Merge branch 'feature/update-gnu-standards' into 'master'

feat(build): update gnu17->gnu23 and gnu++2b->gnu++26

See merge request espressif/esp-idf!41014

Author: Lapshin

components/newlib/platform_include/stdatomic.h

@@ -0,0 +1,20 @@
+/*
+ * SPDX-FileCopyrightText: 2025 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+#pragma once
+#include_next <stdatomic.h>
+
+/* The ATOMIC_VAR_INIT macro was deprecated in:
+ *  - C17
+ *  - C++20
+ * and removed in subsequent standards.
+ * Since users may change the standard version for their projects,
+ * IDF should remain compatible across different standards.
+ */
+#if __STDC_VERSION__ > 201710L || __cplusplus > 202002L
+# ifndef ATOMIC_VAR_INIT
+#   define ATOMIC_VAR_INIT(val) (val)
+# endif
+#endif

components/newlib/test_apps/newlib/main/test_misaligned_mem_performance.c

@@ -11,7 +11,7 @@
 
 #define MAX_MEMTEST_SIZE 4096
 
-uint32_t test_function_dest_src_size(void (*foo)(), bool pass_size)
+uint32_t test_function_dest_src_size(void (*foo)(...), bool pass_size)
 {
     uint32_t ccount1, ccount2;
     char* test_des = heap_caps_aligned_alloc(32, MAX_MEMTEST_SIZE, MALLOC_CAP_INTERNAL | MALLOC_CAP_8BIT);

docs/en/api-guides/c.rst

@@ -17,7 +17,7 @@ In general, all C features supported by the compiler (currently GCC) can be used
 C Version
 ---------
 
-**GNU dialect of ISO C17** (``--std=gnu17``) is the current default C version in ESP-IDF.
+**GNU dialect of ISO C23** (``--std=gnu23``) is the current default C version in ESP-IDF.
 
 To compile the source code of a certain component using a different language standard, set the desired compiler flag in the component's ``CMakeLists.txt`` file:
 
@@ -38,4 +38,4 @@ The following features are not supported in ESP-IDF.
 Nested Function Pointers
 ^^^^^^^^^^^^^^^^^^^^^^^^
 
-The **GNU dialect of ISO C17** supports `nested functions <https://gcc.gnu.org/onlinedocs/gcc/Nested-Functions.html>`_. However, ESP-IDF does not support referencing nested functions as pointers. This is due to the fact that the GCC compiler generates a `trampoline <https://gcc.gnu.org/onlinedocs/gccint/Trampolines.html>`_ (i.e., small piece of executable code) on the stack when a pointer to a nested function is referenced. ESP-IDF does not permit executing code from a stack, thus use of pointers to nested functions is not supported.
+The **GNU dialect of ISO C23** supports `nested functions <https://gcc.gnu.org/onlinedocs/gcc/Nested-Functions.html>`_. However, ESP-IDF does not support referencing nested functions as pointers. This is due to the fact that the GCC compiler generates a `trampoline <https://gcc.gnu.org/onlinedocs/gccint/Trampolines.html>`_ (i.e., small piece of executable code) on the stack when a pointer to a nested function is referenced. ESP-IDF does not permit executing code from a stack, thus use of pointers to nested functions is not supported.

docs/en/api-guides/cplusplus.rst

@@ -26,7 +26,7 @@ The following C++ features are supported:
 C++ Language Standard
 ---------------------
 
-By default, ESP-IDF compiles C++ code with C++23 language standard with GNU extensions (``-std=gnu++23``).
+By default, ESP-IDF compiles C++ code with C++26 language standard with GNU extensions (``-std=gnu++26``).
 
 To compile the source code of a certain component using a different language standard, set the desired compiler flag in the component's ``CMakeLists.txt`` file:
 
@@ -182,7 +182,7 @@ Designated Initializers
 
 Many of the ESP-IDF components use :ref:`api_reference_config_structures` as arguments to the initialization functions. ESP-IDF examples written in C routinely use `designated initializers <https://en.cppreference.com/w/c/language/struct_initialization>`_ to fill these structures in a readable and a maintainable way.
 
-C and C++ languages have different rules with regards to the designated initializers. For example, C++23 (currently the default in ESP-IDF) does not support out-of-order designated initialization, nested designated initialization, mixing of designated initializers and regular initializers, and designated initialization of arrays. Therefore, when porting ESP-IDF C examples to C++, some changes to the structure initializers may be necessary. See the `C++ aggregate initialization reference <https://en.cppreference.com/w/cpp/language/aggregate_initialization>`_ for more details.
+C and C++ languages have different rules with regards to the designated initializers. For example, C++26 (currently the default in ESP-IDF) does not support out-of-order designated initialization, nested designated initialization, mixing of designated initializers and regular initializers, and designated initialization of arrays. Therefore, when porting ESP-IDF C examples to C++, some changes to the structure initializers may be necessary. See the `C++ aggregate initialization reference <https://en.cppreference.com/w/cpp/language/aggregate_initialization>`_ for more details.
 
 
 ``iostream``

docs/zh_CN/api-guides/c.rst

@@ -17,7 +17,7 @@ Newlib 的版本号记录在 :component_file:`newlib/sbom.yml` 文件中。
 C 版本
 ------
 
-**ISO C17 的 GNU 方言** (``--std=gnu17``) 是 ESP-IDF 中当前默认的 C 语言版本。
+**ISO C23 的 GNU 方言** (``--std=gnu23``) 是 ESP-IDF 中当前默认的 C 语言版本。
 
 使用不同的语言标准编译某个组件的源代码，请在组件的 ``CMakeLists.txt`` 文件中设置所需的编译器标志：
 
@@ -38,4 +38,4 @@ ESP-IDF 不支持以下功能。
 嵌套函数的指针
 ^^^^^^^^^^^^^^
 
-**ISO C17 的 GNU 方言** 支持 `嵌套函数 <https://gcc.gnu.org/onlinedocs/gcc/Nested-Functions.html>`_，但 ESP-IDF 不支持将嵌套函数引用为指针。这是因为 GCC 编译器在引用嵌套函数的指针时，会在栈上生成一个 `跳板 <https://gcc.gnu.org/onlinedocs/gccint/Trampolines.html>`_ （即，一小段可执行代码），ESP-IDF 不允许从栈执行代码，因此不支持使用指向嵌套函数的指针。
+**ISO C23 的 GNU 方言** 支持 `嵌套函数 <https://gcc.gnu.org/onlinedocs/gcc/Nested-Functions.html>`_，但 ESP-IDF 不支持将嵌套函数引用为指针。这是因为 GCC 编译器在引用嵌套函数的指针时，会在栈上生成一个 `跳板 <https://gcc.gnu.org/onlinedocs/gccint/Trampolines.html>`_ （即，一小段可执行代码），ESP-IDF 不允许从栈执行代码，因此不支持使用指向嵌套函数的指针。

docs/zh_CN/api-guides/cplusplus.rst

@@ -26,7 +26,7 @@ ESP-IDF 支持以下 C++ 功能：
 C++ 语言标准
 ---------------------
 
-默认情况下，ESP-IDF 使用 C++23 语言标准和 GNU 扩展 (``-std=gnu++23``) 编译 C++ 代码。
+默认情况下，ESP-IDF 使用 C++26 语言标准和 GNU 扩展 (``-std=gnu++26``) 编译 C++ 代码。
 
 要使用其他语言标准编译特定组件的源代码，请按以下步骤，在组件的 CMakeLists.txt 文件中设置所需的编译器标志：
 
@@ -182,7 +182,7 @@ ESP-IDF 希望应用程序入口点 ``app_main`` 以 C 链接定义。当 ``app_
 
 许多 ESP-IDF 组件会以 :ref:`api_reference_config_structures` 作为初始化函数的参数。用 C 编写的 ESP-IDF 示例通常使用 `指定初始化器 <https://en.cppreference.com/w/c/language/struct_initialization>`_，以可读且可维护的方式填充有关结构体。
 
-C 和 C++ 语言对于指定初始化器有不同的规则。例如，C++23（当前在 ESP-IDF 中默认使用）不支持无序指定初始化、嵌套指定初始化、混合使用指定初始化器和常规初始化器，而对数组进行指定初始化。因此，当将 ESP-IDF 的 C 示例移植到 C++ 时，可能需要对结构体初始化器进行一些更改。详细信息请参阅 `C++ aggregate initialization reference <https://en.cppreference.com/w/cpp/language/aggregate_initialization>`_。
+C 和 C++ 语言对于指定初始化器有不同的规则。例如，C++26（当前在 ESP-IDF 中默认使用）不支持无序指定初始化、嵌套指定初始化、混合使用指定初始化器和常规初始化器，而对数组进行指定初始化。因此，当将 ESP-IDF 的 C 示例移植到 C++ 时，可能需要对结构体初始化器进行一些更改。详细信息请参阅 `C++ aggregate initialization reference <https://en.cppreference.com/w/cpp/language/aggregate_initialization>`_。
 
 
 ``iostream``

tools/cmake/build.cmake

@@ -159,8 +159,8 @@ function(__build_set_default_build_specifications)
         # function, which must be called after project().
         # Please update docs/en/api-guides/c.rst, docs/en/api-guides/cplusplus.rst and
         # tools/test_apps/system/cxx_build_test/main/test_cxx_standard.cpp when changing this.
-        list(APPEND c_compile_options   "-std=gnu17")
-        list(APPEND cxx_compile_options "-std=gnu++2b")
+        list(APPEND c_compile_options   "-std=gnu23")
+        list(APPEND cxx_compile_options "-std=gnu++26")
     endif()
 
     idf_build_set_property(COMPILE_DEFINITIONS "${compile_definitions}" APPEND)
@@ -183,7 +183,7 @@ function(__linux_build_set_lang_version)
 
     # Building for Linux target, fall back to an older version of the standard
     # if the preferred one is not supported by the compiler.
-    set(preferred_c_versions gnu17 gnu11 gnu99)
+    set(preferred_c_versions gnu23 gnu17 gnu11 gnu99)
     set(ver_found FALSE)
     foreach(c_version ${preferred_c_versions})
         check_c_compiler_flag("-std=${c_version}" ver_${c_version}_supported)
@@ -198,7 +198,7 @@ function(__linux_build_set_lang_version)
                             "${preferred_c_versions}. Please upgrade the host compiler.")
     endif()
 
-    set(preferred_cxx_versions gnu++2b gnu++20 gnu++2a gnu++17 gnu++14)
+    set(preferred_cxx_versions gnu++26 gnu++2b 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)

tools/test_apps/system/cxx_build_test/main/test_cxx_standard.cpp

@@ -4,7 +4,7 @@
  * SPDX-License-Identifier: Unlicense OR CC0-1.0
  */
 /*
- * Current GCC-14.2.0 value for -std=gnu++23 and -std=gnu++2b.
+ * The latest available C++ standard in current IDF's GCC: gnu++26.
  * If you change the C++ standard for IDF, you also need to change this.
  */
-static_assert(__cplusplus == 202302L);
+static_assert(__cplusplus == 202400L);