Merge branch 'contrib/github_pr_11025' into 'master'

Enable support for C++23 in esp-idf (GitHub PR)

Closes IDFGH-9684

See merge request espressif/esp-idf!23144

components/esp_common/include/esp_macros.h

@@ -32,7 +32,7 @@ extern "C" {
  * - MACRO_ARGS(__VA_ARGS__) if __VA_ARGS__ was not empty
  * - MACRO_NO_ARGS() if __VA_ARGS__ was empty
  *
- * @note In the future, we want to switch to C++20. We also want to become compatible with clang. Hence, we provide two
+ * @note In the future, we want to become compatible with clang. Hence, we provide two
  * versions of the following macros which are using variadic arguments. One is using the GNU extension ##__VA_ARGS__.
  * The other is using the C++20 feature __VA_OPT__(,). This allows users to compile their code with standard C++20
  * enabled instead of the GNU extension. Below C++20, we haven't found any good alternative to using ##__VA_ARGS__.

components/log/include/esp_log.h

@@ -288,7 +288,7 @@ void esp_log_writev(esp_log_level_t level, const char* tag, const char* format,
 /// Log at ``ESP_LOG_ERROR`` level. @see ``printf``,``ESP_LOGE``,``ESP_DRAM_LOGE``
 
 /**
- * In the future, we want to switch to C++20. We also want to become compatible with clang.
+ * In the future, we want to become compatible with clang.
  * Hence, we provide two versions of the following macros which are using variadic arguments.
  * The first one is using the GNU extension \#\#__VA_ARGS__. The second one is using the C++20 feature __VA_OPT__(,).
  * This allows users to compile their code with standard C++20 enabled instead of the GNU extension.

docs/en/api-guides/cplusplus.rst

@@ -23,14 +23,14 @@ esp-idf-cxx Component
 C++ language standard
 ---------------------
 
-By default, ESP-IDF compiles C++ code with C++20 language standard with GNU extensions (``-std=gnu++20``).
+By default, ESP-IDF compiles C++ code with C++23 language standard with GNU extensions (``-std=gnu++23``).
 
 To compile the source code of a certain component using a different language standard, set the desired compiler flag in the component CMakeLists.txt file:
 
 .. code-block:: cmake
 
     idf_component_register( ... )
-    target_compile_options(${COMPONENT_LIB} PRIVATE -std=gnu++2b)
+    target_compile_options(${COMPONENT_LIB} PRIVATE -std=gnu++11)
 
 Use ``PUBLIC`` instead of ``PRIVATE`` if the public header files of the component also need to be compiled with the same language standard.
 

tools/cmake/build.cmake

@@ -129,7 +129,12 @@ function(__build_set_lang_version)
         # Use latest supported versions.
         # Please update docs/en/api-guides/cplusplus.rst when changing this.
         set(c_std gnu17)
-        set(cxx_std gnu++20)
+        if(NOT ${env_idf_toolchain} STREQUAL "clang")
+            set(cxx_std gnu++23)
+        else()
+            # TODO: IDF-7241 - remove the exception for clang
+            set(cxx_std gnu++20)
+        endif()
     else()
         enable_language(C CXX)
         # Building for Linux target, fall back to an older version of the standard
@@ -149,7 +154,7 @@ function(__build_set_lang_version)
                                 "${preferred_c_versions}. Please upgrade the host compiler.")
         endif()
 
-        set(preferred_cxx_versions gnu++20 gnu++2a gnu++17 gnu++14)
+        set(preferred_cxx_versions gnu++23 gnu++20 gnu++2a gnu++17 gnu++14)
         set(ver_found FALSE)
         foreach(cxx_version ${preferred_cxx_versions})
             check_cxx_compiler_flag("-std=${cxx_version}" ver_${cxx_version}_supported)