esp-idf uses imported targets as dummy targets that are never linked.
Previous CMake versions would ignore these and not error on unset
IMPORTED_LOCATION if they are never actually linked. CMake 4.2 and newer
errors during codemodel-v2 api queries when imported targets are missing
IMPORTED_LOCATION, so set a dummy location that would error when
actually linked, which fixes the error during api queries.
Closes https://github.com/espressif/esp-idf/pull/18103
As part of inter-procedural optimizations (IPA), the compiler may
perform tasks such as constant propagation for functions. This involves
generating a specialized version of a given function with a new symbol
name that includes a suffix. For example, during constant propagation,
the compiler might create a specialized version named
`spiflash_start_core.constprop.0` for the `spiflash_start_core`
function. Additionally, the compiler may generate multiple clones of a
single function. Currently, when ldgen performs symbol placement, it
does not account for these compiler-generated functions, leading to
their incorrect or unexpected placement in memory (markers).
Consider a linker fragment with:
```
[mapping:spi_flash]
archive: libspi_flash.a
entries:
esp_flash_api: spiflash_start_core (noflash)
```
The `spiflash_start_core` function should be placed in IRAM. However,
the compiler might generate an optimized version of this function with a
`.constprop.0` suffix, resulting in a
`.text.spiflash_start_core.constprop.0` input section. Currently, ldgen
does not handle this situation, leading to misplaced symbols.
Since `.` is not allowed in C identifiers, it should be safe to consider
all input sections for a symbol with any `.` suffix as representing that
symbol. This means considering the symbol suffixes should not cause any
ambiguity.
This change automatically places all input sections, including those
with possible suffixes for a given symbol, into the specified memory. In
other words, specifying a function name like `spiflash_start_core` in a
linker fragment automatically includes input section names matching
`spiflash_start_core(\..*)?$`.
Signed-off-by: Frantisek Hrbata <frantisek.hrbata@espressif.com>
Closes https://github.com/espressif/esp-idf/issues/13629
NMI interrupt level has been freed for all the Xtensa targets, making it possible
for the main application to use it. An example has been added to show how to
proceed.
