_common(
+unsafe fn prepare_msg_common(
     mut context: *mut dc_context_t,
     mut chat_id: uint32_t,
     mut msg: *mut dc_msg_t,
@@ -571,7 +553,7 @@ unsafe extern "C" fn prepare_msg_common(
     free(pathNfilename as *mut libc::c_void);
     return (*msg).id;
 }
-unsafe extern "C" fn prepare_msg_raw(
+unsafe fn prepare_msg_raw(
     mut context: *mut dc_context_t,
     mut chat: *mut dc_chat_t,
     mut msg: *const dc_msg_t,
@@ -832,7 +814,7 @@ unsafe extern "C" fn prepare_msg_raw(
     sqlite3_finalize(stmt);
     return msg_id;
 }
-unsafe extern "C" fn get_parent_mime_headers(
+unsafe fn get_parent_mime_headers(
     mut chat: *const dc_chat_t,
     mut parent_rfc724_mid: *mut *mut libc::c_char,
     mut parent_in_reply_to: *mut *mut libc::c_char,
@@ -880,8 +862,7 @@ unsafe extern "C" fn get_parent_mime_headers(
     sqlite3_finalize(stmt);
     return success;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_chat_is_self_talk(mut chat: *const dc_chat_t) -> libc::c_int {
+pub unsafe fn dc_chat_is_self_talk(mut chat: *const dc_chat_t) -> libc::c_int {
     if chat.is_null() || (*chat).magic != 0xc4a7c4a7u32 {
         return 0i32;
     }
@@ -890,7 +871,7 @@ pub unsafe extern "C" fn dc_chat_is_self_talk(mut chat: *const dc_chat_t) -> lib
 /* ******************************************************************************
  * Sending messages
  ******************************************************************************/
-unsafe extern "C" fn last_msg_in_chat_encrypted(
+unsafe fn last_msg_in_chat_encrypted(
     mut sql: *mut dc_sqlite3_t,
     mut chat_id: uint32_t,
 ) -> libc::c_int {
@@ -914,8 +895,7 @@ unsafe extern "C" fn last_msg_in_chat_encrypted(
     sqlite3_finalize(stmt);
     return last_is_encrypted;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_chat_update_param(mut chat: *mut dc_chat_t) -> libc::c_int {
+pub unsafe fn dc_chat_update_param(mut chat: *mut dc_chat_t) -> libc::c_int {
     let mut success: libc::c_int = 0i32;
     let mut stmt: *mut sqlite3_stmt = dc_sqlite3_prepare(
         (*(*chat).context).sql,
@@ -931,8 +911,7 @@ pub unsafe extern "C" fn dc_chat_update_param(mut chat: *mut dc_chat_t) -> libc:
     sqlite3_finalize(stmt);
     return success;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_is_contact_in_chat(
+pub unsafe fn dc_is_contact_in_chat(
     mut context: *mut dc_context_t,
     mut chat_id: uint32_t,
     mut contact_id: uint32_t,
@@ -958,8 +937,7 @@ pub unsafe extern "C" fn dc_is_contact_in_chat(
     sqlite3_finalize(stmt);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_unarchive_chat(mut context: *mut dc_context_t, mut chat_id: uint32_t) {
+pub unsafe fn dc_unarchive_chat(mut context: *mut dc_context_t, mut chat_id: uint32_t) {
     let mut stmt: *mut sqlite3_stmt = dc_sqlite3_prepare(
         (*context).sql,
         b"UPDATE chats SET archived=0 WHERE id=?\x00" as *const u8 as *const libc::c_char,
@@ -968,8 +946,7 @@ pub unsafe extern "C" fn dc_unarchive_chat(mut context: *mut dc_context_t, mut c
     sqlite3_step(stmt);
     sqlite3_finalize(stmt);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_send_msg(
+pub unsafe fn dc_send_msg(
     mut context: *mut dc_context_t,
     mut chat_id: uint32_t,
     mut msg: *mut dc_msg_t,
@@ -1021,8 +998,7 @@ pub unsafe extern "C" fn dc_send_msg(
     }
     return (*msg).id;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_send_text_msg(
+pub unsafe fn dc_send_text_msg(
     mut context: *mut dc_context_t,
     mut chat_id: uint32_t,
     mut text_to_send: *const libc::c_char,
@@ -1040,8 +1016,7 @@ pub unsafe extern "C" fn dc_send_text_msg(
     dc_msg_unref(msg);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_set_draft(
+pub unsafe fn dc_set_draft(
     mut context: *mut dc_context_t,
     mut chat_id: uint32_t,
     mut msg: *mut dc_msg_t,
@@ -1061,7 +1036,7 @@ pub unsafe extern "C" fn dc_set_draft(
         );
     };
 }
-unsafe extern "C" fn set_draft_raw(
+unsafe fn set_draft_raw(
     mut context: *mut dc_context_t,
     mut chat_id: uint32_t,
     mut msg: *mut dc_msg_t,
@@ -1144,10 +1119,7 @@ unsafe extern "C" fn set_draft_raw(
     free(pathNfilename as *mut libc::c_void);
     return sth_changed;
 }
-unsafe extern "C" fn get_draft_msg_id(
-    mut context: *mut dc_context_t,
-    mut chat_id: uint32_t,
-) -> uint32_t {
+unsafe fn get_draft_msg_id(mut context: *mut dc_context_t, mut chat_id: uint32_t) -> uint32_t {
     let mut draft_msg_id: uint32_t = 0i32 as uint32_t;
     let mut stmt: *mut sqlite3_stmt = dc_sqlite3_prepare(
         (*context).sql,
@@ -1161,11 +1133,7 @@ unsafe extern "C" fn get_draft_msg_id(
     sqlite3_finalize(stmt);
     return draft_msg_id;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_draft(
-    mut context: *mut dc_context_t,
-    mut chat_id: uint32_t,
-) -> *mut dc_msg_t {
+pub unsafe fn dc_get_draft(mut context: *mut dc_context_t, mut chat_id: uint32_t) -> *mut dc_msg_t {
     let mut draft_msg_id: uint32_t = 0i32 as uint32_t;
     let mut draft_msg: *mut dc_msg_t = 0 as *mut dc_msg_t;
     if context.is_null()
@@ -1185,8 +1153,7 @@ pub unsafe extern "C" fn dc_get_draft(
     }
     return draft_msg;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_chat_msgs(
+pub unsafe fn dc_get_chat_msgs(
     mut context: *mut dc_context_t,
     mut chat_id: uint32_t,
     mut flags: uint32_t,
@@ -1252,11 +1219,7 @@ pub unsafe extern "C" fn dc_get_chat_msgs(
         return 0 as *mut dc_array_t;
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_msg_cnt(
-    mut context: *mut dc_context_t,
-    mut chat_id: uint32_t,
-) -> libc::c_int {
+pub unsafe fn dc_get_msg_cnt(mut context: *mut dc_context_t, mut chat_id: uint32_t) -> libc::c_int {
     let mut ret: libc::c_int = 0i32;
     let mut stmt: *mut sqlite3_stmt = 0 as *mut sqlite3_stmt;
     if !(context.is_null() || (*context).magic != 0x11a11807i32 as libc::c_uint) {
@@ -1272,8 +1235,7 @@ pub unsafe extern "C" fn dc_get_msg_cnt(
     sqlite3_finalize(stmt);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_fresh_msg_cnt(
+pub unsafe fn dc_get_fresh_msg_cnt(
     mut context: *mut dc_context_t,
     mut chat_id: uint32_t,
 ) -> libc::c_int {
@@ -1293,11 +1255,7 @@ pub unsafe extern "C" fn dc_get_fresh_msg_cnt(
     sqlite3_finalize(stmt);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_marknoticed_chat(
-    mut context: *mut dc_context_t,
-    mut chat_id: uint32_t,
-) {
+pub unsafe fn dc_marknoticed_chat(mut context: *mut dc_context_t, mut chat_id: uint32_t) {
     let mut check: *mut sqlite3_stmt = 0 as *mut sqlite3_stmt;
     let mut update: *mut sqlite3_stmt = 0 as *mut sqlite3_stmt;
     if !(context.is_null() || (*context).magic != 0x11a11807i32 as libc::c_uint) {
@@ -1326,8 +1284,7 @@ pub unsafe extern "C" fn dc_marknoticed_chat(
     sqlite3_finalize(check);
     sqlite3_finalize(update);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_marknoticed_all_chats(mut context: *mut dc_context_t) {
+pub unsafe fn dc_marknoticed_all_chats(mut context: *mut dc_context_t) {
     let mut check: *mut sqlite3_stmt = 0 as *mut sqlite3_stmt;
     let mut update: *mut sqlite3_stmt = 0 as *mut sqlite3_stmt;
     if !(context.is_null() || (*context).magic != 0x11a11807i32 as libc::c_uint) {
@@ -1353,8 +1310,7 @@ pub unsafe extern "C" fn dc_marknoticed_all_chats(mut context: *mut dc_context_t
     sqlite3_finalize(check);
     sqlite3_finalize(update);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_chat_media(
+pub unsafe fn dc_get_chat_media(
     mut context: *mut dc_context_t,
     mut chat_id: uint32_t,
     mut msg_type: libc::c_int,
@@ -1395,8 +1351,7 @@ pub unsafe extern "C" fn dc_get_chat_media(
     sqlite3_finalize(stmt);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_next_media(
+pub unsafe fn dc_get_next_media(
     mut context: *mut dc_context_t,
     mut curr_msg_id: uint32_t,
     mut dir: libc::c_int,
@@ -1448,8 +1403,7 @@ pub unsafe extern "C" fn dc_get_next_media(
     dc_msg_unref(msg);
     return ret_msg_id;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_archive_chat(
+pub unsafe fn dc_archive_chat(
     mut context: *mut dc_context_t,
     mut chat_id: uint32_t,
     mut archive: libc::c_int,
@@ -1486,8 +1440,7 @@ pub unsafe extern "C" fn dc_archive_chat(
         0i32 as uintptr_t,
     );
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_delete_chat(mut context: *mut dc_context_t, mut chat_id: uint32_t) {
+pub unsafe fn dc_delete_chat(mut context: *mut dc_context_t, mut chat_id: uint32_t) {
     /* Up to 2017-11-02 deleting a group also implied leaving it, see above why we have changed this. */
     let mut pending_transaction: libc::c_int = 0i32;
     let mut obj: *mut dc_chat_t = dc_chat_new(context);
@@ -1552,8 +1505,7 @@ pub unsafe extern "C" fn dc_delete_chat(mut context: *mut dc_context_t, mut chat
     dc_chat_unref(obj);
     sqlite3_free(q3 as *mut libc::c_void);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_chat_contacts(
+pub unsafe fn dc_get_chat_contacts(
     mut context: *mut dc_context_t,
     mut chat_id: uint32_t,
 ) -> *mut dc_array_t {
@@ -1577,11 +1529,7 @@ pub unsafe extern "C" fn dc_get_chat_contacts(
     sqlite3_finalize(stmt);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_chat(
-    mut context: *mut dc_context_t,
-    mut chat_id: uint32_t,
-) -> *mut dc_chat_t {
+pub unsafe fn dc_get_chat(mut context: *mut dc_context_t, mut chat_id: uint32_t) -> *mut dc_chat_t {
     let mut success: libc::c_int = 0i32;
     let mut obj: *mut dc_chat_t = dc_chat_new(context);
     if !(context.is_null() || (*context).magic != 0x11a11807i32 as libc::c_uint) {
@@ -1597,8 +1545,7 @@ pub unsafe extern "C" fn dc_get_chat(
     };
 }
 // handle group chats
-#[no_mangle]
-pub unsafe extern "C" fn dc_create_group_chat(
+pub unsafe fn dc_create_group_chat(
     mut context: *mut dc_context_t,
     mut verified: libc::c_int,
     mut chat_name: *const libc::c_char,
@@ -1656,8 +1603,7 @@ pub unsafe extern "C" fn dc_create_group_chat(
 }
 /* you MUST NOT modify this or the following strings */
 // Context functions to work with chats
-#[no_mangle]
-pub unsafe extern "C" fn dc_add_to_chat_contacts_table(
+pub unsafe fn dc_add_to_chat_contacts_table(
     mut context: *mut dc_context_t,
     mut chat_id: uint32_t,
     mut contact_id: uint32_t,
@@ -1679,16 +1625,14 @@ pub unsafe extern "C" fn dc_add_to_chat_contacts_table(
     sqlite3_finalize(stmt);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_add_contact_to_chat(
+pub unsafe fn dc_add_contact_to_chat(
     mut context: *mut dc_context_t,
     mut chat_id: uint32_t,
     mut contact_id: uint32_t,
 ) -> libc::c_int {
     return dc_add_contact_to_chat_ex(context, chat_id, contact_id, 0i32);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_add_contact_to_chat_ex(
+pub unsafe fn dc_add_contact_to_chat_ex(
     mut context: *mut dc_context_t,
     mut chat_id: uint32_t,
     mut contact_id: uint32_t,
@@ -1811,10 +1755,7 @@ pub unsafe extern "C" fn dc_add_contact_to_chat_ex(
     free(self_addr as *mut libc::c_void);
     return success;
 }
-unsafe extern "C" fn real_group_exists(
-    mut context: *mut dc_context_t,
-    mut chat_id: uint32_t,
-) -> libc::c_int {
+unsafe fn real_group_exists(mut context: *mut dc_context_t, mut chat_id: uint32_t) -> libc::c_int {
     // check if a group or a verified group exists under the given ID
     let mut stmt: *mut sqlite3_stmt = 0 as *mut sqlite3_stmt;
     let mut ret: libc::c_int = 0i32;
@@ -1837,15 +1778,10 @@ unsafe extern "C" fn real_group_exists(
     sqlite3_finalize(stmt);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_reset_gossiped_timestamp(
-    mut context: *mut dc_context_t,
-    mut chat_id: uint32_t,
-) {
+pub unsafe fn dc_reset_gossiped_timestamp(mut context: *mut dc_context_t, mut chat_id: uint32_t) {
     dc_set_gossiped_timestamp(context, chat_id, 0i32 as time_t);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_set_gossiped_timestamp(
+pub unsafe fn dc_set_gossiped_timestamp(
     mut context: *mut dc_context_t,
     mut chat_id: uint32_t,
     mut timestamp: time_t,
@@ -1882,8 +1818,7 @@ pub unsafe extern "C" fn dc_set_gossiped_timestamp(
     sqlite3_step(stmt);
     sqlite3_finalize(stmt);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_remove_contact_from_chat(
+pub unsafe fn dc_remove_contact_from_chat(
     mut context: *mut dc_context_t,
     mut chat_id: uint32_t,
     mut contact_id: uint32_t,
@@ -1969,8 +1904,7 @@ pub unsafe extern "C" fn dc_remove_contact_from_chat(
     dc_msg_unref(msg);
     return success;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_set_group_explicitly_left(
+pub unsafe fn dc_set_group_explicitly_left(
     mut context: *mut dc_context_t,
     mut grpid: *const libc::c_char,
 ) {
@@ -1984,8 +1918,7 @@ pub unsafe extern "C" fn dc_set_group_explicitly_left(
         sqlite3_finalize(stmt);
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_is_group_explicitly_left(
+pub unsafe fn dc_is_group_explicitly_left(
     mut context: *mut dc_context_t,
     mut grpid: *const libc::c_char,
 ) -> libc::c_int {
@@ -1998,8 +1931,7 @@ pub unsafe extern "C" fn dc_is_group_explicitly_left(
     sqlite3_finalize(stmt);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_set_chat_name(
+pub unsafe fn dc_set_chat_name(
     mut context: *mut dc_context_t,
     mut chat_id: uint32_t,
     mut new_name: *const libc::c_char,
@@ -2072,8 +2004,7 @@ pub unsafe extern "C" fn dc_set_chat_name(
     dc_msg_unref(msg);
     return success;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_set_chat_profile_image(
+pub unsafe fn dc_set_chat_profile_image(
     mut context: *mut dc_context_t,
     mut chat_id: uint32_t,
     mut new_image: *const libc::c_char,
@@ -2156,8 +2087,7 @@ pub unsafe extern "C" fn dc_set_chat_profile_image(
     free(new_image_rel as *mut libc::c_void);
     return success;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_forward_msgs(
+pub unsafe fn dc_forward_msgs(
     mut context: *mut dc_context_t,
     mut msg_ids: *const uint32_t,
     mut msg_cnt: libc::c_int,
@@ -2289,28 +2219,24 @@ pub unsafe extern "C" fn dc_forward_msgs(
     sqlite3_free(q3 as *mut libc::c_void);
     dc_param_unref(original_param);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_chat_get_id(mut chat: *const dc_chat_t) -> uint32_t {
+pub unsafe fn dc_chat_get_id(mut chat: *const dc_chat_t) -> uint32_t {
     if chat.is_null() || (*chat).magic != 0xc4a7c4a7u32 {
         return 0i32 as uint32_t;
     }
     return (*chat).id;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_chat_get_type(mut chat: *const dc_chat_t) -> libc::c_int {
+pub unsafe fn dc_chat_get_type(mut chat: *const dc_chat_t) -> libc::c_int {
     if chat.is_null() || (*chat).magic != 0xc4a7c4a7u32 {
         return 0i32;
     }
     return (*chat).type_0;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_chat_get_name(mut chat: *const dc_chat_t) -> *mut libc::c_char {
+pub unsafe fn dc_chat_get_name(mut chat: *const dc_chat_t) -> *mut libc::c_char {
     if chat.is_null() || (*chat).magic != 0xc4a7c4a7u32 {
         return dc_strdup(b"Err\x00" as *const u8 as *const libc::c_char);
     }
     return dc_strdup((*chat).name);
 }
-#[no_mangle]
 pub unsafe extern "C" fn dc_chat_get_subtitle(mut chat: *const dc_chat_t) -> *mut libc::c_char {
     /* returns either the address or the number of chat members */
     let mut ret: *mut libc::c_char = 0 as *mut libc::c_char;
@@ -2346,8 +2272,7 @@ pub unsafe extern "C" fn dc_chat_get_subtitle(mut chat: *const dc_chat_t) -> *mu
         dc_strdup(b"Err\x00" as *const u8 as *const libc::c_char)
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_chat_contact_cnt(
+pub unsafe fn dc_get_chat_contact_cnt(
     mut context: *mut dc_context_t,
     mut chat_id: uint32_t,
 ) -> libc::c_int {
@@ -2364,10 +2289,7 @@ pub unsafe extern "C" fn dc_get_chat_contact_cnt(
     sqlite3_finalize(stmt);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_chat_get_profile_image(
-    mut chat: *const dc_chat_t,
-) -> *mut libc::c_char {
+pub unsafe fn dc_chat_get_profile_image(mut chat: *const dc_chat_t) -> *mut libc::c_char {
     let mut image_rel: *mut libc::c_char = 0 as *mut libc::c_char;
     let mut image_abs: *mut libc::c_char = 0 as *mut libc::c_char;
     let mut contacts: *mut dc_array_t = 0 as *mut dc_array_t;
@@ -2392,8 +2314,7 @@ pub unsafe extern "C" fn dc_chat_get_profile_image(
     dc_contact_unref(contact);
     return image_abs;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_chat_get_color(mut chat: *const dc_chat_t) -> uint32_t {
+pub unsafe fn dc_chat_get_color(mut chat: *const dc_chat_t) -> uint32_t {
     let mut color: uint32_t = 0i32 as uint32_t;
     let mut contacts: *mut dc_array_t = 0 as *mut dc_array_t;
     let mut contact: *mut dc_contact_t = 0 as *mut dc_contact_t;
@@ -2415,36 +2336,31 @@ pub unsafe extern "C" fn dc_chat_get_color(mut chat: *const dc_chat_t) -> uint32
     dc_contact_unref(contact);
     return color;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_chat_get_archived(mut chat: *const dc_chat_t) -> libc::c_int {
+pub unsafe fn dc_chat_get_archived(mut chat: *const dc_chat_t) -> libc::c_int {
     if chat.is_null() || (*chat).magic != 0xc4a7c4a7u32 {
         return 0i32;
     }
     return (*chat).archived;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_chat_is_unpromoted(mut chat: *const dc_chat_t) -> libc::c_int {
+pub unsafe fn dc_chat_is_unpromoted(mut chat: *const dc_chat_t) -> libc::c_int {
     if chat.is_null() || (*chat).magic != 0xc4a7c4a7u32 {
         return 0i32;
     }
     return dc_param_get_int((*chat).param, 'U' as i32, 0i32);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_chat_is_verified(mut chat: *const dc_chat_t) -> libc::c_int {
+pub unsafe fn dc_chat_is_verified(mut chat: *const dc_chat_t) -> libc::c_int {
     if chat.is_null() || (*chat).magic != 0xc4a7c4a7u32 {
         return 0i32;
     }
     return ((*chat).type_0 == 130i32) as libc::c_int;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_chat_is_sending_locations(mut chat: *const dc_chat_t) -> libc::c_int {
+pub unsafe fn dc_chat_is_sending_locations(mut chat: *const dc_chat_t) -> libc::c_int {
     if chat.is_null() || (*chat).magic != 0xc4a7c4a7u32 {
         return 0i32;
     }
     return (*chat).is_sending_locations;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_chat_cnt(mut context: *mut dc_context_t) -> size_t {
+pub unsafe fn dc_get_chat_cnt(mut context: *mut dc_context_t) -> size_t {
     let mut ret: size_t = 0i32 as size_t;
     let mut stmt: *mut sqlite3_stmt = 0 as *mut sqlite3_stmt;
     if !(context.is_null()
@@ -2464,8 +2380,7 @@ pub unsafe extern "C" fn dc_get_chat_cnt(mut context: *mut dc_context_t) -> size
     sqlite3_finalize(stmt);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_chat_id_by_grpid(
+pub unsafe fn dc_get_chat_id_by_grpid(
     mut context: *mut dc_context_t,
     mut grpid: *const libc::c_char,
     mut ret_blocked: *mut libc::c_int,
@@ -2499,8 +2414,7 @@ pub unsafe extern "C" fn dc_get_chat_id_by_grpid(
     sqlite3_finalize(stmt);
     return chat_id;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_add_device_msg(
+pub unsafe fn dc_add_device_msg(
     mut context: *mut dc_context_t,
     mut chat_id: uint32_t,
     mut text: *const libc::c_char,
diff --git a/src/dc_chatlist.rs b/src/dc_chatlist.rs
index 441a68ca9..8e0ef4d5e 100644
--- a/src/dc_chatlist.rs
+++ b/src/dc_chatlist.rs
@@ -24,8 +24,7 @@ pub struct dc_chatlist_t {
 }
 
 // handle chatlists
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_chatlist(
+pub unsafe fn dc_get_chatlist(
     mut context: *mut dc_context_t,
     mut listflags: libc::c_int,
     mut query_str: *const libc::c_char,
@@ -83,8 +82,7 @@ pub unsafe extern "C" fn dc_get_chatlist(
  * Rendering the deaddrop in the described way
  * would not add extra work in the UI then.
  */
-#[no_mangle]
-pub unsafe extern "C" fn dc_chatlist_new(mut context: *mut dc_context_t) -> *mut dc_chatlist_t {
+pub unsafe fn dc_chatlist_new(mut context: *mut dc_context_t) -> *mut dc_chatlist_t {
     let mut chatlist: *mut dc_chatlist_t = 0 as *mut dc_chatlist_t;
     chatlist = calloc(
         1i32 as libc::c_ulong,
@@ -101,8 +99,7 @@ pub unsafe extern "C" fn dc_chatlist_new(mut context: *mut dc_context_t) -> *mut
     }
     return chatlist;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_chatlist_unref(mut chatlist: *mut dc_chatlist_t) {
+pub unsafe fn dc_chatlist_unref(mut chatlist: *mut dc_chatlist_t) {
     if chatlist.is_null() || (*chatlist).magic != 0xc4a71157u32 {
         return;
     }
@@ -111,8 +108,7 @@ pub unsafe extern "C" fn dc_chatlist_unref(mut chatlist: *mut dc_chatlist_t) {
     (*chatlist).magic = 0i32 as uint32_t;
     free(chatlist as *mut libc::c_void);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_chatlist_empty(mut chatlist: *mut dc_chatlist_t) {
+pub unsafe fn dc_chatlist_empty(mut chatlist: *mut dc_chatlist_t) {
     if chatlist.is_null() || (*chatlist).magic != 0xc4a71157u32 {
         return;
     }
@@ -124,7 +120,7 @@ pub unsafe extern "C" fn dc_chatlist_empty(mut chatlist: *mut dc_chatlist_t) {
  *
  * @private @memberof dc_chatlist_t
  */
-unsafe extern "C" fn dc_chatlist_load_from_db(
+unsafe fn dc_chatlist_load_from_db(
     mut chatlist: *mut dc_chatlist_t,
     mut listflags: libc::c_int,
     mut query__: *const libc::c_char,
@@ -230,8 +226,7 @@ unsafe extern "C" fn dc_chatlist_load_from_db(
     return success;
 }
 // Context functions to work with chatlist
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_archived_cnt(mut context: *mut dc_context_t) -> libc::c_int {
+pub unsafe fn dc_get_archived_cnt(mut context: *mut dc_context_t) -> libc::c_int {
     let mut ret: libc::c_int = 0i32;
     let mut stmt: *mut sqlite3_stmt = dc_sqlite3_prepare(
         (*context).sql,
@@ -244,7 +239,7 @@ pub unsafe extern "C" fn dc_get_archived_cnt(mut context: *mut dc_context_t) ->
     sqlite3_finalize(stmt);
     return ret;
 }
-unsafe extern "C" fn get_last_deaddrop_fresh_msg(mut context: *mut dc_context_t) -> uint32_t {
+unsafe fn get_last_deaddrop_fresh_msg(mut context: *mut dc_context_t) -> uint32_t {
     let mut ret: uint32_t = 0i32 as uint32_t;
     let mut stmt: *mut sqlite3_stmt = 0 as *mut sqlite3_stmt;
     stmt =
@@ -258,15 +253,13 @@ unsafe extern "C" fn get_last_deaddrop_fresh_msg(mut context: *mut dc_context_t)
     sqlite3_finalize(stmt);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_chatlist_get_cnt(mut chatlist: *const dc_chatlist_t) -> size_t {
+pub unsafe fn dc_chatlist_get_cnt(mut chatlist: *const dc_chatlist_t) -> size_t {
     if chatlist.is_null() || (*chatlist).magic != 0xc4a71157u32 {
         return 0i32 as size_t;
     }
     return (*chatlist).cnt;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_chatlist_get_chat_id(
+pub unsafe fn dc_chatlist_get_chat_id(
     mut chatlist: *const dc_chatlist_t,
     mut index: size_t,
 ) -> uint32_t {
@@ -282,8 +275,7 @@ pub unsafe extern "C" fn dc_chatlist_get_chat_id(
         index.wrapping_mul(2i32 as libc::c_ulong),
     );
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_chatlist_get_msg_id(
+pub unsafe fn dc_chatlist_get_msg_id(
     mut chatlist: *const dc_chatlist_t,
     mut index: size_t,
 ) -> uint32_t {
@@ -301,8 +293,7 @@ pub unsafe extern "C" fn dc_chatlist_get_msg_id(
             .wrapping_add(1i32 as libc::c_ulong),
     );
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_chatlist_get_summary(
+pub unsafe fn dc_chatlist_get_summary(
     mut chatlist: *const dc_chatlist_t,
     mut index: size_t,
     mut chat: *mut dc_chat_t,
@@ -379,10 +370,7 @@ pub unsafe extern "C" fn dc_chatlist_get_summary(
     dc_chat_unref(chat_to_delete);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_chatlist_get_context(
-    mut chatlist: *mut dc_chatlist_t,
-) -> *mut dc_context_t {
+pub unsafe fn dc_chatlist_get_context(mut chatlist: *mut dc_chatlist_t) -> *mut dc_context_t {
     if chatlist.is_null() || (*chatlist).magic != 0xc4a71157u32 {
         return 0 as *mut dc_context_t;
     }
diff --git a/src/dc_configure.rs b/src/dc_configure.rs
index b7dcc0ff7..974c81bc6 100644
--- a/src/dc_configure.rs
+++ b/src/dc_configure.rs
@@ -62,8 +62,7 @@ pub struct outlk_autodiscover_t {
     pub redirect: *mut libc::c_char,
 }
 // connect
-#[no_mangle]
-pub unsafe extern "C" fn dc_configure(mut context: *mut dc_context_t) {
+pub unsafe fn dc_configure(mut context: *mut dc_context_t) {
     if 0 != dc_has_ongoing(context) {
         dc_log_warning(
             context,
@@ -76,8 +75,7 @@ pub unsafe extern "C" fn dc_configure(mut context: *mut dc_context_t) {
     dc_job_kill_action(context, 900i32);
     dc_job_add(context, 900i32, 0i32, 0 as *const libc::c_char, 0i32);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_has_ongoing(mut context: *mut dc_context_t) -> libc::c_int {
+pub unsafe fn dc_has_ongoing(mut context: *mut dc_context_t) -> libc::c_int {
     if context.is_null() || (*context).magic != 0x11a11807i32 as libc::c_uint {
         return 0i32;
     }
@@ -87,8 +85,7 @@ pub unsafe extern "C" fn dc_has_ongoing(mut context: *mut dc_context_t) -> libc:
         0i32
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_is_configured(mut context: *const dc_context_t) -> libc::c_int {
+pub unsafe fn dc_is_configured(mut context: *const dc_context_t) -> libc::c_int {
     if context.is_null() || (*context).magic != 0x11a11807i32 as libc::c_uint {
         return 0i32;
     }
@@ -103,8 +100,7 @@ pub unsafe extern "C" fn dc_is_configured(mut context: *const dc_context_t) -> l
         0i32
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_stop_ongoing_process(mut context: *mut dc_context_t) {
+pub unsafe fn dc_stop_ongoing_process(mut context: *mut dc_context_t) {
     if context.is_null() || (*context).magic != 0x11a11807i32 as libc::c_uint {
         return;
     }
@@ -124,8 +120,7 @@ pub unsafe extern "C" fn dc_stop_ongoing_process(mut context: *mut dc_context_t)
     };
 }
 // the other dc_job_do_DC_JOB_*() functions are declared static in the c-file
-#[no_mangle]
-pub unsafe extern "C" fn dc_job_do_DC_JOB_CONFIGURE_IMAP(
+pub unsafe fn dc_job_do_DC_JOB_CONFIGURE_IMAP(
     mut context: *mut dc_context_t,
     mut job: *mut dc_job_t,
 ) {
@@ -1349,16 +1344,14 @@ pub unsafe extern "C" fn dc_job_do_DC_JOB_CONFIGURE_IMAP(
         0i32 as uintptr_t,
     );
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_free_ongoing(mut context: *mut dc_context_t) {
+pub unsafe fn dc_free_ongoing(mut context: *mut dc_context_t) {
     if context.is_null() || (*context).magic != 0x11a11807i32 as libc::c_uint {
         return;
     }
     (*context).ongoing_running = 0i32;
     (*context).shall_stop_ongoing = 1i32;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_configure_folders(
+pub unsafe fn dc_configure_folders(
     mut context: *mut dc_context_t,
     mut imap: *mut dc_imap_t,
     mut flags: libc::c_int,
@@ -1472,7 +1465,7 @@ pub unsafe extern "C" fn dc_configure_folders(
     free(mvbox_folder as *mut libc::c_void);
     free(fallback_folder as *mut libc::c_void);
 }
-unsafe extern "C" fn free_folders(mut folders: *mut clist) {
+unsafe fn free_folders(mut folders: *mut clist) {
     if !folders.is_null() {
         let mut iter1: *mut clistiter = 0 as *mut clistiter;
         iter1 = (*folders).first;
@@ -1494,7 +1487,7 @@ unsafe extern "C" fn free_folders(mut folders: *mut clist) {
         clist_free(folders);
     };
 }
-unsafe extern "C" fn list_folders(mut imap: *mut dc_imap_t) -> *mut clist {
+unsafe fn list_folders(mut imap: *mut dc_imap_t) -> *mut clist {
     let mut imap_list: *mut clist = 0 as *mut clist;
     let mut iter1: *mut clistiter = 0 as *mut clistiter;
     let mut ret_list: *mut clist = clist_new();
@@ -1593,9 +1586,7 @@ unsafe extern "C" fn list_folders(mut imap: *mut dc_imap_t) -> *mut clist {
     }
     return ret_list;
 }
-unsafe extern "C" fn get_folder_meaning_by_name(
-    mut folder_name: *const libc::c_char,
-) -> libc::c_int {
+unsafe fn get_folder_meaning_by_name(mut folder_name: *const libc::c_char) -> libc::c_int {
     // try to get the folder meaning by the name of the folder.
     // only used if the server does not support XLIST.
     let mut ret_meaning: libc::c_int = 0i32;
@@ -1615,7 +1606,7 @@ unsafe extern "C" fn get_folder_meaning_by_name(
     free(lower as *mut libc::c_void);
     return ret_meaning;
 }
-unsafe extern "C" fn get_folder_meaning(mut flags: *mut mailimap_mbx_list_flags) -> libc::c_int {
+unsafe fn get_folder_meaning(mut flags: *mut mailimap_mbx_list_flags) -> libc::c_int {
     let mut ret_meaning: libc::c_int = 0i32;
     if !flags.is_null() {
         let mut iter2: *mut clistiter = 0 as *mut clistiter;
@@ -1666,7 +1657,7 @@ unsafe extern "C" fn get_folder_meaning(mut flags: *mut mailimap_mbx_list_flags)
     }
     return ret_meaning;
 }
-unsafe extern "C" fn moz_autoconfigure(
+unsafe fn moz_autoconfigure(
     mut context: *mut dc_context_t,
     mut url: *const libc::c_char,
     mut param_in: *const dc_loginparam_t,
@@ -1743,7 +1734,7 @@ unsafe extern "C" fn moz_autoconfigure(
     free(moz_ac.in_emaillocalpart as *mut libc::c_void);
     return moz_ac.out;
 }
-unsafe extern "C" fn moz_autoconfigure_text_cb(
+unsafe fn moz_autoconfigure_text_cb(
     mut userdata: *mut libc::c_void,
     mut text: *const libc::c_char,
     mut len: libc::c_int,
@@ -1821,7 +1812,7 @@ unsafe extern "C" fn moz_autoconfigure_text_cb(
     }
     free(val as *mut libc::c_void);
 }
-unsafe extern "C" fn moz_autoconfigure_endtag_cb(
+unsafe fn moz_autoconfigure_endtag_cb(
     mut userdata: *mut libc::c_void,
     mut tag: *const libc::c_char,
 ) {
@@ -1846,7 +1837,7 @@ unsafe extern "C" fn moz_autoconfigure_endtag_cb(
         (*moz_ac).tag_config = 0i32
     };
 }
-unsafe extern "C" fn moz_autoconfigure_starttag_cb(
+unsafe fn moz_autoconfigure_starttag_cb(
     mut userdata: *mut libc::c_void,
     mut tag: *const libc::c_char,
     mut attr: *mut *mut libc::c_char,
@@ -1891,7 +1882,7 @@ unsafe extern "C" fn moz_autoconfigure_starttag_cb(
         (*moz_ac).tag_config = 12i32
     };
 }
-unsafe extern "C" fn read_autoconf_file(
+unsafe fn read_autoconf_file(
     mut context: *mut dc_context_t,
     mut url: *const libc::c_char,
 ) -> *mut libc::c_char {
@@ -1919,7 +1910,7 @@ unsafe extern "C" fn read_autoconf_file(
     }
     return filecontent;
 }
-unsafe extern "C" fn outlk_autodiscover(
+unsafe fn outlk_autodiscover(
     mut context: *mut dc_context_t,
     mut url__: *const libc::c_char,
     mut param_in: *const dc_loginparam_t,
@@ -2012,7 +2003,7 @@ unsafe extern "C" fn outlk_autodiscover(
     outlk_clean_config(&mut outlk_ad);
     return outlk_ad.out;
 }
-unsafe extern "C" fn outlk_clean_config(mut outlk_ad: *mut outlk_autodiscover_t) {
+unsafe fn outlk_clean_config(mut outlk_ad: *mut outlk_autodiscover_t) {
     let mut i: libc::c_int = 0;
     i = 0i32;
     while i < 6i32 {
@@ -2021,7 +2012,7 @@ unsafe extern "C" fn outlk_clean_config(mut outlk_ad: *mut outlk_autodiscover_t)
         i += 1
     }
 }
-unsafe extern "C" fn outlk_autodiscover_text_cb(
+unsafe fn outlk_autodiscover_text_cb(
     mut userdata: *mut libc::c_void,
     mut text: *const libc::c_char,
     mut len: libc::c_int,
@@ -2032,7 +2023,7 @@ unsafe extern "C" fn outlk_autodiscover_text_cb(
     free((*outlk_ad).config[(*outlk_ad).tag_config as usize] as *mut libc::c_void);
     (*outlk_ad).config[(*outlk_ad).tag_config as usize] = val;
 }
-unsafe extern "C" fn outlk_autodiscover_endtag_cb(
+unsafe fn outlk_autodiscover_endtag_cb(
     mut userdata: *mut libc::c_void,
     mut tag: *const libc::c_char,
 ) {
@@ -2084,7 +2075,7 @@ unsafe extern "C" fn outlk_autodiscover_endtag_cb(
     }
     (*outlk_ad).tag_config = 0i32;
 }
-unsafe extern "C" fn outlk_autodiscover_starttag_cb(
+unsafe fn outlk_autodiscover_starttag_cb(
     mut userdata: *mut libc::c_void,
     mut tag: *const libc::c_char,
     mut attr: *mut *mut libc::c_char,
@@ -2104,8 +2095,7 @@ unsafe extern "C" fn outlk_autodiscover_starttag_cb(
         (*outlk_ad).tag_config = 5i32
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_alloc_ongoing(mut context: *mut dc_context_t) -> libc::c_int {
+pub unsafe fn dc_alloc_ongoing(mut context: *mut dc_context_t) -> libc::c_int {
     if context.is_null() || (*context).magic != 0x11a11807i32 as libc::c_uint {
         return 0i32;
     }
@@ -2122,8 +2112,7 @@ pub unsafe extern "C" fn dc_alloc_ongoing(mut context: *mut dc_context_t) -> lib
     (*context).shall_stop_ongoing = 0i32;
     return 1i32;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_connect_to_configured_imap(
+pub unsafe fn dc_connect_to_configured_imap(
     mut context: *mut dc_context_t,
     mut imap: *mut dc_imap_t,
 ) -> libc::c_int {
diff --git a/src/dc_contact.rs b/src/dc_contact.rs
index 0b2e0c33d..a7dd61e87 100644
--- a/src/dc_contact.rs
+++ b/src/dc_contact.rs
@@ -31,11 +31,7 @@ pub struct dc_contact_t {
     pub origin: libc::c_int,
 }
 
-#[no_mangle]
-pub unsafe extern "C" fn dc_marknoticed_contact(
-    mut context: *mut dc_context_t,
-    mut contact_id: uint32_t,
-) {
+pub unsafe fn dc_marknoticed_contact(mut context: *mut dc_context_t, mut contact_id: uint32_t) {
     if context.is_null() || (*context).magic != 0x11a11807i32 as libc::c_uint {
         return;
     }
@@ -55,7 +51,6 @@ pub unsafe extern "C" fn dc_marknoticed_contact(
     );
 }
 // handle contacts
-#[no_mangle]
 pub unsafe extern "C" fn dc_may_be_valid_addr(mut addr: *const libc::c_char) -> libc::c_int {
     if addr.is_null() {
         return 0i32;
@@ -74,8 +69,7 @@ pub unsafe extern "C" fn dc_may_be_valid_addr(mut addr: *const libc::c_char) ->
     }
     return 1i32;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_lookup_contact_id_by_addr(
+pub unsafe fn dc_lookup_contact_id_by_addr(
     mut context: *mut dc_context_t,
     mut addr: *const libc::c_char,
 ) -> uint32_t {
@@ -120,8 +114,7 @@ pub unsafe extern "C" fn dc_lookup_contact_id_by_addr(
     free(addr_self as *mut libc::c_void);
     return contact_id as uint32_t;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_addr_normalize(mut addr: *const libc::c_char) -> *mut libc::c_char {
+pub unsafe fn dc_addr_normalize(mut addr: *const libc::c_char) -> *mut libc::c_char {
     let mut addr_normalized: *mut libc::c_char = dc_strdup(addr);
     dc_trim(addr_normalized);
     if strncmp(
@@ -137,8 +130,7 @@ pub unsafe extern "C" fn dc_addr_normalize(mut addr: *const libc::c_char) -> *mu
     }
     return addr_normalized;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_create_contact(
+pub unsafe fn dc_create_contact(
     mut context: *mut dc_context_t,
     mut name: *const libc::c_char,
     mut addr: *const libc::c_char,
@@ -169,8 +161,7 @@ pub unsafe extern "C" fn dc_create_contact(
     }
     return contact_id;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_block_contact(
+pub unsafe fn dc_block_contact(
     mut context: *mut dc_context_t,
     mut contact_id: uint32_t,
     mut new_blocking: libc::c_int,
@@ -253,8 +244,7 @@ pub unsafe extern "C" fn dc_block_contact(
  * dc_create_contact() or dc_add_address_book())
  * only affect the given-name.
  */
-#[no_mangle]
-pub unsafe extern "C" fn dc_contact_new(mut context: *mut dc_context_t) -> *mut dc_contact_t {
+pub unsafe fn dc_contact_new(mut context: *mut dc_context_t) -> *mut dc_contact_t {
     let mut contact: *mut dc_contact_t = 0 as *mut dc_contact_t;
     contact = calloc(
         1i32 as libc::c_ulong,
@@ -267,8 +257,7 @@ pub unsafe extern "C" fn dc_contact_new(mut context: *mut dc_context_t) -> *mut
     (*contact).context = context;
     return contact;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_contact_unref(mut contact: *mut dc_contact_t) {
+pub unsafe fn dc_contact_unref(mut contact: *mut dc_contact_t) {
     if contact.is_null() || (*contact).magic != 0xc047ac7i32 as libc::c_uint {
         return;
     }
@@ -276,8 +265,7 @@ pub unsafe extern "C" fn dc_contact_unref(mut contact: *mut dc_contact_t) {
     (*contact).magic = 0i32 as uint32_t;
     free(contact as *mut libc::c_void);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_contact_empty(mut contact: *mut dc_contact_t) {
+pub unsafe fn dc_contact_empty(mut contact: *mut dc_contact_t) {
     if contact.is_null() || (*contact).magic != 0xc047ac7i32 as libc::c_uint {
         return;
     }
@@ -310,8 +298,7 @@ pub unsafe extern "C" fn dc_contact_empty(mut contact: *mut dc_contact_t) {
 /* contacts with at least this origin value are shown in the contact list */
 /* contacts with at least this origin value are verified and known not to be spam */
 /* contacts with at least this origin value start a new "normal" chat, defaults to off */
-#[no_mangle]
-pub unsafe extern "C" fn dc_contact_load_from_db(
+pub unsafe fn dc_contact_load_from_db(
     mut contact: *mut dc_contact_t,
     mut sql: *mut dc_sqlite3_t,
     mut contact_id: uint32_t,
@@ -357,8 +344,7 @@ pub unsafe extern "C" fn dc_contact_load_from_db(
     sqlite3_finalize(stmt);
     return success;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_is_contact_blocked(
+pub unsafe fn dc_is_contact_blocked(
     mut context: *mut dc_context_t,
     mut contact_id: uint32_t,
 ) -> libc::c_int {
@@ -373,8 +359,7 @@ pub unsafe extern "C" fn dc_is_contact_blocked(
     return is_blocked;
 }
 /*can be NULL*/
-#[no_mangle]
-pub unsafe extern "C" fn dc_add_or_lookup_contact(
+pub unsafe fn dc_add_or_lookup_contact(
     mut context: *mut dc_context_t,
     mut name: *const libc::c_char,
     mut addr__: *const libc::c_char,
@@ -559,8 +544,7 @@ pub unsafe extern "C" fn dc_add_or_lookup_contact(
     sqlite3_finalize(stmt);
     return row_id;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_add_address_book(
+pub unsafe fn dc_add_address_book(
     mut context: *mut dc_context_t,
     mut adr_book: *const libc::c_char,
 ) -> libc::c_int {
@@ -606,8 +590,7 @@ pub unsafe extern "C" fn dc_add_address_book(
     return modify_cnt;
 }
 // Working with names
-#[no_mangle]
-pub unsafe extern "C" fn dc_normalize_name(mut full_name: *mut libc::c_char) {
+pub unsafe fn dc_normalize_name(mut full_name: *mut libc::c_char) {
     if full_name.is_null() {
         return;
     }
@@ -640,8 +623,7 @@ pub unsafe extern "C" fn dc_normalize_name(mut full_name: *mut libc::c_char) {
         dc_trim(full_name);
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_contacts(
+pub unsafe fn dc_get_contacts(
     mut context: *mut dc_context_t,
     mut listflags: uint32_t,
     mut query: *const libc::c_char,
@@ -736,8 +718,7 @@ pub unsafe extern "C" fn dc_get_contacts(
     free(self_name2 as *mut libc::c_void);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_blocked_cnt(mut context: *mut dc_context_t) -> libc::c_int {
+pub unsafe fn dc_get_blocked_cnt(mut context: *mut dc_context_t) -> libc::c_int {
     let mut ret: libc::c_int = 0i32;
     let mut stmt: *mut sqlite3_stmt = 0 as *mut sqlite3_stmt;
     if !(context.is_null() || (*context).magic != 0x11a11807i32 as libc::c_uint) {
@@ -754,10 +735,7 @@ pub unsafe extern "C" fn dc_get_blocked_cnt(mut context: *mut dc_context_t) -> l
     sqlite3_finalize(stmt);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_blocked_contacts(
-    mut context: *mut dc_context_t,
-) -> *mut dc_array_t {
+pub unsafe fn dc_get_blocked_contacts(mut context: *mut dc_context_t) -> *mut dc_array_t {
     let mut ret: *mut dc_array_t = dc_array_new(context, 100i32 as size_t);
     let mut stmt: *mut sqlite3_stmt = 0 as *mut sqlite3_stmt;
     if !(context.is_null() || (*context).magic != 0x11a11807i32 as libc::c_uint) {
@@ -774,8 +752,7 @@ pub unsafe extern "C" fn dc_get_blocked_contacts(
     sqlite3_finalize(stmt);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_contact_encrinfo(
+pub unsafe fn dc_get_contact_encrinfo(
     mut context: *mut dc_context_t,
     mut contact_id: uint32_t,
 ) -> *mut libc::c_char {
@@ -888,7 +865,7 @@ pub unsafe extern "C" fn dc_get_contact_encrinfo(
     free(fingerprint_other_unverified as *mut libc::c_void);
     return ret.buf;
 }
-unsafe extern "C" fn cat_fingerprint(
+unsafe fn cat_fingerprint(
     mut ret: *mut dc_strbuilder_t,
     mut addr: *const libc::c_char,
     mut fingerprint_verified: *const libc::c_char,
@@ -922,8 +899,7 @@ unsafe extern "C" fn cat_fingerprint(
         dc_strbuilder_cat(ret, fingerprint_unverified);
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_delete_contact(
+pub unsafe fn dc_delete_contact(
     mut context: *mut dc_context_t,
     mut contact_id: uint32_t,
 ) -> libc::c_int {
@@ -972,8 +948,7 @@ pub unsafe extern "C" fn dc_delete_contact(
     sqlite3_finalize(stmt);
     return success;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_contact(
+pub unsafe fn dc_get_contact(
     mut context: *mut dc_context_t,
     mut contact_id: uint32_t,
 ) -> *mut dc_contact_t {
@@ -984,35 +959,25 @@ pub unsafe extern "C" fn dc_get_contact(
     }
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_contact_get_id(mut contact: *const dc_contact_t) -> uint32_t {
+pub unsafe fn dc_contact_get_id(mut contact: *const dc_contact_t) -> uint32_t {
     if contact.is_null() || (*contact).magic != 0xc047ac7i32 as libc::c_uint {
         return 0i32 as uint32_t;
     }
     return (*contact).id;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_contact_get_addr(
-    mut contact: *const dc_contact_t,
-) -> *mut libc::c_char {
+pub unsafe fn dc_contact_get_addr(mut contact: *const dc_contact_t) -> *mut libc::c_char {
     if contact.is_null() || (*contact).magic != 0xc047ac7i32 as libc::c_uint {
         return dc_strdup(0 as *const libc::c_char);
     }
     return dc_strdup((*contact).addr);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_contact_get_name(
-    mut contact: *const dc_contact_t,
-) -> *mut libc::c_char {
+pub unsafe fn dc_contact_get_name(mut contact: *const dc_contact_t) -> *mut libc::c_char {
     if contact.is_null() || (*contact).magic != 0xc047ac7i32 as libc::c_uint {
         return dc_strdup(0 as *const libc::c_char);
     }
     return dc_strdup((*contact).name);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_contact_get_display_name(
-    mut contact: *const dc_contact_t,
-) -> *mut libc::c_char {
+pub unsafe fn dc_contact_get_display_name(mut contact: *const dc_contact_t) -> *mut libc::c_char {
     if contact.is_null() || (*contact).magic != 0xc047ac7i32 as libc::c_uint {
         return dc_strdup(0 as *const libc::c_char);
     }
@@ -1021,10 +986,7 @@ pub unsafe extern "C" fn dc_contact_get_display_name(
     }
     return dc_strdup((*contact).addr);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_contact_get_name_n_addr(
-    mut contact: *const dc_contact_t,
-) -> *mut libc::c_char {
+pub unsafe fn dc_contact_get_name_n_addr(mut contact: *const dc_contact_t) -> *mut libc::c_char {
     if contact.is_null() || (*contact).magic != 0xc047ac7i32 as libc::c_uint {
         return dc_strdup(0 as *const libc::c_char);
     }
@@ -1037,10 +999,7 @@ pub unsafe extern "C" fn dc_contact_get_name_n_addr(
     }
     return dc_strdup((*contact).addr);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_contact_get_first_name(
-    mut contact: *const dc_contact_t,
-) -> *mut libc::c_char {
+pub unsafe fn dc_contact_get_first_name(mut contact: *const dc_contact_t) -> *mut libc::c_char {
     if contact.is_null() || (*contact).magic != 0xc047ac7i32 as libc::c_uint {
         return dc_strdup(0 as *const libc::c_char);
     }
@@ -1049,10 +1008,7 @@ pub unsafe extern "C" fn dc_contact_get_first_name(
     }
     return dc_strdup((*contact).addr);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_first_name(
-    mut full_name: *const libc::c_char,
-) -> *mut libc::c_char {
+pub unsafe fn dc_get_first_name(mut full_name: *const libc::c_char) -> *mut libc::c_char {
     let mut first_name: *mut libc::c_char = dc_strdup(full_name);
     let mut p1: *mut libc::c_char = strchr(first_name, ' ' as i32);
     if !p1.is_null() {
@@ -1065,10 +1021,7 @@ pub unsafe extern "C" fn dc_get_first_name(
     }
     return first_name;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_contact_get_profile_image(
-    mut contact: *const dc_contact_t,
-) -> *mut libc::c_char {
+pub unsafe fn dc_contact_get_profile_image(mut contact: *const dc_contact_t) -> *mut libc::c_char {
     let mut selfavatar: *mut libc::c_char = 0 as *mut libc::c_char;
     let mut image_abs: *mut libc::c_char = 0 as *mut libc::c_char;
     if !(contact.is_null() || (*contact).magic != 0xc047ac7i32 as libc::c_uint) {
@@ -1086,26 +1039,22 @@ pub unsafe extern "C" fn dc_contact_get_profile_image(
     free(selfavatar as *mut libc::c_void);
     return image_abs;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_contact_get_color(mut contact: *const dc_contact_t) -> uint32_t {
+pub unsafe fn dc_contact_get_color(mut contact: *const dc_contact_t) -> uint32_t {
     if contact.is_null() || (*contact).magic != 0xc047ac7i32 as libc::c_uint {
         return 0i32 as uint32_t;
     }
     return dc_str_to_color((*contact).addr) as uint32_t;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_contact_is_blocked(mut contact: *const dc_contact_t) -> libc::c_int {
+pub unsafe fn dc_contact_is_blocked(mut contact: *const dc_contact_t) -> libc::c_int {
     if contact.is_null() || (*contact).magic != 0xc047ac7i32 as libc::c_uint {
         return 0i32;
     }
     return (*contact).blocked;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_contact_is_verified(mut contact: *mut dc_contact_t) -> libc::c_int {
+pub unsafe fn dc_contact_is_verified(mut contact: *mut dc_contact_t) -> libc::c_int {
     return dc_contact_is_verified_ex(contact, 0 as *const dc_apeerstate_t);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_contact_is_verified_ex(
+pub unsafe fn dc_contact_is_verified_ex(
     mut contact: *mut dc_contact_t,
     mut peerstate: *const dc_apeerstate_t,
 ) -> libc::c_int {
@@ -1148,8 +1097,7 @@ pub unsafe extern "C" fn dc_contact_is_verified_ex(
     return contact_verified;
 }
 // Working with e-mail-addresses
-#[no_mangle]
-pub unsafe extern "C" fn dc_addr_cmp(
+pub unsafe fn dc_addr_cmp(
     mut addr1: *const libc::c_char,
     mut addr2: *const libc::c_char,
 ) -> libc::c_int {
@@ -1160,8 +1108,7 @@ pub unsafe extern "C" fn dc_addr_cmp(
     free(norm2 as *mut libc::c_void);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_addr_equals_self(
+pub unsafe fn dc_addr_equals_self(
     mut context: *mut dc_context_t,
     mut addr: *const libc::c_char,
 ) -> libc::c_int {
@@ -1187,8 +1134,7 @@ pub unsafe extern "C" fn dc_addr_equals_self(
     free(normalized_addr as *mut libc::c_void);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_addr_equals_contact(
+pub unsafe fn dc_addr_equals_contact(
     mut context: *mut dc_context_t,
     mut addr: *const libc::c_char,
     mut contact_id: uint32_t,
@@ -1210,8 +1156,7 @@ pub unsafe extern "C" fn dc_addr_equals_contact(
     return addr_are_equal;
 }
 // Context functions to work with contacts
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_real_contact_cnt(mut context: *mut dc_context_t) -> size_t {
+pub unsafe fn dc_get_real_contact_cnt(mut context: *mut dc_context_t) -> size_t {
     let mut ret: size_t = 0i32 as size_t;
     let mut stmt: *mut sqlite3_stmt = 0 as *mut sqlite3_stmt;
     if !(context.is_null()
@@ -1230,8 +1175,7 @@ pub unsafe extern "C" fn dc_get_real_contact_cnt(mut context: *mut dc_context_t)
     sqlite3_finalize(stmt);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_contact_origin(
+pub unsafe fn dc_get_contact_origin(
     mut context: *mut dc_context_t,
     mut contact_id: uint32_t,
     mut ret_blocked: *mut libc::c_int,
@@ -1254,8 +1198,7 @@ pub unsafe extern "C" fn dc_get_contact_origin(
     dc_contact_unref(contact);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_real_contact_exists(
+pub unsafe fn dc_real_contact_exists(
     mut context: *mut dc_context_t,
     mut contact_id: uint32_t,
 ) -> libc::c_int {
@@ -1278,8 +1221,7 @@ pub unsafe extern "C" fn dc_real_contact_exists(
     sqlite3_finalize(stmt);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_scaleup_contact_origin(
+pub unsafe fn dc_scaleup_contact_origin(
     mut context: *mut dc_context_t,
     mut contact_id: uint32_t,
     mut origin: libc::c_int,
diff --git a/src/dc_context.rs b/src/dc_context.rs
index ecbd94b0f..a91d79c1a 100644
--- a/src/dc_context.rs
+++ b/src/dc_context.rs
@@ -64,8 +64,7 @@ unsafe impl Send for dc_context_t {}
 unsafe impl Sync for dc_context_t {}
 
 // create/open/config/information
-#[no_mangle]
-pub unsafe extern "C" fn dc_context_new(
+pub unsafe fn dc_context_new(
     mut cb: dc_callback_t,
     mut userdata: *mut libc::c_void,
     mut os_name: *const libc::c_char,
@@ -164,7 +163,7 @@ pub unsafe extern "C" fn dc_context_new(
     );
     return context;
 }
-unsafe extern "C" fn cb_receive_imf(
+unsafe fn cb_receive_imf(
     mut imap: *mut dc_imap_t,
     mut imf_raw_not_terminated: *const libc::c_char,
     mut imf_raw_bytes: size_t,
@@ -182,7 +181,7 @@ unsafe extern "C" fn cb_receive_imf(
         flags,
     );
 }
-unsafe extern "C" fn cb_precheck_imf(
+unsafe fn cb_precheck_imf(
     mut imap: *mut dc_imap_t,
     mut rfc724_mid: *const libc::c_char,
     mut server_folder: *const libc::c_char,
@@ -237,7 +236,7 @@ unsafe extern "C" fn cb_precheck_imf(
     free(old_server_folder as *mut libc::c_void);
     return rfc724_mid_exists;
 }
-unsafe extern "C" fn cb_set_config(
+unsafe fn cb_set_config(
     mut imap: *mut dc_imap_t,
     mut key: *const libc::c_char,
     mut value: *const libc::c_char,
@@ -252,7 +251,7 @@ unsafe extern "C" fn cb_set_config(
  *
  * @private @memberof dc_context_t
  */
-unsafe extern "C" fn cb_get_config(
+unsafe fn cb_get_config(
     mut imap: *mut dc_imap_t,
     mut key: *const libc::c_char,
     mut def: *const libc::c_char,
@@ -266,7 +265,7 @@ unsafe extern "C" fn cb_get_config(
  *
  * @private @memberof dc_context_t
  */
-unsafe extern "C" fn cb_dummy(
+unsafe fn cb_dummy(
     mut context: *mut dc_context_t,
     mut event: libc::c_int,
     mut data1: uintptr_t,
@@ -274,8 +273,7 @@ unsafe extern "C" fn cb_dummy(
 ) -> uintptr_t {
     return 0i32 as uintptr_t;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_context_unref(mut context: *mut dc_context_t) {
+pub unsafe fn dc_context_unref(mut context: *mut dc_context_t) {
     if context.is_null() || (*context).magic != 0x11a11807i32 as libc::c_uint {
         return;
     }
@@ -301,8 +299,7 @@ pub unsafe extern "C" fn dc_context_unref(mut context: *mut dc_context_t) {
     (*context).magic = 0i32 as uint32_t;
     free(context as *mut libc::c_void);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_close(mut context: *mut dc_context_t) {
+pub unsafe fn dc_close(mut context: *mut dc_context_t) {
     if context.is_null() || (*context).magic != 0x11a11807i32 as libc::c_uint {
         return;
     }
@@ -318,22 +315,19 @@ pub unsafe extern "C" fn dc_close(mut context: *mut dc_context_t) {
     free((*context).blobdir as *mut libc::c_void);
     (*context).blobdir = 0 as *mut libc::c_char;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_is_open(mut context: *const dc_context_t) -> libc::c_int {
+pub unsafe fn dc_is_open(mut context: *const dc_context_t) -> libc::c_int {
     if context.is_null() || (*context).magic != 0x11a11807i32 as libc::c_uint {
         return 0i32;
     }
     return dc_sqlite3_is_open((*context).sql);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_userdata(mut context: *mut dc_context_t) -> *mut libc::c_void {
+pub unsafe fn dc_get_userdata(mut context: *mut dc_context_t) -> *mut libc::c_void {
     if context.is_null() || (*context).magic != 0x11a11807i32 as libc::c_uint {
         return 0 as *mut libc::c_void;
     }
     return (*context).userdata;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_open(
+pub unsafe fn dc_open(
     mut context: *mut dc_context_t,
     mut dbfile: *const libc::c_char,
     mut blobdir: *const libc::c_char,
@@ -363,15 +357,13 @@ pub unsafe extern "C" fn dc_open(
     }
     return success;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_blobdir(mut context: *const dc_context_t) -> *mut libc::c_char {
+pub unsafe fn dc_get_blobdir(mut context: *const dc_context_t) -> *mut libc::c_char {
     if context.is_null() || (*context).magic != 0x11a11807i32 as libc::c_uint {
         return dc_strdup(0 as *const libc::c_char);
     }
     return dc_strdup((*context).blobdir);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_set_config(
+pub unsafe fn dc_set_config(
     mut context: *mut dc_context_t,
     mut key: *const libc::c_char,
     mut value: *const libc::c_char,
@@ -426,7 +418,7 @@ pub unsafe extern "C" fn dc_set_config(
 /* ******************************************************************************
  * INI-handling, Information
  ******************************************************************************/
-unsafe extern "C" fn is_settable_config_key(mut key: *const libc::c_char) -> libc::c_int {
+unsafe fn is_settable_config_key(mut key: *const libc::c_char) -> libc::c_int {
     let mut i: libc::c_int = 0i32;
     while (i as libc::c_ulong)
         < (::std::mem::size_of::<[*const libc::c_char; 33]>() as libc::c_ulong)
@@ -474,8 +466,7 @@ static mut config_keys: [*const libc::c_char; 33] = [
     b"configured_server_flags\x00" as *const u8 as *const libc::c_char,
     b"configured\x00" as *const u8 as *const libc::c_char,
 ];
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_config(
+pub unsafe fn dc_get_config(
     mut context: *mut dc_context_t,
     mut key: *const libc::c_char,
 ) -> *mut libc::c_char {
@@ -534,7 +525,7 @@ pub unsafe extern "C" fn dc_get_config(
     }
     return value;
 }
-unsafe extern "C" fn is_gettable_config_key(mut key: *const libc::c_char) -> libc::c_int {
+unsafe fn is_gettable_config_key(mut key: *const libc::c_char) -> libc::c_int {
     let mut i: libc::c_int = 0i32;
     while (i as libc::c_ulong)
         < (::std::mem::size_of::<[*const libc::c_char; 3]>() as libc::c_ulong)
@@ -553,7 +544,7 @@ static mut sys_config_keys: [*const libc::c_char; 3] = [
     b"sys.msgsize_max_recommended\x00" as *const u8 as *const libc::c_char,
     b"sys.config_keys\x00" as *const u8 as *const libc::c_char,
 ];
-unsafe extern "C" fn get_sys_config_str(mut key: *const libc::c_char) -> *mut libc::c_char {
+unsafe fn get_sys_config_str(mut key: *const libc::c_char) -> *mut libc::c_char {
     if strcmp(key, b"sys.version\x00" as *const u8 as *const libc::c_char) == 0i32 {
         return dc_strdup(b"0.42.0\x00" as *const u8 as *const libc::c_char);
     } else if strcmp(
@@ -575,7 +566,7 @@ unsafe extern "C" fn get_sys_config_str(mut key: *const libc::c_char) -> *mut li
         return dc_strdup(0 as *const libc::c_char);
     };
 }
-unsafe extern "C" fn get_config_keys_str() -> *mut libc::c_char {
+unsafe fn get_config_keys_str() -> *mut libc::c_char {
     let mut ret: dc_strbuilder_t = dc_strbuilder_t {
         buf: 0 as *mut libc::c_char,
         allocated: 0,
@@ -607,8 +598,7 @@ unsafe extern "C" fn get_config_keys_str() -> *mut libc::c_char {
     }
     return ret.buf;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_info(mut context: *mut dc_context_t) -> *mut libc::c_char {
+pub unsafe fn dc_get_info(mut context: *mut dc_context_t) -> *mut libc::c_char {
     let mut unset: *const libc::c_char = b"0\x00" as *const u8 as *const libc::c_char;
     let mut displayname: *mut libc::c_char = 0 as *mut libc::c_char;
     let mut temp: *mut libc::c_char = 0 as *mut libc::c_char;
@@ -785,12 +775,10 @@ pub unsafe extern "C" fn dc_get_info(mut context: *mut dc_context_t) -> *mut lib
     dc_key_unref(self_public);
     return ret.buf;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_version_str() -> *mut libc::c_char {
+pub unsafe fn dc_get_version_str() -> *mut libc::c_char {
     return dc_strdup(b"0.42.0\x00" as *const u8 as *const libc::c_char);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_fresh_msgs(mut context: *mut dc_context_t) -> *mut dc_array_t {
+pub unsafe fn dc_get_fresh_msgs(mut context: *mut dc_context_t) -> *mut dc_array_t {
     let mut show_deaddrop: libc::c_int = 0i32;
     let mut ret: *mut dc_array_t = dc_array_new(context, 128i32 as size_t);
     let mut stmt: *mut sqlite3_stmt = 0 as *mut sqlite3_stmt;
@@ -809,8 +797,7 @@ pub unsafe extern "C" fn dc_get_fresh_msgs(mut context: *mut dc_context_t) -> *m
     sqlite3_finalize(stmt);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_search_msgs(
+pub unsafe fn dc_search_msgs(
     mut context: *mut dc_context_t,
     mut chat_id: uint32_t,
     mut query: *const libc::c_char,
@@ -876,8 +863,7 @@ pub unsafe extern "C" fn dc_search_msgs(
         return 0 as *mut dc_array_t;
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_is_inbox(
+pub unsafe fn dc_is_inbox(
     mut context: *mut dc_context_t,
     mut folder_name: *const libc::c_char,
 ) -> libc::c_int {
@@ -895,8 +881,7 @@ pub unsafe extern "C" fn dc_is_inbox(
     }
     return is_inbox;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_is_sentbox(
+pub unsafe fn dc_is_sentbox(
     mut context: *mut dc_context_t,
     mut folder_name: *const libc::c_char,
 ) -> libc::c_int {
@@ -916,8 +901,7 @@ pub unsafe extern "C" fn dc_is_sentbox(
     free(sentbox_name as *mut libc::c_void);
     return is_sentbox;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_is_mvbox(
+pub unsafe fn dc_is_mvbox(
     mut context: *mut dc_context_t,
     mut folder_name: *const libc::c_char,
 ) -> libc::c_int {
diff --git a/src/dc_dehtml.rs b/src/dc_dehtml.rs
index ca3d68b6b..629a0c1a6 100644
--- a/src/dc_dehtml.rs
+++ b/src/dc_dehtml.rs
@@ -16,8 +16,7 @@ pub struct dehtml_t {
 
 /* ** library-internal *********************************************************/
 /* dc_dehtml() returns way too many lineends; however, an optimisation on this issue is not needed as the lineends are typically remove in further processing by the caller */
-#[no_mangle]
-pub unsafe extern "C" fn dc_dehtml(mut buf_terminated: *mut libc::c_char) -> *mut libc::c_char {
+pub unsafe fn dc_dehtml(mut buf_terminated: *mut libc::c_char) -> *mut libc::c_char {
     dc_trim(buf_terminated);
     if *buf_terminated.offset(0isize) as libc::c_int == 0i32 {
         return dc_strdup(b"\x00" as *const u8 as *const libc::c_char);
@@ -63,7 +62,7 @@ pub unsafe extern "C" fn dc_dehtml(mut buf_terminated: *mut libc::c_char) -> *mu
         return dehtml.strbuilder.buf;
     };
 }
-unsafe extern "C" fn dehtml_text_cb(
+unsafe fn dehtml_text_cb(
     mut userdata: *mut libc::c_void,
     mut text: *const libc::c_char,
     mut len: libc::c_int,
@@ -99,10 +98,7 @@ unsafe extern "C" fn dehtml_text_cb(
         }
     };
 }
-unsafe extern "C" fn dehtml_endtag_cb(
-    mut userdata: *mut libc::c_void,
-    mut tag: *const libc::c_char,
-) {
+unsafe fn dehtml_endtag_cb(mut userdata: *mut libc::c_void, mut tag: *const libc::c_char) {
     let mut dehtml: *mut dehtml_t = userdata as *mut dehtml_t;
     if strcmp(tag, b"p\x00" as *const u8 as *const libc::c_char) == 0i32
         || strcmp(tag, b"div\x00" as *const u8 as *const libc::c_char) == 0i32
@@ -148,7 +144,7 @@ unsafe extern "C" fn dehtml_endtag_cb(
         );
     };
 }
-unsafe extern "C" fn dehtml_starttag_cb(
+unsafe fn dehtml_starttag_cb(
     mut userdata: *mut libc::c_void,
     mut tag: *const libc::c_char,
     mut attr: *mut *mut libc::c_char,
diff --git a/src/dc_e2ee.rs b/src/dc_e2ee.rs
index 4775593da..44547971d 100644
--- a/src/dc_e2ee.rs
+++ b/src/dc_e2ee.rs
@@ -34,8 +34,7 @@ pub struct dc_e2ee_helper_t {
     pub gossipped_addr: *mut dc_hash_t,
 }
 
-#[no_mangle]
-pub unsafe extern "C" fn dc_e2ee_encrypt(
+pub unsafe fn dc_e2ee_encrypt(
     mut context: *mut dc_context_t,
     mut recipients_addr: *const clist,
     mut force_unencrypted: libc::c_int,
@@ -400,7 +399,7 @@ pub unsafe extern "C" fn dc_e2ee_encrypt(
 /* ******************************************************************************
  * Tools
  ******************************************************************************/
-unsafe extern "C" fn new_data_part(
+unsafe fn new_data_part(
     mut data: *mut libc::c_void,
     mut data_bytes: size_t,
     mut default_content_type: *mut libc::c_char,
@@ -508,7 +507,7 @@ unsafe extern "C" fn new_data_part(
 /* ******************************************************************************
  * Generate Keypairs
  ******************************************************************************/
-unsafe extern "C" fn load_or_generate_self_public_key(
+unsafe fn load_or_generate_self_public_key(
     mut context: *mut dc_context_t,
     mut public_key: *mut dc_key_t,
     mut self_addr: *const libc::c_char,
@@ -638,8 +637,7 @@ unsafe extern "C" fn load_or_generate_self_public_key(
     return success;
 }
 /* returns 1 if sth. was decrypted, 0 in other cases */
-#[no_mangle]
-pub unsafe extern "C" fn dc_e2ee_decrypt(
+pub unsafe fn dc_e2ee_decrypt(
     mut context: *mut dc_context_t,
     mut in_out_message: *mut mailmime,
     mut helper: *mut dc_e2ee_helper_t,
@@ -774,7 +772,7 @@ pub unsafe extern "C" fn dc_e2ee_decrypt(
     free(from as *mut libc::c_void);
     free(self_addr as *mut libc::c_void);
 }
-unsafe extern "C" fn update_gossip_peerstates(
+unsafe fn update_gossip_peerstates(
     mut context: *mut dc_context_t,
     mut message_time: time_t,
     mut imffields: *mut mailimf_fields,
@@ -867,7 +865,7 @@ unsafe extern "C" fn update_gossip_peerstates(
     }
     return gossipped_addr;
 }
-unsafe extern "C" fn decrypt_recursive(
+unsafe fn decrypt_recursive(
     mut context: *mut dc_context_t,
     mut mime: *mut mailmime,
     mut private_keyring: *const dc_keyring_t,
@@ -972,7 +970,7 @@ unsafe extern "C" fn decrypt_recursive(
     }
     return 0i32;
 }
-unsafe extern "C" fn decrypt_part(
+unsafe fn decrypt_part(
     mut context: *mut dc_context_t,
     mut mime: *mut mailmime,
     mut private_keyring: *const dc_keyring_t,
@@ -1116,7 +1114,7 @@ unsafe extern "C" fn decrypt_part(
 /* ******************************************************************************
  * Decrypt
  ******************************************************************************/
-unsafe extern "C" fn has_decrypted_pgp_armor(
+unsafe fn has_decrypted_pgp_armor(
     mut str__: *const libc::c_char,
     mut str_bytes: libc::c_int,
 ) -> libc::c_int {
@@ -1155,7 +1153,7 @@ unsafe extern "C" fn has_decrypted_pgp_armor(
  * @param mime The mime struture to check
  * @return 1=multipart/report found in MIME, 0=no multipart/report found
  */
-unsafe extern "C" fn contains_report(mut mime: *mut mailmime) -> libc::c_int {
+unsafe fn contains_report(mut mime: *mut mailmime) -> libc::c_int {
     if (*mime).mm_type == MAILMIME_MULTIPLE as libc::c_int {
         if (*(*(*mime).mm_content_type).ct_type).tp_type
             == MAILMIME_TYPE_COMPOSITE_TYPE as libc::c_int
@@ -1197,8 +1195,7 @@ unsafe extern "C" fn contains_report(mut mime: *mut mailmime) -> libc::c_int {
     return 0i32;
 }
 /* frees data referenced by "mailmime" but not freed by mailmime_free(). After calling this function, in_out_message cannot be used any longer! */
-#[no_mangle]
-pub unsafe extern "C" fn dc_e2ee_thanks(mut helper: *mut dc_e2ee_helper_t) {
+pub unsafe fn dc_e2ee_thanks(mut helper: *mut dc_e2ee_helper_t) {
     if helper.is_null() {
         return;
     }
@@ -1216,10 +1213,7 @@ pub unsafe extern "C" fn dc_e2ee_thanks(mut helper: *mut dc_e2ee_helper_t) {
     };
 }
 /* makes sure, the private key exists, needed only for exporting keys and the case no message was sent before */
-#[no_mangle]
-pub unsafe extern "C" fn dc_ensure_secret_key_exists(
-    mut context: *mut dc_context_t,
-) -> libc::c_int {
+pub unsafe fn dc_ensure_secret_key_exists(mut context: *mut dc_context_t) -> libc::c_int {
     /* normally, the key is generated as soon as the first mail is send
     (this is to gain some extra-random-seed by the message content and the timespan between program start and message sending) */
     let mut success: libc::c_int = 0i32;
diff --git a/src/dc_hash.rs b/src/dc_hash.rs
index 9b5d3ed5f..a039b4b0e 100644
--- a/src/dc_hash.rs
+++ b/src/dc_hash.rs
@@ -66,8 +66,7 @@ pub struct _dc_hashelem {
 /*
  * Access routines.  To delete an element, insert a NULL pointer.
  */
-#[no_mangle]
-pub unsafe extern "C" fn dc_hash_init(
+pub unsafe fn dc_hash_init(
     mut pNew: *mut dc_hash_t,
     mut keyClass: libc::c_int,
     mut copyKey: libc::c_int,
@@ -103,8 +102,7 @@ pub unsafe extern "C" fn dc_hash_init(
     (*pNew).htsize = 0i32;
     (*pNew).ht = 0 as *mut _ht;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_hash_insert(
+pub unsafe fn dc_hash_insert(
     mut pH: *mut dc_hash_t,
     mut pKey: *const libc::c_void,
     mut nKey: libc::c_int,
@@ -119,9 +117,7 @@ pub unsafe extern "C" fn dc_hash_insert(
     /* New element added to the pH */
     let mut new_elem: *mut dc_hashelem_t = 0 as *mut dc_hashelem_t;
     /* The hash function */
-    let mut xHash: Option<
-        unsafe extern "C" fn(_: *const libc::c_void, _: libc::c_int) -> libc::c_int,
-    > = None;
+    let mut xHash: Option<unsafe fn(_: *const libc::c_void, _: libc::c_int) -> libc::c_int> = None;
     if 0 != pH.is_null() as libc::c_int as libc::c_long {
         __assert_rtn(
             (*::std::mem::transmute::<&[u8; 15], &[libc::c_char; 15]>(b"dc_hash_insert\x00"))
@@ -259,16 +255,14 @@ unsafe extern "C" fn insertElement(
  * "new_size" must be a power of 2.  The hash table might fail
  * to resize if sjhashMalloc() fails.
  */
-unsafe extern "C" fn rehash(mut pH: *mut dc_hash_t, mut new_size: libc::c_int) {
+unsafe fn rehash(mut pH: *mut dc_hash_t, mut new_size: libc::c_int) {
     /* The new hash table */
     let mut new_ht: *mut _ht = 0 as *mut _ht;
     /* For looping over existing elements */
     let mut elem: *mut dc_hashelem_t = 0 as *mut dc_hashelem_t;
     let mut next_elem: *mut dc_hashelem_t = 0 as *mut dc_hashelem_t;
     /* The hash function */
-    let mut xHash: Option<
-        unsafe extern "C" fn(_: *const libc::c_void, _: libc::c_int) -> libc::c_int,
-    > = None;
+    let mut xHash: Option<unsafe fn(_: *const libc::c_void, _: libc::c_int) -> libc::c_int> = None;
     if 0 != !(new_size & new_size - 1i32 == 0i32) as libc::c_int as libc::c_long {
         __assert_rtn(
             (*::std::mem::transmute::<&[u8; 7], &[libc::c_char; 7]>(b"rehash\x00")).as_ptr(),
@@ -310,9 +304,9 @@ unsafe extern "C" fn rehash(mut pH: *mut dc_hash_t, mut new_size: libc::c_int) {
  * of hashFunction() is a pointer to a function that takes two parameters
  * with types "const void*" and "int" and returns an "int".
  */
-unsafe extern "C" fn hashFunction(
+unsafe fn hashFunction(
     mut keyClass: libc::c_int,
-) -> Option<unsafe extern "C" fn(_: *const libc::c_void, _: libc::c_int) -> libc::c_int> {
+) -> Option<unsafe fn(_: *const libc::c_void, _: libc::c_int) -> libc::c_int> {
     match keyClass {
         1 => return Some(intHash),
         2 => return Some(ptrHash),
@@ -324,7 +318,7 @@ unsafe extern "C" fn hashFunction(
 }
 /* Hash and comparison functions when the mode is SJHASH_BINARY
  */
-unsafe extern "C" fn binHash(mut pKey: *const libc::c_void, mut nKey: libc::c_int) -> libc::c_int {
+unsafe fn binHash(mut pKey: *const libc::c_void, mut nKey: libc::c_int) -> libc::c_int {
     let mut h: libc::c_int = 0i32;
     let mut z: *const libc::c_char = pKey as *const libc::c_char;
     loop {
@@ -341,13 +335,13 @@ unsafe extern "C" fn binHash(mut pKey: *const libc::c_void, mut nKey: libc::c_in
 }
 /* Hash and comparison functions when the mode is SJHASH_STRING
  */
-unsafe extern "C" fn strHash(mut pKey: *const libc::c_void, mut nKey: libc::c_int) -> libc::c_int {
+unsafe fn strHash(mut pKey: *const libc::c_void, mut nKey: libc::c_int) -> libc::c_int {
     return sjhashNoCase(pKey as *const libc::c_char, nKey);
 }
 /* This function computes a hash on the name of a keyword.
  * Case is not significant.
  */
-unsafe extern "C" fn sjhashNoCase(mut z: *const libc::c_char, mut n: libc::c_int) -> libc::c_int {
+unsafe fn sjhashNoCase(mut z: *const libc::c_char, mut n: libc::c_int) -> libc::c_int {
     let mut h: libc::c_int = 0i32;
     if n <= 0i32 {
         n = strlen(z) as libc::c_int
@@ -623,13 +617,13 @@ static mut sjhashUpperToLower: [libc::c_uchar; 256] = [
 ];
 /* Hash and comparison functions when the mode is SJHASH_POINTER
  */
-unsafe extern "C" fn ptrHash(mut pKey: *const libc::c_void, mut nKey: libc::c_int) -> libc::c_int {
+unsafe fn ptrHash(mut pKey: *const libc::c_void, mut nKey: libc::c_int) -> libc::c_int {
     let mut x: uintptr_t = pKey as uintptr_t;
     return (x ^ x << 8i32 ^ x >> 8i32) as libc::c_int;
 }
 /* Hash and comparison functions when the mode is SJHASH_INT
  */
-unsafe extern "C" fn intHash(mut pKey: *const libc::c_void, mut nKey: libc::c_int) -> libc::c_int {
+unsafe fn intHash(mut pKey: *const libc::c_void, mut nKey: libc::c_int) -> libc::c_int {
     return nKey ^ nKey << 8i32 ^ nKey >> 8i32;
 }
 /*
@@ -640,7 +634,7 @@ unsafe extern "C" fn intHash(mut pKey: *const libc::c_void, mut nKey: libc::c_in
 ** May you find forgiveness for yourself and forgive others.
 ** May you share freely, never taking more than you give.
 */
-unsafe extern "C" fn sjhashMalloc(mut bytes: libc::c_long) -> *mut libc::c_void {
+unsafe fn sjhashMalloc(mut bytes: libc::c_long) -> *mut libc::c_void {
     let mut p: *mut libc::c_void = malloc(bytes as libc::c_ulong);
     if !p.is_null() {
         memset(p, 0i32, bytes as libc::c_ulong);
@@ -650,7 +644,7 @@ unsafe extern "C" fn sjhashMalloc(mut bytes: libc::c_long) -> *mut libc::c_void
 /* Remove a single entry from the hash table given a pointer to that
  * element and a hash on the element's key.
  */
-unsafe extern "C" fn removeElementGivenHash(
+unsafe fn removeElementGivenHash(
     mut pH: *mut dc_hash_t,
     mut elem: *mut dc_hashelem_t,
     mut h: libc::c_int,
@@ -682,7 +676,7 @@ unsafe extern "C" fn removeElementGivenHash(
  * hash table that matches the given key.  The hash for this key has
  * already been computed and is passed as the 4th parameter.
  */
-unsafe extern "C" fn findElementGivenHash(
+unsafe fn findElementGivenHash(
     mut pH: *const dc_hash_t,
     mut pKey: *const libc::c_void,
     mut nKey: libc::c_int,
@@ -694,7 +688,7 @@ unsafe extern "C" fn findElementGivenHash(
     let mut count: libc::c_int = 0;
     /* comparison function */
     let mut xCompare: Option<
-        unsafe extern "C" fn(
+        unsafe fn(
             _: *const libc::c_void,
             _: libc::c_int,
             _: *const libc::c_void,
@@ -724,10 +718,10 @@ unsafe extern "C" fn findElementGivenHash(
 }
 /* Return a pointer to the appropriate hash function given the key class.
  */
-unsafe extern "C" fn compareFunction(
+unsafe fn compareFunction(
     mut keyClass: libc::c_int,
 ) -> Option<
-    unsafe extern "C" fn(
+    unsafe fn(
         _: *const libc::c_void,
         _: libc::c_int,
         _: *const libc::c_void,
@@ -743,7 +737,7 @@ unsafe extern "C" fn compareFunction(
     }
     return None;
 }
-unsafe extern "C" fn binCompare(
+unsafe fn binCompare(
     mut pKey1: *const libc::c_void,
     mut n1: libc::c_int,
     mut pKey2: *const libc::c_void,
@@ -754,7 +748,7 @@ unsafe extern "C" fn binCompare(
     }
     return memcmp(pKey1, pKey2, n1 as libc::c_ulong);
 }
-unsafe extern "C" fn strCompare(
+unsafe fn strCompare(
     mut pKey1: *const libc::c_void,
     mut n1: libc::c_int,
     mut pKey2: *const libc::c_void,
@@ -772,7 +766,7 @@ unsafe extern "C" fn strCompare(
 /* Some systems have stricmp().  Others have strcasecmp().  Because
  * there is no consistency, we will define our own.
  */
-unsafe extern "C" fn sjhashStrNICmp(
+unsafe fn sjhashStrNICmp(
     mut zLeft: *const libc::c_char,
     mut zRight: *const libc::c_char,
     mut N: libc::c_int,
@@ -801,7 +795,7 @@ unsafe extern "C" fn sjhashStrNICmp(
             - sjhashUpperToLower[*b as usize] as libc::c_int
     };
 }
-unsafe extern "C" fn ptrCompare(
+unsafe fn ptrCompare(
     mut pKey1: *const libc::c_void,
     mut n1: libc::c_int,
     mut pKey2: *const libc::c_void,
@@ -815,7 +809,7 @@ unsafe extern "C" fn ptrCompare(
     }
     return 1i32;
 }
-unsafe extern "C" fn intCompare(
+unsafe fn intCompare(
     mut pKey1: *const libc::c_void,
     mut n1: libc::c_int,
     mut pKey2: *const libc::c_void,
@@ -823,8 +817,7 @@ unsafe extern "C" fn intCompare(
 ) -> libc::c_int {
     return n2 - n1;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_hash_find(
+pub unsafe fn dc_hash_find(
     mut pH: *const dc_hash_t,
     mut pKey: *const libc::c_void,
     mut nKey: libc::c_int,
@@ -834,9 +827,7 @@ pub unsafe extern "C" fn dc_hash_find(
     /* The element that matches key */
     let mut elem: *mut dc_hashelem_t = 0 as *mut dc_hashelem_t;
     /* The hash function */
-    let mut xHash: Option<
-        unsafe extern "C" fn(_: *const libc::c_void, _: libc::c_int) -> libc::c_int,
-    > = None;
+    let mut xHash: Option<unsafe fn(_: *const libc::c_void, _: libc::c_int) -> libc::c_int> = None;
     if pH.is_null() || (*pH).ht.is_null() {
         return 0 as *mut libc::c_void;
     }
@@ -869,8 +860,7 @@ pub unsafe extern "C" fn dc_hash_find(
         0 as *mut libc::c_void
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_hash_clear(mut pH: *mut dc_hash_t) {
+pub unsafe fn dc_hash_clear(mut pH: *mut dc_hash_t) {
     /* For looping over all elements of the table */
     let mut elem: *mut dc_hashelem_t = 0 as *mut dc_hashelem_t;
     if pH.is_null() {
diff --git a/src/dc_imap.rs b/src/dc_imap.rs
index 3ff55f202..b8cadc3a9 100644
--- a/src/dc_imap.rs
+++ b/src/dc_imap.rs
@@ -48,8 +48,7 @@ pub struct dc_imap_t {
     pub skip_log_capabilities: libc::c_int,
 }
 
-#[no_mangle]
-pub unsafe extern "C" fn dc_imap_new(
+pub unsafe fn dc_imap_new(
     mut get_config: dc_get_config_t,
     mut set_config: dc_set_config_t,
     mut precheck_imf: dc_precheck_imf_t,
@@ -108,8 +107,7 @@ pub unsafe extern "C" fn dc_imap_new(
     );
     return imap;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_imap_unref(mut imap: *mut dc_imap_t) {
+pub unsafe fn dc_imap_unref(mut imap: *mut dc_imap_t) {
     if imap.is_null() {
         return;
     }
@@ -129,8 +127,7 @@ pub unsafe extern "C" fn dc_imap_unref(mut imap: *mut dc_imap_t) {
     }
     free(imap as *mut libc::c_void);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_imap_disconnect(mut imap: *mut dc_imap_t) {
+pub unsafe fn dc_imap_disconnect(mut imap: *mut dc_imap_t) {
     if imap.is_null() {
         return;
     }
@@ -144,7 +141,7 @@ pub unsafe extern "C" fn dc_imap_disconnect(mut imap: *mut dc_imap_t) {
 /* ******************************************************************************
  * Connect/Disconnect
  ******************************************************************************/
-unsafe extern "C" fn free_connect_param(mut imap: *mut dc_imap_t) {
+unsafe fn free_connect_param(mut imap: *mut dc_imap_t) {
     free((*imap).addr as *mut libc::c_void);
     (*imap).addr = 0 as *mut libc::c_char;
     free((*imap).imap_server as *mut libc::c_void);
@@ -159,7 +156,7 @@ unsafe extern "C" fn free_connect_param(mut imap: *mut dc_imap_t) {
     (*imap).can_idle = 0i32;
     (*imap).has_xlist = 0i32;
 }
-unsafe extern "C" fn unsetup_handle(mut imap: *mut dc_imap_t) {
+unsafe fn unsetup_handle(mut imap: *mut dc_imap_t) {
     if imap.is_null() {
         return;
     }
@@ -182,8 +179,7 @@ unsafe extern "C" fn unsetup_handle(mut imap: *mut dc_imap_t) {
     }
     *(*imap).selected_folder.offset(0isize) = 0i32 as libc::c_char;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_imap_connect(
+pub unsafe fn dc_imap_connect(
     mut imap: *mut dc_imap_t,
     mut lp: *const dc_loginparam_t,
 ) -> libc::c_int {
@@ -269,7 +265,7 @@ pub unsafe extern "C" fn dc_imap_connect(
     }
     return success;
 }
-unsafe extern "C" fn setup_handle_if_needed(mut imap: *mut dc_imap_t) -> libc::c_int {
+unsafe fn setup_handle_if_needed(mut imap: *mut dc_imap_t) -> libc::c_int {
     let mut current_block: u64;
     let mut r: libc::c_int = 0i32;
     let mut success: libc::c_int = 0i32;
@@ -435,7 +431,7 @@ unsafe extern "C" fn setup_handle_if_needed(mut imap: *mut dc_imap_t) -> libc::c
     (*imap).should_reconnect = 0i32;
     return success;
 }
-unsafe extern "C" fn get_error_msg(
+unsafe fn get_error_msg(
     mut imap: *mut dc_imap_t,
     mut what_failed: *const libc::c_char,
     mut code: libc::c_int,
@@ -478,11 +474,7 @@ unsafe extern "C" fn get_error_msg(
     stock = 0 as *mut libc::c_char;
     return msg.buf;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_imap_is_error(
-    mut imap: *mut dc_imap_t,
-    mut code: libc::c_int,
-) -> libc::c_int {
+pub unsafe fn dc_imap_is_error(mut imap: *mut dc_imap_t, mut code: libc::c_int) -> libc::c_int {
     if code == MAILIMAP_NO_ERROR as libc::c_int
         || code == MAILIMAP_NO_ERROR_AUTHENTICATED as libc::c_int
         || code == MAILIMAP_NO_ERROR_NON_AUTHENTICATED as libc::c_int
@@ -499,7 +491,6 @@ pub unsafe extern "C" fn dc_imap_is_error(
     }
     return 1i32;
 }
-#[no_mangle]
 pub unsafe extern "C" fn dc_imap_set_watch_folder(
     mut imap: *mut dc_imap_t,
     mut watch_folder: *const libc::c_char,
@@ -510,12 +501,10 @@ pub unsafe extern "C" fn dc_imap_set_watch_folder(
     free((*imap).watch_folder as *mut libc::c_void);
     (*imap).watch_folder = dc_strdup(watch_folder);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_imap_is_connected(mut imap: *const dc_imap_t) -> libc::c_int {
+pub unsafe fn dc_imap_is_connected(mut imap: *const dc_imap_t) -> libc::c_int {
     return (!imap.is_null() && 0 != (*imap).connected) as libc::c_int;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_imap_fetch(mut imap: *mut dc_imap_t) -> libc::c_int {
+pub unsafe fn dc_imap_fetch(mut imap: *mut dc_imap_t) -> libc::c_int {
     let mut success: libc::c_int = 0i32;
     if !(imap.is_null() || 0 == (*imap).connected) {
         setup_handle_if_needed(imap);
@@ -524,7 +513,7 @@ pub unsafe extern "C" fn dc_imap_fetch(mut imap: *mut dc_imap_t) -> libc::c_int
     }
     return success;
 }
-unsafe extern "C" fn fetch_from_single_folder(
+unsafe fn fetch_from_single_folder(
     mut imap: *mut dc_imap_t,
     mut folder: *const libc::c_char,
 ) -> libc::c_int {
@@ -817,7 +806,7 @@ unsafe extern "C" fn fetch_from_single_folder(
     }
     return read_cnt as libc::c_int;
 }
-unsafe extern "C" fn set_config_lastseenuid(
+unsafe fn set_config_lastseenuid(
     mut imap: *mut dc_imap_t,
     mut folder: *const libc::c_char,
     mut uidvalidity: uint32_t,
@@ -836,7 +825,7 @@ unsafe extern "C" fn set_config_lastseenuid(
     free(val as *mut libc::c_void);
     free(key as *mut libc::c_void);
 }
-unsafe extern "C" fn peek_rfc724_mid(mut msg_att: *mut mailimap_msg_att) -> *const libc::c_char {
+unsafe fn peek_rfc724_mid(mut msg_att: *mut mailimap_msg_att) -> *const libc::c_char {
     if msg_att.is_null() {
         return 0 as *const libc::c_char;
     }
@@ -870,7 +859,7 @@ unsafe extern "C" fn peek_rfc724_mid(mut msg_att: *mut mailimap_msg_att) -> *con
     }
     return 0 as *const libc::c_char;
 }
-unsafe extern "C" fn unquote_rfc724_mid(mut in_0: *const libc::c_char) -> *mut libc::c_char {
+unsafe fn unquote_rfc724_mid(mut in_0: *const libc::c_char) -> *mut libc::c_char {
     /* remove < and > from the given message id */
     let mut out: *mut libc::c_char = dc_strdup(in_0);
     let mut out_len: libc::c_int = strlen(out) as libc::c_int;
@@ -888,7 +877,7 @@ unsafe extern "C" fn unquote_rfc724_mid(mut in_0: *const libc::c_char) -> *mut l
 /* ******************************************************************************
  * Fetch Messages
  ******************************************************************************/
-unsafe extern "C" fn peek_uid(mut msg_att: *mut mailimap_msg_att) -> uint32_t {
+unsafe fn peek_uid(mut msg_att: *mut mailimap_msg_att) -> uint32_t {
     /* search the UID in a list of attributes returned by a FETCH command */
     let mut iter1: *mut clistiter = 0 as *mut clistiter;
     iter1 = (*(*msg_att).att_list).first;
@@ -913,7 +902,7 @@ unsafe extern "C" fn peek_uid(mut msg_att: *mut mailimap_msg_att) -> uint32_t {
     }
     return 0i32 as uint32_t;
 }
-unsafe extern "C" fn fetch_single_msg(
+unsafe fn fetch_single_msg(
     mut imap: *mut dc_imap_t,
     mut folder: *const libc::c_char,
     mut server_uid: uint32_t,
@@ -1008,7 +997,7 @@ unsafe extern "C" fn fetch_single_msg(
     }
     return if 0 != retry_later { 0i32 } else { 1i32 };
 }
-unsafe extern "C" fn peek_body(
+unsafe fn peek_body(
     mut msg_att: *mut mailimap_msg_att,
     mut p_msg: *mut *mut libc::c_char,
     mut p_msg_bytes: *mut size_t,
@@ -1076,7 +1065,7 @@ unsafe extern "C" fn peek_body(
         }
     }
 }
-unsafe extern "C" fn get_config_lastseenuid(
+unsafe fn get_config_lastseenuid(
     mut imap: *mut dc_imap_t,
     mut folder: *const libc::c_char,
     mut uidvalidity: *mut uint32_t,
@@ -1111,10 +1100,7 @@ unsafe extern "C" fn get_config_lastseenuid(
 /* ******************************************************************************
  * Handle folders
  ******************************************************************************/
-unsafe extern "C" fn select_folder(
-    mut imap: *mut dc_imap_t,
-    mut folder: *const libc::c_char,
-) -> libc::c_int {
+unsafe fn select_folder(mut imap: *mut dc_imap_t, mut folder: *const libc::c_char) -> libc::c_int {
     if imap.is_null() {
         return 0i32;
     }
@@ -1164,8 +1150,7 @@ unsafe extern "C" fn select_folder(
     (*imap).selected_folder = dc_strdup(folder);
     return 1i32;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_imap_idle(mut imap: *mut dc_imap_t) {
+pub unsafe fn dc_imap_idle(mut imap: *mut dc_imap_t) {
     let mut current_block: u64;
     let mut r: libc::c_int = 0i32;
     let mut r2: libc::c_int = 0i32;
@@ -1260,7 +1245,7 @@ pub unsafe extern "C" fn dc_imap_idle(mut imap: *mut dc_imap_t) {
         }
     };
 }
-unsafe extern "C" fn fake_idle(mut imap: *mut dc_imap_t) {
+unsafe fn fake_idle(mut imap: *mut dc_imap_t) {
     /* Idle using timeouts. This is also needed if we're not yet configured -
     in this case, we're waiting for a configure job */
     let mut fake_idle_start_time: time_t = time(0 as *mut time_t);
@@ -1314,8 +1299,7 @@ unsafe extern "C" fn fake_idle(mut imap: *mut dc_imap_t) {
         }
     }
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_imap_interrupt_idle(mut imap: *mut dc_imap_t) {
+pub unsafe fn dc_imap_interrupt_idle(mut imap: *mut dc_imap_t) {
     if imap.is_null() {
         return;
     }
@@ -1329,8 +1313,7 @@ pub unsafe extern "C" fn dc_imap_interrupt_idle(mut imap: *mut dc_imap_t) {
     pthread_cond_signal(&mut (*imap).watch_cond);
     pthread_mutex_unlock(&mut (*imap).watch_condmutex);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_imap_move(
+pub unsafe fn dc_imap_move(
     mut imap: *mut dc_imap_t,
     mut folder: *const libc::c_char,
     mut uid: uint32_t,
@@ -1479,7 +1462,7 @@ pub unsafe extern "C" fn dc_imap_move(
         res as libc::c_uint
     }) as dc_imap_res;
 }
-unsafe extern "C" fn add_flag(
+unsafe fn add_flag(
     mut imap: *mut dc_imap_t,
     mut server_uid: uint32_t,
     mut flag: *mut mailimap_flag,
@@ -1508,8 +1491,7 @@ unsafe extern "C" fn add_flag(
         1i32
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_imap_set_seen(
+pub unsafe fn dc_imap_set_seen(
     mut imap: *mut dc_imap_t,
     mut folder: *const libc::c_char,
     mut uid: uint32_t,
@@ -1553,8 +1535,7 @@ pub unsafe extern "C" fn dc_imap_set_seen(
         res as libc::c_uint
     }) as dc_imap_res;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_imap_set_mdnsent(
+pub unsafe fn dc_imap_set_mdnsent(
     mut imap: *mut dc_imap_t,
     mut folder: *const libc::c_char,
     mut uid: uint32_t,
@@ -1713,7 +1694,7 @@ pub unsafe extern "C" fn dc_imap_set_mdnsent(
         res as libc::c_uint
     }) as dc_imap_res;
 }
-unsafe extern "C" fn peek_flag_keyword(
+unsafe fn peek_flag_keyword(
     mut msg_att: *mut mailimap_msg_att,
     mut flag_keyword: *const libc::c_char,
 ) -> libc::c_int {
@@ -1771,8 +1752,7 @@ unsafe extern "C" fn peek_flag_keyword(
     return 0i32;
 }
 /* only returns 0 on connection problems; we should try later again in this case */
-#[no_mangle]
-pub unsafe extern "C" fn dc_imap_delete_msg(
+pub unsafe fn dc_imap_delete_msg(
     mut imap: *mut dc_imap_t,
     mut rfc724_mid: *const libc::c_char,
     mut folder: *const libc::c_char,
diff --git a/src/dc_imex.rs b/src/dc_imex.rs
index 7342d18a5..81365ed1d 100644
--- a/src/dc_imex.rs
+++ b/src/dc_imex.rs
@@ -26,8 +26,7 @@ use crate::x::*;
 // param1 is a directory where the keys are searched in and read from
 // param1 is a directory where the backup is written to
 // param1 is the file with the backup to import
-#[no_mangle]
-pub unsafe extern "C" fn dc_imex(
+pub unsafe fn dc_imex(
     mut context: *mut dc_context_t,
     mut what: libc::c_int,
     mut param1: *const libc::c_char,
@@ -41,8 +40,7 @@ pub unsafe extern "C" fn dc_imex(
     dc_job_add(context, 910i32, 0i32, (*param).packed, 0i32);
     dc_param_unref(param);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_imex_has_backup(
+pub unsafe fn dc_imex_has_backup(
     mut context: *mut dc_context_t,
     mut dir_name: *const libc::c_char,
 ) -> *mut libc::c_char {
@@ -121,8 +119,7 @@ pub unsafe extern "C" fn dc_imex_has_backup(
     dc_sqlite3_unref(test_sql);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_check_password(
+pub unsafe fn dc_check_password(
     mut context: *mut dc_context_t,
     mut test_pw: *const libc::c_char,
 ) -> libc::c_int {
@@ -151,10 +148,7 @@ pub unsafe extern "C" fn dc_check_password(
     dc_loginparam_unref(loginparam);
     return success;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_initiate_key_transfer(
-    mut context: *mut dc_context_t,
-) -> *mut libc::c_char {
+pub unsafe fn dc_initiate_key_transfer(mut context: *mut dc_context_t) -> *mut libc::c_char {
     let mut current_block: u64;
     let mut success: libc::c_int = 0i32;
     let mut setup_code: *mut libc::c_char = 0 as *mut libc::c_char;
@@ -255,7 +249,6 @@ pub unsafe extern "C" fn dc_initiate_key_transfer(
     dc_free_ongoing(context);
     return setup_code;
 }
-#[no_mangle]
 pub unsafe extern "C" fn dc_render_setup_file(
     mut context: *mut dc_context_t,
     mut passphrase: *const libc::c_char,
@@ -349,8 +342,7 @@ pub unsafe extern "C" fn dc_render_setup_file(
     free(self_addr as *mut libc::c_void);
     return ret_setupfilecontent;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_create_setup_code(mut context: *mut dc_context_t) -> *mut libc::c_char {
+pub unsafe fn dc_create_setup_code(mut context: *mut dc_context_t) -> *mut libc::c_char {
     let mut random_val: uint16_t = 0i32 as uint16_t;
     let mut i: libc::c_int = 0i32;
     let mut ret: dc_strbuilder_t = dc_strbuilder_t {
@@ -384,8 +376,7 @@ pub unsafe extern "C" fn dc_create_setup_code(mut context: *mut dc_context_t) ->
     }
     return ret.buf;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_continue_key_transfer(
+pub unsafe fn dc_continue_key_transfer(
     mut context: *mut dc_context_t,
     mut msg_id: uint32_t,
     mut setup_code: *const libc::c_char,
@@ -464,7 +455,7 @@ pub unsafe extern "C" fn dc_continue_key_transfer(
     free(norm_sc as *mut libc::c_void);
     return success;
 }
-unsafe extern "C" fn set_self_key(
+unsafe fn set_self_key(
     mut context: *mut dc_context_t,
     mut armored: *const libc::c_char,
     mut set_default: libc::c_int,
@@ -582,8 +573,7 @@ unsafe extern "C" fn set_self_key(
     dc_key_unref(public_key);
     return success;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_decrypt_setup_file(
+pub unsafe fn dc_decrypt_setup_file(
     mut context: *mut dc_context_t,
     mut passphrase: *const libc::c_char,
     mut filecontent: *const libc::c_char,
@@ -647,8 +637,7 @@ pub unsafe extern "C" fn dc_decrypt_setup_file(
     }
     return payload;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_normalize_setup_code(
+pub unsafe fn dc_normalize_setup_code(
     mut context: *mut dc_context_t,
     mut in_0: *const libc::c_char,
 ) -> *mut libc::c_char {
@@ -688,11 +677,7 @@ pub unsafe extern "C" fn dc_normalize_setup_code(
     }
     return out.buf;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_job_do_DC_JOB_IMEX_IMAP(
-    mut context: *mut dc_context_t,
-    mut job: *mut dc_job_t,
-) {
+pub unsafe fn dc_job_do_DC_JOB_IMEX_IMAP(mut context: *mut dc_context_t, mut job: *mut dc_job_t) {
     let mut current_block: u64;
     let mut success: libc::c_int = 0i32;
     let mut ongoing_allocated_here: libc::c_int = 0i32;
@@ -954,7 +939,7 @@ pub unsafe extern "C" fn dc_job_do_DC_JOB_IMEX_IMAP(
 /* ******************************************************************************
  * Import backup
  ******************************************************************************/
-unsafe extern "C" fn import_backup(
+unsafe fn import_backup(
     mut context: *mut dc_context_t,
     mut backup_to_import: *const libc::c_char,
 ) -> libc::c_int {
@@ -1096,7 +1081,7 @@ unsafe extern "C" fn import_backup(
  ******************************************************************************/
 /* the FILE_PROGRESS macro calls the callback with the permille of files processed.
 The macro avoids weird values of 0% or 100% while still working. */
-unsafe extern "C" fn export_backup(
+unsafe fn export_backup(
     mut context: *mut dc_context_t,
     mut dir: *const libc::c_char,
 ) -> libc::c_int {
@@ -1374,7 +1359,7 @@ unsafe extern "C" fn export_backup(
 /* ******************************************************************************
  * Classic key import
  ******************************************************************************/
-unsafe extern "C" fn import_self_keys(
+unsafe fn import_self_keys(
     mut context: *mut dc_context_t,
     mut dir_name: *const libc::c_char,
 ) -> libc::c_int {
@@ -1508,7 +1493,7 @@ unsafe extern "C" fn import_self_keys(
     free(buf2 as *mut libc::c_void);
     return imported_cnt;
 }
-unsafe extern "C" fn export_self_keys(
+unsafe fn export_self_keys(
     mut context: *mut dc_context_t,
     mut dir: *const libc::c_char,
 ) -> libc::c_int {
@@ -1549,7 +1534,7 @@ unsafe extern "C" fn export_self_keys(
 /* ******************************************************************************
  * Classic key export
  ******************************************************************************/
-unsafe extern "C" fn export_key_to_asc_file(
+unsafe fn export_key_to_asc_file(
     mut context: *mut dc_context_t,
     mut dir: *const libc::c_char,
     mut id: libc::c_int,
diff --git a/src/dc_job.rs b/src/dc_job.rs
index e334e28f0..1c25d4518 100644
--- a/src/dc_job.rs
+++ b/src/dc_job.rs
@@ -45,8 +45,7 @@ pub struct dc_job_t {
     pub pending_error: *mut libc::c_char,
 }
 
-#[no_mangle]
-pub unsafe extern "C" fn dc_perform_imap_jobs(mut context: *mut dc_context_t) {
+pub unsafe fn dc_perform_imap_jobs(mut context: *mut dc_context_t) {
     dc_log_info(
         context,
         0i32,
@@ -64,7 +63,7 @@ pub unsafe extern "C" fn dc_perform_imap_jobs(mut context: *mut dc_context_t) {
         b"INBOX-jobs ended.\x00" as *const u8 as *const libc::c_char,
     );
 }
-unsafe extern "C" fn dc_job_perform(
+unsafe fn dc_job_perform(
     mut context: *mut dc_context_t,
     mut thread: libc::c_int,
     mut probe_network: libc::c_int,
@@ -243,7 +242,7 @@ unsafe extern "C" fn dc_job_perform(
     free(job.pending_error as *mut libc::c_void);
     sqlite3_finalize(select_stmt);
 }
-unsafe extern "C" fn dc_job_delete(mut context: *mut dc_context_t, mut job: *const dc_job_t) {
+unsafe fn dc_job_delete(mut context: *mut dc_context_t, mut job: *const dc_job_t) {
     let mut delete_stmt: *mut sqlite3_stmt = dc_sqlite3_prepare(
         (*context).sql,
         b"DELETE FROM jobs WHERE id=?;\x00" as *const u8 as *const libc::c_char,
@@ -255,7 +254,7 @@ unsafe extern "C" fn dc_job_delete(mut context: *mut dc_context_t, mut job: *con
 /* ******************************************************************************
  * Tools
  ******************************************************************************/
-unsafe extern "C" fn get_backoff_time_offset(mut c_tries: libc::c_int) -> time_t {
+unsafe fn get_backoff_time_offset(mut c_tries: libc::c_int) -> time_t {
     // results in ~3 weeks for the last backoff timespan
     let mut N: time_t = pow(2i32 as libc::c_double, (c_tries - 1i32) as libc::c_double) as time_t;
     N = N * 60i32 as libc::c_long;
@@ -265,7 +264,7 @@ unsafe extern "C" fn get_backoff_time_offset(mut c_tries: libc::c_int) -> time_t
     }
     return seconds;
 }
-unsafe extern "C" fn dc_job_update(mut context: *mut dc_context_t, mut job: *const dc_job_t) {
+unsafe fn dc_job_update(mut context: *mut dc_context_t, mut job: *const dc_job_t) {
     let mut stmt: *mut sqlite3_stmt = dc_sqlite3_prepare(
         (*context).sql,
         b"UPDATE jobs SET desired_timestamp=?, tries=?, param=? WHERE id=?;\x00" as *const u8
@@ -278,10 +277,7 @@ unsafe extern "C" fn dc_job_update(mut context: *mut dc_context_t, mut job: *con
     sqlite3_step(stmt);
     sqlite3_finalize(stmt);
 }
-unsafe extern "C" fn dc_suspend_smtp_thread(
-    mut context: *mut dc_context_t,
-    mut suspend: libc::c_int,
-) {
+unsafe fn dc_suspend_smtp_thread(mut context: *mut dc_context_t, mut suspend: libc::c_int) {
     pthread_mutex_lock(&mut (*context).smtpidle_condmutex);
     (*context).smtp_suspended = suspend;
     pthread_mutex_unlock(&mut (*context).smtpidle_condmutex);
@@ -434,8 +430,7 @@ unsafe extern "C" fn dc_job_do_DC_JOB_SEND(mut context: *mut dc_context_t, mut j
     free(filename as *mut libc::c_void);
 }
 // this value does not increase the number of tries
-#[no_mangle]
-pub unsafe extern "C" fn dc_job_try_again_later(
+pub unsafe fn dc_job_try_again_later(
     mut job: *mut dc_job_t,
     mut try_again: libc::c_int,
     mut pending_error: *const libc::c_char,
@@ -447,10 +442,7 @@ pub unsafe extern "C" fn dc_job_try_again_later(
     free((*job).pending_error as *mut libc::c_void);
     (*job).pending_error = dc_strdup_keep_null(pending_error);
 }
-unsafe extern "C" fn dc_job_do_DC_JOB_MOVE_MSG(
-    mut context: *mut dc_context_t,
-    mut job: *mut dc_job_t,
-) {
+unsafe fn dc_job_do_DC_JOB_MOVE_MSG(mut context: *mut dc_context_t, mut job: *mut dc_job_t) {
     let mut current_block: u64;
     let mut msg: *mut dc_msg_t = dc_msg_new_untyped(context);
     let mut dest_folder: *mut libc::c_char = 0 as *mut libc::c_char;
@@ -534,7 +526,7 @@ unsafe extern "C" fn dc_job_do_DC_JOB_MOVE_MSG(
 /* ******************************************************************************
  * IMAP-jobs
  ******************************************************************************/
-unsafe extern "C" fn connect_to_inbox(mut context: *mut dc_context_t) -> libc::c_int {
+unsafe fn connect_to_inbox(mut context: *mut dc_context_t) -> libc::c_int {
     let mut ret_connected: libc::c_int = 0i32;
     ret_connected = dc_connect_to_configured_imap(context, (*context).inbox);
     if !(0 == ret_connected) {
@@ -545,7 +537,7 @@ unsafe extern "C" fn connect_to_inbox(mut context: *mut dc_context_t) -> libc::c
     }
     return ret_connected;
 }
-unsafe extern "C" fn dc_job_do_DC_JOB_MARKSEEN_MDN_ON_IMAP(
+unsafe fn dc_job_do_DC_JOB_MARKSEEN_MDN_ON_IMAP(
     mut context: *mut dc_context_t,
     mut job: *mut dc_job_t,
 ) {
@@ -602,7 +594,7 @@ unsafe extern "C" fn dc_job_do_DC_JOB_MARKSEEN_MDN_ON_IMAP(
     free(folder as *mut libc::c_void);
     free(dest_folder as *mut libc::c_void);
 }
-unsafe extern "C" fn dc_job_do_DC_JOB_MARKSEEN_MSG_ON_IMAP(
+unsafe fn dc_job_do_DC_JOB_MARKSEEN_MSG_ON_IMAP(
     mut context: *mut dc_context_t,
     mut job: *mut dc_job_t,
 ) {
@@ -745,7 +737,7 @@ unsafe extern "C" fn dc_job_do_DC_JOB_MARKSEEN_MSG_ON_IMAP(
     }
     dc_msg_unref(msg);
 }
-unsafe extern "C" fn dc_send_mdn(mut context: *mut dc_context_t, mut msg_id: uint32_t) {
+unsafe fn dc_send_mdn(mut context: *mut dc_context_t, mut msg_id: uint32_t) {
     let mut mimefactory: dc_mimefactory_t = dc_mimefactory_t {
         from_addr: 0 as *mut libc::c_char,
         from_displayname: 0 as *mut libc::c_char,
@@ -790,7 +782,7 @@ unsafe extern "C" fn dc_send_mdn(mut context: *mut dc_context_t, mut msg_id: uin
  * @param mimefactory An instance of dc_mimefactory_t with a loaded and rendered message or MDN
  * @return 1=success, 0=error
  */
-unsafe extern "C" fn dc_add_smtp_job(
+unsafe fn dc_add_smtp_job(
     mut context: *mut dc_context_t,
     mut action: libc::c_int,
     mut mimefactory: *mut dc_mimefactory_t,
@@ -854,8 +846,7 @@ unsafe extern "C" fn dc_add_smtp_job(
     free(pathNfilename as *mut libc::c_void);
     return success;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_job_add(
+pub unsafe fn dc_job_add(
     mut context: *mut dc_context_t,
     mut action: libc::c_int,
     mut foreign_id: libc::c_int,
@@ -904,8 +895,7 @@ pub unsafe extern "C" fn dc_job_add(
         dc_interrupt_smtp_idle(context);
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_interrupt_smtp_idle(mut context: *mut dc_context_t) {
+pub unsafe fn dc_interrupt_smtp_idle(mut context: *mut dc_context_t) {
     if context.is_null() || (*context).magic != 0x11a11807i32 as libc::c_uint {
         dc_log_warning(
             context,
@@ -925,8 +915,7 @@ pub unsafe extern "C" fn dc_interrupt_smtp_idle(mut context: *mut dc_context_t)
     pthread_cond_signal(&mut (*context).smtpidle_cond);
     pthread_mutex_unlock(&mut (*context).smtpidle_condmutex);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_interrupt_imap_idle(mut context: *mut dc_context_t) {
+pub unsafe fn dc_interrupt_imap_idle(mut context: *mut dc_context_t) {
     if context.is_null()
         || (*context).magic != 0x11a11807i32 as libc::c_uint
         || (*context).inbox.is_null()
@@ -948,7 +937,7 @@ pub unsafe extern "C" fn dc_interrupt_imap_idle(mut context: *mut dc_context_t)
     pthread_mutex_unlock(&mut (*context).inboxidle_condmutex);
     dc_imap_interrupt_idle((*context).inbox);
 }
-unsafe extern "C" fn dc_job_do_DC_JOB_DELETE_MSG_ON_IMAP(
+unsafe fn dc_job_do_DC_JOB_DELETE_MSG_ON_IMAP(
     mut context: *mut dc_context_t,
     mut job: *mut dc_job_t,
 ) {
@@ -1011,11 +1000,7 @@ unsafe extern "C" fn dc_job_do_DC_JOB_DELETE_MSG_ON_IMAP(
     dc_msg_unref(msg);
 }
 /* delete all pending jobs with the given action */
-#[no_mangle]
-pub unsafe extern "C" fn dc_job_kill_action(
-    mut context: *mut dc_context_t,
-    mut action: libc::c_int,
-) {
+pub unsafe fn dc_job_kill_action(mut context: *mut dc_context_t, mut action: libc::c_int) {
     if context.is_null() {
         return;
     }
@@ -1027,8 +1012,7 @@ pub unsafe extern "C" fn dc_job_kill_action(
     sqlite3_step(stmt);
     sqlite3_finalize(stmt);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_perform_imap_fetch(mut context: *mut dc_context_t) {
+pub unsafe fn dc_perform_imap_fetch(mut context: *mut dc_context_t) {
     let mut start: libc::clock_t = clock();
     if 0 == connect_to_inbox(context) {
         return;
@@ -1067,8 +1051,7 @@ pub unsafe extern "C" fn dc_perform_imap_fetch(mut context: *mut dc_context_t) {
         clock().wrapping_sub(start) as libc::c_double * 1000.0f64 / 1000000i32 as libc::c_double,
     );
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_perform_imap_idle(mut context: *mut dc_context_t) {
+pub unsafe fn dc_perform_imap_idle(mut context: *mut dc_context_t) {
     if context.is_null() || (*context).magic != 0x11a11807i32 as libc::c_uint {
         return;
     }
@@ -1097,8 +1080,7 @@ pub unsafe extern "C" fn dc_perform_imap_idle(mut context: *mut dc_context_t) {
         b"INBOX-IDLE ended.\x00" as *const u8 as *const libc::c_char,
     );
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_perform_mvbox_fetch(mut context: *mut dc_context_t) {
+pub unsafe fn dc_perform_mvbox_fetch(mut context: *mut dc_context_t) {
     if context.is_null() || (*context).magic != 0x11a11807i32 as libc::c_uint {
         return;
     }
@@ -1109,8 +1091,7 @@ pub unsafe extern "C" fn dc_perform_mvbox_fetch(mut context: *mut dc_context_t)
     );
     dc_jobthread_fetch(&mut (*context).mvbox_thread, use_network);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_perform_mvbox_idle(mut context: *mut dc_context_t) {
+pub unsafe fn dc_perform_mvbox_idle(mut context: *mut dc_context_t) {
     if context.is_null() || (*context).magic != 0x11a11807i32 as libc::c_uint {
         return;
     }
@@ -1121,8 +1102,7 @@ pub unsafe extern "C" fn dc_perform_mvbox_idle(mut context: *mut dc_context_t) {
     );
     dc_jobthread_idle(&mut (*context).mvbox_thread, use_network);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_interrupt_mvbox_idle(mut context: *mut dc_context_t) {
+pub unsafe fn dc_interrupt_mvbox_idle(mut context: *mut dc_context_t) {
     if context.is_null() || (*context).magic != 0x11a11807i32 as libc::c_uint {
         dc_log_warning(
             context,
@@ -1133,8 +1113,7 @@ pub unsafe extern "C" fn dc_interrupt_mvbox_idle(mut context: *mut dc_context_t)
     }
     dc_jobthread_interrupt_idle(&mut (*context).mvbox_thread);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_perform_sentbox_fetch(mut context: *mut dc_context_t) {
+pub unsafe fn dc_perform_sentbox_fetch(mut context: *mut dc_context_t) {
     if context.is_null() || (*context).magic != 0x11a11807i32 as libc::c_uint {
         return;
     }
@@ -1145,8 +1124,7 @@ pub unsafe extern "C" fn dc_perform_sentbox_fetch(mut context: *mut dc_context_t
     );
     dc_jobthread_fetch(&mut (*context).sentbox_thread, use_network);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_perform_sentbox_idle(mut context: *mut dc_context_t) {
+pub unsafe fn dc_perform_sentbox_idle(mut context: *mut dc_context_t) {
     if context.is_null() || (*context).magic != 0x11a11807i32 as libc::c_uint {
         return;
     }
@@ -1157,8 +1135,7 @@ pub unsafe extern "C" fn dc_perform_sentbox_idle(mut context: *mut dc_context_t)
     );
     dc_jobthread_idle(&mut (*context).sentbox_thread, use_network);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_interrupt_sentbox_idle(mut context: *mut dc_context_t) {
+pub unsafe fn dc_interrupt_sentbox_idle(mut context: *mut dc_context_t) {
     if context.is_null() || (*context).magic != 0x11a11807i32 as libc::c_uint {
         dc_log_warning(
             context,
@@ -1169,8 +1146,7 @@ pub unsafe extern "C" fn dc_interrupt_sentbox_idle(mut context: *mut dc_context_
     }
     dc_jobthread_interrupt_idle(&mut (*context).sentbox_thread);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_perform_smtp_jobs(mut context: *mut dc_context_t) {
+pub unsafe fn dc_perform_smtp_jobs(mut context: *mut dc_context_t) {
     pthread_mutex_lock(&mut (*context).smtpidle_condmutex);
     let mut probe_smtp_network: libc::c_int = (*context).probe_smtp_network;
     (*context).probe_smtp_network = 0i32;
@@ -1201,8 +1177,7 @@ pub unsafe extern "C" fn dc_perform_smtp_jobs(mut context: *mut dc_context_t) {
     (*context).smtp_doing_jobs = 0i32;
     pthread_mutex_unlock(&mut (*context).smtpidle_condmutex);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_perform_smtp_idle(mut context: *mut dc_context_t) {
+pub unsafe fn dc_perform_smtp_idle(mut context: *mut dc_context_t) {
     if context.is_null() || (*context).magic != 0x11a11807i32 as libc::c_uint {
         dc_log_warning(
             context,
@@ -1252,10 +1227,7 @@ pub unsafe extern "C" fn dc_perform_smtp_idle(mut context: *mut dc_context_t) {
         b"SMTP-idle ended.\x00" as *const u8 as *const libc::c_char,
     );
 }
-unsafe extern "C" fn get_next_wakeup_time(
-    mut context: *mut dc_context_t,
-    mut thread: libc::c_int,
-) -> time_t {
+unsafe fn get_next_wakeup_time(mut context: *mut dc_context_t, mut thread: libc::c_int) -> time_t {
     let mut wakeup_time: time_t = 0i32 as time_t;
     let mut stmt: *mut sqlite3_stmt = 0 as *mut sqlite3_stmt;
     stmt = dc_sqlite3_prepare(
@@ -1273,8 +1245,7 @@ unsafe extern "C" fn get_next_wakeup_time(
     sqlite3_finalize(stmt);
     return wakeup_time;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_maybe_network(mut context: *mut dc_context_t) {
+pub unsafe fn dc_maybe_network(mut context: *mut dc_context_t) {
     pthread_mutex_lock(&mut (*context).smtpidle_condmutex);
     (*context).probe_smtp_network = 1i32;
     pthread_mutex_unlock(&mut (*context).smtpidle_condmutex);
@@ -1286,8 +1257,7 @@ pub unsafe extern "C" fn dc_maybe_network(mut context: *mut dc_context_t) {
     dc_interrupt_mvbox_idle(context);
     dc_interrupt_sentbox_idle(context);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_job_action_exists(
+pub unsafe fn dc_job_action_exists(
     mut context: *mut dc_context_t,
     mut action: libc::c_int,
 ) -> libc::c_int {
@@ -1303,11 +1273,7 @@ pub unsafe extern "C" fn dc_job_action_exists(
     return job_exists;
 }
 /* special case for DC_JOB_SEND_MSG_TO_SMTP */
-#[no_mangle]
-pub unsafe extern "C" fn dc_job_send_msg(
-    mut context: *mut dc_context_t,
-    mut msg_id: uint32_t,
-) -> libc::c_int {
+pub unsafe fn dc_job_send_msg(mut context: *mut dc_context_t, mut msg_id: uint32_t) -> libc::c_int {
     let mut success: libc::c_int = 0i32;
     let mut mimefactory: dc_mimefactory_t = dc_mimefactory_t {
         from_addr: 0 as *mut libc::c_char,
diff --git a/src/dc_jobthread.rs b/src/dc_jobthread.rs
index 7a791ecd9..4cad0fafb 100644
--- a/src/dc_jobthread.rs
+++ b/src/dc_jobthread.rs
@@ -30,8 +30,7 @@ pub struct dc_jobthread_t {
     pub using_handle: libc::c_int,
 }
 
-#[no_mangle]
-pub unsafe extern "C" fn dc_jobthread_init(
+pub unsafe fn dc_jobthread_init(
     mut jobthread: *mut dc_jobthread_t,
     mut context: *mut dc_context_t,
     mut name: *const libc::c_char,
@@ -51,8 +50,7 @@ pub unsafe extern "C" fn dc_jobthread_init(
     (*jobthread).suspended = 0i32;
     (*jobthread).using_handle = 0i32;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_jobthread_exit(mut jobthread: *mut dc_jobthread_t) {
+pub unsafe fn dc_jobthread_exit(mut jobthread: *mut dc_jobthread_t) {
     if jobthread.is_null() {
         return;
     }
@@ -63,11 +61,7 @@ pub unsafe extern "C" fn dc_jobthread_exit(mut jobthread: *mut dc_jobthread_t) {
     free((*jobthread).folder_config_name as *mut libc::c_void);
     (*jobthread).folder_config_name = 0 as *mut libc::c_char;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_jobthread_suspend(
-    mut jobthread: *mut dc_jobthread_t,
-    mut suspend: libc::c_int,
-) {
+pub unsafe fn dc_jobthread_suspend(mut jobthread: *mut dc_jobthread_t, mut suspend: libc::c_int) {
     if jobthread.is_null() {
         return;
     }
@@ -105,7 +99,6 @@ pub unsafe extern "C" fn dc_jobthread_suspend(
         pthread_mutex_unlock(&mut (*jobthread).mutex);
     };
 }
-#[no_mangle]
 pub unsafe extern "C" fn dc_jobthread_interrupt_idle(mut jobthread: *mut dc_jobthread_t) {
     if jobthread.is_null() {
         return;
@@ -127,11 +120,7 @@ pub unsafe extern "C" fn dc_jobthread_interrupt_idle(mut jobthread: *mut dc_jobt
     pthread_cond_signal(&mut (*jobthread).idle_cond);
     pthread_mutex_unlock(&mut (*jobthread).mutex);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_jobthread_fetch(
-    mut jobthread: *mut dc_jobthread_t,
-    mut use_network: libc::c_int,
-) {
+pub unsafe fn dc_jobthread_fetch(mut jobthread: *mut dc_jobthread_t, mut use_network: libc::c_int) {
     let mut start: libc::clock_t = 0;
     if jobthread.is_null() {
         return;
@@ -179,7 +168,7 @@ pub unsafe extern "C" fn dc_jobthread_fetch(
 /* ******************************************************************************
  * the typical fetch, idle, interrupt-idle
  ******************************************************************************/
-unsafe extern "C" fn connect_to_imap(mut jobthread: *mut dc_jobthread_t) -> libc::c_int {
+unsafe fn connect_to_imap(mut jobthread: *mut dc_jobthread_t) -> libc::c_int {
     let mut ret_connected: libc::c_int = 0i32;
     let mut mvbox_name: *mut libc::c_char = 0 as *mut libc::c_char;
     if 0 != dc_imap_is_connected((*jobthread).imap) {
@@ -211,11 +200,7 @@ unsafe extern "C" fn connect_to_imap(mut jobthread: *mut dc_jobthread_t) -> libc
     free(mvbox_name as *mut libc::c_void);
     return ret_connected;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_jobthread_idle(
-    mut jobthread: *mut dc_jobthread_t,
-    mut use_network: libc::c_int,
-) {
+pub unsafe fn dc_jobthread_idle(mut jobthread: *mut dc_jobthread_t, mut use_network: libc::c_int) {
     if jobthread.is_null() {
         return;
     }
diff --git a/src/dc_jsmn.rs b/src/dc_jsmn.rs
index 965a0ca3e..b3698ffe2 100644
--- a/src/dc_jsmn.rs
+++ b/src/dc_jsmn.rs
@@ -69,8 +69,7 @@ pub struct jsmn_parser {
 /* *
  * Create JSON parser over an array of tokens
  */
-#[no_mangle]
-pub unsafe extern "C" fn jsmn_init(mut parser: *mut jsmn_parser) {
+pub unsafe fn jsmn_init(mut parser: *mut jsmn_parser) {
     (*parser).pos = 0i32 as libc::c_uint;
     (*parser).toknext = 0i32 as libc::c_uint;
     (*parser).toksuper = -1i32;
@@ -79,8 +78,7 @@ pub unsafe extern "C" fn jsmn_init(mut parser: *mut jsmn_parser) {
  * Run JSON parser. It parses a JSON data string into and array of tokens, each describing
  * a single JSON object.
  */
-#[no_mangle]
-pub unsafe extern "C" fn jsmn_parse(
+pub unsafe fn jsmn_parse(
     mut parser: *mut jsmn_parser,
     mut js: *const libc::c_char,
     mut len: size_t,
@@ -227,7 +225,7 @@ pub unsafe extern "C" fn jsmn_parse(
 /* *
  * Fills next available token with JSON primitive.
  */
-unsafe extern "C" fn jsmn_parse_primitive(
+unsafe fn jsmn_parse_primitive(
     mut parser: *mut jsmn_parser,
     mut js: *const libc::c_char,
     mut len: size_t,
@@ -270,7 +268,7 @@ unsafe extern "C" fn jsmn_parse_primitive(
 /* *
  * Fills token type and boundaries.
  */
-unsafe extern "C" fn jsmn_fill_token(
+unsafe fn jsmn_fill_token(
     mut token: *mut jsmntok_t,
     mut type_0: jsmntype_t,
     mut start: libc::c_int,
@@ -305,7 +303,7 @@ THE SOFTWARE.
 /* *
  * Allocates a fresh unused token from the token pool.
  */
-unsafe extern "C" fn jsmn_alloc_token(
+unsafe fn jsmn_alloc_token(
     mut parser: *mut jsmn_parser,
     mut tokens: *mut jsmntok_t,
     mut num_tokens: size_t,
@@ -325,7 +323,7 @@ unsafe extern "C" fn jsmn_alloc_token(
 /* *
  * Fills next token with JSON string.
  */
-unsafe extern "C" fn jsmn_parse_string(
+unsafe fn jsmn_parse_string(
     mut parser: *mut jsmn_parser,
     mut js: *const libc::c_char,
     mut len: size_t,
diff --git a/src/dc_key.rs b/src/dc_key.rs
index eb164e574..811c80b72 100644
--- a/src/dc_key.rs
+++ b/src/dc_key.rs
@@ -22,21 +22,18 @@ pub struct dc_key_t {
     pub _m_heap_refcnt: libc::c_int,
 }
 
-#[no_mangle]
 #[inline]
 #[cfg(target_os = "macos")]
-pub unsafe extern "C" fn toupper(mut _c: libc::c_int) -> libc::c_int {
+pub unsafe fn toupper(mut _c: libc::c_int) -> libc::c_int {
     return __toupper(_c);
 }
 
-#[no_mangle]
 #[inline]
 #[cfg(not(target_os = "macos"))]
-pub unsafe extern "C" fn toupper(mut _c: libc::c_int) -> libc::c_int {
+pub unsafe fn toupper(mut _c: libc::c_int) -> libc::c_int {
     return _toupper(_c);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_key_new() -> *mut dc_key_t {
+pub unsafe fn dc_key_new() -> *mut dc_key_t {
     let mut key: *mut dc_key_t = 0 as *mut dc_key_t;
     key = calloc(
         1i32 as libc::c_ulong,
@@ -48,16 +45,14 @@ pub unsafe extern "C" fn dc_key_new() -> *mut dc_key_t {
     (*key)._m_heap_refcnt = 1i32;
     return key;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_key_ref(mut key: *mut dc_key_t) -> *mut dc_key_t {
+pub unsafe fn dc_key_ref(mut key: *mut dc_key_t) -> *mut dc_key_t {
     if key.is_null() {
         return 0 as *mut dc_key_t;
     }
     (*key)._m_heap_refcnt += 1;
     return key;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_key_unref(mut key: *mut dc_key_t) {
+pub unsafe fn dc_key_unref(mut key: *mut dc_key_t) {
     if key.is_null() {
         return;
     }
@@ -68,7 +63,7 @@ pub unsafe extern "C" fn dc_key_unref(mut key: *mut dc_key_t) {
     dc_key_empty(key);
     free(key as *mut libc::c_void);
 }
-unsafe extern "C" fn dc_key_empty(mut key: *mut dc_key_t) {
+unsafe fn dc_key_empty(mut key: *mut dc_key_t) {
     if key.is_null() {
         return;
     }
@@ -80,15 +75,13 @@ unsafe extern "C" fn dc_key_empty(mut key: *mut dc_key_t) {
     (*key).bytes = 0i32;
     (*key).type_0 = 0i32;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_wipe_secret_mem(mut buf: *mut libc::c_void, mut buf_bytes: size_t) {
+pub unsafe fn dc_wipe_secret_mem(mut buf: *mut libc::c_void, mut buf_bytes: size_t) {
     if buf.is_null() || buf_bytes <= 0i32 as libc::c_ulong {
         return;
     }
     memset(buf, 0i32, buf_bytes);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_key_set_from_binary(
+pub unsafe fn dc_key_set_from_binary(
     mut key: *mut dc_key_t,
     mut data: *const libc::c_void,
     mut bytes: libc::c_int,
@@ -107,18 +100,13 @@ pub unsafe extern "C" fn dc_key_set_from_binary(
     (*key).type_0 = type_0;
     return 1i32;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_key_set_from_key(
-    mut key: *mut dc_key_t,
-    mut o: *const dc_key_t,
-) -> libc::c_int {
+pub unsafe fn dc_key_set_from_key(mut key: *mut dc_key_t, mut o: *const dc_key_t) -> libc::c_int {
     dc_key_empty(key);
     if key.is_null() || o.is_null() {
         return 0i32;
     }
     return dc_key_set_from_binary(key, (*o).binary, (*o).bytes, (*o).type_0);
 }
-#[no_mangle]
 pub unsafe extern "C" fn dc_key_set_from_stmt(
     mut key: *mut dc_key_t,
     mut stmt: *mut sqlite3_stmt,
@@ -136,8 +124,7 @@ pub unsafe extern "C" fn dc_key_set_from_stmt(
         type_0,
     );
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_key_set_from_base64(
+pub unsafe fn dc_key_set_from_base64(
     mut key: *mut dc_key_t,
     mut base64: *const libc::c_char,
     mut type_0: libc::c_int,
@@ -170,8 +157,7 @@ pub unsafe extern "C" fn dc_key_set_from_base64(
     mmap_string_unref(result);
     return 1i32;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_key_set_from_file(
+pub unsafe fn dc_key_set_from_file(
     mut key: *mut dc_key_t,
     mut pathNfilename: *const libc::c_char,
     mut context: *mut dc_context_t,
@@ -253,11 +239,7 @@ pub unsafe extern "C" fn dc_key_set_from_file(
     free(buf as *mut libc::c_void);
     return success;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_key_equals(
-    mut key: *const dc_key_t,
-    mut o: *const dc_key_t,
-) -> libc::c_int {
+pub unsafe fn dc_key_equals(mut key: *const dc_key_t, mut o: *const dc_key_t) -> libc::c_int {
     if key.is_null()
         || o.is_null()
         || (*key).binary.is_null()
@@ -279,8 +261,7 @@ pub unsafe extern "C" fn dc_key_equals(
         0i32
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_key_save_self_keypair(
+pub unsafe fn dc_key_save_self_keypair(
     mut public_key: *const dc_key_t,
     mut private_key: *const dc_key_t,
     mut addr: *const libc::c_char,
@@ -318,8 +299,7 @@ pub unsafe extern "C" fn dc_key_save_self_keypair(
     sqlite3_finalize(stmt);
     return success;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_key_load_self_public(
+pub unsafe fn dc_key_load_self_public(
     mut key: *mut dc_key_t,
     mut self_addr: *const libc::c_char,
     mut sql: *mut dc_sqlite3_t,
@@ -342,8 +322,7 @@ pub unsafe extern "C" fn dc_key_load_self_public(
     sqlite3_finalize(stmt);
     return success;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_key_load_self_private(
+pub unsafe fn dc_key_load_self_private(
     mut key: *mut dc_key_t,
     mut self_addr: *const libc::c_char,
     mut sql: *mut dc_sqlite3_t,
@@ -367,8 +346,7 @@ pub unsafe extern "C" fn dc_key_load_self_private(
     return success;
 }
 /* the result must be freed */
-#[no_mangle]
-pub unsafe extern "C" fn dc_render_base64(
+pub unsafe fn dc_render_base64(
     mut buf: *const libc::c_void,
     mut buf_bytes: size_t,
     mut break_every: libc::c_int,
@@ -409,7 +387,7 @@ pub unsafe extern "C" fn dc_render_base64(
 /* ******************************************************************************
  * Render keys
  ******************************************************************************/
-unsafe extern "C" fn crc_octets(mut octets: *const libc::c_uchar, mut len: size_t) -> libc::c_long {
+unsafe fn crc_octets(mut octets: *const libc::c_uchar, mut len: size_t) -> libc::c_long {
     let mut crc: libc::c_long = 0xb704cei64;
     loop {
         let fresh0 = len;
@@ -432,8 +410,7 @@ unsafe extern "C" fn crc_octets(mut octets: *const libc::c_uchar, mut len: size_
     return crc & 0xffffffi64;
 }
 /* the result must be freed */
-#[no_mangle]
-pub unsafe extern "C" fn dc_key_render_base64(
+pub unsafe fn dc_key_render_base64(
     mut key: *const dc_key_t,
     mut break_every: libc::c_int,
     mut break_chars: *const libc::c_char,
@@ -451,8 +428,7 @@ pub unsafe extern "C" fn dc_key_render_base64(
     );
 }
 /* each header line must be terminated by \r\n, the result must be freed */
-#[no_mangle]
-pub unsafe extern "C" fn dc_key_render_asc(
+pub unsafe fn dc_key_render_asc(
     mut key: *const dc_key_t,
     mut add_header_lines: *const libc::c_char,
 ) -> *mut libc::c_char {
@@ -496,8 +472,7 @@ pub unsafe extern "C" fn dc_key_render_asc(
     free(base64 as *mut libc::c_void);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_key_render_asc_to_file(
+pub unsafe fn dc_key_render_asc_to_file(
     mut key: *const dc_key_t,
     mut file: *const libc::c_char,
     mut context: *mut dc_context_t,
@@ -527,10 +502,7 @@ pub unsafe extern "C" fn dc_key_render_asc_to_file(
     free(file_content as *mut libc::c_void);
     return success;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_format_fingerprint(
-    mut fingerprint: *const libc::c_char,
-) -> *mut libc::c_char {
+pub unsafe fn dc_format_fingerprint(mut fingerprint: *const libc::c_char) -> *mut libc::c_char {
     let mut i: libc::c_int = 0i32;
     let mut fingerprint_len: libc::c_int = strlen(fingerprint) as libc::c_int;
     let mut ret: dc_strbuilder_t = dc_strbuilder_t {
@@ -557,10 +529,7 @@ pub unsafe extern "C" fn dc_format_fingerprint(
     }
     return ret.buf;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_normalize_fingerprint(
-    mut in_0: *const libc::c_char,
-) -> *mut libc::c_char {
+pub unsafe fn dc_normalize_fingerprint(mut in_0: *const libc::c_char) -> *mut libc::c_char {
     if in_0.is_null() {
         return 0 as *mut libc::c_char;
     }
@@ -587,8 +556,7 @@ pub unsafe extern "C" fn dc_normalize_fingerprint(
     }
     return out.buf;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_key_get_fingerprint(mut key: *const dc_key_t) -> *mut libc::c_char {
+pub unsafe fn dc_key_get_fingerprint(mut key: *const dc_key_t) -> *mut libc::c_char {
     let mut fingerprint_buf: *mut uint8_t = 0 as *mut uint8_t;
     let mut fingerprint_bytes: size_t = 0i32 as size_t;
     let mut fingerprint_hex: *mut libc::c_char = 0 as *mut libc::c_char;
@@ -604,10 +572,7 @@ pub unsafe extern "C" fn dc_key_get_fingerprint(mut key: *const dc_key_t) -> *mu
         dc_strdup(0 as *const libc::c_char)
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_key_get_formatted_fingerprint(
-    mut key: *const dc_key_t,
-) -> *mut libc::c_char {
+pub unsafe fn dc_key_get_formatted_fingerprint(mut key: *const dc_key_t) -> *mut libc::c_char {
     let mut rawhex: *mut libc::c_char = dc_key_get_fingerprint(key);
     let mut formatted: *mut libc::c_char = dc_format_fingerprint(rawhex);
     free(rawhex as *mut libc::c_void);
diff --git a/src/dc_keyhistory.rs b/src/dc_keyhistory.rs
index a31bed7b2..07e596ad0 100644
--- a/src/dc_keyhistory.rs
+++ b/src/dc_keyhistory.rs
@@ -9,8 +9,7 @@ use crate::x::*;
 
 /* yes: uppercase */
 /* library private: key-history */
-#[no_mangle]
-pub unsafe extern "C" fn dc_add_to_keyhistory(
+pub unsafe fn dc_add_to_keyhistory(
     mut context: *mut dc_context_t,
     mut rfc724_mid: *const libc::c_char,
     mut sending_time: time_t,
diff --git a/src/dc_keyring.rs b/src/dc_keyring.rs
index 825fab144..c325dfa3f 100644
--- a/src/dc_keyring.rs
+++ b/src/dc_keyring.rs
@@ -16,8 +16,7 @@ pub struct dc_keyring_t {
     pub allocated: libc::c_int,
 }
 
-#[no_mangle]
-pub unsafe extern "C" fn dc_keyring_new() -> *mut dc_keyring_t {
+pub unsafe fn dc_keyring_new() -> *mut dc_keyring_t {
     let mut keyring: *mut dc_keyring_t = 0 as *mut dc_keyring_t;
     keyring = calloc(
         1i32 as libc::c_ulong,
@@ -28,8 +27,7 @@ pub unsafe extern "C" fn dc_keyring_new() -> *mut dc_keyring_t {
     }
     return keyring;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_keyring_unref(mut keyring: *mut dc_keyring_t) {
+pub unsafe fn dc_keyring_unref(mut keyring: *mut dc_keyring_t) {
     if keyring.is_null() {
         return;
     }
@@ -42,8 +40,7 @@ pub unsafe extern "C" fn dc_keyring_unref(mut keyring: *mut dc_keyring_t) {
     free(keyring as *mut libc::c_void);
 }
 /* the reference counter of the key is increased by one */
-#[no_mangle]
-pub unsafe extern "C" fn dc_keyring_add(mut keyring: *mut dc_keyring_t, mut to_add: *mut dc_key_t) {
+pub unsafe fn dc_keyring_add(mut keyring: *mut dc_keyring_t, mut to_add: *mut dc_key_t) {
     if keyring.is_null() || to_add.is_null() {
         return;
     }
@@ -63,8 +60,7 @@ pub unsafe extern "C" fn dc_keyring_add(mut keyring: *mut dc_keyring_t, mut to_a
     *fresh0 = dc_key_ref(to_add);
     (*keyring).count += 1;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_keyring_load_self_private_for_decrypting(
+pub unsafe fn dc_keyring_load_self_private_for_decrypting(
     mut keyring: *mut dc_keyring_t,
     mut self_addr: *const libc::c_char,
     mut sql: *mut dc_sqlite3_t,
diff --git a/src/dc_location.rs b/src/dc_location.rs
index 07456172c..6b0b5c6d1 100644
--- a/src/dc_location.rs
+++ b/src/dc_location.rs
@@ -42,8 +42,7 @@ pub struct dc_kml_t {
 }
 
 // location streaming
-#[no_mangle]
-pub unsafe extern "C" fn dc_send_locations_to_chat(
+pub unsafe fn dc_send_locations_to_chat(
     mut context: *mut dc_context_t,
     mut chat_id: uint32_t,
     mut seconds: libc::c_int,
@@ -128,15 +127,11 @@ pub unsafe extern "C" fn dc_send_locations_to_chat(
 /* ******************************************************************************
  * job to send locations out to all chats that want them
  ******************************************************************************/
-unsafe extern "C" fn schedule_MAYBE_SEND_LOCATIONS(
-    mut context: *mut dc_context_t,
-    mut flags: libc::c_int,
-) {
+unsafe fn schedule_MAYBE_SEND_LOCATIONS(mut context: *mut dc_context_t, mut flags: libc::c_int) {
     if 0 != flags & 0x1i32 || 0 == dc_job_action_exists(context, 5005i32) {
         dc_job_add(context, 5005i32, 0i32, 0 as *const libc::c_char, 60i32);
     };
 }
-#[no_mangle]
 pub unsafe extern "C" fn dc_is_sending_locations_to_chat(
     mut context: *mut dc_context_t,
     mut chat_id: uint32_t,
@@ -167,8 +162,7 @@ pub unsafe extern "C" fn dc_is_sending_locations_to_chat(
     sqlite3_finalize(stmt);
     return is_sending_locations;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_set_location(
+pub unsafe fn dc_set_location(
     mut context: *mut dc_context_t,
     mut latitude: libc::c_double,
     mut longitude: libc::c_double,
@@ -218,8 +212,7 @@ pub unsafe extern "C" fn dc_set_location(
     sqlite3_finalize(stmt_insert);
     return continue_streaming;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_locations(
+pub unsafe fn dc_get_locations(
     mut context: *mut dc_context_t,
     mut chat_id: uint32_t,
     mut contact_id: uint32_t,
@@ -287,7 +280,7 @@ pub unsafe extern "C" fn dc_get_locations(
     sqlite3_finalize(stmt);
     return ret;
 }
-unsafe extern "C" fn is_marker(mut txt: *const libc::c_char) -> libc::c_int {
+unsafe fn is_marker(mut txt: *const libc::c_char) -> libc::c_int {
     if !txt.is_null() {
         let mut len: libc::c_int = dc_utf8_strlen(txt) as libc::c_int;
         if len == 1i32 && *txt.offset(0isize) as libc::c_int != ' ' as i32 {
@@ -296,8 +289,7 @@ unsafe extern "C" fn is_marker(mut txt: *const libc::c_char) -> libc::c_int {
     }
     return 0i32;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_delete_all_locations(mut context: *mut dc_context_t) {
+pub unsafe fn dc_delete_all_locations(mut context: *mut dc_context_t) {
     let mut stmt: *mut sqlite3_stmt = 0 as *mut sqlite3_stmt;
     if !(context.is_null() || (*context).magic != 0x11a11807i32 as libc::c_uint) {
         stmt = dc_sqlite3_prepare(
@@ -314,8 +306,7 @@ pub unsafe extern "C" fn dc_delete_all_locations(mut context: *mut dc_context_t)
     }
     sqlite3_finalize(stmt);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_location_kml(
+pub unsafe fn dc_get_location_kml(
     mut context: *mut dc_context_t,
     mut chat_id: uint32_t,
     mut last_added_location_id: *mut uint32_t,
@@ -414,7 +405,7 @@ pub unsafe extern "C" fn dc_get_location_kml(
 /* ******************************************************************************
  * create kml-files
  ******************************************************************************/
-unsafe extern "C" fn get_kml_timestamp(mut utc: time_t) -> *mut libc::c_char {
+unsafe fn get_kml_timestamp(mut utc: time_t) -> *mut libc::c_char {
     // Returns a string formatted as YYYY-MM-DDTHH:MM:SSZ. The trailing `Z` indicates UTC.
     let mut wanted_struct: tm = tm {
         tm_sec: 0,
@@ -444,8 +435,7 @@ unsafe extern "C" fn get_kml_timestamp(mut utc: time_t) -> *mut libc::c_char {
         wanted_struct.tm_sec as libc::c_int,
     );
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_set_kml_sent_timestamp(
+pub unsafe fn dc_set_kml_sent_timestamp(
     mut context: *mut dc_context_t,
     mut chat_id: uint32_t,
     mut timestamp: time_t,
@@ -461,8 +451,7 @@ pub unsafe extern "C" fn dc_set_kml_sent_timestamp(
     sqlite3_step(stmt);
     sqlite3_finalize(stmt);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_set_msg_location_id(
+pub unsafe fn dc_set_msg_location_id(
     mut context: *mut dc_context_t,
     mut msg_id: uint32_t,
     mut location_id: uint32_t,
@@ -477,8 +466,7 @@ pub unsafe extern "C" fn dc_set_msg_location_id(
     sqlite3_step(stmt);
     sqlite3_finalize(stmt);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_save_locations(
+pub unsafe fn dc_save_locations(
     mut context: *mut dc_context_t,
     mut chat_id: uint32_t,
     mut contact_id: uint32_t,
@@ -537,8 +525,7 @@ pub unsafe extern "C" fn dc_save_locations(
     sqlite3_finalize(stmt_insert);
     return newest_location_id;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_kml_parse(
+pub unsafe fn dc_kml_parse(
     mut context: *mut dc_context_t,
     mut content: *const libc::c_char,
     mut content_bytes: size_t,
@@ -581,7 +568,7 @@ pub unsafe extern "C" fn dc_kml_parse(
     free(content_nullterminated as *mut libc::c_void);
     return kml;
 }
-unsafe extern "C" fn kml_text_cb(
+unsafe fn kml_text_cb(
     mut userdata: *mut libc::c_void,
     mut text: *const libc::c_char,
     mut len: libc::c_int,
@@ -661,7 +648,7 @@ unsafe extern "C" fn kml_text_cb(
         free(val as *mut libc::c_void);
     };
 }
-unsafe extern "C" fn kml_endtag_cb(mut userdata: *mut libc::c_void, mut tag: *const libc::c_char) {
+unsafe fn kml_endtag_cb(mut userdata: *mut libc::c_void, mut tag: *const libc::c_char) {
     let mut kml: *mut dc_kml_t = userdata as *mut dc_kml_t;
     if strcmp(tag, b"placemark\x00" as *const u8 as *const libc::c_char) == 0i32 {
         if 0 != (*kml).tag & 0x1i32
@@ -682,7 +669,7 @@ unsafe extern "C" fn kml_endtag_cb(mut userdata: *mut libc::c_void, mut tag: *co
 /* ******************************************************************************
  * parse kml-files
  ******************************************************************************/
-unsafe extern "C" fn kml_starttag_cb(
+unsafe fn kml_starttag_cb(
     mut userdata: *mut libc::c_void,
     mut tag: *const libc::c_char,
     mut attr: *mut *mut libc::c_char,
@@ -723,8 +710,7 @@ unsafe extern "C" fn kml_starttag_cb(
         }
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_kml_unref(mut kml: *mut dc_kml_t) {
+pub unsafe fn dc_kml_unref(mut kml: *mut dc_kml_t) {
     if kml.is_null() {
         return;
     }
@@ -732,8 +718,7 @@ pub unsafe extern "C" fn dc_kml_unref(mut kml: *mut dc_kml_t) {
     free((*kml).addr as *mut libc::c_void);
     free(kml as *mut libc::c_void);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_job_do_DC_JOB_MAYBE_SEND_LOCATIONS(
+pub unsafe fn dc_job_do_DC_JOB_MAYBE_SEND_LOCATIONS(
     mut context: *mut dc_context_t,
     mut job: *mut dc_job_t,
 ) {
@@ -798,8 +783,7 @@ pub unsafe extern "C" fn dc_job_do_DC_JOB_MAYBE_SEND_LOCATIONS(
     sqlite3_finalize(stmt_chats);
     sqlite3_finalize(stmt_locations);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_job_do_DC_JOB_MAYBE_SEND_LOC_ENDED(
+pub unsafe fn dc_job_do_DC_JOB_MAYBE_SEND_LOC_ENDED(
     mut context: *mut dc_context_t,
     mut job: *mut dc_job_t,
 ) {
diff --git a/src/dc_log.rs b/src/dc_log.rs
index 2b3af495d..a05d72cf2 100644
--- a/src/dc_log.rs
+++ b/src/dc_log.rs
@@ -7,7 +7,6 @@ use crate::dc_tools::*;
 use crate::types::*;
 use crate::x::*;
 
-#[no_mangle]
 pub unsafe extern "C" fn dc_log_event(
     mut context: *mut dc_context_t,
     mut event_code: libc::c_int,
@@ -24,7 +23,7 @@ function.  These errors must be shown to the user by a bubble or so.
 usually not reported using dc_log_error() - its up to the caller to
 decide, what should be reported or done.  However, these "Normal" errors
 are usually logged by dc_log_warning(). */
-unsafe extern "C" fn log_vprintf(
+unsafe fn log_vprintf(
     mut context: *mut dc_context_t,
     mut event: libc::c_int,
     mut data1: libc::c_int,
@@ -58,7 +57,6 @@ unsafe extern "C" fn log_vprintf(
     );
     free(msg as *mut libc::c_void);
 }
-#[no_mangle]
 pub unsafe extern "C" fn dc_log_event_seq(
     mut context: *mut dc_context_t,
     mut event_code: libc::c_int,
@@ -75,7 +73,6 @@ pub unsafe extern "C" fn dc_log_event_seq(
     log_vprintf(context, event_code, *sequence_start, msg, va_0);
     *sequence_start = 0i32;
 }
-#[no_mangle]
 pub unsafe extern "C" fn dc_log_error(
     mut context: *mut dc_context_t,
     mut data1: libc::c_int,
@@ -84,7 +81,6 @@ pub unsafe extern "C" fn dc_log_error(
 ) {
     log_vprintf(context, 400i32, data1, msg, va_1);
 }
-#[no_mangle]
 pub unsafe extern "C" fn dc_log_warning(
     mut context: *mut dc_context_t,
     mut data1: libc::c_int,
@@ -93,7 +89,6 @@ pub unsafe extern "C" fn dc_log_warning(
 ) {
     log_vprintf(context, 300i32, data1, msg, va_2);
 }
-#[no_mangle]
 pub unsafe extern "C" fn dc_log_info(
     mut context: *mut dc_context_t,
     mut data1: libc::c_int,
diff --git a/src/dc_loginparam.rs b/src/dc_loginparam.rs
index 60f56c8a4..4f597f8e1 100644
--- a/src/dc_loginparam.rs
+++ b/src/dc_loginparam.rs
@@ -24,8 +24,7 @@ pub struct dc_loginparam_t {
     pub server_flags: libc::c_int,
 }
 
-#[no_mangle]
-pub unsafe extern "C" fn dc_loginparam_new() -> *mut dc_loginparam_t {
+pub unsafe fn dc_loginparam_new() -> *mut dc_loginparam_t {
     let mut loginparam: *mut dc_loginparam_t = 0 as *mut dc_loginparam_t;
     loginparam = calloc(
         1i32 as libc::c_ulong,
@@ -36,8 +35,7 @@ pub unsafe extern "C" fn dc_loginparam_new() -> *mut dc_loginparam_t {
     }
     return loginparam;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_loginparam_unref(mut loginparam: *mut dc_loginparam_t) {
+pub unsafe fn dc_loginparam_unref(mut loginparam: *mut dc_loginparam_t) {
     if loginparam.is_null() {
         return;
     }
@@ -45,8 +43,7 @@ pub unsafe extern "C" fn dc_loginparam_unref(mut loginparam: *mut dc_loginparam_
     free(loginparam as *mut libc::c_void);
 }
 /* clears all data and frees its memory. All pointers are NULL after this function is called. */
-#[no_mangle]
-pub unsafe extern "C" fn dc_loginparam_empty(mut loginparam: *mut dc_loginparam_t) {
+pub unsafe fn dc_loginparam_empty(mut loginparam: *mut dc_loginparam_t) {
     if loginparam.is_null() {
         return;
     }
@@ -68,8 +65,7 @@ pub unsafe extern "C" fn dc_loginparam_empty(mut loginparam: *mut dc_loginparam_
     (*loginparam).send_pw = 0 as *mut libc::c_char;
     (*loginparam).server_flags = 0i32;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_loginparam_read(
+pub unsafe fn dc_loginparam_read(
     mut loginparam: *mut dc_loginparam_t,
     mut sql: *mut dc_sqlite3_t,
     mut prefix: *const libc::c_char,
@@ -148,8 +144,7 @@ pub unsafe extern "C" fn dc_loginparam_read(
     (*loginparam).server_flags = dc_sqlite3_get_config_int(sql, key, 0i32);
     sqlite3_free(key as *mut libc::c_void);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_loginparam_write(
+pub unsafe fn dc_loginparam_write(
     mut loginparam: *const dc_loginparam_t,
     mut sql: *mut dc_sqlite3_t,
     mut prefix: *const libc::c_char,
@@ -227,8 +222,7 @@ pub unsafe extern "C" fn dc_loginparam_write(
     dc_sqlite3_set_config_int(sql, key, (*loginparam).server_flags);
     sqlite3_free(key as *mut libc::c_void);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_loginparam_get_readable(
+pub unsafe fn dc_loginparam_get_readable(
     mut loginparam: *const dc_loginparam_t,
 ) -> *mut libc::c_char {
     let mut unset: *const libc::c_char = b"0\x00" as *const u8 as *const libc::c_char;
@@ -281,7 +275,7 @@ pub unsafe extern "C" fn dc_loginparam_get_readable(
     free(flags_readable as *mut libc::c_void);
     return ret;
 }
-unsafe extern "C" fn get_readable_flags(mut flags: libc::c_int) -> *mut libc::c_char {
+unsafe fn get_readable_flags(mut flags: libc::c_int) -> *mut libc::c_char {
     let mut strbuilder: dc_strbuilder_t = dc_strbuilder_t {
         buf: 0 as *mut libc::c_char,
         allocated: 0,
diff --git a/src/dc_lot.rs b/src/dc_lot.rs
index 5b481a3c4..196720851 100644
--- a/src/dc_lot.rs
+++ b/src/dc_lot.rs
@@ -40,8 +40,7 @@ pub struct dc_lot_t {
  *
  * NB: _Lot_ is used in the meaning _heap_ here.
  */
-#[no_mangle]
-pub unsafe extern "C" fn dc_lot_new() -> *mut dc_lot_t {
+pub unsafe fn dc_lot_new() -> *mut dc_lot_t {
     let mut lot: *mut dc_lot_t = 0 as *mut dc_lot_t;
     lot = calloc(
         1i32 as libc::c_ulong,
@@ -54,8 +53,7 @@ pub unsafe extern "C" fn dc_lot_new() -> *mut dc_lot_t {
     (*lot).text1_meaning = 0i32;
     return lot;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_lot_empty(mut lot: *mut dc_lot_t) {
+pub unsafe fn dc_lot_empty(mut lot: *mut dc_lot_t) {
     if lot.is_null() || (*lot).magic != 0x107107i32 as libc::c_uint {
         return;
     }
@@ -74,8 +72,7 @@ pub unsafe extern "C" fn dc_lot_empty(mut lot: *mut dc_lot_t) {
     (*lot).state = 0i32;
     (*lot).id = 0i32 as uint32_t;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_lot_unref(mut set: *mut dc_lot_t) {
+pub unsafe fn dc_lot_unref(mut set: *mut dc_lot_t) {
     if set.is_null() || (*set).magic != 0x107107i32 as libc::c_uint {
         return;
     }
@@ -83,43 +80,37 @@ pub unsafe extern "C" fn dc_lot_unref(mut set: *mut dc_lot_t) {
     (*set).magic = 0i32 as uint32_t;
     free(set as *mut libc::c_void);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_lot_get_text1(mut lot: *const dc_lot_t) -> *mut libc::c_char {
+pub unsafe fn dc_lot_get_text1(mut lot: *const dc_lot_t) -> *mut libc::c_char {
     if lot.is_null() || (*lot).magic != 0x107107i32 as libc::c_uint {
         return 0 as *mut libc::c_char;
     }
     return dc_strdup_keep_null((*lot).text1);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_lot_get_text2(mut lot: *const dc_lot_t) -> *mut libc::c_char {
+pub unsafe fn dc_lot_get_text2(mut lot: *const dc_lot_t) -> *mut libc::c_char {
     if lot.is_null() || (*lot).magic != 0x107107i32 as libc::c_uint {
         return 0 as *mut libc::c_char;
     }
     return dc_strdup_keep_null((*lot).text2);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_lot_get_text1_meaning(mut lot: *const dc_lot_t) -> libc::c_int {
+pub unsafe fn dc_lot_get_text1_meaning(mut lot: *const dc_lot_t) -> libc::c_int {
     if lot.is_null() || (*lot).magic != 0x107107i32 as libc::c_uint {
         return 0i32;
     }
     return (*lot).text1_meaning;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_lot_get_state(mut lot: *const dc_lot_t) -> libc::c_int {
+pub unsafe fn dc_lot_get_state(mut lot: *const dc_lot_t) -> libc::c_int {
     if lot.is_null() || (*lot).magic != 0x107107i32 as libc::c_uint {
         return 0i32;
     }
     return (*lot).state;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_lot_get_id(mut lot: *const dc_lot_t) -> uint32_t {
+pub unsafe fn dc_lot_get_id(mut lot: *const dc_lot_t) -> uint32_t {
     if lot.is_null() || (*lot).magic != 0x107107i32 as libc::c_uint {
         return 0i32 as uint32_t;
     }
     return (*lot).id;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_lot_get_timestamp(mut lot: *const dc_lot_t) -> time_t {
+pub unsafe fn dc_lot_get_timestamp(mut lot: *const dc_lot_t) -> time_t {
     if lot.is_null() || (*lot).magic != 0x107107i32 as libc::c_uint {
         return 0i32 as time_t;
     }
@@ -127,8 +118,7 @@ pub unsafe extern "C" fn dc_lot_get_timestamp(mut lot: *const dc_lot_t) -> time_
 }
 /* library-internal */
 /* in practice, the user additionally cuts the string himself pixel-accurate */
-#[no_mangle]
-pub unsafe extern "C" fn dc_lot_fill(
+pub unsafe fn dc_lot_fill(
     mut lot: *mut dc_lot_t,
     mut msg: *const dc_msg_t,
     mut chat: *const dc_chat_t,
diff --git a/src/dc_mimefactory.rs b/src/dc_mimefactory.rs
index 7025093ba..929d3b548 100644
--- a/src/dc_mimefactory.rs
+++ b/src/dc_mimefactory.rs
@@ -50,8 +50,7 @@ pub const DC_MF_MDN_LOADED: dc_mimefactory_loaded_t = 2;
 pub const DC_MF_MSG_LOADED: dc_mimefactory_loaded_t = 1;
 pub const DC_MF_NOTHING_LOADED: dc_mimefactory_loaded_t = 0;
 
-#[no_mangle]
-pub unsafe extern "C" fn dc_mimefactory_init(
+pub unsafe fn dc_mimefactory_init(
     mut factory: *mut dc_mimefactory_t,
     mut context: *mut dc_context_t,
 ) {
@@ -65,8 +64,7 @@ pub unsafe extern "C" fn dc_mimefactory_init(
     );
     (*factory).context = context;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_mimefactory_empty(mut factory: *mut dc_mimefactory_t) {
+pub unsafe fn dc_mimefactory_empty(mut factory: *mut dc_mimefactory_t) {
     if factory.is_null() {
         return;
     }
@@ -106,8 +104,7 @@ pub unsafe extern "C" fn dc_mimefactory_empty(mut factory: *mut dc_mimefactory_t
     (*factory).error = 0 as *mut libc::c_char;
     (*factory).timestamp = 0i32 as time_t;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_mimefactory_load_msg(
+pub unsafe fn dc_mimefactory_load_msg(
     mut factory: *mut dc_mimefactory_t,
     mut msg_id: uint32_t,
 ) -> libc::c_int {
@@ -242,7 +239,7 @@ pub unsafe extern "C" fn dc_mimefactory_load_msg(
     sqlite3_finalize(stmt);
     return success;
 }
-unsafe extern "C" fn load_from(mut factory: *mut dc_mimefactory_t) {
+unsafe fn load_from(mut factory: *mut dc_mimefactory_t) {
     (*factory).from_addr = dc_sqlite3_get_config(
         (*(*factory).context).sql,
         b"configured_addr\x00" as *const u8 as *const libc::c_char,
@@ -262,8 +259,7 @@ unsafe extern "C" fn load_from(mut factory: *mut dc_mimefactory_t) {
         (*factory).selfstatus = dc_stock_str((*factory).context, 13i32)
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_mimefactory_load_mdn(
+pub unsafe fn dc_mimefactory_load_mdn(
     mut factory: *mut dc_mimefactory_t,
     mut msg_id: uint32_t,
 ) -> libc::c_int {
@@ -324,8 +320,7 @@ pub unsafe extern "C" fn dc_mimefactory_load_mdn(
     dc_contact_unref(contact);
     return success;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_mimefactory_render(mut factory: *mut dc_mimefactory_t) -> libc::c_int {
+pub unsafe fn dc_mimefactory_render(mut factory: *mut dc_mimefactory_t) -> libc::c_int {
     let mut subject: *mut mailimf_subject = 0 as *mut mailimf_subject;
     let mut current_block: u64;
     let mut imf_fields: *mut mailimf_fields = 0 as *mut mailimf_fields;
@@ -1016,7 +1011,7 @@ pub unsafe extern "C" fn dc_mimefactory_render(mut factory: *mut dc_mimefactory_
     free(grpimage as *mut libc::c_void);
     return success;
 }
-unsafe extern "C" fn get_subject(
+unsafe fn get_subject(
     mut chat: *const dc_chat_t,
     mut msg: *const dc_msg_t,
     mut afwd_email: libc::c_int,
@@ -1053,14 +1048,14 @@ unsafe extern "C" fn get_subject(
     free(raw_subject as *mut libc::c_void);
     return ret;
 }
-unsafe extern "C" fn set_error(mut factory: *mut dc_mimefactory_t, mut text: *const libc::c_char) {
+unsafe fn set_error(mut factory: *mut dc_mimefactory_t, mut text: *const libc::c_char) {
     if factory.is_null() {
         return;
     }
     free((*factory).error as *mut libc::c_void);
     (*factory).error = dc_strdup_keep_null(text);
 }
-unsafe extern "C" fn build_body_text(mut text: *mut libc::c_char) -> *mut mailmime {
+unsafe fn build_body_text(mut text: *mut libc::c_char) -> *mut mailmime {
     let mut mime_fields: *mut mailmime_fields = 0 as *mut mailmime_fields;
     let mut message_part: *mut mailmime = 0 as *mut mailmime;
     let mut content: *mut mailmime_content = 0 as *mut mailmime_content;
@@ -1078,7 +1073,7 @@ unsafe extern "C" fn build_body_text(mut text: *mut libc::c_char) -> *mut mailmi
     mailmime_set_body_text(message_part, text, strlen(text));
     return message_part;
 }
-unsafe extern "C" fn build_body_file(
+unsafe fn build_body_file(
     mut msg: *const dc_msg_t,
     mut base_name: *const libc::c_char,
     mut ret_file_name_as_sent: *mut *mut libc::c_char,
@@ -1264,7 +1259,7 @@ unsafe extern "C" fn build_body_file(
 /* ******************************************************************************
  * Render
  ******************************************************************************/
-unsafe extern "C" fn is_file_size_okay(mut msg: *const dc_msg_t) -> libc::c_int {
+unsafe fn is_file_size_okay(mut msg: *const dc_msg_t) -> libc::c_int {
     let mut file_size_okay: libc::c_int = 1i32;
     let mut pathNfilename: *mut libc::c_char =
         dc_param_get((*msg).param, 'f' as i32, 0 as *const libc::c_char);
diff --git a/src/dc_mimeparser.rs b/src/dc_mimeparser.rs
index 44d36870b..c1a81455b 100644
--- a/src/dc_mimeparser.rs
+++ b/src/dc_mimeparser.rs
@@ -57,14 +57,12 @@ pub struct dc_mimeparser_t {
 }
 
 // deprecated
-#[no_mangle]
-pub unsafe extern "C" fn dc_no_compound_msgs() {
+pub unsafe fn dc_no_compound_msgs() {
     s_generate_compound_msgs = 0i32;
 }
 // deprecated: flag to switch generation of compound messages on and off.
 static mut s_generate_compound_msgs: libc::c_int = 1i32;
-#[no_mangle]
-pub unsafe extern "C" fn dc_mimeparser_new(
+pub unsafe fn dc_mimeparser_new(
     mut blobdir: *const libc::c_char,
     mut context: *mut dc_context_t,
 ) -> *mut dc_mimeparser_t {
@@ -87,8 +85,7 @@ pub unsafe extern "C" fn dc_mimeparser_new(
     dc_hash_init(&mut (*mimeparser).header, 3i32, 0i32);
     return mimeparser;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_mimeparser_unref(mut mimeparser: *mut dc_mimeparser_t) {
+pub unsafe fn dc_mimeparser_unref(mut mimeparser: *mut dc_mimeparser_t) {
     if mimeparser.is_null() {
         return;
     }
@@ -102,8 +99,7 @@ pub unsafe extern "C" fn dc_mimeparser_unref(mut mimeparser: *mut dc_mimeparser_
     free((*mimeparser).e2ee_helper as *mut libc::c_void);
     free(mimeparser as *mut libc::c_void);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_mimeparser_empty(mut mimeparser: *mut dc_mimeparser_t) {
+pub unsafe fn dc_mimeparser_empty(mut mimeparser: *mut dc_mimeparser_t) {
     if mimeparser.is_null() {
         return;
     }
@@ -144,7 +140,7 @@ pub unsafe extern "C" fn dc_mimeparser_empty(mut mimeparser: *mut dc_mimeparser_
     dc_kml_unref((*mimeparser).kml);
     (*mimeparser).kml = 0 as *mut dc_kml_t;
 }
-unsafe extern "C" fn dc_mimepart_unref(mut mimepart: *mut dc_mimepart_t) {
+unsafe fn dc_mimepart_unref(mut mimepart: *mut dc_mimepart_t) {
     if mimepart.is_null() {
         return;
     }
@@ -155,8 +151,7 @@ unsafe extern "C" fn dc_mimepart_unref(mut mimepart: *mut dc_mimepart_t) {
     dc_param_unref((*mimepart).param);
     free(mimepart as *mut libc::c_void);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_mimeparser_parse(
+pub unsafe fn dc_mimeparser_parse(
     mut mimeparser: *mut dc_mimeparser_t,
     mut body_not_terminated: *const libc::c_char,
     mut body_bytes: size_t,
@@ -439,7 +434,7 @@ pub unsafe extern "C" fn dc_mimeparser_parse(
 /* ******************************************************************************
  * a MIME part
  ******************************************************************************/
-unsafe extern "C" fn dc_mimepart_new() -> *mut dc_mimepart_t {
+unsafe fn dc_mimepart_new() -> *mut dc_mimepart_t {
     let mut mimepart: *mut dc_mimepart_t = 0 as *mut dc_mimepart_t;
     mimepart = calloc(
         1i32 as libc::c_ulong,
@@ -452,8 +447,7 @@ unsafe extern "C" fn dc_mimepart_new() -> *mut dc_mimepart_t {
     (*mimepart).param = dc_param_new();
     return mimepart;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_mimeparser_get_last_nonmeta(
+pub unsafe fn dc_mimeparser_get_last_nonmeta(
     mut mimeparser: *mut dc_mimeparser_t,
 ) -> *mut dc_mimepart_t {
     if !mimeparser.is_null() && !(*mimeparser).parts.is_null() {
@@ -472,8 +466,7 @@ pub unsafe extern "C" fn dc_mimeparser_get_last_nonmeta(
     return 0 as *mut dc_mimepart_t;
 }
 /*the result must be freed*/
-#[no_mangle]
-pub unsafe extern "C" fn mailimf_find_first_addr(
+pub unsafe fn mailimf_find_first_addr(
     mut mb_list: *const mailimf_mailbox_list,
 ) -> *mut libc::c_char {
     if mb_list.is_null() {
@@ -498,8 +491,7 @@ pub unsafe extern "C" fn mailimf_find_first_addr(
     return 0 as *mut libc::c_char;
 }
 /* the following functions can be used only after a call to dc_mimeparser_parse() */
-#[no_mangle]
-pub unsafe extern "C" fn dc_mimeparser_lookup_field(
+pub unsafe fn dc_mimeparser_lookup_field(
     mut mimeparser: *mut dc_mimeparser_t,
     mut field_name: *const libc::c_char,
 ) -> *mut mailimf_field {
@@ -509,8 +501,7 @@ pub unsafe extern "C" fn dc_mimeparser_lookup_field(
         strlen(field_name) as libc::c_int,
     ) as *mut mailimf_field;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_mimeparser_lookup_optional_field(
+pub unsafe fn dc_mimeparser_lookup_optional_field(
     mut mimeparser: *mut dc_mimeparser_t,
     mut field_name: *const libc::c_char,
 ) -> *mut mailimf_optional_field {
@@ -524,7 +515,7 @@ pub unsafe extern "C" fn dc_mimeparser_lookup_optional_field(
     }
     return 0 as *mut mailimf_optional_field;
 }
-unsafe extern "C" fn dc_mimeparser_parse_mime_recursive(
+unsafe fn dc_mimeparser_parse_mime_recursive(
     mut mimeparser: *mut dc_mimeparser_t,
     mut mime: *mut mailmime,
 ) -> libc::c_int {
@@ -827,7 +818,7 @@ unsafe extern "C" fn dc_mimeparser_parse_mime_recursive(
     }
     return any_part_added;
 }
-unsafe extern "C" fn hash_header(
+unsafe fn hash_header(
     mut out: *mut dc_hash_t,
     mut in_0: *const mailimf_fields,
     mut context: *mut dc_context_t,
@@ -899,7 +890,7 @@ unsafe extern "C" fn hash_header(
         }
     }
 }
-unsafe extern "C" fn mailmime_get_mime_type(
+unsafe fn mailmime_get_mime_type(
     mut mime: *mut mailmime,
     mut msg_type: *mut libc::c_int,
     mut raw_mime: *mut *mut libc::c_char,
@@ -1069,7 +1060,7 @@ unsafe extern "C" fn mailmime_get_mime_type(
     }
     return 0i32;
 }
-unsafe extern "C" fn reconcat_mime(
+unsafe fn reconcat_mime(
     mut raw_mime: *mut *mut libc::c_char,
     mut type_0: *const libc::c_char,
     mut subtype: *const libc::c_char,
@@ -1090,7 +1081,7 @@ unsafe extern "C" fn reconcat_mime(
         )
     };
 }
-unsafe extern "C" fn mailmime_is_attachment_disposition(mut mime: *mut mailmime) -> libc::c_int {
+unsafe fn mailmime_is_attachment_disposition(mut mime: *mut mailmime) -> libc::c_int {
     if !(*mime).mm_mime_fields.is_null() {
         let mut cur: *mut clistiter = (*(*(*mime).mm_mime_fields).fld_list).first;
         while !cur.is_null() {
@@ -1120,8 +1111,7 @@ unsafe extern "C" fn mailmime_is_attachment_disposition(mut mime: *mut mailmime)
     return 0i32;
 }
 /* low-level-tools for working with mailmime structures directly */
-#[no_mangle]
-pub unsafe extern "C" fn mailmime_find_ct_parameter(
+pub unsafe fn mailmime_find_ct_parameter(
     mut mime: *mut mailmime,
     mut name: *const libc::c_char,
 ) -> *mut mailmime_parameter {
@@ -1153,7 +1143,7 @@ pub unsafe extern "C" fn mailmime_find_ct_parameter(
     }
     return 0 as *mut mailmime_parameter;
 }
-unsafe extern "C" fn dc_mimeparser_add_single_part_if_known(
+unsafe fn dc_mimeparser_add_single_part_if_known(
     mut mimeparser: *mut dc_mimeparser_t,
     mut mime: *mut mailmime,
 ) -> libc::c_int {
@@ -1476,7 +1466,7 @@ unsafe extern "C" fn dc_mimeparser_add_single_part_if_known(
         0i32
     };
 }
-unsafe extern "C" fn do_add_single_file_part(
+unsafe fn do_add_single_file_part(
     mut parser: *mut dc_mimeparser_t,
     mut msg_type: libc::c_int,
     mut mime_type: libc::c_int,
@@ -1528,10 +1518,7 @@ unsafe extern "C" fn do_add_single_file_part(
     free(pathNfilename as *mut libc::c_void);
     dc_mimepart_unref(part);
 }
-unsafe extern "C" fn do_add_single_part(
-    mut parser: *mut dc_mimeparser_t,
-    mut part: *mut dc_mimepart_t,
-) {
+unsafe fn do_add_single_part(mut parser: *mut dc_mimeparser_t, mut part: *mut dc_mimepart_t) {
     if 0 != (*(*parser).e2ee_helper).encrypted
         && (*(*(*parser).e2ee_helper).signatures).count > 0i32
     {
@@ -1545,8 +1532,7 @@ unsafe extern "C" fn do_add_single_part(
         0 as *mut libc::c_uint,
     );
 }
-#[no_mangle]
-pub unsafe extern "C" fn mailmime_transfer_decode(
+pub unsafe fn mailmime_transfer_decode(
     mut mime: *mut mailmime,
     mut ret_decoded_data: *mut *const libc::c_char,
     mut ret_decoded_data_bytes: *mut size_t,
@@ -1627,8 +1613,7 @@ pub unsafe extern "C" fn mailmime_transfer_decode(
     *ret_to_mmap_string_unref = transfer_decoding_buffer;
     return 1i32;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_mimeparser_is_mailinglist_message(
+pub unsafe fn dc_mimeparser_is_mailinglist_message(
     mut mimeparser: *mut dc_mimeparser_t,
 ) -> libc::c_int {
     if mimeparser.is_null() {
@@ -1661,8 +1646,7 @@ pub unsafe extern "C" fn dc_mimeparser_is_mailinglist_message(
     }
     return 0i32;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_mimeparser_sender_equals_recipient(
+pub unsafe fn dc_mimeparser_sender_equals_recipient(
     mut mimeparser: *mut dc_mimeparser_t,
 ) -> libc::c_int {
     let mut sender_equals_recipient: libc::c_int = 0i32;
@@ -1710,10 +1694,7 @@ pub unsafe extern "C" fn dc_mimeparser_sender_equals_recipient(
     free(from_addr_norm as *mut libc::c_void);
     return sender_equals_recipient;
 }
-#[no_mangle]
-pub unsafe extern "C" fn mailimf_get_recipients(
-    mut imffields: *mut mailimf_fields,
-) -> *mut dc_hash_t {
+pub unsafe fn mailimf_get_recipients(mut imffields: *mut mailimf_fields) -> *mut dc_hash_t {
     /* the returned value must be dc_hash_clear()'d and free()'d. returned addresses are normalized. */
     let mut recipients: *mut dc_hash_t =
         malloc(::std::mem::size_of::<dc_hash_t>() as libc::c_ulong) as *mut dc_hash_t;
@@ -1801,7 +1782,7 @@ pub unsafe extern "C" fn mailimf_get_recipients(
 /* ******************************************************************************
  * low-level-tools for getting a list of all recipients
  ******************************************************************************/
-unsafe extern "C" fn mailimf_get_recipients__add_addr(
+unsafe fn mailimf_get_recipients__add_addr(
     mut recipients: *mut dc_hash_t,
     mut mb: *mut mailimf_mailbox,
 ) {
@@ -1817,8 +1798,7 @@ unsafe extern "C" fn mailimf_get_recipients__add_addr(
     };
 }
 /*the result is a pointer to mime, must not be freed*/
-#[no_mangle]
-pub unsafe extern "C" fn mailimf_find_field(
+pub unsafe fn mailimf_find_field(
     mut header: *mut mailimf_fields,
     mut wanted_fld_type: libc::c_int,
 ) -> *mut mailimf_field {
@@ -1845,8 +1825,7 @@ pub unsafe extern "C" fn mailimf_find_field(
     }
     return 0 as *mut mailimf_field;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_mimeparser_repl_msg_by_error(
+pub unsafe fn dc_mimeparser_repl_msg_by_error(
     mut mimeparser: *mut dc_mimeparser_t,
     mut error_msg: *const libc::c_char,
 ) {
@@ -1873,10 +1852,7 @@ pub unsafe extern "C" fn dc_mimeparser_repl_msg_by_error(
     carray_set_size((*mimeparser).parts, 1i32 as libc::c_uint);
 }
 /*the result is a pointer to mime, must not be freed*/
-#[no_mangle]
-pub unsafe extern "C" fn mailmime_find_mailimf_fields(
-    mut mime: *mut mailmime,
-) -> *mut mailimf_fields {
+pub unsafe fn mailmime_find_mailimf_fields(mut mime: *mut mailmime) -> *mut mailimf_fields {
     if mime.is_null() {
         return 0 as *mut mailimf_fields;
     }
@@ -1906,8 +1882,7 @@ pub unsafe extern "C" fn mailmime_find_mailimf_fields(
     }
     return 0 as *mut mailimf_fields;
 }
-#[no_mangle]
-pub unsafe extern "C" fn mailimf_find_optional_field(
+pub unsafe fn mailimf_find_optional_field(
     mut header: *mut mailimf_fields,
     mut wanted_fld_name: *const libc::c_char,
 ) -> *mut mailimf_optional_field {
diff --git a/src/dc_move.rs b/src/dc_move.rs
index b5936a885..82d7c72e4 100644
--- a/src/dc_move.rs
+++ b/src/dc_move.rs
@@ -12,8 +12,7 @@ use crate::dc_tools::*;
 use crate::types::*;
 use crate::x::*;
 
-#[no_mangle]
-pub unsafe extern "C" fn dc_do_heuristics_moves(
+pub unsafe fn dc_do_heuristics_moves(
     mut context: *mut dc_context_t,
     mut folder: *const libc::c_char,
     mut msg_id: uint32_t,
diff --git a/src/dc_msg.rs b/src/dc_msg.rs
index 666036782..b4eca8797 100644
--- a/src/dc_msg.rs
+++ b/src/dc_msg.rs
@@ -47,8 +47,7 @@ pub struct dc_msg_t {
 }
 
 // handle messages
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_msg_info(
+pub unsafe fn dc_get_msg_info(
     mut context: *mut dc_context_t,
     mut msg_id: uint32_t,
 ) -> *mut libc::c_char {
@@ -293,8 +292,7 @@ pub unsafe extern "C" fn dc_get_msg_info(
     free(rawtxt as *mut libc::c_void);
     return ret.buf;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_new_untyped(mut context: *mut dc_context_t) -> *mut dc_msg_t {
+pub unsafe fn dc_msg_new_untyped(mut context: *mut dc_context_t) -> *mut dc_msg_t {
     return dc_msg_new(context, 0i32);
 }
 /* *
@@ -307,8 +305,7 @@ pub unsafe extern "C" fn dc_msg_new_untyped(mut context: *mut dc_context_t) -> *
 // to check if a mail was sent, use dc_msg_is_sent()
 // approx. max. lenght returned by dc_msg_get_text()
 // approx. max. lenght returned by dc_get_msg_info()
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_new(
+pub unsafe fn dc_msg_new(
     mut context: *mut dc_context_t,
     mut viewtype: libc::c_int,
 ) -> *mut dc_msg_t {
@@ -327,8 +324,7 @@ pub unsafe extern "C" fn dc_msg_new(
     (*msg).param = dc_param_new();
     return msg;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_unref(mut msg: *mut dc_msg_t) {
+pub unsafe fn dc_msg_unref(mut msg: *mut dc_msg_t) {
     if msg.is_null() || (*msg).magic != 0x11561156i32 as libc::c_uint {
         return;
     }
@@ -337,8 +333,7 @@ pub unsafe extern "C" fn dc_msg_unref(mut msg: *mut dc_msg_t) {
     (*msg).magic = 0i32 as uint32_t;
     free(msg as *mut libc::c_void);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_empty(mut msg: *mut dc_msg_t) {
+pub unsafe fn dc_msg_empty(mut msg: *mut dc_msg_t) {
     if msg.is_null() || (*msg).magic != 0x11561156i32 as libc::c_uint {
         return;
     }
@@ -353,8 +348,7 @@ pub unsafe extern "C" fn dc_msg_empty(mut msg: *mut dc_msg_t) {
     dc_param_set_packed((*msg).param, 0 as *const libc::c_char);
     (*msg).hidden = 0i32;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_get_filemime(mut msg: *const dc_msg_t) -> *mut libc::c_char {
+pub unsafe fn dc_msg_get_filemime(mut msg: *const dc_msg_t) -> *mut libc::c_char {
     let mut ret: *mut libc::c_char = 0 as *mut libc::c_char;
     let mut file: *mut libc::c_char = 0 as *mut libc::c_char;
     if !(msg.is_null() || (*msg).magic != 0x11561156i32 as libc::c_uint) {
@@ -378,8 +372,7 @@ pub unsafe extern "C" fn dc_msg_get_filemime(mut msg: *const dc_msg_t) -> *mut l
         dc_strdup(0 as *const libc::c_char)
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_guess_msgtype_from_suffix(
+pub unsafe fn dc_msg_guess_msgtype_from_suffix(
     mut pathNfilename: *const libc::c_char,
     mut ret_msgtype: *mut libc::c_int,
     mut ret_mime: *mut *mut libc::c_char,
@@ -432,8 +425,7 @@ pub unsafe extern "C" fn dc_msg_guess_msgtype_from_suffix(
     free(suffix as *mut libc::c_void);
     free(dummy_buf as *mut libc::c_void);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_get_file(mut msg: *const dc_msg_t) -> *mut libc::c_char {
+pub unsafe fn dc_msg_get_file(mut msg: *const dc_msg_t) -> *mut libc::c_char {
     let mut file_rel: *mut libc::c_char = 0 as *mut libc::c_char;
     let mut file_abs: *mut libc::c_char = 0 as *mut libc::c_char;
     if !(msg.is_null() || (*msg).magic != 0x11561156i32 as libc::c_uint) {
@@ -449,15 +441,13 @@ pub unsafe extern "C" fn dc_msg_get_file(mut msg: *const dc_msg_t) -> *mut libc:
         dc_strdup(0 as *const libc::c_char)
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_has_location(mut msg: *const dc_msg_t) -> libc::c_int {
+pub unsafe fn dc_msg_has_location(mut msg: *const dc_msg_t) -> libc::c_int {
     if msg.is_null() || (*msg).magic != 0x11561156i32 as libc::c_uint {
         return 0i32;
     }
     return ((*msg).location_id != 0i32 as libc::c_uint) as libc::c_int;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_get_timestamp(mut msg: *const dc_msg_t) -> time_t {
+pub unsafe fn dc_msg_get_timestamp(mut msg: *const dc_msg_t) -> time_t {
     if msg.is_null() || (*msg).magic != 0x11561156i32 as libc::c_uint {
         return 0i32 as time_t;
     }
@@ -467,8 +457,7 @@ pub unsafe extern "C" fn dc_msg_get_timestamp(mut msg: *const dc_msg_t) -> time_
         (*msg).timestamp_sort
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_load_from_db(
+pub unsafe fn dc_msg_load_from_db(
     mut msg: *mut dc_msg_t,
     mut context: *mut dc_context_t,
     mut id: uint32_t,
@@ -496,7 +485,7 @@ pub unsafe extern "C" fn dc_msg_load_from_db(
     sqlite3_finalize(stmt);
     return success;
 }
-unsafe extern "C" fn dc_msg_set_from_stmt(
+unsafe fn dc_msg_set_from_stmt(
     mut msg: *mut dc_msg_t,
     mut row: *mut sqlite3_stmt,
     mut row_offset: libc::c_int,
@@ -573,8 +562,7 @@ unsafe extern "C" fn dc_msg_set_from_stmt(
     }
     return 1i32;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_mime_headers(
+pub unsafe fn dc_get_mime_headers(
     mut context: *mut dc_context_t,
     mut msg_id: uint32_t,
 ) -> *mut libc::c_char {
@@ -593,8 +581,7 @@ pub unsafe extern "C" fn dc_get_mime_headers(
     sqlite3_finalize(stmt);
     return eml;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_delete_msgs(
+pub unsafe fn dc_delete_msgs(
     mut context: *mut dc_context_t,
     mut msg_ids: *const uint32_t,
     mut msg_cnt: libc::c_int,
@@ -631,8 +618,7 @@ pub unsafe extern "C" fn dc_delete_msgs(
         dc_job_add(context, 105i32, 0i32, 0 as *const libc::c_char, 10i32);
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_update_msg_chat_id(
+pub unsafe fn dc_update_msg_chat_id(
     mut context: *mut dc_context_t,
     mut msg_id: uint32_t,
     mut chat_id: uint32_t,
@@ -646,8 +632,7 @@ pub unsafe extern "C" fn dc_update_msg_chat_id(
     sqlite3_step(stmt);
     sqlite3_finalize(stmt);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_markseen_msgs(
+pub unsafe fn dc_markseen_msgs(
     mut context: *mut dc_context_t,
     mut msg_ids: *const uint32_t,
     mut msg_cnt: libc::c_int,
@@ -717,8 +702,7 @@ pub unsafe extern "C" fn dc_markseen_msgs(
     }
     sqlite3_finalize(stmt);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_update_msg_state(
+pub unsafe fn dc_update_msg_state(
     mut context: *mut dc_context_t,
     mut msg_id: uint32_t,
     mut state: libc::c_int,
@@ -732,8 +716,7 @@ pub unsafe extern "C" fn dc_update_msg_state(
     sqlite3_step(stmt);
     sqlite3_finalize(stmt);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_star_msgs(
+pub unsafe fn dc_star_msgs(
     mut context: *mut dc_context_t,
     mut msg_ids: *const uint32_t,
     mut msg_cnt: libc::c_int,
@@ -763,11 +746,7 @@ pub unsafe extern "C" fn dc_star_msgs(
     sqlite3_finalize(stmt);
     dc_sqlite3_commit((*context).sql);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_msg(
-    mut context: *mut dc_context_t,
-    mut msg_id: uint32_t,
-) -> *mut dc_msg_t {
+pub unsafe fn dc_get_msg(mut context: *mut dc_context_t, mut msg_id: uint32_t) -> *mut dc_msg_t {
     let mut success: libc::c_int = 0i32;
     let mut obj: *mut dc_msg_t = dc_msg_new_untyped(context);
     if !(context.is_null() || (*context).magic != 0x11a11807i32 as libc::c_uint) {
@@ -782,22 +761,19 @@ pub unsafe extern "C" fn dc_get_msg(
         return 0 as *mut dc_msg_t;
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_get_id(mut msg: *const dc_msg_t) -> uint32_t {
+pub unsafe fn dc_msg_get_id(mut msg: *const dc_msg_t) -> uint32_t {
     if msg.is_null() || (*msg).magic != 0x11561156i32 as libc::c_uint {
         return 0i32 as uint32_t;
     }
     return (*msg).id;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_get_from_id(mut msg: *const dc_msg_t) -> uint32_t {
+pub unsafe fn dc_msg_get_from_id(mut msg: *const dc_msg_t) -> uint32_t {
     if msg.is_null() || (*msg).magic != 0x11561156i32 as libc::c_uint {
         return 0i32 as uint32_t;
     }
     return (*msg).from_id;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_get_chat_id(mut msg: *const dc_msg_t) -> uint32_t {
+pub unsafe fn dc_msg_get_chat_id(mut msg: *const dc_msg_t) -> uint32_t {
     if msg.is_null() || (*msg).magic != 0x11561156i32 as libc::c_uint {
         return 0i32 as uint32_t;
     }
@@ -807,36 +783,31 @@ pub unsafe extern "C" fn dc_msg_get_chat_id(mut msg: *const dc_msg_t) -> uint32_
         (*msg).chat_id
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_get_viewtype(mut msg: *const dc_msg_t) -> libc::c_int {
+pub unsafe fn dc_msg_get_viewtype(mut msg: *const dc_msg_t) -> libc::c_int {
     if msg.is_null() || (*msg).magic != 0x11561156i32 as libc::c_uint {
         return 0i32;
     }
     return (*msg).type_0;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_get_state(mut msg: *const dc_msg_t) -> libc::c_int {
+pub unsafe fn dc_msg_get_state(mut msg: *const dc_msg_t) -> libc::c_int {
     if msg.is_null() || (*msg).magic != 0x11561156i32 as libc::c_uint {
         return 0i32;
     }
     return (*msg).state;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_get_received_timestamp(mut msg: *const dc_msg_t) -> time_t {
+pub unsafe fn dc_msg_get_received_timestamp(mut msg: *const dc_msg_t) -> time_t {
     if msg.is_null() || (*msg).magic != 0x11561156i32 as libc::c_uint {
         return 0i32 as time_t;
     }
     return (*msg).timestamp_rcvd;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_get_sort_timestamp(mut msg: *const dc_msg_t) -> time_t {
+pub unsafe fn dc_msg_get_sort_timestamp(mut msg: *const dc_msg_t) -> time_t {
     if msg.is_null() || (*msg).magic != 0x11561156i32 as libc::c_uint {
         return 0i32 as time_t;
     }
     return (*msg).timestamp_sort;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_get_text(mut msg: *const dc_msg_t) -> *mut libc::c_char {
+pub unsafe fn dc_msg_get_text(mut msg: *const dc_msg_t) -> *mut libc::c_char {
     let mut ret: *mut libc::c_char = 0 as *mut libc::c_char;
     if msg.is_null() || (*msg).magic != 0x11561156i32 as libc::c_uint {
         return dc_strdup(0 as *const libc::c_char);
@@ -845,8 +816,7 @@ pub unsafe extern "C" fn dc_msg_get_text(mut msg: *const dc_msg_t) -> *mut libc:
     dc_truncate_str(ret, 30000i32);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_get_filename(mut msg: *const dc_msg_t) -> *mut libc::c_char {
+pub unsafe fn dc_msg_get_filename(mut msg: *const dc_msg_t) -> *mut libc::c_char {
     let mut ret: *mut libc::c_char = 0 as *mut libc::c_char;
     let mut pathNfilename: *mut libc::c_char = 0 as *mut libc::c_char;
     if !(msg.is_null() || (*msg).magic != 0x11561156i32 as libc::c_uint) {
@@ -862,8 +832,7 @@ pub unsafe extern "C" fn dc_msg_get_filename(mut msg: *const dc_msg_t) -> *mut l
         dc_strdup(0 as *const libc::c_char)
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_get_filebytes(mut msg: *const dc_msg_t) -> uint64_t {
+pub unsafe fn dc_msg_get_filebytes(mut msg: *const dc_msg_t) -> uint64_t {
     let mut ret: uint64_t = 0i32 as uint64_t;
     let mut file: *mut libc::c_char = 0 as *mut libc::c_char;
     if !(msg.is_null() || (*msg).magic != 0x11561156i32 as libc::c_uint) {
@@ -875,29 +844,25 @@ pub unsafe extern "C" fn dc_msg_get_filebytes(mut msg: *const dc_msg_t) -> uint6
     free(file as *mut libc::c_void);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_get_width(mut msg: *const dc_msg_t) -> libc::c_int {
+pub unsafe fn dc_msg_get_width(mut msg: *const dc_msg_t) -> libc::c_int {
     if msg.is_null() || (*msg).magic != 0x11561156i32 as libc::c_uint {
         return 0i32;
     }
     return dc_param_get_int((*msg).param, 'w' as i32, 0i32);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_get_height(mut msg: *const dc_msg_t) -> libc::c_int {
+pub unsafe fn dc_msg_get_height(mut msg: *const dc_msg_t) -> libc::c_int {
     if msg.is_null() || (*msg).magic != 0x11561156i32 as libc::c_uint {
         return 0i32;
     }
     return dc_param_get_int((*msg).param, 'h' as i32, 0i32);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_get_duration(mut msg: *const dc_msg_t) -> libc::c_int {
+pub unsafe fn dc_msg_get_duration(mut msg: *const dc_msg_t) -> libc::c_int {
     if msg.is_null() || (*msg).magic != 0x11561156i32 as libc::c_uint {
         return 0i32;
     }
     return dc_param_get_int((*msg).param, 'd' as i32, 0i32);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_get_showpadlock(mut msg: *const dc_msg_t) -> libc::c_int {
+pub unsafe fn dc_msg_get_showpadlock(mut msg: *const dc_msg_t) -> libc::c_int {
     if msg.is_null() || (*msg).magic != 0x11561156i32 as libc::c_uint || (*msg).context.is_null() {
         return 0i32;
     }
@@ -906,8 +871,7 @@ pub unsafe extern "C" fn dc_msg_get_showpadlock(mut msg: *const dc_msg_t) -> lib
     }
     return 0i32;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_get_summary(
+pub unsafe fn dc_msg_get_summary(
     mut msg: *const dc_msg_t,
     mut chat: *const dc_chat_t,
 ) -> *mut dc_lot_t {
@@ -943,8 +907,7 @@ pub unsafe extern "C" fn dc_msg_get_summary(
     dc_chat_unref(chat_to_delete);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_get_summarytext(
+pub unsafe fn dc_msg_get_summarytext(
     mut msg: *const dc_msg_t,
     mut approx_characters: libc::c_int,
 ) -> *mut libc::c_char {
@@ -960,8 +923,7 @@ pub unsafe extern "C" fn dc_msg_get_summarytext(
     );
 }
 /* the returned value must be free()'d */
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_get_summarytext_by_raw(
+pub unsafe fn dc_msg_get_summarytext_by_raw(
     mut type_0: libc::c_int,
     mut text: *const libc::c_char,
     mut param: *mut dc_param_t,
@@ -1033,30 +995,26 @@ pub unsafe extern "C" fn dc_msg_get_summarytext_by_raw(
     }
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_has_deviating_timestamp(mut msg: *const dc_msg_t) -> libc::c_int {
+pub unsafe fn dc_msg_has_deviating_timestamp(mut msg: *const dc_msg_t) -> libc::c_int {
     let mut cnv_to_local: libc::c_long = dc_gm2local_offset();
     let mut sort_timestamp: time_t = dc_msg_get_sort_timestamp(msg) + cnv_to_local;
     let mut send_timestamp: time_t = dc_msg_get_timestamp(msg) + cnv_to_local;
     return (sort_timestamp / 86400i32 as libc::c_long != send_timestamp / 86400i32 as libc::c_long)
         as libc::c_int;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_is_sent(mut msg: *const dc_msg_t) -> libc::c_int {
+pub unsafe fn dc_msg_is_sent(mut msg: *const dc_msg_t) -> libc::c_int {
     if msg.is_null() || (*msg).magic != 0x11561156i32 as libc::c_uint {
         return 0i32;
     }
     return if (*msg).state >= 26i32 { 1i32 } else { 0i32 };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_is_starred(mut msg: *const dc_msg_t) -> libc::c_int {
+pub unsafe fn dc_msg_is_starred(mut msg: *const dc_msg_t) -> libc::c_int {
     if msg.is_null() || (*msg).magic != 0x11561156i32 as libc::c_uint {
         return 0i32;
     }
     return if 0 != (*msg).starred { 1i32 } else { 0i32 };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_is_forwarded(mut msg: *const dc_msg_t) -> libc::c_int {
+pub unsafe fn dc_msg_is_forwarded(mut msg: *const dc_msg_t) -> libc::c_int {
     if msg.is_null() || (*msg).magic != 0x11561156i32 as libc::c_uint {
         return 0i32;
     }
@@ -1066,8 +1024,7 @@ pub unsafe extern "C" fn dc_msg_is_forwarded(mut msg: *const dc_msg_t) -> libc::
         0i32
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_is_info(mut msg: *const dc_msg_t) -> libc::c_int {
+pub unsafe fn dc_msg_is_info(mut msg: *const dc_msg_t) -> libc::c_int {
     if msg.is_null() || (*msg).magic != 0x11561156i32 as libc::c_uint {
         return 0i32;
     }
@@ -1080,8 +1037,7 @@ pub unsafe extern "C" fn dc_msg_is_info(mut msg: *const dc_msg_t) -> libc::c_int
     }
     return 0i32;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_is_increation(mut msg: *const dc_msg_t) -> libc::c_int {
+pub unsafe fn dc_msg_is_increation(mut msg: *const dc_msg_t) -> libc::c_int {
     if msg.is_null() || (*msg).magic != 0x11561156i32 as libc::c_uint || (*msg).context.is_null() {
         return 0i32;
     }
@@ -1093,8 +1049,7 @@ pub unsafe extern "C" fn dc_msg_is_increation(mut msg: *const dc_msg_t) -> libc:
         || (*msg).type_0 == 60i32)
         && (*msg).state == 18i32) as libc::c_int;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_is_setupmessage(mut msg: *const dc_msg_t) -> libc::c_int {
+pub unsafe fn dc_msg_is_setupmessage(mut msg: *const dc_msg_t) -> libc::c_int {
     if msg.is_null() || (*msg).magic != 0x11561156i32 as libc::c_uint || (*msg).type_0 != 60i32 {
         return 0i32;
     }
@@ -1104,8 +1059,7 @@ pub unsafe extern "C" fn dc_msg_is_setupmessage(mut msg: *const dc_msg_t) -> lib
         0i32
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_get_setupcodebegin(mut msg: *const dc_msg_t) -> *mut libc::c_char {
+pub unsafe fn dc_msg_get_setupcodebegin(mut msg: *const dc_msg_t) -> *mut libc::c_char {
     let mut filename: *mut libc::c_char = 0 as *mut libc::c_char;
     let mut buf: *mut libc::c_char = 0 as *mut libc::c_char;
     let mut buf_bytes: size_t = 0i32 as size_t;
@@ -1154,16 +1108,14 @@ pub unsafe extern "C" fn dc_msg_get_setupcodebegin(mut msg: *const dc_msg_t) ->
         dc_strdup(0 as *const libc::c_char)
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_set_text(mut msg: *mut dc_msg_t, mut text: *const libc::c_char) {
+pub unsafe fn dc_msg_set_text(mut msg: *mut dc_msg_t, mut text: *const libc::c_char) {
     if msg.is_null() || (*msg).magic != 0x11561156i32 as libc::c_uint {
         return;
     }
     free((*msg).text as *mut libc::c_void);
     (*msg).text = dc_strdup(text);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_set_file(
+pub unsafe fn dc_msg_set_file(
     mut msg: *mut dc_msg_t,
     mut file: *const libc::c_char,
     mut filemime: *const libc::c_char,
@@ -1174,8 +1126,7 @@ pub unsafe extern "C" fn dc_msg_set_file(
     dc_param_set((*msg).param, 'f' as i32, file);
     dc_param_set((*msg).param, 'm' as i32, filemime);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_set_dimension(
+pub unsafe fn dc_msg_set_dimension(
     mut msg: *mut dc_msg_t,
     mut width: libc::c_int,
     mut height: libc::c_int,
@@ -1186,15 +1137,13 @@ pub unsafe extern "C" fn dc_msg_set_dimension(
     dc_param_set_int((*msg).param, 'w' as i32, width);
     dc_param_set_int((*msg).param, 'h' as i32, height);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_set_duration(mut msg: *mut dc_msg_t, mut duration: libc::c_int) {
+pub unsafe fn dc_msg_set_duration(mut msg: *mut dc_msg_t, mut duration: libc::c_int) {
     if msg.is_null() || (*msg).magic != 0x11561156i32 as libc::c_uint {
         return;
     }
     dc_param_set_int((*msg).param, 'd' as i32, duration);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_latefiling_mediasize(
+pub unsafe fn dc_msg_latefiling_mediasize(
     mut msg: *mut dc_msg_t,
     mut width: libc::c_int,
     mut height: libc::c_int,
@@ -1211,8 +1160,7 @@ pub unsafe extern "C" fn dc_msg_latefiling_mediasize(
         dc_msg_save_param_to_disk(msg);
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_save_param_to_disk(mut msg: *mut dc_msg_t) {
+pub unsafe fn dc_msg_save_param_to_disk(mut msg: *mut dc_msg_t) {
     if msg.is_null()
         || (*msg).magic != 0x11561156i32 as libc::c_uint
         || (*msg).context.is_null()
@@ -1229,8 +1177,7 @@ pub unsafe extern "C" fn dc_msg_save_param_to_disk(mut msg: *mut dc_msg_t) {
     sqlite3_step(stmt);
     sqlite3_finalize(stmt);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_new_load(
+pub unsafe fn dc_msg_new_load(
     mut context: *mut dc_context_t,
     mut msg_id: uint32_t,
 ) -> *mut dc_msg_t {
@@ -1238,11 +1185,7 @@ pub unsafe extern "C" fn dc_msg_new_load(
     dc_msg_load_from_db(msg, context, msg_id);
     return msg;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_delete_msg_from_db(
-    mut context: *mut dc_context_t,
-    mut msg_id: uint32_t,
-) {
+pub unsafe fn dc_delete_msg_from_db(mut context: *mut dc_context_t, mut msg_id: uint32_t) {
     let mut msg: *mut dc_msg_t = dc_msg_new_untyped(context);
     let mut stmt: *mut sqlite3_stmt = 0 as *mut sqlite3_stmt;
     if !(0 == dc_msg_load_from_db(msg, context, msg_id)) {
@@ -1271,11 +1214,7 @@ Do not use too long subjects - we add a tag after the subject which gets truncat
 It should also be very clear, the subject is _not_ the whole message.
 The value is also used for CC:-summaries */
 // Context functions to work with messages
-#[no_mangle]
-pub unsafe extern "C" fn dc_msg_exists(
-    mut context: *mut dc_context_t,
-    mut msg_id: uint32_t,
-) -> libc::c_int {
+pub unsafe fn dc_msg_exists(mut context: *mut dc_context_t, mut msg_id: uint32_t) -> libc::c_int {
     let mut msg_exists: libc::c_int = 0i32;
     let mut stmt: *mut sqlite3_stmt = 0 as *mut sqlite3_stmt;
     if !(context.is_null()
@@ -1297,8 +1236,7 @@ pub unsafe extern "C" fn dc_msg_exists(
     sqlite3_finalize(stmt);
     return msg_exists;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_update_msg_move_state(
+pub unsafe fn dc_update_msg_move_state(
     mut context: *mut dc_context_t,
     mut rfc724_mid: *const libc::c_char,
     mut state: dc_move_state_t,
@@ -1314,8 +1252,7 @@ pub unsafe extern "C" fn dc_update_msg_move_state(
     sqlite3_step(stmt);
     sqlite3_finalize(stmt);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_set_msg_failed(
+pub unsafe fn dc_set_msg_failed(
     mut context: *mut dc_context_t,
     mut msg_id: uint32_t,
     mut error: *const libc::c_char,
@@ -1354,8 +1291,7 @@ pub unsafe extern "C" fn dc_set_msg_failed(
     dc_msg_unref(msg);
 }
 /* returns 1 if an event should be send */
-#[no_mangle]
-pub unsafe extern "C" fn dc_mdn_from_ext(
+pub unsafe fn dc_mdn_from_ext(
     mut context: *mut dc_context_t,
     mut from_id: uint32_t,
     mut rfc724_mid: *const libc::c_char,
@@ -1465,8 +1401,7 @@ pub unsafe extern "C" fn dc_mdn_from_ext(
     return read_by_all;
 }
 /* the number of messages assigned to real chat (!=deaddrop, !=trash) */
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_real_msg_cnt(mut context: *mut dc_context_t) -> size_t {
+pub unsafe fn dc_get_real_msg_cnt(mut context: *mut dc_context_t) -> size_t {
     let mut stmt: *mut sqlite3_stmt = 0 as *mut sqlite3_stmt;
     let mut ret: size_t = 0i32 as size_t;
     if !(*(*context).sql).cobj.is_null() {
@@ -1486,8 +1421,7 @@ pub unsafe extern "C" fn dc_get_real_msg_cnt(mut context: *mut dc_context_t) ->
     sqlite3_finalize(stmt);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_deaddrop_msg_cnt(mut context: *mut dc_context_t) -> size_t {
+pub unsafe fn dc_get_deaddrop_msg_cnt(mut context: *mut dc_context_t) -> size_t {
     let mut stmt: *mut sqlite3_stmt = 0 as *mut sqlite3_stmt;
     let mut ret: size_t = 0i32 as size_t;
     if !(context.is_null()
@@ -1505,8 +1439,7 @@ pub unsafe extern "C" fn dc_get_deaddrop_msg_cnt(mut context: *mut dc_context_t)
     sqlite3_finalize(stmt);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_rfc724_mid_cnt(
+pub unsafe fn dc_rfc724_mid_cnt(
     mut context: *mut dc_context_t,
     mut rfc724_mid: *const libc::c_char,
 ) -> libc::c_int {
@@ -1530,8 +1463,7 @@ pub unsafe extern "C" fn dc_rfc724_mid_cnt(
     sqlite3_finalize(stmt);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_rfc724_mid_exists(
+pub unsafe fn dc_rfc724_mid_exists(
     mut context: *mut dc_context_t,
     mut rfc724_mid: *const libc::c_char,
     mut ret_server_folder: *mut *mut libc::c_char,
@@ -1569,8 +1501,7 @@ pub unsafe extern "C" fn dc_rfc724_mid_exists(
     sqlite3_finalize(stmt);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_update_server_uid(
+pub unsafe fn dc_update_server_uid(
     mut context: *mut dc_context_t,
     mut rfc724_mid: *const libc::c_char,
     mut server_folder: *const libc::c_char,
diff --git a/src/dc_oauth2.rs b/src/dc_oauth2.rs
index 73059039f..f497d9fa1 100644
--- a/src/dc_oauth2.rs
+++ b/src/dc_oauth2.rs
@@ -24,8 +24,7 @@ pub struct oauth2_t {
     pub get_userinfo: *mut libc::c_char,
 }
 
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_oauth2_url(
+pub unsafe fn dc_get_oauth2_url(
     mut context: *mut dc_context_t,
     mut addr: *const libc::c_char,
     mut redirect_uri: *const libc::c_char,
@@ -60,7 +59,7 @@ pub unsafe extern "C" fn dc_get_oauth2_url(
     free(oauth2 as *mut libc::c_void);
     return oauth2_url;
 }
-unsafe extern "C" fn replace_in_uri(
+unsafe fn replace_in_uri(
     mut uri: *mut *mut libc::c_char,
     mut key: *const libc::c_char,
     mut value: *const libc::c_char,
@@ -71,7 +70,7 @@ unsafe extern "C" fn replace_in_uri(
         free(value_urlencoded as *mut libc::c_void);
     };
 }
-unsafe extern "C" fn get_info(mut addr: *const libc::c_char) -> *mut oauth2_t {
+unsafe fn get_info(mut addr: *const libc::c_char) -> *mut oauth2_t {
     let mut oauth2: *mut oauth2_t = 0 as *mut oauth2_t;
     let mut addr_normalized: *mut libc::c_char = 0 as *mut libc::c_char;
     let mut domain: *const libc::c_char = 0 as *const libc::c_char;
@@ -133,8 +132,7 @@ unsafe extern "C" fn get_info(mut addr: *const libc::c_char) -> *mut oauth2_t {
 }
 // the following function may block due http-requests;
 // must not be called from the main thread or by the ui!
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_oauth2_access_token(
+pub unsafe fn dc_get_oauth2_access_token(
     mut context: *mut dc_context_t,
     mut addr: *const libc::c_char,
     mut code: *const libc::c_char,
@@ -462,10 +460,7 @@ pub unsafe extern "C" fn dc_get_oauth2_access_token(
         dc_strdup(0 as *const libc::c_char)
     };
 }
-unsafe extern "C" fn jsondup(
-    mut json: *const libc::c_char,
-    mut tok: *mut jsmntok_t,
-) -> *mut libc::c_char {
+unsafe fn jsondup(mut json: *const libc::c_char, mut tok: *mut jsmntok_t) -> *mut libc::c_char {
     if (*tok).type_0 as libc::c_uint == JSMN_STRING as libc::c_int as libc::c_uint
         || (*tok).type_0 as libc::c_uint == JSMN_PRIMITIVE as libc::c_int as libc::c_uint
     {
@@ -493,7 +488,7 @@ unsafe extern "C" fn jsoneq(
     }
     return -1i32;
 }
-unsafe extern "C" fn is_expired(mut context: *mut dc_context_t) -> libc::c_int {
+unsafe fn is_expired(mut context: *mut dc_context_t) -> libc::c_int {
     let mut expire_timestamp: time_t = dc_sqlite3_get_config_int64(
         (*context).sql,
         b"oauth2_timestamp_expires\x00" as *const u8 as *const libc::c_char,
@@ -507,8 +502,7 @@ unsafe extern "C" fn is_expired(mut context: *mut dc_context_t) -> libc::c_int {
     }
     return 1i32;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_oauth2_addr(
+pub unsafe fn dc_get_oauth2_addr(
     mut context: *mut dc_context_t,
     mut addr: *const libc::c_char,
     mut code: *const libc::c_char,
@@ -536,7 +530,7 @@ pub unsafe extern "C" fn dc_get_oauth2_addr(
     free(oauth2 as *mut libc::c_void);
     return addr_out;
 }
-unsafe extern "C" fn get_oauth2_addr(
+unsafe fn get_oauth2_addr(
     mut context: *mut dc_context_t,
     mut oauth2: *const oauth2_t,
     mut access_token: *const libc::c_char,
diff --git a/src/dc_param.rs b/src/dc_param.rs
index 2988f4c29..0cd05b55b 100644
--- a/src/dc_param.rs
+++ b/src/dc_param.rs
@@ -23,11 +23,7 @@ pub struct dc_param_t {
 
 // values for DC_PARAM_FORCE_PLAINTEXT
 /* user functions */
-#[no_mangle]
-pub unsafe extern "C" fn dc_param_exists(
-    mut param: *mut dc_param_t,
-    mut key: libc::c_int,
-) -> libc::c_int {
+pub unsafe fn dc_param_exists(mut param: *mut dc_param_t, mut key: libc::c_int) -> libc::c_int {
     let mut p2: *mut libc::c_char = 0 as *mut libc::c_char;
     if param.is_null() || key == 0i32 {
         return 0i32;
@@ -67,8 +63,7 @@ unsafe extern "C" fn find_param(
     return p1;
 }
 /* the value may be an empty string, "def" is returned only if the value unset.  The result must be free()'d in any case. */
-#[no_mangle]
-pub unsafe extern "C" fn dc_param_get(
+pub unsafe fn dc_param_get(
     mut param: *const dc_param_t,
     mut key: libc::c_int,
     mut def: *const libc::c_char,
@@ -100,8 +95,7 @@ pub unsafe extern "C" fn dc_param_get(
     *p2 = bak;
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_param_get_int(
+pub unsafe fn dc_param_get_int(
     mut param: *const dc_param_t,
     mut key: libc::c_int,
     mut def: int32_t,
@@ -117,8 +111,7 @@ pub unsafe extern "C" fn dc_param_get_int(
     free(str as *mut libc::c_void);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_param_set(
+pub unsafe fn dc_param_set(
     mut param: *mut dc_param_t,
     mut key: libc::c_int,
     mut value: *const libc::c_char,
@@ -199,8 +192,7 @@ pub unsafe extern "C" fn dc_param_set(
     free((*param).packed as *mut libc::c_void);
     (*param).packed = new1;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_param_set_int(
+pub unsafe fn dc_param_set_int(
     mut param: *mut dc_param_t,
     mut key: libc::c_int,
     mut value: int32_t,
@@ -219,8 +211,7 @@ pub unsafe extern "C" fn dc_param_set_int(
     free(value_str as *mut libc::c_void);
 }
 /* library-private */
-#[no_mangle]
-pub unsafe extern "C" fn dc_param_new() -> *mut dc_param_t {
+pub unsafe fn dc_param_new() -> *mut dc_param_t {
     let mut param: *mut dc_param_t = 0 as *mut dc_param_t;
     param = calloc(
         1i32 as libc::c_ulong,
@@ -232,15 +223,13 @@ pub unsafe extern "C" fn dc_param_new() -> *mut dc_param_t {
     (*param).packed = calloc(1i32 as libc::c_ulong, 1i32 as libc::c_ulong) as *mut libc::c_char;
     return param;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_param_empty(mut param: *mut dc_param_t) {
+pub unsafe fn dc_param_empty(mut param: *mut dc_param_t) {
     if param.is_null() {
         return;
     }
     *(*param).packed.offset(0isize) = 0i32 as libc::c_char;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_param_unref(mut param: *mut dc_param_t) {
+pub unsafe fn dc_param_unref(mut param: *mut dc_param_t) {
     if param.is_null() {
         return;
     }
@@ -248,11 +237,7 @@ pub unsafe extern "C" fn dc_param_unref(mut param: *mut dc_param_t) {
     free((*param).packed as *mut libc::c_void);
     free(param as *mut libc::c_void);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_param_set_packed(
-    mut param: *mut dc_param_t,
-    mut packed: *const libc::c_char,
-) {
+pub unsafe fn dc_param_set_packed(mut param: *mut dc_param_t, mut packed: *const libc::c_char) {
     if param.is_null() {
         return;
     }
@@ -262,8 +247,7 @@ pub unsafe extern "C" fn dc_param_set_packed(
         (*param).packed = dc_strdup(packed)
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_param_set_urlencoded(
+pub unsafe fn dc_param_set_urlencoded(
     mut param: *mut dc_param_t,
     mut urlencoded: *const libc::c_char,
 ) {
diff --git a/src/dc_pgp.rs b/src/dc_pgp.rs
index fde81ab18..83eacce64 100644
--- a/src/dc_pgp.rs
+++ b/src/dc_pgp.rs
@@ -16,19 +16,15 @@ use crate::x::*;
 /* ** library-private **********************************************************/
 /* validation errors */
 /* misc. */
-#[no_mangle]
-pub unsafe extern "C" fn dc_pgp_init() {}
-#[no_mangle]
-pub unsafe extern "C" fn dc_pgp_exit() {}
-#[no_mangle]
-pub unsafe extern "C" fn dc_pgp_rand_seed(
+pub unsafe fn dc_pgp_init() {}
+pub unsafe fn dc_pgp_exit() {}
+pub unsafe fn dc_pgp_rand_seed(
     mut context: *mut dc_context_t,
     mut buf: *const libc::c_void,
     mut bytes: size_t,
 ) {
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_split_armored_data(
+pub unsafe fn dc_split_armored_data(
     mut buf: *mut libc::c_char,
     mut ret_headerline: *mut *const libc::c_char,
     mut ret_setupcodebegin: *mut *const libc::c_char,
@@ -146,8 +142,7 @@ pub unsafe extern "C" fn dc_split_armored_data(
     return success;
 }
 /* public key encryption */
-#[no_mangle]
-pub unsafe extern "C" fn dc_pgp_create_keypair(
+pub unsafe fn dc_pgp_create_keypair(
     mut context: *mut dc_context_t,
     mut addr: *const libc::c_char,
     mut ret_public_key: *mut dc_key_t,
@@ -208,8 +203,7 @@ pub unsafe extern "C" fn dc_pgp_create_keypair(
     return success;
 }
 /* returns 0 if there is no error, otherwise logs the error if a context is provided and returns 1*/
-#[no_mangle]
-pub unsafe extern "C" fn dc_pgp_handle_rpgp_error(mut context: *mut dc_context_t) -> libc::c_int {
+pub unsafe fn dc_pgp_handle_rpgp_error(mut context: *mut dc_context_t) -> libc::c_int {
     let mut success: libc::c_int = 0i32;
     let mut len: libc::c_int = 0i32;
     let mut msg: *mut libc::c_char = 0 as *mut libc::c_char;
@@ -231,8 +225,7 @@ pub unsafe extern "C" fn dc_pgp_handle_rpgp_error(mut context: *mut dc_context_t
     }
     return success;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_pgp_is_valid_key(
+pub unsafe fn dc_pgp_is_valid_key(
     mut context: *mut dc_context_t,
     mut raw_key: *const dc_key_t,
 ) -> libc::c_int {
@@ -261,8 +254,7 @@ pub unsafe extern "C" fn dc_pgp_is_valid_key(
     }
     return key_is_valid;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_pgp_calc_fingerprint(
+pub unsafe fn dc_pgp_calc_fingerprint(
     mut raw_key: *const dc_key_t,
     mut ret_fingerprint: *mut *mut uint8_t,
     mut ret_fingerprint_bytes: *mut size_t,
@@ -304,8 +296,7 @@ pub unsafe extern "C" fn dc_pgp_calc_fingerprint(
     }
     return success;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_pgp_split_key(
+pub unsafe fn dc_pgp_split_key(
     mut context: *mut dc_context_t,
     mut private_in: *const dc_key_t,
     mut ret_public_key: *mut dc_key_t,
@@ -354,8 +345,7 @@ pub unsafe extern "C" fn dc_pgp_split_key(
     }
     return success;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_pgp_pk_encrypt(
+pub unsafe fn dc_pgp_pk_encrypt(
     mut context: *mut dc_context_t,
     mut plain_text: *const libc::c_void,
     mut plain_bytes: size_t,
@@ -524,8 +514,7 @@ pub unsafe extern "C" fn dc_pgp_pk_encrypt(
     }
     return success;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_pgp_pk_decrypt(
+pub unsafe fn dc_pgp_pk_decrypt(
     mut context: *mut dc_context_t,
     mut ctext: *const libc::c_void,
     mut ctext_bytes: size_t,
@@ -688,8 +677,7 @@ pub unsafe extern "C" fn dc_pgp_pk_decrypt(
     return success;
 }
 /* symm. encryption */
-#[no_mangle]
-pub unsafe extern "C" fn dc_pgp_symm_encrypt(
+pub unsafe fn dc_pgp_symm_encrypt(
     mut context: *mut dc_context_t,
     mut passphrase: *const libc::c_char,
     mut plain: *const libc::c_void,
@@ -721,8 +709,7 @@ pub unsafe extern "C" fn dc_pgp_symm_encrypt(
     }
     return success;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_pgp_symm_decrypt(
+pub unsafe fn dc_pgp_symm_decrypt(
     mut context: *mut dc_context_t,
     mut passphrase: *const libc::c_char,
     mut ctext: *const libc::c_void,
diff --git a/src/dc_qr.rs b/src/dc_qr.rs
index df03a1feb..2f3512feb 100644
--- a/src/dc_qr.rs
+++ b/src/dc_qr.rs
@@ -25,8 +25,7 @@ use crate::x::*;
 // text1=text
 // text1=URL
 // text1=error string
-#[no_mangle]
-pub unsafe extern "C" fn dc_check_qr(
+pub unsafe fn dc_check_qr(
     mut context: *mut dc_context_t,
     mut qr: *const libc::c_char,
 ) -> *mut dc_lot_t {
diff --git a/src/dc_receive_imf.rs b/src/dc_receive_imf.rs
index 2d7be11af..b512a9a46 100644
--- a/src/dc_receive_imf.rs
+++ b/src/dc_receive_imf.rs
@@ -26,8 +26,7 @@ use crate::pgp;
 use crate::types::*;
 use crate::x::*;
 
-#[no_mangle]
-pub unsafe extern "C" fn dc_receive_imf(
+pub unsafe fn dc_receive_imf(
     mut context: *mut dc_context_t,
     mut imf_raw_not_terminated: *const libc::c_char,
     mut imf_raw_bytes: size_t,
@@ -1017,7 +1016,7 @@ pub unsafe extern "C" fn dc_receive_imf(
 /* ******************************************************************************
  * Misc. Tools
  ******************************************************************************/
-unsafe extern "C" fn calc_timestamps(
+unsafe fn calc_timestamps(
     mut context: *mut dc_context_t,
     mut chat_id: uint32_t,
     mut from_id: uint32_t,
@@ -1068,7 +1067,7 @@ which tries to create or find out the chat_id by:
 
 So when the function returns, the caller has the group id matching the current
 state of the group. */
-unsafe extern "C" fn create_or_lookup_group(
+unsafe fn create_or_lookup_group(
     mut context: *mut dc_context_t,
     mut mime_parser: *mut dc_mimeparser_t,
     mut allow_creation: libc::c_int,
@@ -1534,7 +1533,7 @@ unsafe extern "C" fn create_or_lookup_group(
 /* ******************************************************************************
  * Handle groups for received messages
  ******************************************************************************/
-unsafe extern "C" fn create_or_lookup_adhoc_group(
+unsafe fn create_or_lookup_adhoc_group(
     mut context: *mut dc_context_t,
     mut mime_parser: *mut dc_mimeparser_t,
     mut allow_creation: libc::c_int,
@@ -1650,7 +1649,7 @@ unsafe extern "C" fn create_or_lookup_adhoc_group(
         *ret_chat_id_blocked = chat_id_blocked
     };
 }
-unsafe extern "C" fn create_group_record(
+unsafe fn create_group_record(
     mut context: *mut dc_context_t,
     mut grpid: *const libc::c_char,
     mut grpname: *const libc::c_char,
@@ -1683,7 +1682,7 @@ unsafe extern "C" fn create_group_record(
     sqlite3_finalize(stmt);
     return chat_id;
 }
-unsafe extern "C" fn create_adhoc_grp_id(
+unsafe fn create_adhoc_grp_id(
     mut context: *mut dc_context_t,
     mut member_ids: *mut dc_array_t,
 ) -> *mut libc::c_char {
@@ -1768,7 +1767,7 @@ unsafe extern "C" fn create_adhoc_grp_id(
     free(member_cs.buf as *mut libc::c_void);
     return ret;
 }
-unsafe extern "C" fn search_chat_ids_by_contact_ids(
+unsafe fn search_chat_ids_by_contact_ids(
     mut context: *mut dc_context_t,
     mut unsorted_contact_ids: *const dc_array_t,
 ) -> *mut dc_array_t {
@@ -1838,7 +1837,7 @@ unsafe extern "C" fn search_chat_ids_by_contact_ids(
     sqlite3_free(q3 as *mut libc::c_void);
     return chat_ids;
 }
-unsafe extern "C" fn check_verified_properties(
+unsafe fn check_verified_properties(
     mut context: *mut dc_context_t,
     mut mimeparser: *mut dc_mimeparser_t,
     mut from_id: uint32_t,
@@ -1983,7 +1982,7 @@ unsafe extern "C" fn check_verified_properties(
     sqlite3_free(q3 as *mut libc::c_void);
     return everythings_okay;
 }
-unsafe extern "C" fn set_better_msg(
+unsafe fn set_better_msg(
     mut mime_parser: *mut dc_mimeparser_t,
     mut better_msg: *mut *mut libc::c_char,
 ) {
@@ -1997,7 +1996,7 @@ unsafe extern "C" fn set_better_msg(
         }
     };
 }
-unsafe extern "C" fn dc_is_reply_to_known_message(
+unsafe fn dc_is_reply_to_known_message(
     mut context: *mut dc_context_t,
     mut mime_parser: *mut dc_mimeparser_t,
 ) -> libc::c_int {
@@ -2046,7 +2045,7 @@ unsafe extern "C" fn dc_is_reply_to_known_message(
     }
     return 0i32;
 }
-unsafe extern "C" fn is_known_rfc724_mid_in_list(
+unsafe fn is_known_rfc724_mid_in_list(
     mut context: *mut dc_context_t,
     mut mid_list: *const clist,
 ) -> libc::c_int {
@@ -2076,7 +2075,7 @@ unsafe extern "C" fn is_known_rfc724_mid_in_list(
 /* ******************************************************************************
  * Check if a message is a reply to a known message (messenger or non-messenger)
  ******************************************************************************/
-unsafe extern "C" fn is_known_rfc724_mid(
+unsafe fn is_known_rfc724_mid(
     mut context: *mut dc_context_t,
     mut rfc724_mid: *const libc::c_char,
 ) -> libc::c_int {
@@ -2094,7 +2093,7 @@ unsafe extern "C" fn is_known_rfc724_mid(
     }
     return is_known;
 }
-unsafe extern "C" fn dc_is_reply_to_messenger_message(
+unsafe fn dc_is_reply_to_messenger_message(
     mut context: *mut dc_context_t,
     mut mime_parser: *mut dc_mimeparser_t,
 ) -> libc::c_int {
@@ -2136,7 +2135,7 @@ unsafe extern "C" fn dc_is_reply_to_messenger_message(
     }
     return 0i32;
 }
-unsafe extern "C" fn is_msgrmsg_rfc724_mid_in_list(
+unsafe fn is_msgrmsg_rfc724_mid_in_list(
     mut context: *mut dc_context_t,
     mut mid_list: *const clist,
 ) -> libc::c_int {
@@ -2165,7 +2164,7 @@ unsafe extern "C" fn is_msgrmsg_rfc724_mid_in_list(
 /* ******************************************************************************
  * Check if a message is a reply to any messenger message
  ******************************************************************************/
-unsafe extern "C" fn is_msgrmsg_rfc724_mid(
+unsafe fn is_msgrmsg_rfc724_mid(
     mut context: *mut dc_context_t,
     mut rfc724_mid: *const libc::c_char,
 ) -> libc::c_int {
@@ -2184,7 +2183,7 @@ unsafe extern "C" fn is_msgrmsg_rfc724_mid(
     }
     return is_msgrmsg;
 }
-unsafe extern "C" fn dc_add_or_lookup_contacts_by_address_list(
+unsafe fn dc_add_or_lookup_contacts_by_address_list(
     mut context: *mut dc_context_t,
     mut adr_list: *const mailimf_address_list,
     mut origin: libc::c_int,
@@ -2235,7 +2234,7 @@ unsafe extern "C" fn dc_add_or_lookup_contacts_by_address_list(
         }
     }
 }
-unsafe extern "C" fn dc_add_or_lookup_contacts_by_mailbox_list(
+unsafe fn dc_add_or_lookup_contacts_by_mailbox_list(
     mut context: *mut dc_context_t,
     mut mb_list: *const mailimf_mailbox_list,
     mut origin: libc::c_int,
@@ -2272,7 +2271,7 @@ unsafe extern "C" fn dc_add_or_lookup_contacts_by_mailbox_list(
 /* ******************************************************************************
  * Add contacts to database on receiving messages
  ******************************************************************************/
-unsafe extern "C" fn add_or_lookup_contact_by_addr(
+unsafe fn add_or_lookup_contact_by_addr(
     mut context: *mut dc_context_t,
     mut display_name_enc: *const libc::c_char,
     mut addr_spec: *const libc::c_char,
diff --git a/src/dc_saxparser.rs b/src/dc_saxparser.rs
index 582e86e97..56b12d175 100644
--- a/src/dc_saxparser.rs
+++ b/src/dc_saxparser.rs
@@ -14,25 +14,19 @@ pub struct dc_saxparser_t {
 }
 
 /* len is only informational, text is already null-terminated */
-pub type dc_saxparser_text_cb_t = Option<
-    unsafe extern "C" fn(_: *mut libc::c_void, _: *const libc::c_char, _: libc::c_int) -> (),
->;
+pub type dc_saxparser_text_cb_t =
+    Option<unsafe fn(_: *mut libc::c_void, _: *const libc::c_char, _: libc::c_int) -> ()>;
 pub type dc_saxparser_endtag_cb_t =
-    Option<unsafe extern "C" fn(_: *mut libc::c_void, _: *const libc::c_char) -> ()>;
+    Option<unsafe fn(_: *mut libc::c_void, _: *const libc::c_char) -> ()>;
 pub type dc_saxparser_starttag_cb_t = Option<
-    unsafe extern "C" fn(
-        _: *mut libc::c_void,
-        _: *const libc::c_char,
-        _: *mut *mut libc::c_char,
-    ) -> (),
+    unsafe fn(_: *mut libc::c_void, _: *const libc::c_char, _: *mut *mut libc::c_char) -> (),
 >;
 
 #[inline]
-unsafe extern "C" fn isascii(mut _c: libc::c_int) -> libc::c_int {
+unsafe fn isascii(mut _c: libc::c_int) -> libc::c_int {
     return (_c & !0x7fi32 == 0i32) as libc::c_int;
 }
 
-#[no_mangle]
 pub unsafe extern "C" fn dc_saxparser_init(
     mut saxparser: *mut dc_saxparser_t,
     mut userdata: *mut libc::c_void,
@@ -42,24 +36,23 @@ pub unsafe extern "C" fn dc_saxparser_init(
     (*saxparser).endtag_cb = Some(def_endtag_cb);
     (*saxparser).text_cb = Some(def_text_cb);
 }
-unsafe extern "C" fn def_text_cb(
+unsafe fn def_text_cb(
     mut userdata: *mut libc::c_void,
     mut text: *const libc::c_char,
     mut len: libc::c_int,
 ) {
 }
-unsafe extern "C" fn def_endtag_cb(mut userdata: *mut libc::c_void, mut tag: *const libc::c_char) {}
+unsafe fn def_endtag_cb(mut userdata: *mut libc::c_void, mut tag: *const libc::c_char) {}
 /* ******************************************************************************
  * Tools
  ******************************************************************************/
-unsafe extern "C" fn def_starttag_cb(
+unsafe fn def_starttag_cb(
     mut userdata: *mut libc::c_void,
     mut tag: *const libc::c_char,
     mut attr: *mut *mut libc::c_char,
 ) {
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_saxparser_set_tag_handler(
+pub unsafe fn dc_saxparser_set_tag_handler(
     mut saxparser: *mut dc_saxparser_t,
     mut starttag_cb: dc_saxparser_starttag_cb_t,
     mut endtag_cb: dc_saxparser_endtag_cb_t,
@@ -78,8 +71,7 @@ pub unsafe extern "C" fn dc_saxparser_set_tag_handler(
         Some(def_endtag_cb)
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_saxparser_set_text_handler(
+pub unsafe fn dc_saxparser_set_text_handler(
     mut saxparser: *mut dc_saxparser_t,
     mut text_cb: dc_saxparser_text_cb_t,
 ) {
@@ -92,8 +84,7 @@ pub unsafe extern "C" fn dc_saxparser_set_text_handler(
         Some(def_text_cb)
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_saxparser_parse(
+pub unsafe fn dc_saxparser_parse(
     mut saxparser: *mut dc_saxparser_t,
     mut buf_start__: *const libc::c_char,
 ) {
@@ -386,10 +377,7 @@ pub unsafe extern "C" fn dc_saxparser_parse(
     do_free_attr(attr.as_mut_ptr(), free_attr.as_mut_ptr());
     free(buf_start as *mut libc::c_void);
 }
-unsafe extern "C" fn do_free_attr(
-    mut attr: *mut *mut libc::c_char,
-    mut free_attr: *mut libc::c_int,
-) {
+unsafe fn do_free_attr(mut attr: *mut *mut libc::c_char, mut free_attr: *mut libc::c_int) {
     /* "attr" are key/value pairs; the function frees the data if the corresponding bit in "free_attr" is set.
     (we need this as we try to use the strings from the "main" document instead of allocating small strings) */
     let mut i: libc::c_int = 0i32;
@@ -409,7 +397,7 @@ unsafe extern "C" fn do_free_attr(
     let ref mut fresh0 = *attr.offset(0isize);
     *fresh0 = 0 as *mut libc::c_char;
 }
-unsafe extern "C" fn call_text_cb(
+unsafe fn call_text_cb(
     mut saxparser: *mut dc_saxparser_t,
     mut text: *mut libc::c_char,
     mut len: size_t,
@@ -450,10 +438,7 @@ Returns s, or if the decoded string is longer than s, returns a malloced string
 that must be freed.
 Function based upon ezxml_decode() from the "ezxml" parser which is
 Copyright 2004-2006 Aaron Voisine <aaron@voisine.org> */
-unsafe extern "C" fn xml_decode(
-    mut s: *mut libc::c_char,
-    mut type_0: libc::c_char,
-) -> *mut libc::c_char {
+unsafe fn xml_decode(mut s: *mut libc::c_char, mut type_0: libc::c_char) -> *mut libc::c_char {
     let mut e: *mut libc::c_char = 0 as *mut libc::c_char;
     let mut r: *mut libc::c_char = s;
     let mut original_buf: *const libc::c_char = s;
@@ -1123,8 +1108,7 @@ static mut s_ent: [*const libc::c_char; 508] = [
     0 as *const libc::c_char,
     0 as *const libc::c_char,
 ];
-#[no_mangle]
-pub unsafe extern "C" fn dc_attr_find(
+pub unsafe fn dc_attr_find(
     mut attr: *mut *mut libc::c_char,
     mut key: *const libc::c_char,
 ) -> *const libc::c_char {
diff --git a/src/dc_securejoin.rs b/src/dc_securejoin.rs
index abfd3f558..12e5eb993 100644
--- a/src/dc_securejoin.rs
+++ b/src/dc_securejoin.rs
@@ -26,8 +26,7 @@ use crate::dc_tools::*;
 use crate::types::*;
 use crate::x::*;
 
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_securejoin_qr(
+pub unsafe fn dc_get_securejoin_qr(
     mut context: *mut dc_context_t,
     mut group_chat_id: uint32_t,
 ) -> *mut libc::c_char {
@@ -148,7 +147,7 @@ pub unsafe extern "C" fn dc_get_securejoin_qr(
         dc_strdup(0 as *const libc::c_char)
     };
 }
-unsafe extern "C" fn get_self_fingerprint(mut context: *mut dc_context_t) -> *mut libc::c_char {
+unsafe fn get_self_fingerprint(mut context: *mut dc_context_t) -> *mut libc::c_char {
     let mut self_addr: *mut libc::c_char = 0 as *mut libc::c_char;
     let mut self_key: *mut dc_key_t = dc_key_new();
     let mut fingerprint: *mut libc::c_char = 0 as *mut libc::c_char;
@@ -165,8 +164,7 @@ unsafe extern "C" fn get_self_fingerprint(mut context: *mut dc_context_t) -> *mu
     dc_key_unref(self_key);
     return fingerprint;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_join_securejoin(
+pub unsafe fn dc_join_securejoin(
     mut context: *mut dc_context_t,
     mut qr: *const libc::c_char,
 ) -> uint32_t {
@@ -293,7 +291,7 @@ pub unsafe extern "C" fn dc_join_securejoin(
     }
     return ret_chat_id as uint32_t;
 }
-unsafe extern "C" fn send_handshake_msg(
+unsafe fn send_handshake_msg(
     mut context: *mut dc_context_t,
     mut contact_chat_id: uint32_t,
     mut step: *const libc::c_char,
@@ -329,7 +327,7 @@ unsafe extern "C" fn send_handshake_msg(
     dc_send_msg(context, contact_chat_id, msg);
     dc_msg_unref(msg);
 }
-unsafe extern "C" fn chat_id_2_contact_id(
+unsafe fn chat_id_2_contact_id(
     mut context: *mut dc_context_t,
     mut contact_chat_id: uint32_t,
 ) -> uint32_t {
@@ -341,7 +339,7 @@ unsafe extern "C" fn chat_id_2_contact_id(
     dc_array_unref(contacts);
     return contact_id;
 }
-unsafe extern "C" fn fingerprint_equals_sender(
+unsafe fn fingerprint_equals_sender(
     mut context: *mut dc_context_t,
     mut fingerprint: *const libc::c_char,
     mut contact_chat_id: uint32_t,
@@ -372,8 +370,7 @@ unsafe extern "C" fn fingerprint_equals_sender(
     return fingerprint_equal;
 }
 /* library private: secure-join */
-#[no_mangle]
-pub unsafe extern "C" fn dc_handle_securejoin_handshake(
+pub unsafe fn dc_handle_securejoin_handshake(
     mut context: *mut dc_context_t,
     mut mimeparser: *mut dc_mimeparser_t,
     mut contact_id: uint32_t,
@@ -904,11 +901,11 @@ pub unsafe extern "C" fn dc_handle_securejoin_handshake(
     free(grpid as *mut libc::c_void);
     return ret;
 }
-unsafe extern "C" fn end_bobs_joining(mut context: *mut dc_context_t, mut status: libc::c_int) {
+unsafe fn end_bobs_joining(mut context: *mut dc_context_t, mut status: libc::c_int) {
     (*context).bobs_status = status;
     dc_stop_ongoing_process(context);
 }
-unsafe extern "C" fn secure_connection_established(
+unsafe fn secure_connection_established(
     mut context: *mut dc_context_t,
     mut contact_chat_id: uint32_t,
 ) {
@@ -933,7 +930,7 @@ unsafe extern "C" fn secure_connection_established(
     free(msg as *mut libc::c_void);
     dc_contact_unref(contact);
 }
-unsafe extern "C" fn lookup_field(
+unsafe fn lookup_field(
     mut mimeparser: *mut dc_mimeparser_t,
     mut key: *const libc::c_char,
 ) -> *const libc::c_char {
@@ -951,7 +948,7 @@ unsafe extern "C" fn lookup_field(
     }
     return value;
 }
-unsafe extern "C" fn could_not_establish_secure_connection(
+unsafe fn could_not_establish_secure_connection(
     mut context: *mut dc_context_t,
     mut contact_chat_id: uint32_t,
     mut details: *const libc::c_char,
@@ -978,7 +975,7 @@ unsafe extern "C" fn could_not_establish_secure_connection(
     free(msg as *mut libc::c_void);
     dc_contact_unref(contact);
 }
-unsafe extern "C" fn mark_peer_as_verified(
+unsafe fn mark_peer_as_verified(
     mut context: *mut dc_context_t,
     mut fingerprint: *const libc::c_char,
 ) -> libc::c_int {
@@ -998,7 +995,7 @@ unsafe extern "C" fn mark_peer_as_verified(
 /* ******************************************************************************
  * Tools: Misc.
  ******************************************************************************/
-unsafe extern "C" fn encrypted_and_signed(
+unsafe fn encrypted_and_signed(
     mut mimeparser: *mut dc_mimeparser_t,
     mut expected_fingerprint: *const libc::c_char,
 ) -> libc::c_int {
@@ -1044,8 +1041,7 @@ unsafe extern "C" fn encrypted_and_signed(
     }
     return 1i32;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_handle_degrade_event(
+pub unsafe fn dc_handle_degrade_event(
     mut context: *mut dc_context_t,
     mut peerstate: *mut dc_apeerstate_t,
 ) {
diff --git a/src/dc_simplify.rs b/src/dc_simplify.rs
index 52cea97f6..b935a49f3 100644
--- a/src/dc_simplify.rs
+++ b/src/dc_simplify.rs
@@ -14,8 +14,7 @@ pub struct dc_simplify_t {
     pub is_cut_at_end: libc::c_int,
 }
 
-#[no_mangle]
-pub unsafe extern "C" fn dc_simplify_new() -> *mut dc_simplify_t {
+pub unsafe fn dc_simplify_new() -> *mut dc_simplify_t {
     let mut simplify: *mut dc_simplify_t = 0 as *mut dc_simplify_t;
     simplify = calloc(
         1i32 as libc::c_ulong,
@@ -26,8 +25,7 @@ pub unsafe extern "C" fn dc_simplify_new() -> *mut dc_simplify_t {
     }
     return simplify;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_simplify_unref(mut simplify: *mut dc_simplify_t) {
+pub unsafe fn dc_simplify_unref(mut simplify: *mut dc_simplify_t) {
     if simplify.is_null() {
         return;
     }
@@ -36,8 +34,7 @@ pub unsafe extern "C" fn dc_simplify_unref(mut simplify: *mut dc_simplify_t) {
 /* Simplify and normalise text: Remove quotes, signatures, unnecessary
 lineends etc.
 The data returned from Simplify() must be free()'d when no longer used, private */
-#[no_mangle]
-pub unsafe extern "C" fn dc_simplify_simplify(
+pub unsafe fn dc_simplify_simplify(
     mut simplify: *mut dc_simplify_t,
     mut in_unterminated: *const libc::c_char,
     mut in_bytes: libc::c_int,
@@ -79,7 +76,7 @@ pub unsafe extern "C" fn dc_simplify_simplify(
 /* ******************************************************************************
  * Simplify Plain Text
  ******************************************************************************/
-unsafe extern "C" fn dc_simplify_simplify_plain_text(
+unsafe fn dc_simplify_simplify_plain_text(
     mut simplify: *mut dc_simplify_t,
     mut buf_terminated: *const libc::c_char,
     mut is_msgrmsg: libc::c_int,
@@ -281,7 +278,7 @@ unsafe extern "C" fn dc_simplify_simplify_plain_text(
 /* ******************************************************************************
  * Tools
  ******************************************************************************/
-unsafe extern "C" fn is_empty_line(mut buf: *const libc::c_char) -> libc::c_int {
+unsafe fn is_empty_line(mut buf: *const libc::c_char) -> libc::c_int {
     /* force unsigned - otherwise the `> ' '` comparison will fail */
     let mut p1: *const libc::c_uchar = buf as *const libc::c_uchar;
     while 0 != *p1 {
@@ -292,7 +289,7 @@ unsafe extern "C" fn is_empty_line(mut buf: *const libc::c_char) -> libc::c_int
     }
     return 1i32;
 }
-unsafe extern "C" fn is_quoted_headline(mut buf: *const libc::c_char) -> libc::c_int {
+unsafe fn is_quoted_headline(mut buf: *const libc::c_char) -> libc::c_int {
     /* This function may be called for the line _directly_ before a quote.
     The function checks if the line contains sth. like "On 01.02.2016, xy@z wrote:" in various languages.
     - Currently, we simply check if the last character is a ':'.
@@ -306,7 +303,7 @@ unsafe extern "C" fn is_quoted_headline(mut buf: *const libc::c_char) -> libc::c
     }
     return 0i32;
 }
-unsafe extern "C" fn is_plain_quote(mut buf: *const libc::c_char) -> libc::c_int {
+unsafe fn is_plain_quote(mut buf: *const libc::c_char) -> libc::c_int {
     if *buf.offset(0isize) as libc::c_int == '>' as i32 {
         return 1i32;
     }
diff --git a/src/dc_smtp.rs b/src/dc_smtp.rs
index 39b26036f..d21687ebe 100644
--- a/src/dc_smtp.rs
+++ b/src/dc_smtp.rs
@@ -22,8 +22,7 @@ pub struct dc_smtp_t {
     pub error_etpan: libc::c_int,
 }
 
-#[no_mangle]
-pub unsafe extern "C" fn dc_smtp_new(mut context: *mut dc_context_t) -> *mut dc_smtp_t {
+pub unsafe fn dc_smtp_new(mut context: *mut dc_context_t) -> *mut dc_smtp_t {
     let mut smtp: *mut dc_smtp_t = 0 as *mut dc_smtp_t;
     smtp = calloc(
         1i32 as libc::c_ulong,
@@ -36,8 +35,7 @@ pub unsafe extern "C" fn dc_smtp_new(mut context: *mut dc_context_t) -> *mut dc_
     (*smtp).context = context;
     return smtp;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_smtp_unref(mut smtp: *mut dc_smtp_t) {
+pub unsafe fn dc_smtp_unref(mut smtp: *mut dc_smtp_t) {
     if smtp.is_null() {
         return;
     }
@@ -46,8 +44,7 @@ pub unsafe extern "C" fn dc_smtp_unref(mut smtp: *mut dc_smtp_t) {
     free((*smtp).error as *mut libc::c_void);
     free(smtp as *mut libc::c_void);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_smtp_disconnect(mut smtp: *mut dc_smtp_t) {
+pub unsafe fn dc_smtp_disconnect(mut smtp: *mut dc_smtp_t) {
     if smtp.is_null() {
         return;
     }
@@ -56,16 +53,14 @@ pub unsafe extern "C" fn dc_smtp_disconnect(mut smtp: *mut dc_smtp_t) {
         (*smtp).etpan = 0 as *mut mailsmtp
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_smtp_is_connected(mut smtp: *const dc_smtp_t) -> libc::c_int {
+pub unsafe fn dc_smtp_is_connected(mut smtp: *const dc_smtp_t) -> libc::c_int {
     return if !smtp.is_null() && !(*smtp).etpan.is_null() {
         1i32
     } else {
         0i32
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_smtp_connect(
+pub unsafe fn dc_smtp_connect(
     mut smtp: *mut dc_smtp_t,
     mut lp: *const dc_loginparam_t,
 ) -> libc::c_int {
@@ -397,8 +392,7 @@ unsafe extern "C" fn body_progress(
     mut user_data: *mut libc::c_void,
 ) {
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_smtp_send_msg(
+pub unsafe fn dc_smtp_send_msg(
     mut smtp: *mut dc_smtp_t,
     mut recipients: *const clist,
     mut data_not_terminated: *const libc::c_char,
@@ -513,7 +507,7 @@ pub unsafe extern "C" fn dc_smtp_send_msg(
     }
     return success;
 }
-unsafe extern "C" fn log_error(
+unsafe fn log_error(
     mut smtp: *mut dc_smtp_t,
     mut what_failed: *const libc::c_char,
     mut r: libc::c_int,
diff --git a/src/dc_sqlite3.rs b/src/dc_sqlite3.rs
index ce788b642..4dd683118 100644
--- a/src/dc_sqlite3.rs
+++ b/src/dc_sqlite3.rs
@@ -23,8 +23,7 @@ pub struct dc_sqlite3_t {
     pub context: *mut dc_context_t,
 }
 
-#[no_mangle]
-pub unsafe extern "C" fn dc_sqlite3_new(mut context: *mut dc_context_t) -> *mut dc_sqlite3_t {
+pub unsafe fn dc_sqlite3_new(mut context: *mut dc_context_t) -> *mut dc_sqlite3_t {
     let mut sql: *mut dc_sqlite3_t = 0 as *mut dc_sqlite3_t;
     sql = calloc(
         1i32 as libc::c_ulong,
@@ -36,8 +35,7 @@ pub unsafe extern "C" fn dc_sqlite3_new(mut context: *mut dc_context_t) -> *mut
     (*sql).context = context;
     return sql;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_sqlite3_unref(mut sql: *mut dc_sqlite3_t) {
+pub unsafe fn dc_sqlite3_unref(mut sql: *mut dc_sqlite3_t) {
     if sql.is_null() {
         return;
     }
@@ -46,8 +44,7 @@ pub unsafe extern "C" fn dc_sqlite3_unref(mut sql: *mut dc_sqlite3_t) {
     }
     free(sql as *mut libc::c_void);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_sqlite3_close(mut sql: *mut dc_sqlite3_t) {
+pub unsafe fn dc_sqlite3_close(mut sql: *mut dc_sqlite3_t) {
     if sql.is_null() {
         return;
     }
@@ -61,8 +58,7 @@ pub unsafe extern "C" fn dc_sqlite3_close(mut sql: *mut dc_sqlite3_t) {
         b"Database closed.\x00" as *const u8 as *const libc::c_char,
     );
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_sqlite3_open(
+pub unsafe fn dc_sqlite3_open(
     mut sql: *mut dc_sqlite3_t,
     mut dbfile: *const libc::c_char,
     mut flags: libc::c_int,
@@ -842,8 +838,7 @@ pub unsafe extern "C" fn dc_sqlite3_open(
     return 0i32;
 }
 /* handle configurations, private */
-#[no_mangle]
-pub unsafe extern "C" fn dc_sqlite3_set_config(
+pub unsafe fn dc_sqlite3_set_config(
     mut sql: *mut dc_sqlite3_t,
     mut key: *const libc::c_char,
     mut value: *const libc::c_char,
@@ -925,8 +920,7 @@ pub unsafe extern "C" fn dc_sqlite3_set_config(
 }
 /* tools, these functions are compatible to the corresponding sqlite3_* functions */
 /* the result mus be freed using sqlite3_finalize() */
-#[no_mangle]
-pub unsafe extern "C" fn dc_sqlite3_prepare(
+pub unsafe fn dc_sqlite3_prepare(
     mut sql: *mut dc_sqlite3_t,
     mut querystr: *const libc::c_char,
 ) -> *mut sqlite3_stmt {
@@ -951,7 +945,6 @@ pub unsafe extern "C" fn dc_sqlite3_prepare(
     }
     return stmt;
 }
-#[no_mangle]
 pub unsafe extern "C" fn dc_sqlite3_log_error(
     mut sql: *mut dc_sqlite3_t,
     mut msg_format: *const libc::c_char,
@@ -980,16 +973,14 @@ pub unsafe extern "C" fn dc_sqlite3_log_error(
     );
     sqlite3_free(msg as *mut libc::c_void);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_sqlite3_is_open(mut sql: *const dc_sqlite3_t) -> libc::c_int {
+pub unsafe fn dc_sqlite3_is_open(mut sql: *const dc_sqlite3_t) -> libc::c_int {
     if sql.is_null() || (*sql).cobj.is_null() {
         return 0i32;
     }
     return 1i32;
 }
 /* the returned string must be free()'d, returns NULL on errors */
-#[no_mangle]
-pub unsafe extern "C" fn dc_sqlite3_get_config(
+pub unsafe fn dc_sqlite3_get_config(
     mut sql: *mut dc_sqlite3_t,
     mut key: *const libc::c_char,
     mut def: *const libc::c_char,
@@ -1014,8 +1005,7 @@ pub unsafe extern "C" fn dc_sqlite3_get_config(
     sqlite3_finalize(stmt);
     return dc_strdup_keep_null(def);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_sqlite3_execute(
+pub unsafe fn dc_sqlite3_execute(
     mut sql: *mut dc_sqlite3_t,
     mut querystr: *const libc::c_char,
 ) -> libc::c_int {
@@ -1038,8 +1028,7 @@ pub unsafe extern "C" fn dc_sqlite3_execute(
     sqlite3_finalize(stmt);
     return success;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_sqlite3_set_config_int(
+pub unsafe fn dc_sqlite3_set_config_int(
     mut sql: *mut dc_sqlite3_t,
     mut key: *const libc::c_char,
     mut value: int32_t,
@@ -1055,8 +1044,7 @@ pub unsafe extern "C" fn dc_sqlite3_set_config_int(
     free(value_str as *mut libc::c_void);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_sqlite3_get_config_int(
+pub unsafe fn dc_sqlite3_get_config_int(
     mut sql: *mut dc_sqlite3_t,
     mut key: *const libc::c_char,
     mut def: int32_t,
@@ -1069,8 +1057,7 @@ pub unsafe extern "C" fn dc_sqlite3_get_config_int(
     free(str as *mut libc::c_void);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_sqlite3_table_exists(
+pub unsafe fn dc_sqlite3_table_exists(
     mut sql: *mut dc_sqlite3_t,
     mut name: *const libc::c_char,
 ) -> libc::c_int {
@@ -1107,8 +1094,7 @@ pub unsafe extern "C" fn dc_sqlite3_table_exists(
     }
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_sqlite3_set_config_int64(
+pub unsafe fn dc_sqlite3_set_config_int64(
     mut sql: *mut dc_sqlite3_t,
     mut key: *const libc::c_char,
     mut value: int64_t,
@@ -1124,8 +1110,7 @@ pub unsafe extern "C" fn dc_sqlite3_set_config_int64(
     free(value_str as *mut libc::c_void);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_sqlite3_get_config_int64(
+pub unsafe fn dc_sqlite3_get_config_int64(
     mut sql: *mut dc_sqlite3_t,
     mut key: *const libc::c_char,
     mut def: int64_t,
@@ -1143,8 +1128,7 @@ pub unsafe extern "C" fn dc_sqlite3_get_config_int64(
     free(str as *mut libc::c_void);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_sqlite3_try_execute(
+pub unsafe fn dc_sqlite3_try_execute(
     mut sql: *mut dc_sqlite3_t,
     mut querystr: *const libc::c_char,
 ) -> libc::c_int {
@@ -1170,8 +1154,7 @@ pub unsafe extern "C" fn dc_sqlite3_try_execute(
     sqlite3_finalize(stmt);
     return success;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_sqlite3_get_rowid(
+pub unsafe fn dc_sqlite3_get_rowid(
     mut sql: *mut dc_sqlite3_t,
     mut table: *const libc::c_char,
     mut field: *const libc::c_char,
@@ -1195,8 +1178,7 @@ pub unsafe extern "C" fn dc_sqlite3_get_rowid(
     sqlite3_free(q3 as *mut libc::c_void);
     return id;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_sqlite3_get_rowid2(
+pub unsafe fn dc_sqlite3_get_rowid2(
     mut sql: *mut dc_sqlite3_t,
     mut table: *const libc::c_char,
     mut field: *const libc::c_char,
@@ -1224,15 +1206,11 @@ pub unsafe extern "C" fn dc_sqlite3_get_rowid2(
     sqlite3_free(q3 as *mut libc::c_void);
     return id;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_sqlite3_begin_transaction(mut sql: *mut dc_sqlite3_t) {}
-#[no_mangle]
-pub unsafe extern "C" fn dc_sqlite3_commit(mut sql: *mut dc_sqlite3_t) {}
-#[no_mangle]
-pub unsafe extern "C" fn dc_sqlite3_rollback(mut sql: *mut dc_sqlite3_t) {}
+pub unsafe fn dc_sqlite3_begin_transaction(mut sql: *mut dc_sqlite3_t) {}
+pub unsafe fn dc_sqlite3_commit(mut sql: *mut dc_sqlite3_t) {}
+pub unsafe fn dc_sqlite3_rollback(mut sql: *mut dc_sqlite3_t) {}
 /* housekeeping */
-#[no_mangle]
-pub unsafe extern "C" fn dc_housekeeping(mut context: *mut dc_context_t) {
+pub unsafe fn dc_housekeeping(mut context: *mut dc_context_t) {
     let mut keep_files_newer_than: time_t = 0;
     let mut stmt: *mut sqlite3_stmt = 0 as *mut sqlite3_stmt;
     let mut dir_handle: *mut DIR = 0 as *mut DIR;
@@ -1418,7 +1396,7 @@ pub unsafe extern "C" fn dc_housekeeping(mut context: *mut dc_context_t) {
         b"Housekeeping done.\x00" as *const u8 as *const libc::c_char,
     );
 }
-unsafe extern "C" fn is_file_in_use(
+unsafe fn is_file_in_use(
     mut files_in_use: *mut dc_hash_t,
     mut namespc: *const libc::c_char,
     mut name: *const libc::c_char,
@@ -1445,10 +1423,7 @@ unsafe extern "C" fn is_file_in_use(
 /* ******************************************************************************
  * Housekeeping
  ******************************************************************************/
-unsafe extern "C" fn maybe_add_file(
-    mut files_in_use: *mut dc_hash_t,
-    mut file: *const libc::c_char,
-) {
+unsafe fn maybe_add_file(mut files_in_use: *mut dc_hash_t, mut file: *const libc::c_char) {
     if strncmp(
         file,
         b"$BLOBDIR/\x00" as *const u8 as *const libc::c_char,
@@ -1465,7 +1440,7 @@ unsafe extern "C" fn maybe_add_file(
         1i32 as *mut libc::c_void,
     );
 }
-unsafe extern "C" fn maybe_add_from_param(
+unsafe fn maybe_add_from_param(
     mut context: *mut dc_context_t,
     mut files_in_use: *mut dc_hash_t,
     mut query: *const libc::c_char,
diff --git a/src/dc_stock.rs b/src/dc_stock.rs
index b7ed5c3f7..2767c9649 100644
--- a/src/dc_stock.rs
+++ b/src/dc_stock.rs
@@ -10,14 +10,13 @@ use crate::x::*;
 
 /* Return the string with the given ID by calling DC_EVENT_GET_STRING.
 The result must be free()'d! */
-#[no_mangle]
-pub unsafe extern "C" fn dc_stock_str(
+pub unsafe fn dc_stock_str(
     mut context: *mut dc_context_t,
     mut id: libc::c_int,
 ) -> *mut libc::c_char {
     return get_string(context, id, 0i32);
 }
-unsafe extern "C" fn get_string(
+unsafe fn get_string(
     mut context: *mut dc_context_t,
     mut id: libc::c_int,
     mut qty: libc::c_int,
@@ -39,7 +38,7 @@ unsafe extern "C" fn get_string(
 /* Add translated strings that are used by the messager backend.
 As the logging functions may use these strings, do not log any
 errors from here. */
-unsafe extern "C" fn default_string(mut id: libc::c_int) -> *mut libc::c_char {
+unsafe fn default_string(mut id: libc::c_int) -> *mut libc::c_char {
     match id {
         1 => {
             return dc_strdup(b"No messages.\x00" as *const u8 as
@@ -216,8 +215,7 @@ unsafe extern "C" fn default_string(mut id: libc::c_int) -> *mut libc::c_char {
 }
 /* Replaces the first `%1$s` in the given String-ID by the given value.
 The result must be free()'d! */
-#[no_mangle]
-pub unsafe extern "C" fn dc_stock_str_repl_string(
+pub unsafe fn dc_stock_str_repl_string(
     mut context: *mut dc_context_t,
     mut id: libc::c_int,
     mut to_insert: *const libc::c_char,
@@ -235,8 +233,7 @@ pub unsafe extern "C" fn dc_stock_str_repl_string(
     );
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_stock_str_repl_int(
+pub unsafe fn dc_stock_str_repl_int(
     mut context: *mut dc_context_t,
     mut id: libc::c_int,
     mut to_insert_int: libc::c_int,
@@ -261,8 +258,7 @@ pub unsafe extern "C" fn dc_stock_str_repl_int(
 }
 /* Replaces the first `%1$s` and `%2$s` in the given String-ID by the two given strings.
 The result must be free()'d! */
-#[no_mangle]
-pub unsafe extern "C" fn dc_stock_str_repl_string2(
+pub unsafe fn dc_stock_str_repl_string2(
     mut context: *mut dc_context_t,
     mut id: libc::c_int,
     mut to_insert: *const libc::c_char,
@@ -292,8 +288,7 @@ pub unsafe extern "C" fn dc_stock_str_repl_string2(
     return ret;
 }
 /* Misc. */
-#[no_mangle]
-pub unsafe extern "C" fn dc_stock_system_msg(
+pub unsafe fn dc_stock_system_msg(
     mut context: *mut dc_context_t,
     mut str_id: libc::c_int,
     mut param1: *const libc::c_char,
diff --git a/src/dc_strbuilder.rs b/src/dc_strbuilder.rs
index 1ad2e7a62..837789a16 100644
--- a/src/dc_strbuilder.rs
+++ b/src/dc_strbuilder.rs
@@ -12,8 +12,7 @@ pub struct dc_strbuilder_t {
     pub eos: *mut libc::c_char,
 }
 
-#[no_mangle]
-pub unsafe extern "C" fn dc_strbuilder_init(
+pub unsafe fn dc_strbuilder_init(
     mut strbuilder: *mut dc_strbuilder_t,
     mut init_bytes: libc::c_int,
 ) {
@@ -33,7 +32,7 @@ pub unsafe extern "C" fn dc_strbuilder_init(
     (*strbuilder).free = (*strbuilder).allocated - 1i32;
     (*strbuilder).eos = (*strbuilder).buf;
 }
-pub unsafe extern "C" fn dc_strbuilder_cat(
+pub unsafe fn dc_strbuilder_cat(
     mut strbuilder: *mut dc_strbuilder_t,
     mut text: *const libc::c_char,
 ) -> *mut libc::c_char {
@@ -66,8 +65,7 @@ pub unsafe extern "C" fn dc_strbuilder_cat(
     (*strbuilder).free -= len;
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_strbuilder_empty(mut strbuilder: *mut dc_strbuilder_t) {
+pub unsafe fn dc_strbuilder_empty(mut strbuilder: *mut dc_strbuilder_t) {
     *(*strbuilder).buf.offset(0isize) = 0i32 as libc::c_char;
     (*strbuilder).free = (*strbuilder).allocated - 1i32;
     (*strbuilder).eos = (*strbuilder).buf;
diff --git a/src/dc_strencode.rs b/src/dc_strencode.rs
index 2eef05a2c..0f25ff490 100644
--- a/src/dc_strencode.rs
+++ b/src/dc_strencode.rs
@@ -5,15 +5,12 @@ use crate::types::*;
 use crate::x::*;
 
 #[inline]
-unsafe extern "C" fn isascii(mut _c: libc::c_int) -> libc::c_int {
+unsafe fn isascii(mut _c: libc::c_int) -> libc::c_int {
     return (_c & !0x7fi32 == 0i32) as libc::c_int;
 }
 
 #[inline]
-unsafe extern "C" fn __isctype(
-    mut _c: __darwin_ct_rune_t,
-    mut _f: libc::c_ulong,
-) -> __darwin_ct_rune_t {
+unsafe fn __isctype(mut _c: __darwin_ct_rune_t, mut _f: libc::c_ulong) -> __darwin_ct_rune_t {
     return if _c < 0i32 || _c >= 1i32 << 8i32 {
         0i32
     } else {
@@ -21,7 +18,6 @@ unsafe extern "C" fn __isctype(
     };
 }
 
-#[no_mangle]
 #[inline]
 pub fn isalnum(mut _c: libc::c_int) -> libc::c_int {
     if _c < std::u8::MAX as libc::c_int {
@@ -39,7 +35,6 @@ fn test_isalnum() {
     assert_eq!(isalnum('Q' as libc::c_int), 1);
 }
 
-#[no_mangle]
 #[inline]
 pub fn isdigit(mut _c: libc::c_int) -> libc::c_int {
     if _c < std::u8::MAX as libc::c_int {
@@ -49,7 +44,6 @@ pub fn isdigit(mut _c: libc::c_int) -> libc::c_int {
     }
 }
 
-#[no_mangle]
 pub unsafe extern "C" fn dc_urlencode(mut to_encode: *const libc::c_char) -> *mut libc::c_char {
     let mut pstr: *const libc::c_char = to_encode;
     if to_encode.is_null() {
@@ -97,14 +91,13 @@ pub unsafe extern "C" fn dc_urlencode(mut to_encode: *const libc::c_char) -> *mu
 /* ******************************************************************************
  * URL encoding and decoding, RFC 3986
  ******************************************************************************/
-unsafe extern "C" fn int_2_uppercase_hex(mut code: libc::c_char) -> libc::c_char {
+unsafe fn int_2_uppercase_hex(mut code: libc::c_char) -> libc::c_char {
     static mut hex: [libc::c_char; 17] = [
         48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 65, 66, 67, 68, 69, 70, 0,
     ];
     return hex[(code as libc::c_int & 15i32) as usize];
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_urldecode(mut to_decode: *const libc::c_char) -> *mut libc::c_char {
+pub unsafe fn dc_urldecode(mut to_decode: *const libc::c_char) -> *mut libc::c_char {
     let mut pstr: *const libc::c_char = to_decode;
     if to_decode.is_null() {
         return dc_strdup(b"\x00" as *const u8 as *const libc::c_char);
@@ -140,17 +133,14 @@ pub unsafe extern "C" fn dc_urldecode(mut to_decode: *const libc::c_char) -> *mu
     *pbuf = '\u{0}' as i32 as libc::c_char;
     return buf;
 }
-unsafe extern "C" fn hex_2_int(mut ch: libc::c_char) -> libc::c_char {
+unsafe fn hex_2_int(mut ch: libc::c_char) -> libc::c_char {
     return (if 0 != isdigit(ch as libc::c_int) {
         ch as libc::c_int - '0' as i32
     } else {
         tolower(ch as libc::c_int) - 'a' as i32 + 10i32
     }) as libc::c_char;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_encode_header_words(
-    mut to_encode: *const libc::c_char,
-) -> *mut libc::c_char {
+pub unsafe fn dc_encode_header_words(mut to_encode: *const libc::c_char) -> *mut libc::c_char {
     let mut current_block: u64;
     let mut ret_str: *mut libc::c_char = 0 as *mut libc::c_char;
     let mut cur: *const libc::c_char = to_encode;
@@ -247,7 +237,7 @@ pub unsafe extern "C" fn dc_encode_header_words(
     }
     return ret_str;
 }
-unsafe extern "C" fn quote_word(
+unsafe fn quote_word(
     mut display_charset: *const libc::c_char,
     mut mmapstr: *mut MMAPString,
     mut word: *const libc::c_char,
@@ -310,7 +300,7 @@ unsafe extern "C" fn quote_word(
     }
     return 1i32;
 }
-unsafe extern "C" fn get_word(
+unsafe fn get_word(
     mut begin: *const libc::c_char,
     mut pend: *mut *const libc::c_char,
     mut pto_be_quoted: *mut libc::c_int,
@@ -332,7 +322,7 @@ unsafe extern "C" fn get_word(
  * Encode/decode header words, RFC 2047
  ******************************************************************************/
 /* see comment below */
-unsafe extern "C" fn to_be_quoted(mut word: *const libc::c_char, mut size: size_t) -> libc::c_int {
+unsafe fn to_be_quoted(mut word: *const libc::c_char, mut size: size_t) -> libc::c_int {
     let mut cur: *const libc::c_char = word;
     let mut i: size_t = 0i32 as size_t;
     i = 0i32 as size_t;
@@ -351,10 +341,7 @@ unsafe extern "C" fn to_be_quoted(mut word: *const libc::c_char, mut size: size_
     }
     return 0i32;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_decode_header_words(
-    mut in_0: *const libc::c_char,
-) -> *mut libc::c_char {
+pub unsafe fn dc_decode_header_words(mut in_0: *const libc::c_char) -> *mut libc::c_char {
     if in_0.is_null() {
         return 0 as *mut libc::c_char;
     }
@@ -373,8 +360,7 @@ pub unsafe extern "C" fn dc_decode_header_words(
     }
     return out;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_encode_modified_utf7(
+pub unsafe fn dc_encode_modified_utf7(
     mut to_encode: *const libc::c_char,
     mut change_spaces: libc::c_int,
 ) -> *mut libc::c_char {
@@ -527,8 +513,7 @@ static mut base64chars: [libc::c_char; 65] = [
     89, 90, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114,
     115, 116, 117, 118, 119, 120, 121, 122, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 43, 44, 0,
 ];
-#[no_mangle]
-pub unsafe extern "C" fn dc_decode_modified_utf7(
+pub unsafe fn dc_decode_modified_utf7(
     mut to_decode: *const libc::c_char,
     mut change_spaces: libc::c_int,
 ) -> *mut libc::c_char {
@@ -658,8 +643,7 @@ pub unsafe extern "C" fn dc_decode_modified_utf7(
     *dst = '\u{0}' as i32 as libc::c_char;
     return res;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_needs_ext_header(mut to_check: *const libc::c_char) -> libc::c_int {
+pub unsafe fn dc_needs_ext_header(mut to_check: *const libc::c_char) -> libc::c_int {
     if !to_check.is_null() {
         while 0 != *to_check {
             if 0 == isalnum(*to_check as libc::c_int)
@@ -675,10 +659,7 @@ pub unsafe extern "C" fn dc_needs_ext_header(mut to_check: *const libc::c_char)
     }
     return 0i32;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_encode_ext_header(
-    mut to_encode: *const libc::c_char,
-) -> *mut libc::c_char {
+pub unsafe fn dc_encode_ext_header(mut to_encode: *const libc::c_char) -> *mut libc::c_char {
     let mut pstr: *const libc::c_char = to_encode;
     if to_encode.is_null() {
         return dc_strdup(b"utf-8\'\'\x00" as *const u8 as *const libc::c_char);
@@ -720,10 +701,7 @@ pub unsafe extern "C" fn dc_encode_ext_header(
     *pbuf = '\u{0}' as i32 as libc::c_char;
     return buf;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_decode_ext_header(
-    mut to_decode: *const libc::c_char,
-) -> *mut libc::c_char {
+pub unsafe fn dc_decode_ext_header(mut to_decode: *const libc::c_char) -> *mut libc::c_char {
     let mut decoded: *mut libc::c_char = 0 as *mut libc::c_char;
     let mut charset: *mut libc::c_char = 0 as *mut libc::c_char;
     let mut p2: *const libc::c_char = 0 as *const libc::c_char;
diff --git a/src/dc_token.rs b/src/dc_token.rs
index 0790e3186..1ff0a0578 100644
--- a/src/dc_token.rs
+++ b/src/dc_token.rs
@@ -14,8 +14,7 @@ pub type dc_tokennamespc_t = libc::c_uint;
 pub const DC_TOKEN_AUTH: dc_tokennamespc_t = 110;
 pub const DC_TOKEN_INVITENUMBER: dc_tokennamespc_t = 100;
 // Functions to read/write token from/to the database. A token is any string associated with a key.
-#[no_mangle]
-pub unsafe extern "C" fn dc_token_save(
+pub unsafe fn dc_token_save(
     mut context: *mut dc_context_t,
     mut namespc: dc_tokennamespc_t,
     mut foreign_id: uint32_t,
@@ -38,8 +37,7 @@ pub unsafe extern "C" fn dc_token_save(
     }
     sqlite3_finalize(stmt);
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_token_lookup(
+pub unsafe fn dc_token_lookup(
     mut context: *mut dc_context_t,
     mut namespc: dc_tokennamespc_t,
     mut foreign_id: uint32_t,
@@ -60,8 +58,7 @@ pub unsafe extern "C" fn dc_token_lookup(
     sqlite3_finalize(stmt);
     return token;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_token_exists(
+pub unsafe fn dc_token_exists(
     mut context: *mut dc_context_t,
     mut namespc: dc_tokennamespc_t,
     mut token: *const libc::c_char,
diff --git a/src/dc_tools.rs b/src/dc_tools.rs
index 0fb52fb69..1954a7281 100644
--- a/src/dc_tools.rs
+++ b/src/dc_tools.rs
@@ -14,13 +14,12 @@ no references to dc_context_t and other "larger" classes here. */
 // for carray etc.
 /* ** library-private **********************************************************/
 /* math tools */
-#[no_mangle]
-pub unsafe extern "C" fn dc_exactly_one_bit_set(mut v: libc::c_int) -> libc::c_int {
+pub unsafe fn dc_exactly_one_bit_set(mut v: libc::c_int) -> libc::c_int {
     return (0 != v && 0 == v & v - 1i32) as libc::c_int;
 }
 /* string tools */
 /* dc_strdup() returns empty string if NULL is given, never returns NULL (exits on errors) */
-pub unsafe extern "C" fn dc_strdup(mut s: *const libc::c_char) -> *mut libc::c_char {
+pub unsafe fn dc_strdup(mut s: *const libc::c_char) -> *mut libc::c_char {
     let mut ret: *mut libc::c_char = 0 as *mut libc::c_char;
     if !s.is_null() {
         ret = strdup(s);
@@ -36,20 +35,17 @@ pub unsafe extern "C" fn dc_strdup(mut s: *const libc::c_char) -> *mut libc::c_c
     return ret;
 }
 /* strdup(NULL) is undefined, safe_strdup_keep_null(NULL) returns NULL in this case */
-#[no_mangle]
-pub unsafe extern "C" fn dc_strdup_keep_null(mut s: *const libc::c_char) -> *mut libc::c_char {
+pub unsafe fn dc_strdup_keep_null(mut s: *const libc::c_char) -> *mut libc::c_char {
     return if !s.is_null() {
         dc_strdup(s)
     } else {
         0 as *mut libc::c_char
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_atoi_null_is_0(mut s: *const libc::c_char) -> libc::c_int {
+pub unsafe fn dc_atoi_null_is_0(mut s: *const libc::c_char) -> libc::c_int {
     return if !s.is_null() { atoi(s) } else { 0i32 };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_atof(mut str: *const libc::c_char) -> libc::c_double {
+pub unsafe fn dc_atof(mut str: *const libc::c_char) -> libc::c_double {
     // hack around atof() that may accept only `,` as decimal point on mac
     let mut test: *mut libc::c_char =
         dc_mprintf(b"%f\x00" as *const u8 as *const libc::c_char, 1.2f64);
@@ -65,8 +61,7 @@ pub unsafe extern "C" fn dc_atof(mut str: *const libc::c_char) -> libc::c_double
     free(str_locale as *mut libc::c_void);
     return f;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_str_replace(
+pub unsafe fn dc_str_replace(
     mut haystack: *mut *mut libc::c_char,
     mut needle: *const libc::c_char,
     mut replacement: *const libc::c_char,
@@ -114,8 +109,7 @@ pub unsafe extern "C" fn dc_str_replace(
     }
     return replacements;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_ftoa(mut f: libc::c_double) -> *mut libc::c_char {
+pub unsafe fn dc_ftoa(mut f: libc::c_double) -> *mut libc::c_char {
     // hack around printf(%f) that may return `,` as decimal point on mac
     let mut test: *mut libc::c_char =
         dc_mprintf(b"%f\x00" as *const u8 as *const libc::c_char, 1.2f64);
@@ -129,8 +123,7 @@ pub unsafe extern "C" fn dc_ftoa(mut f: libc::c_double) -> *mut libc::c_char {
     free(test as *mut libc::c_void);
     return str;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_ltrim(mut buf: *mut libc::c_char) {
+pub unsafe fn dc_ltrim(mut buf: *mut libc::c_char) {
     let mut len: size_t = 0i32 as size_t;
     let mut cur: *const libc::c_uchar = 0 as *const libc::c_uchar;
     if !buf.is_null() && 0 != *buf as libc::c_int {
@@ -149,8 +142,7 @@ pub unsafe extern "C" fn dc_ltrim(mut buf: *mut libc::c_char) {
         }
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_rtrim(mut buf: *mut libc::c_char) {
+pub unsafe fn dc_rtrim(mut buf: *mut libc::c_char) {
     let mut len: size_t = 0i32 as size_t;
     let mut cur: *mut libc::c_uchar = 0 as *mut libc::c_uchar;
     if !buf.is_null() && 0 != *buf as libc::c_int {
@@ -171,14 +163,12 @@ pub unsafe extern "C" fn dc_rtrim(mut buf: *mut libc::c_char) {
         ) = '\u{0}' as i32 as libc::c_uchar
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_trim(mut buf: *mut libc::c_char) {
+pub unsafe fn dc_trim(mut buf: *mut libc::c_char) {
     dc_ltrim(buf);
     dc_rtrim(buf);
 }
 /* the result must be free()'d */
-#[no_mangle]
-pub unsafe extern "C" fn dc_strlower(mut in_0: *const libc::c_char) -> *mut libc::c_char {
+pub unsafe fn dc_strlower(mut in_0: *const libc::c_char) -> *mut libc::c_char {
     let mut out: *mut libc::c_char = dc_strdup(in_0);
     let mut p: *mut libc::c_char = out;
     while 0 != *p {
@@ -187,16 +177,14 @@ pub unsafe extern "C" fn dc_strlower(mut in_0: *const libc::c_char) -> *mut libc
     }
     return out;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_strlower_in_place(mut in_0: *mut libc::c_char) {
+pub unsafe fn dc_strlower_in_place(mut in_0: *mut libc::c_char) {
     let mut p: *mut libc::c_char = in_0;
     while 0 != *p {
         *p = tolower(*p as libc::c_int) as libc::c_char;
         p = p.offset(1isize)
     }
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_str_contains(
+pub unsafe fn dc_str_contains(
     mut haystack: *const libc::c_char,
     mut needle: *const libc::c_char,
 ) -> libc::c_int {
@@ -218,8 +206,7 @@ pub unsafe extern "C" fn dc_str_contains(
     return ret;
 }
 /* the result must be free()'d */
-#[no_mangle]
-pub unsafe extern "C" fn dc_null_terminate(
+pub unsafe fn dc_null_terminate(
     mut in_0: *const libc::c_char,
     mut bytes: libc::c_int,
 ) -> *mut libc::c_char {
@@ -233,11 +220,7 @@ pub unsafe extern "C" fn dc_null_terminate(
     *out.offset(bytes as isize) = 0i32 as libc::c_char;
     return out;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_binary_to_uc_hex(
-    mut buf: *const uint8_t,
-    mut bytes: size_t,
-) -> *mut libc::c_char {
+pub unsafe fn dc_binary_to_uc_hex(mut buf: *const uint8_t, mut bytes: size_t) -> *mut libc::c_char {
     let mut hex: *mut libc::c_char = 0 as *mut libc::c_char;
     let mut i: libc::c_int = 0i32;
     if !(buf.is_null() || bytes <= 0i32 as libc::c_ulong) {
@@ -263,7 +246,6 @@ pub unsafe extern "C" fn dc_binary_to_uc_hex(
     return hex;
 }
 /* remove all \r characters from string */
-#[no_mangle]
 pub unsafe extern "C" fn dc_remove_cr_chars(mut buf: *mut libc::c_char) {
     /* search for first `\r` */
     let mut p1: *const libc::c_char = buf;
@@ -284,13 +266,11 @@ pub unsafe extern "C" fn dc_remove_cr_chars(mut buf: *mut libc::c_char) {
     }
     *p2 = 0i32 as libc::c_char;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_unify_lineends(mut buf: *mut libc::c_char) {
+pub unsafe fn dc_unify_lineends(mut buf: *mut libc::c_char) {
     dc_remove_cr_chars(buf);
 }
 /* replace bad UTF-8 characters by sequences of `_` (to avoid problems in filenames, we do not use eg. `?`) the function is useful if strings are unexpectingly encoded eg. as ISO-8859-1 */
-#[no_mangle]
-pub unsafe extern "C" fn dc_replace_bad_utf8_chars(mut buf: *mut libc::c_char) {
+pub unsafe fn dc_replace_bad_utf8_chars(mut buf: *mut libc::c_char) {
     let mut current_block: u64;
     if buf.is_null() {
         return;
@@ -357,8 +337,7 @@ pub unsafe extern "C" fn dc_replace_bad_utf8_chars(mut buf: *mut libc::c_char) {
         }
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_utf8_strlen(mut s: *const libc::c_char) -> size_t {
+pub unsafe fn dc_utf8_strlen(mut s: *const libc::c_char) -> size_t {
     if s.is_null() {
         return 0i32 as size_t;
     }
@@ -372,11 +351,7 @@ pub unsafe extern "C" fn dc_utf8_strlen(mut s: *const libc::c_char) -> size_t {
     }
     return j;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_truncate_str(
-    mut buf: *mut libc::c_char,
-    mut approx_chars: libc::c_int,
-) {
+pub unsafe fn dc_truncate_str(mut buf: *mut libc::c_char, mut approx_chars: libc::c_int) {
     if approx_chars > 0i32
         && strlen(buf)
             > (approx_chars as libc::c_ulong)
@@ -395,8 +370,7 @@ pub unsafe extern "C" fn dc_truncate_str(
         strcat(p, b"[...]\x00" as *const u8 as *const libc::c_char);
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_truncate_n_unwrap_str(
+pub unsafe fn dc_truncate_n_unwrap_str(
     mut buf: *mut libc::c_char,
     mut approx_characters: libc::c_int,
     mut do_unwrap: libc::c_int,
@@ -439,7 +413,7 @@ pub unsafe extern "C" fn dc_truncate_n_unwrap_str(
         dc_remove_cr_chars(buf);
     };
 }
-unsafe extern "C" fn dc_utf8_strnlen(mut s: *const libc::c_char, mut n: size_t) -> size_t {
+unsafe fn dc_utf8_strnlen(mut s: *const libc::c_char, mut n: size_t) -> size_t {
     if s.is_null() {
         return 0i32 as size_t;
     }
@@ -454,10 +428,7 @@ unsafe extern "C" fn dc_utf8_strnlen(mut s: *const libc::c_char, mut n: size_t)
     return j;
 }
 /* split string into lines*/
-#[no_mangle]
-pub unsafe extern "C" fn dc_split_into_lines(
-    mut buf_terminated: *const libc::c_char,
-) -> *mut carray {
+pub unsafe fn dc_split_into_lines(mut buf_terminated: *const libc::c_char) -> *mut carray {
     let mut lines: *mut carray = carray_new(1024i32 as libc::c_uint);
     let mut line_chars: size_t = 0i32 as size_t;
     let mut p1: *const libc::c_char = buf_terminated;
@@ -485,8 +456,7 @@ pub unsafe extern "C" fn dc_split_into_lines(
     );
     return lines;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_free_splitted_lines(mut lines: *mut carray) {
+pub unsafe fn dc_free_splitted_lines(mut lines: *mut carray) {
     if !lines.is_null() {
         let mut i: libc::c_int = 0;
         let mut cnt: libc::c_int = carray_count(lines) as libc::c_int;
@@ -499,8 +469,7 @@ pub unsafe extern "C" fn dc_free_splitted_lines(mut lines: *mut carray) {
     };
 }
 /* insert a break every n characters, the return must be free()'d */
-#[no_mangle]
-pub unsafe extern "C" fn dc_insert_breaks(
+pub unsafe fn dc_insert_breaks(
     mut in_0: *const libc::c_char,
     mut break_every: libc::c_int,
     mut break_chars: *const libc::c_char,
@@ -534,8 +503,7 @@ pub unsafe extern "C" fn dc_insert_breaks(
     *o = 0i32 as libc::c_char;
     return out;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_str_from_clist(
+pub unsafe fn dc_str_from_clist(
     mut list: *const clist,
     mut delimiter: *const libc::c_char,
 ) -> *mut libc::c_char {
@@ -569,8 +537,7 @@ pub unsafe extern "C" fn dc_str_from_clist(
     }
     return str.buf;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_str_to_clist(
+pub unsafe fn dc_str_to_clist(
     mut str: *const libc::c_char,
     mut delimiter: *const libc::c_char,
 ) -> *mut clist {
@@ -600,8 +567,7 @@ pub unsafe extern "C" fn dc_str_to_clist(
     }
     return list;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_str_to_color(mut str: *const libc::c_char) -> libc::c_int {
+pub unsafe fn dc_str_to_color(mut str: *const libc::c_char) -> libc::c_int {
     let mut str_lower: *mut libc::c_char = dc_strlower(str);
     /* the colors must fulfill some criterions as:
     - contrast to black and to white
@@ -644,8 +610,7 @@ pub unsafe extern "C" fn dc_str_to_color(mut str: *const libc::c_char) -> libc::
 }
 /* clist tools */
 /* calls free() for each item content */
-#[no_mangle]
-pub unsafe extern "C" fn clist_free_content(mut haystack: *const clist) {
+pub unsafe fn clist_free_content(mut haystack: *const clist) {
     let mut iter: *mut clistiter = (*haystack).first;
     while !iter.is_null() {
         free((*iter).data);
@@ -657,8 +622,7 @@ pub unsafe extern "C" fn clist_free_content(mut haystack: *const clist) {
         }
     }
 }
-#[no_mangle]
-pub unsafe extern "C" fn clist_search_string_nocase(
+pub unsafe fn clist_search_string_nocase(
     mut haystack: *const clist,
     mut needle: *const libc::c_char,
 ) -> libc::c_int {
@@ -677,8 +641,7 @@ pub unsafe extern "C" fn clist_search_string_nocase(
 }
 /* date/time tools */
 /* the result is UTC or DC_INVALID_TIMESTAMP */
-#[no_mangle]
-pub unsafe extern "C" fn dc_timestamp_from_date(mut date_time: *mut mailimf_date_time) -> time_t {
+pub unsafe fn dc_timestamp_from_date(mut date_time: *mut mailimf_date_time) -> time_t {
     let mut tmval: tm = tm {
         tm_sec: 0,
         tm_min: 0,
@@ -721,8 +684,7 @@ pub unsafe extern "C" fn dc_timestamp_from_date(mut date_time: *mut mailimf_date
     timeval -= (zone_hour * 3600i32 + zone_min * 60i32) as libc::c_long;
     return timeval;
 }
-#[no_mangle]
-pub unsafe extern "C" fn mkgmtime(mut tmp: *mut tm) -> time_t {
+pub unsafe fn mkgmtime(mut tmp: *mut tm) -> time_t {
     let mut dir: libc::c_int = 0i32;
     let mut bits: libc::c_int = 0i32;
     let mut saved_seconds: libc::c_int = 0i32;
@@ -795,7 +757,7 @@ pub unsafe extern "C" fn mkgmtime(mut tmp: *mut tm) -> time_t {
 /* ******************************************************************************
  * date/time tools
  ******************************************************************************/
-unsafe extern "C" fn tmcomp(mut atmp: *mut tm, mut btmp: *mut tm) -> libc::c_int {
+unsafe fn tmcomp(mut atmp: *mut tm, mut btmp: *mut tm) -> libc::c_int {
     let mut result: libc::c_int = 0i32;
     result = (*atmp).tm_year - (*btmp).tm_year;
     if result == 0i32
@@ -821,8 +783,7 @@ unsafe extern "C" fn tmcomp(mut atmp: *mut tm, mut btmp: *mut tm) -> libc::c_int
     return result;
 }
 /* the return value must be free()'d */
-#[no_mangle]
-pub unsafe extern "C" fn dc_timestamp_to_str(mut wanted: time_t) -> *mut libc::c_char {
+pub unsafe fn dc_timestamp_to_str(mut wanted: time_t) -> *mut libc::c_char {
     let mut wanted_struct: tm = tm {
         tm_sec: 0,
         tm_min: 0,
@@ -851,10 +812,7 @@ pub unsafe extern "C" fn dc_timestamp_to_str(mut wanted: time_t) -> *mut libc::c
         wanted_struct.tm_sec as libc::c_int,
     );
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_timestamp_to_mailimap_date_time(
-    mut timeval: time_t,
-) -> *mut mailimap_date_time {
+pub unsafe fn dc_timestamp_to_mailimap_date_time(mut timeval: time_t) -> *mut mailimap_date_time {
     let mut gmt: tm = tm {
         tm_sec: 0,
         tm_min: 0,
@@ -910,8 +868,7 @@ pub unsafe extern "C" fn dc_timestamp_to_mailimap_date_time(
     );
     return date_time;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_gm2local_offset() -> libc::c_long {
+pub unsafe fn dc_gm2local_offset() -> libc::c_long {
     /* returns the offset that must be _added_ to an UTC/GMT-time to create the localtime.
     the function may return nagative values. */
     let mut gmtime: time_t = time(0 as *mut time_t);
@@ -932,8 +889,7 @@ pub unsafe extern "C" fn dc_gm2local_offset() -> libc::c_long {
     return timeinfo.tm_gmtoff;
 }
 /* timesmearing */
-#[no_mangle]
-pub unsafe extern "C" fn dc_smeared_time(mut context: *mut dc_context_t) -> time_t {
+pub unsafe fn dc_smeared_time(mut context: *mut dc_context_t) -> time_t {
     /* function returns a corrected time(NULL) */
     let mut now: time_t = time(0 as *mut time_t);
     pthread_mutex_lock(&mut (*context).smear_critical);
@@ -943,8 +899,7 @@ pub unsafe extern "C" fn dc_smeared_time(mut context: *mut dc_context_t) -> time
     pthread_mutex_unlock(&mut (*context).smear_critical);
     return now;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_create_smeared_timestamp(mut context: *mut dc_context_t) -> time_t {
+pub unsafe fn dc_create_smeared_timestamp(mut context: *mut dc_context_t) -> time_t {
     let mut now: time_t = time(0 as *mut time_t);
     let mut ret: time_t = now;
     pthread_mutex_lock(&mut (*context).smear_critical);
@@ -958,8 +913,7 @@ pub unsafe extern "C" fn dc_create_smeared_timestamp(mut context: *mut dc_contex
     pthread_mutex_unlock(&mut (*context).smear_critical);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_create_smeared_timestamps(
+pub unsafe fn dc_create_smeared_timestamps(
     mut context: *mut dc_context_t,
     mut count: libc::c_int,
 ) -> time_t {
@@ -978,8 +932,7 @@ pub unsafe extern "C" fn dc_create_smeared_timestamps(
     return start;
 }
 /* Message-ID tools */
-#[no_mangle]
-pub unsafe extern "C" fn dc_create_id() -> *mut libc::c_char {
+pub unsafe fn dc_create_id() -> *mut libc::c_char {
     /* generate an id. the generated ID should be as short and as unique as possible:
     - short, because it may also used as part of Message-ID headers or in QR codes
     - unique as two IDs generated on two devices should not be the same. However, collisions are not world-wide but only by the few contacts.
@@ -998,7 +951,7 @@ pub unsafe extern "C" fn dc_create_id() -> *mut libc::c_char {
 /* ******************************************************************************
  * generate Message-IDs
  ******************************************************************************/
-unsafe extern "C" fn encode_66bits_as_base64(
+unsafe fn encode_66bits_as_base64(
     mut v1: uint32_t,
     mut v2: uint32_t,
     mut fill: uint32_t,
@@ -1033,8 +986,7 @@ unsafe extern "C" fn encode_66bits_as_base64(
     *ret.offset(11isize) = 0i32 as libc::c_char;
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_create_incoming_rfc724_mid(
+pub unsafe fn dc_create_incoming_rfc724_mid(
     mut message_timestamp: time_t,
     mut contact_id_from: uint32_t,
     mut contact_ids_to: *mut dc_array_t,
@@ -1061,8 +1013,7 @@ pub unsafe extern "C" fn dc_create_incoming_rfc724_mid(
         largest_id_to as libc::c_ulong,
     );
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_create_outgoing_rfc724_mid(
+pub unsafe fn dc_create_outgoing_rfc724_mid(
     mut grpid: *const libc::c_char,
     mut from_addr: *const libc::c_char,
 ) -> *mut libc::c_char {
@@ -1097,10 +1048,7 @@ pub unsafe extern "C" fn dc_create_outgoing_rfc724_mid(
     free(rand2 as *mut libc::c_void);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_extract_grpid_from_rfc724_mid(
-    mut mid: *const libc::c_char,
-) -> *mut libc::c_char {
+pub unsafe fn dc_extract_grpid_from_rfc724_mid(mut mid: *const libc::c_char) -> *mut libc::c_char {
     /* extract our group ID from Message-IDs as `Gr.12345678901.morerandom@domain.de`; "12345678901" is the wanted ID in this example. */
     let mut success: libc::c_int = 0i32;
     let mut grpid: *mut libc::c_char = 0 as *mut libc::c_char;
@@ -1133,10 +1081,7 @@ pub unsafe extern "C" fn dc_extract_grpid_from_rfc724_mid(
         0 as *mut libc::c_char
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_extract_grpid_from_rfc724_mid_list(
-    mut list: *const clist,
-) -> *mut libc::c_char {
+pub unsafe fn dc_extract_grpid_from_rfc724_mid_list(mut list: *const clist) -> *mut libc::c_char {
     if !list.is_null() {
         let mut cur: *mut clistiter = (*list).first;
         while !cur.is_null() {
@@ -1159,8 +1104,7 @@ pub unsafe extern "C" fn dc_extract_grpid_from_rfc724_mid_list(
     return 0 as *mut libc::c_char;
 }
 /* file tools */
-#[no_mangle]
-pub unsafe extern "C" fn dc_ensure_no_slash(mut pathNfilename: *mut libc::c_char) {
+pub unsafe fn dc_ensure_no_slash(mut pathNfilename: *mut libc::c_char) {
     let mut path_len: libc::c_int = strlen(pathNfilename) as libc::c_int;
     if path_len > 0i32 {
         if *pathNfilename.offset((path_len - 1i32) as isize) as libc::c_int == '/' as i32
@@ -1170,8 +1114,7 @@ pub unsafe extern "C" fn dc_ensure_no_slash(mut pathNfilename: *mut libc::c_char
         }
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_validate_filename(mut filename: *mut libc::c_char) {
+pub unsafe fn dc_validate_filename(mut filename: *mut libc::c_char) {
     /* function modifies the given buffer and replaces all characters not valid in filenames by a "-" */
     let mut p1: *mut libc::c_char = filename;
     while 0 != *p1 {
@@ -1184,10 +1127,7 @@ pub unsafe extern "C" fn dc_validate_filename(mut filename: *mut libc::c_char) {
         p1 = p1.offset(1isize)
     }
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_filename(
-    mut pathNfilename: *const libc::c_char,
-) -> *mut libc::c_char {
+pub unsafe fn dc_get_filename(mut pathNfilename: *const libc::c_char) -> *mut libc::c_char {
     let mut p: *const libc::c_char = strrchr(pathNfilename, '/' as i32);
     if p.is_null() {
         p = strrchr(pathNfilename, '\\' as i32)
@@ -1200,8 +1140,7 @@ pub unsafe extern "C" fn dc_get_filename(
     };
 }
 // the case of the suffix is preserved
-#[no_mangle]
-pub unsafe extern "C" fn dc_split_filename(
+pub unsafe fn dc_split_filename(
     mut pathNfilename: *const libc::c_char,
     mut ret_basename: *mut *mut libc::c_char,
     mut ret_all_suffixes_incl_dot: *mut *mut libc::c_char,
@@ -1232,10 +1171,7 @@ pub unsafe extern "C" fn dc_split_filename(
     };
 }
 // the returned suffix is lower-case
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_filesuffix_lc(
-    mut pathNfilename: *const libc::c_char,
-) -> *mut libc::c_char {
+pub unsafe fn dc_get_filesuffix_lc(mut pathNfilename: *const libc::c_char) -> *mut libc::c_char {
     if !pathNfilename.is_null() {
         let mut p: *const libc::c_char = strrchr(pathNfilename, '.' as i32);
         if !p.is_null() {
@@ -1245,8 +1181,7 @@ pub unsafe extern "C" fn dc_get_filesuffix_lc(
     }
     return 0 as *mut libc::c_char;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_filemeta(
+pub unsafe fn dc_get_filemeta(
     mut buf_start: *const libc::c_void,
     mut buf_bytes: size_t,
     mut ret_width: *mut uint32_t,
@@ -1330,8 +1265,7 @@ pub unsafe extern "C" fn dc_get_filemeta(
     }
     return 0i32;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_abs_path(
+pub unsafe fn dc_get_abs_path(
     mut context: *mut dc_context_t,
     mut pathNfilename: *const libc::c_char,
 ) -> *mut libc::c_char {
@@ -1370,8 +1304,7 @@ pub unsafe extern "C" fn dc_get_abs_path(
     }
     return pathNfilename_abs;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_file_exist(
+pub unsafe fn dc_file_exist(
     mut context: *mut dc_context_t,
     mut pathNfilename: *const libc::c_char,
 ) -> libc::c_int {
@@ -1450,8 +1383,7 @@ pub unsafe extern "C" fn dc_file_exist(
     free(pathNfilename_abs as *mut libc::c_void);
     return exist;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_filebytes(
+pub unsafe fn dc_get_filebytes(
     mut context: *mut dc_context_t,
     mut pathNfilename: *const libc::c_char,
 ) -> uint64_t {
@@ -1530,8 +1462,7 @@ pub unsafe extern "C" fn dc_get_filebytes(
     free(pathNfilename_abs as *mut libc::c_void);
     return filebytes;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_delete_file(
+pub unsafe fn dc_delete_file(
     mut context: *mut dc_context_t,
     mut pathNfilename: *const libc::c_char,
 ) -> libc::c_int {
@@ -1553,8 +1484,7 @@ pub unsafe extern "C" fn dc_delete_file(
     free(pathNfilename_abs as *mut libc::c_void);
     return success;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_copy_file(
+pub unsafe fn dc_copy_file(
     mut context: *mut dc_context_t,
     mut src: *const libc::c_char,
     mut dest: *const libc::c_char,
@@ -1651,8 +1581,7 @@ pub unsafe extern "C" fn dc_copy_file(
     free(dest_abs as *mut libc::c_void);
     return success;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_create_folder(
+pub unsafe fn dc_create_folder(
     mut context: *mut dc_context_t,
     mut pathNfilename: *const libc::c_char,
 ) -> libc::c_int {
@@ -1748,8 +1677,7 @@ pub unsafe extern "C" fn dc_create_folder(
     free(pathNfilename_abs as *mut libc::c_void);
     return success;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_write_file(
+pub unsafe fn dc_write_file(
     mut context: *mut dc_context_t,
     mut pathNfilename: *const libc::c_char,
     mut buf: *const libc::c_void,
@@ -1789,8 +1717,7 @@ pub unsafe extern "C" fn dc_write_file(
     free(pathNfilename_abs as *mut libc::c_void);
     return success;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_read_file(
+pub unsafe fn dc_read_file(
     mut context: *mut dc_context_t,
     mut pathNfilename: *const libc::c_char,
     mut buf: *mut *mut libc::c_void,
@@ -1842,8 +1769,7 @@ pub unsafe extern "C" fn dc_read_file(
     free(pathNfilename_abs as *mut libc::c_void);
     return success;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_get_fine_pathNfilename(
+pub unsafe fn dc_get_fine_pathNfilename(
     mut context: *mut dc_context_t,
     mut pathNfolder: *const libc::c_char,
     mut desired_filenameNsuffix__: *const libc::c_char,
@@ -1899,8 +1825,7 @@ pub unsafe extern "C" fn dc_get_fine_pathNfilename(
     free(pathNfolder_wo_slash as *mut libc::c_void);
     return ret;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_is_blobdir_path(
+pub unsafe fn dc_is_blobdir_path(
     mut context: *mut dc_context_t,
     mut path: *const libc::c_char,
 ) -> libc::c_int {
@@ -1915,11 +1840,7 @@ pub unsafe extern "C" fn dc_is_blobdir_path(
     }
     return 0i32;
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_make_rel_path(
-    mut context: *mut dc_context_t,
-    mut path: *mut *mut libc::c_char,
-) {
+pub unsafe fn dc_make_rel_path(mut context: *mut dc_context_t, mut path: *mut *mut libc::c_char) {
     if context.is_null() || path.is_null() || (*path).is_null() {
         return;
     }
@@ -1931,8 +1852,7 @@ pub unsafe extern "C" fn dc_make_rel_path(
         );
     };
 }
-#[no_mangle]
-pub unsafe extern "C" fn dc_make_rel_and_copy(
+pub unsafe fn dc_make_rel_and_copy(
     mut context: *mut dc_context_t,
     mut path: *mut *mut libc::c_char,
 ) -> libc::c_int {
diff --git a/src/lib.rs b/src/lib.rs
index c6d2720b5..6f7bbad29 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -23,7 +23,6 @@
 extern crate failure;
 
 mod pgp;
-mod types;
 mod x;
 
 pub mod dc_aheader;
@@ -68,6 +67,7 @@ pub mod dc_strbuilder;
 pub mod dc_strencode;
 pub mod dc_token;
 pub mod dc_tools;
+pub mod types;
 
 pub mod constants;
 pub use self::constants::*;
@@ -90,7 +90,7 @@ mod tests {
     };
     use crate::dc_lot::*;
 
-    extern "C" fn cb(ctx: *mut dc_context_t, event: c_int, data1: u64, data2: u64) -> u64 {
+    fn cb(ctx: *mut dc_context_t, event: c_int, data1: u64, data2: u64) -> u64 {
         println!("event: {} ({}, {})", event, data1, data2);
         if data2 > 10000 {
             println!(
diff --git a/src/pgp/c_vec.rs b/src/pgp/c_vec.rs
index 96af846de..651095aa4 100644
--- a/src/pgp/c_vec.rs
+++ b/src/pgp/c_vec.rs
@@ -47,8 +47,7 @@ impl Into<Vec<u8>> for cvec {
 }
 
 /// Get the length of the data of the given [cvec].
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_cvec_len(cvec_ptr: *mut cvec) -> libc::size_t {
+pub unsafe fn rpgp_cvec_len(cvec_ptr: *mut cvec) -> libc::size_t {
     assert!(!cvec_ptr.is_null());
 
     let cvec = &*cvec_ptr;
@@ -56,8 +55,7 @@ pub unsafe extern "C" fn rpgp_cvec_len(cvec_ptr: *mut cvec) -> libc::size_t {
 }
 
 /// Get a pointer to the data of the given [cvec].
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_cvec_data(cvec_ptr: *mut cvec) -> *const u8 {
+pub unsafe fn rpgp_cvec_data(cvec_ptr: *mut cvec) -> *const u8 {
     assert!(!cvec_ptr.is_null());
 
     let cvec = &*cvec_ptr;
@@ -65,8 +63,7 @@ pub unsafe extern "C" fn rpgp_cvec_data(cvec_ptr: *mut cvec) -> *const u8 {
 }
 
 /// Free the given [cvec].
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_cvec_drop(cvec_ptr: *mut cvec) {
+pub unsafe fn rpgp_cvec_drop(cvec_ptr: *mut cvec) {
     assert!(!cvec_ptr.is_null());
 
     let v = &*cvec_ptr;
diff --git a/src/pgp/errors.rs b/src/pgp/errors.rs
index d44226aa7..3b25fefcf 100644
--- a/src/pgp/errors.rs
+++ b/src/pgp/errors.rs
@@ -32,7 +32,6 @@ pub fn take_last_error() -> Option<Box<Error>> {
 
 /// Calculate the number of bytes in the last error's error message **not**
 /// including any trailing `null` characters.
-#[no_mangle]
 pub extern "C" fn rpgp_last_error_length() -> c_int {
     LAST_ERROR.with(|prev| match *prev.borrow() {
         Some(ref err) => err.to_string().len() as c_int + 1,
@@ -51,8 +50,7 @@ pub extern "C" fn rpgp_last_error_length() -> c_int {
 /// If there are no recent errors then this returns `0` (because we wrote 0
 /// bytes). `-1` is returned if there are any errors, for example when passed a
 /// null pointer or a buffer of insufficient size.
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_last_error_message() -> *mut c_char {
+pub unsafe fn rpgp_last_error_message() -> *mut c_char {
     let last_error = match take_last_error() {
         Some(err) => err,
         None => return ptr::null_mut(),
diff --git a/src/pgp/hash.rs b/src/pgp/hash.rs
index 5d79812c3..c98f8966e 100644
--- a/src/pgp/hash.rs
+++ b/src/pgp/hash.rs
@@ -4,11 +4,7 @@ use std::slice;
 use crate::pgp::cvec;
 
 /// Calculate the SHA256 hash of the given bytes.
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_hash_sha256(
-    bytes_ptr: *const u8,
-    bytes_len: libc::size_t,
-) -> *mut cvec {
+pub unsafe fn rpgp_hash_sha256(bytes_ptr: *const u8, bytes_len: libc::size_t) -> *mut cvec {
     assert!(!bytes_ptr.is_null());
     assert!(bytes_len > 0);
 
diff --git a/src/pgp/key.rs b/src/pgp/key.rs
index 474aaae7c..ae6a6c9b9 100644
--- a/src/pgp/key.rs
+++ b/src/pgp/key.rs
@@ -13,11 +13,7 @@ pub type public_or_secret_key = PublicOrSecret;
 /// Creates an in-memory representation of a PGP key, based on the armor file given.
 /// The returned pointer should be stored, and reused when calling methods "on" this key.
 /// When done with it [rpgp_key_drop] should be called, to free the memory.
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_key_from_armor(
-    raw: *const u8,
-    len: libc::size_t,
-) -> *mut public_or_secret_key {
+pub unsafe fn rpgp_key_from_armor(raw: *const u8, len: libc::size_t) -> *mut public_or_secret_key {
     assert!(!raw.is_null());
     assert!(len > 0);
 
@@ -38,7 +34,6 @@ pub unsafe extern "C" fn rpgp_key_from_armor(
 }
 
 /// Creates an in-memory representation of a PGP key, based on the serialized bytes given.
-#[no_mangle]
 pub unsafe extern "C" fn rpgp_key_from_bytes(
     raw: *const u8,
     len: libc::size_t,
@@ -63,8 +58,7 @@ pub unsafe extern "C" fn rpgp_key_from_bytes(
 }
 
 /// Returns the KeyID for the passed in key. The caller is responsible to call [rpgp_string_drop] with the returned memory, to free it.
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_key_id(key_ptr: *mut public_or_secret_key) -> *mut c_char {
+pub unsafe fn rpgp_key_id(key_ptr: *mut public_or_secret_key) -> *mut c_char {
     assert!(!key_ptr.is_null());
 
     let key = &*key_ptr;
@@ -77,8 +71,7 @@ pub unsafe extern "C" fn rpgp_key_id(key_ptr: *mut public_or_secret_key) -> *mut
 }
 
 /// Returns the Fingerprint for the passed in key. The caller is responsible to call [rpgp_cvec_drop] with the returned memory, to free it.
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_key_fingerprint(key_ptr: *mut public_or_secret_key) -> *mut cvec {
+pub unsafe fn rpgp_key_fingerprint(key_ptr: *mut public_or_secret_key) -> *mut cvec {
     assert!(!key_ptr.is_null());
 
     let key = &*key_ptr;
@@ -88,24 +81,21 @@ pub unsafe extern "C" fn rpgp_key_fingerprint(key_ptr: *mut public_or_secret_key
 }
 
 /// Returns `true` if this key is a public key, false otherwise.
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_key_is_public(key_ptr: *mut public_or_secret_key) -> bool {
+pub unsafe fn rpgp_key_is_public(key_ptr: *mut public_or_secret_key) -> bool {
     assert!(!key_ptr.is_null());
 
     (&*key_ptr).is_public()
 }
 
 /// Returns `true` if this key is a secret key, false otherwise.
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_key_is_secret(key_ptr: *mut public_or_secret_key) -> bool {
+pub unsafe fn rpgp_key_is_secret(key_ptr: *mut public_or_secret_key) -> bool {
     assert!(!key_ptr.is_null());
 
     (&*key_ptr).is_secret()
 }
 
 /// Frees the memory of the passed in key, making the pointer invalid after this method was called.
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_key_drop(key_ptr: *mut public_or_secret_key) {
+pub unsafe fn rpgp_key_drop(key_ptr: *mut public_or_secret_key) {
     assert!(!key_ptr.is_null());
 
     let _key = &*key_ptr;
diff --git a/src/pgp/message.rs b/src/pgp/message.rs
index c0ef5cd1e..208bfed34 100644
--- a/src/pgp/message.rs
+++ b/src/pgp/message.rs
@@ -12,11 +12,7 @@ pub use pgp::composed::Message;
 pub type message = Message;
 
 /// Parse an armored message.
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_msg_from_armor(
-    msg_ptr: *const u8,
-    msg_len: libc::size_t,
-) -> *mut message {
+pub unsafe fn rpgp_msg_from_armor(msg_ptr: *const u8, msg_len: libc::size_t) -> *mut message {
     assert!(!msg_ptr.is_null());
     assert!(msg_len > 0);
 
@@ -31,7 +27,6 @@ pub unsafe extern "C" fn rpgp_msg_from_armor(
 }
 
 /// Parse a message in bytes format.
-#[no_mangle]
 pub unsafe extern "C" fn rpgp_msg_from_bytes(
     msg_ptr: *const u8,
     msg_len: libc::size_t,
@@ -47,8 +42,7 @@ pub unsafe extern "C" fn rpgp_msg_from_bytes(
 }
 
 /// Decrypt the passed in message, using a password.
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_msg_decrypt_with_password(
+pub unsafe fn rpgp_msg_decrypt_with_password(
     msg_ptr: *const message,
     password_ptr: *const c_char,
 ) -> *mut message {
@@ -74,8 +68,7 @@ pub unsafe extern "C" fn rpgp_msg_decrypt_with_password(
 }
 
 /// Decrypt the passed in message, without attempting to use a password.
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_msg_decrypt_no_pw(
+pub unsafe fn rpgp_msg_decrypt_no_pw(
     msg_ptr: *const message,
     skeys_ptr: *const *const signed_secret_key,
     skeys_len: libc::size_t,
@@ -155,8 +148,7 @@ pub struct message_decrypt_result {
 }
 
 /// Free a [message_decrypt_result].
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_message_decrypt_result_drop(res_ptr: *mut message_decrypt_result) {
+pub unsafe fn rpgp_message_decrypt_result_drop(res_ptr: *mut message_decrypt_result) {
     assert!(!res_ptr.is_null());
 
     let res = &*res_ptr;
@@ -167,8 +159,7 @@ pub unsafe extern "C" fn rpgp_message_decrypt_result_drop(res_ptr: *mut message_
 
 /// Returns the underlying data of the given message.
 /// Fails when the message is encrypted. Decompresses compressed messages.
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_msg_to_bytes(msg_ptr: *const message) -> *mut cvec {
+pub unsafe fn rpgp_msg_to_bytes(msg_ptr: *const message) -> *mut cvec {
     assert!(!msg_ptr.is_null());
 
     let msg = &*msg_ptr;
@@ -184,8 +175,7 @@ pub unsafe extern "C" fn rpgp_msg_to_bytes(msg_ptr: *const message) -> *mut cvec
 }
 
 /// Encodes the message into its ascii armored representation.
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_msg_to_armored(msg_ptr: *const message) -> *mut cvec {
+pub unsafe fn rpgp_msg_to_armored(msg_ptr: *const message) -> *mut cvec {
     assert!(!msg_ptr.is_null());
 
     let msg = &*msg_ptr;
@@ -199,8 +189,7 @@ pub unsafe extern "C" fn rpgp_msg_to_armored(msg_ptr: *const message) -> *mut cv
 }
 
 /// Encodes the message into its ascii armored representation, returning a string.
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_msg_to_armored_str(msg_ptr: *const message) -> *mut c_char {
+pub unsafe fn rpgp_msg_to_armored_str(msg_ptr: *const message) -> *mut c_char {
     assert!(!msg_ptr.is_null());
 
     let msg = &*msg_ptr;
@@ -214,8 +203,7 @@ pub unsafe extern "C" fn rpgp_msg_to_armored_str(msg_ptr: *const message) -> *mu
 }
 
 /// Free a [message], that was created by rpgp.
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_msg_drop(msg_ptr: *mut message) {
+pub unsafe fn rpgp_msg_drop(msg_ptr: *mut message) {
     assert!(!msg_ptr.is_null());
 
     let _ = &*msg_ptr;
@@ -223,8 +211,7 @@ pub unsafe extern "C" fn rpgp_msg_drop(msg_ptr: *mut message) {
 }
 
 /// Get the number of fingerprints of a given encrypted message.
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_msg_recipients_len(msg_ptr: *mut message) -> u32 {
+pub unsafe fn rpgp_msg_recipients_len(msg_ptr: *mut message) -> u32 {
     assert!(!msg_ptr.is_null());
 
     let msg = &*msg_ptr;
@@ -235,8 +222,7 @@ pub unsafe extern "C" fn rpgp_msg_recipients_len(msg_ptr: *mut message) -> u32 {
 }
 
 /// Get the fingerprint of a given encrypted message, by index, in hexformat.
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_msg_recipients_get(msg_ptr: *mut message, i: u32) -> *mut c_char {
+pub unsafe fn rpgp_msg_recipients_get(msg_ptr: *mut message, i: u32) -> *mut c_char {
     assert!(!msg_ptr.is_null());
 
     let msg = &*msg_ptr;
@@ -251,8 +237,7 @@ pub unsafe extern "C" fn rpgp_msg_recipients_get(msg_ptr: *mut message, i: u32)
     }
 }
 
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_encrypt_bytes_to_keys(
+pub unsafe fn rpgp_encrypt_bytes_to_keys(
     bytes_ptr: *const u8,
     bytes_len: libc::size_t,
     pkeys_ptr: *const *const signed_public_key,
@@ -285,8 +270,7 @@ pub unsafe extern "C" fn rpgp_encrypt_bytes_to_keys(
     Box::into_raw(Box::new(msg))
 }
 
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_sign_encrypt_bytes_to_keys(
+pub unsafe fn rpgp_sign_encrypt_bytes_to_keys(
     bytes_ptr: *const u8,
     bytes_len: libc::size_t,
     pkeys_ptr: *const *const signed_public_key,
@@ -333,8 +317,7 @@ pub unsafe extern "C" fn rpgp_sign_encrypt_bytes_to_keys(
     Box::into_raw(Box::new(encrypted_msg))
 }
 
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_encrypt_bytes_with_password(
+pub unsafe fn rpgp_encrypt_bytes_with_password(
     bytes_ptr: *const u8,
     bytes_len: libc::size_t,
     password_ptr: *const c_char,
diff --git a/src/pgp/mod.rs b/src/pgp/mod.rs
index 39726731b..f0afcc19c 100644
--- a/src/pgp/mod.rs
+++ b/src/pgp/mod.rs
@@ -18,8 +18,7 @@ pub use self::public_key::*;
 pub use self::secret_key::*;
 
 /// Free string, that was created by rpgp.
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_string_drop(p: *mut libc::c_char) {
+pub unsafe fn rpgp_string_drop(p: *mut libc::c_char) {
     let _ = std::ffi::CString::from_raw(p);
     // Drop
 }
diff --git a/src/pgp/public_key.rs b/src/pgp/public_key.rs
index 03babf42b..68e1b7e72 100644
--- a/src/pgp/public_key.rs
+++ b/src/pgp/public_key.rs
@@ -12,11 +12,7 @@ use crate::pgp::cvec;
 pub type signed_public_key = SignedPublicKey;
 
 /// Parse a serialized public key, into the native rPGP memory representation.
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_pkey_from_bytes(
-    raw: *const u8,
-    len: libc::size_t,
-) -> *mut signed_public_key {
+pub unsafe fn rpgp_pkey_from_bytes(raw: *const u8, len: libc::size_t) -> *mut signed_public_key {
     assert!(!raw.is_null());
     assert!(len > 0);
 
@@ -32,7 +28,6 @@ pub unsafe extern "C" fn rpgp_pkey_from_bytes(
 }
 
 /// Serialize the [signed_public_key] to bytes.
-#[no_mangle]
 pub unsafe extern "C" fn rpgp_pkey_to_bytes(pkey_ptr: *mut signed_public_key) -> *mut cvec {
     assert!(!pkey_ptr.is_null());
 
@@ -45,8 +40,7 @@ pub unsafe extern "C" fn rpgp_pkey_to_bytes(pkey_ptr: *mut signed_public_key) ->
 }
 
 /// Get the key id of the given [signed_public_key].
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_pkey_key_id(pkey_ptr: *mut signed_public_key) -> *mut c_char {
+pub unsafe fn rpgp_pkey_key_id(pkey_ptr: *mut signed_public_key) -> *mut c_char {
     assert!(!pkey_ptr.is_null());
 
     let pkey = &*pkey_ptr;
@@ -59,8 +53,7 @@ pub unsafe extern "C" fn rpgp_pkey_key_id(pkey_ptr: *mut signed_public_key) -> *
 }
 
 /// Free the given [signed_public_key].
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_pkey_drop(pkey_ptr: *mut signed_public_key) {
+pub unsafe fn rpgp_pkey_drop(pkey_ptr: *mut signed_public_key) {
     assert!(!pkey_ptr.is_null());
 
     let _pkey = &*pkey_ptr;
diff --git a/src/pgp/secret_key.rs b/src/pgp/secret_key.rs
index ecca1e375..29642c022 100644
--- a/src/pgp/secret_key.rs
+++ b/src/pgp/secret_key.rs
@@ -18,11 +18,7 @@ use crate::pgp::signed_public_key;
 pub type signed_secret_key = SignedSecretKey;
 
 /// Generates a new RSA key.
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_create_rsa_skey(
-    bits: u32,
-    user_id: *const c_char,
-) -> *mut signed_secret_key {
+pub unsafe fn rpgp_create_rsa_skey(bits: u32, user_id: *const c_char) -> *mut signed_secret_key {
     assert!(!user_id.is_null());
 
     let user_id = CStr::from_ptr(user_id);
@@ -37,7 +33,6 @@ pub unsafe extern "C" fn rpgp_create_rsa_skey(
 }
 
 /// Generates a new x25519 key.
-#[no_mangle]
 pub unsafe extern "C" fn rpgp_create_x25519_skey(user_id: *const c_char) -> *mut signed_secret_key {
     assert!(!user_id.is_null());
 
@@ -52,8 +47,7 @@ pub unsafe extern "C" fn rpgp_create_x25519_skey(user_id: *const c_char) -> *mut
 }
 
 /// Serialize a secret key into its byte representation.
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_skey_to_bytes(skey_ptr: *mut signed_secret_key) -> *mut cvec {
+pub unsafe fn rpgp_skey_to_bytes(skey_ptr: *mut signed_secret_key) -> *mut cvec {
     assert!(!skey_ptr.is_null());
 
     let skey = &*skey_ptr;
@@ -65,10 +59,7 @@ pub unsafe extern "C" fn rpgp_skey_to_bytes(skey_ptr: *mut signed_secret_key) ->
 }
 
 /// Get the signed public key matching the given private key. Only works for non password protected keys.
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_skey_public_key(
-    skey_ptr: *mut signed_secret_key,
-) -> *mut signed_public_key {
+pub unsafe fn rpgp_skey_public_key(skey_ptr: *mut signed_secret_key) -> *mut signed_public_key {
     assert!(!skey_ptr.is_null());
 
     let skey = &*skey_ptr;
@@ -80,8 +71,7 @@ pub unsafe extern "C" fn rpgp_skey_public_key(
 }
 
 /// Returns the KeyID for the passed in key.
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_skey_key_id(skey_ptr: *mut signed_secret_key) -> *mut c_char {
+pub unsafe fn rpgp_skey_key_id(skey_ptr: *mut signed_secret_key) -> *mut c_char {
     assert!(!skey_ptr.is_null());
 
     let key = &*skey_ptr;
@@ -94,8 +84,7 @@ pub unsafe extern "C" fn rpgp_skey_key_id(skey_ptr: *mut signed_secret_key) -> *
 }
 
 /// Free the memory of a secret key.
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_skey_drop(skey_ptr: *mut signed_secret_key) {
+pub unsafe fn rpgp_skey_drop(skey_ptr: *mut signed_secret_key) {
     assert!(!skey_ptr.is_null());
 
     let _skey = &*skey_ptr;
@@ -103,11 +92,7 @@ pub unsafe extern "C" fn rpgp_skey_drop(skey_ptr: *mut signed_secret_key) {
 }
 
 /// Creates an in-memory representation of a Secret PGP key, based on the serialized bytes given.
-#[no_mangle]
-pub unsafe extern "C" fn rpgp_skey_from_bytes(
-    raw: *const u8,
-    len: libc::size_t,
-) -> *mut signed_secret_key {
+pub unsafe fn rpgp_skey_from_bytes(raw: *const u8, len: libc::size_t) -> *mut signed_secret_key {
     assert!(!raw.is_null());
     assert!(len > 0);
 
diff --git a/src/types.rs b/src/types.rs
index e367d97d1..e20e5729e 100644
--- a/src/types.rs
+++ b/src/types.rs
@@ -575,7 +575,7 @@ pub union unnamed_6 {
 pub struct mailimap_section_part {
     pub sec_id: *mut clist,
 }
-pub type mailimap_msg_body_handler = unsafe extern "C" fn(
+pub type mailimap_msg_body_handler = unsafe fn(
     _: libc::c_int,
     _: *mut mailimap_msg_att_body_section,
     _: *const libc::c_char,
@@ -1189,14 +1189,14 @@ pub struct _RuneLocale {
     pub __magic: [libc::c_char; 8],
     pub __encoding: [libc::c_char; 32],
     pub __sgetrune: Option<
-        unsafe extern "C" fn(
+        unsafe fn(
             _: *const libc::c_char,
             _: __darwin_size_t,
             _: *mut *const libc::c_char,
         ) -> __darwin_rune_t,
     >,
     pub __sputrune: Option<
-        unsafe extern "C" fn(
+        unsafe fn(
             _: __darwin_rune_t,
             _: *mut libc::c_char,
             _: __darwin_size_t,
@@ -1264,7 +1264,7 @@ pub struct tm {
 }
 
 pub type dc_receive_imf_t = Option<
-    unsafe extern "C" fn(
+    unsafe fn(
         _: *mut dc_imap_t,
         _: *const libc::c_char,
         _: size_t,
@@ -1278,18 +1278,17 @@ dc_context_t is only used for logging and to get information about
 the online state. */
 
 pub type dc_precheck_imf_t = Option<
-    unsafe extern "C" fn(
+    unsafe fn(
         _: *mut dc_imap_t,
         _: *const libc::c_char,
         _: *const libc::c_char,
         _: uint32_t,
     ) -> libc::c_int,
 >;
-pub type dc_set_config_t = Option<
-    unsafe extern "C" fn(_: *mut dc_imap_t, _: *const libc::c_char, _: *const libc::c_char) -> (),
->;
+pub type dc_set_config_t =
+    Option<unsafe fn(_: *mut dc_imap_t, _: *const libc::c_char, _: *const libc::c_char) -> ()>;
 pub type dc_get_config_t = Option<
-    unsafe extern "C" fn(
+    unsafe fn(
         _: *mut dc_imap_t,
         _: *const libc::c_char,
         _: *const libc::c_char,
@@ -1308,13 +1307,12 @@ pub struct _dc_sqlite3 {
 }
 
 #[inline]
-pub unsafe extern "C" fn isascii(mut _c: libc::c_int) -> libc::c_int {
+pub unsafe fn isascii(mut _c: libc::c_int) -> libc::c_int {
     return (_c & !0x7fi32 == 0i32) as libc::c_int;
 }
 
-#[no_mangle]
 #[inline]
-pub unsafe extern "C" fn isspace(mut _c: libc::c_int) -> libc::c_int {
+pub unsafe fn isspace(mut _c: libc::c_int) -> libc::c_int {
     if _c < std::u8::MAX as libc::c_int {
         ((_c as u8 as char) == ' ') as libc::c_int
     } else {
@@ -1322,30 +1320,25 @@ pub unsafe extern "C" fn isspace(mut _c: libc::c_int) -> libc::c_int {
     }
 }
 
-#[no_mangle]
 #[inline]
 #[cfg(target_os = "macos")]
-pub unsafe extern "C" fn tolower(mut _c: libc::c_int) -> libc::c_int {
+pub unsafe fn tolower(mut _c: libc::c_int) -> libc::c_int {
     return __tolower(_c);
 }
 
-#[no_mangle]
 #[inline]
 #[cfg(not(target_os = "macos"))]
-pub unsafe extern "C" fn tolower(mut _c: libc::c_int) -> libc::c_int {
+pub unsafe fn tolower(mut _c: libc::c_int) -> libc::c_int {
     return _tolower(_c);
 }
 
 #[inline]
-pub unsafe extern "C" fn carray_count(mut array: *mut carray) -> libc::c_uint {
+pub unsafe fn carray_count(mut array: *mut carray) -> libc::c_uint {
     return (*array).len;
 }
 
 #[inline]
-pub unsafe extern "C" fn carray_get(
-    mut array: *mut carray,
-    mut indx: libc::c_uint,
-) -> *mut libc::c_void {
+pub unsafe fn carray_get(mut array: *mut carray, mut indx: libc::c_uint) -> *mut libc::c_void {
     return *(*array).array.offset(indx as isize);
 }
 
@@ -1360,12 +1353,7 @@ pub unsafe extern "C" fn carray_get(
  * @return return 0 unless stated otherwise in the event parameter documentation
  */
 pub type dc_callback_t = Option<
-    unsafe extern "C" fn(
-        _: *mut dc_context_t,
-        _: libc::c_int,
-        _: uintptr_t,
-        _: uintptr_t,
-    ) -> uintptr_t,
+    unsafe fn(_: *mut dc_context_t, _: libc::c_int, _: uintptr_t, _: uintptr_t) -> uintptr_t,
 >;
 
 #[derive(Copy, Clone)]