change(ci): enable -Werror=unused-but-set-variable

components/bt/common/osi/config.c

@@ -20,6 +20,7 @@
 #include "osi/allocator.h"
 #include "osi/config.h"
 #include "osi/list.h"
+#include "osi/osi.h"
 
 #define CONFIG_FILE_MAX_SIZE             (1536)//1.5k
 #define CONFIG_FILE_DEFAULE_LENGTH       (2048)
@@ -612,7 +613,7 @@ static bool config_parse(nvs_handle_t fp, config_t *config)
     assert(config != NULL);
 
     esp_err_t err;
-    int line_num = 0;
+    UNUSED_ATTR int line_num = 0;
     int err_code = 0;
     uint16_t i = 0;
     size_t length = CONFIG_FILE_DEFAULE_LENGTH;

components/bt/host/bluedroid/stack/l2cap/l2c_api.c

@@ -2358,6 +2358,8 @@ UINT16 L2CA_FlushChannel (UINT16 lcid, UINT16 num_to_flush)
                     num_flushed1 = 0,
                     num_flushed2 = 0;
 
+    UNUSED(num_flushed1);
+
     p_ccb = l2cu_find_ccb_by_cid(NULL, lcid);
 
     if ( !p_ccb || ((p_lcb = p_ccb->p_lcb) == NULL) ) {

components/esp_driver_cam/test_apps/csi/CMakeLists.txt

@@ -7,6 +7,10 @@ set(COMPONENTS main)
 include($ENV{IDF_PATH}/tools/cmake/project.cmake)
 project(test_csi)
 
+# TODO IDF-15784: remove
+# esp_cam_sensor upstream sets locals without reading them; silence -Wunused-but-set-variable
+idf_component_get_property(esp_cam_sensor_lib espressif__esp_cam_sensor COMPONENT_LIB)
+target_compile_options(${esp_cam_sensor_lib} PRIVATE -Wno-unused-but-set-variable)
 
 message(STATUS "Checking camera registers are not read-write by half-word")
 include($ENV{IDF_PATH}/tools/ci/check_register_rw_half_word.cmake)

components/esp_hw_support/sleep_retention.c

@@ -602,7 +602,7 @@ static void check_and_destroy_final_default(void)
 {
     _lock_acquire_recursive(&s_retention.lock);
     assert(s_retention.highpri == SLEEP_RETENTION_REGDMA_LINK_LOWEST_PRIORITY);
-    uint32_t created_modules = 0;
+    uint32_t __attribute__((unused)) created_modules = 0;
     for (int i = 0; i < SLEEP_RETENTION_MODULE_BITMAP_SZ; i++) {
         created_modules |= s_retention.created_modules.bitmap[i];
     }

components/esp_libc/test_apps/newlib/main/test_time.c

@@ -562,17 +562,6 @@ typedef uint64_t benchmark_tick_t;  /* unit: microseconds */
 #define benchmark_print_units(type, x) printf("%s us: %lu\n", type, (unsigned long)(x))
 #endif
 
-#define N 4096
-const uint32_t ro_tbl[N] = { 2 };
-uint32_t scan_tbl(const volatile uint32_t *p, size_t n)
-{
-    uint32_t sum = 0;
-    for (size_t i = 0; i < n; i++) {
-        sum += p[i];
-    }
-    return sum;
-}
-
 void test_posix_timers_clock_performance(clockid_t clock_id)
 {
     const int MEASUREMENTS = 5000;
@@ -584,14 +573,10 @@ void test_posix_timers_clock_performance(clockid_t clock_id)
     benchmark_tick_t delta;
     benchmark_tick_t delta_sum = 0;
     for (int i = 0; i < PHASE_COUNT; i++) {
-        volatile uint32_t table_sum = 0;
         if (i == PHASE_COUNT / 2) {
             printf("With table scan...\n");
         }
         for (int j = 0; j < MEASUREMENTS; j++) {
-            if (i >= PHASE_COUNT / 2) {
-                table_sum += scan_tbl(ro_tbl, N);
-            }
             start = get_start();
             clock_settime(clock_id, &ts);
             end = get_end();

components/lwip/CMakeLists.txt

@@ -208,6 +208,15 @@ if(CONFIG_LWIP_ENABLE)
         -Wno-array-parameter
     )
 
+    # TODO IDF-15784: remove
+    # vars only used in LWIP_ASSERT / debug; unused when asserts disabled
+    set_source_files_properties(
+        lwip/src/core/netif.c
+        lwip/src/core/ipv4/ip4_napt.c
+        PROPERTIES COMPILE_FLAGS
+        -Wno-unused-but-set-variable
+    )
+
     if(CONFIG_COMPILER_STATIC_ANALYZER AND CONFIG_IDF_TOOLCHAIN_GCC)
         set_source_files_properties(
             lwip/src/core/ipv4/ip4_addr.c

components/wpa_supplicant/CMakeLists.txt

@@ -395,6 +395,14 @@ if(CONFIG_ESP_WIFI_ENABLE_WPA3_OWE_SOFTAP)
 endif()
 set_property(TARGET ${COMPONENT_LIB} APPEND PROPERTY LINK_INTERFACE_MULTIPLICITY 3)
 
+# TODO IDF-15784: remove
+# variables can be unused, need to patch submodule
+set_source_files_properties(
+    esp_supplicant/src/esp_common.c
+    PROPERTIES COMPILE_FLAGS
+    -Wno-unused-but-set-variable
+)
+
 if(CONFIG_COMPILER_STATIC_ANALYZER AND CONFIG_IDF_TOOLCHAIN_GCC)
     set(eloop_analyzer_flags
         -Wno-analyzer-out-of-bounds