fix(build): fix passing CMAKE_<LANG>_FLAGS from ExternalProject_Add

2026-04-27 19:13:21 +00:00 · 2026-03-12 14:02:04 +07:00
parent 4bb6ab870c
commit 338cc50125
13 changed files with 115 additions and 4 deletions
@@ -4,6 +4,8 @@
 # Remove duplicates from a string containing compilation flags
 function(remove_duplicated_flags FLAGS UNIQFLAGS)
    set(FLAGS_LIST "${FLAGS}")
+    # Remove leading and trailing spaces
+    string(STRIP "${FLAGS_LIST}" FLAGS_LIST)
    # Convert the given flags, as a string, into a CMake list type
    separate_arguments(FLAGS_LIST)
    # Remove all the duplicated flags
@@ -1,4 +1,5 @@
 include(${CMAKE_CURRENT_LIST_DIR}/toolchain_flags.cmake)
+include($ENV{IDF_PATH}/tools/cmake/deduplicate_flags.cmake)

 if(NOT CMAKE_PARENT_LIST_FILE)
    message(FATAL_ERROR "toolchain.cmake cannot be used standalone (use chip-specific toolchain file instead)")
@@ -69,17 +70,30 @@ if(_idf_toolchain_dir STREQUAL _current_toolchain_dir)
                            CXX_COMPILE_OPTIONS "${CMAKE_CXX_FLAGS}"
                            ASM_COMPILE_OPTIONS "${CMAKE_ASM_FLAGS}"
                            LINK_OPTIONS "${CMAKE_EXE_LINKER_FLAGS}")
+    # Clear CMAKE_*_FLAGS because all flags are written to response files.
+    set(CMAKE_C_FLAGS "")
+    set(CMAKE_CXX_FLAGS "")
+    set(CMAKE_ASM_FLAGS "")
+    set(CMAKE_EXE_LINKER_FLAGS "")
 else()
    set(IDF_TOOLCHAIN_BUILD_DIR "${_current_toolchain_dir}"
        CACHE PATH "Path to toolchain build directory containing response files and toolchain file copy" FORCE)
 endif()

+# Merge the response file path with any existing CMAKE_*_FLAGS (e.g. from
+# ExternalProject_Add), then remove duplicates. Deduplication is needed because
+# CMake may execute this toolchain file multiple times during initialization.
+remove_duplicated_flags("@\"${IDF_TOOLCHAIN_BUILD_DIR}/cflags\" ${CMAKE_C_FLAGS}" CMAKE_C_FLAGS)
+remove_duplicated_flags("@\"${IDF_TOOLCHAIN_BUILD_DIR}/cxxflags\" ${CMAKE_CXX_FLAGS}" CMAKE_CXX_FLAGS)
+remove_duplicated_flags("@\"${IDF_TOOLCHAIN_BUILD_DIR}/asmflags\" ${CMAKE_ASM_FLAGS}" CMAKE_ASM_FLAGS)
+remove_duplicated_flags("@\"${IDF_TOOLCHAIN_BUILD_DIR}/ldflags\" ${CMAKE_EXE_LINKER_FLAGS}" CMAKE_EXE_LINKER_FLAGS)
+
 # Configure CMake to use response files for compiler and linker flags.
 # Some compilation options enabled by IDF configuration options are not yet
 # defined at this very early CMake stage (toolchain.cmake execution). Response
 # files allow these flags to be dynamically updated during the CMake configuration
 # phase, after the options become available.
-set(CMAKE_C_FLAGS "@\"${IDF_TOOLCHAIN_BUILD_DIR}/cflags\"" CACHE STRING "C Compiler Base Flags" FORCE)
-set(CMAKE_CXX_FLAGS "@\"${IDF_TOOLCHAIN_BUILD_DIR}/cxxflags\"" CACHE STRING "C++ Compiler Base Flags" FORCE)
-set(CMAKE_ASM_FLAGS "@\"${IDF_TOOLCHAIN_BUILD_DIR}/asmflags\"" CACHE STRING "Asm Compiler Base Flags" FORCE)
-set(CMAKE_EXE_LINKER_FLAGS "@\"${IDF_TOOLCHAIN_BUILD_DIR}/ldflags\"" CACHE STRING "Linker Base Flags" FORCE)
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS}" CACHE STRING "C Compiler Base Flags" FORCE)
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}" CACHE STRING "C++ Compiler Base Flags" FORCE)
+set(CMAKE_ASM_FLAGS "${CMAKE_ASM_FLAGS}" CACHE STRING "Asm Compiler Base Flags" FORCE)
+set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS}" CACHE STRING "Linker Base Flags" FORCE)
@@ -16,6 +16,12 @@ tools/test_apps/build_system/embed_test:
      temporary: false
      reason: Hardware independent feature, no need to test on all targets

+tools/test_apps/build_system/external_project:
+  enable:
+    - if: IDF_TARGET in ["esp32", "esp32c3"]
+      temporary: false
+      reason: Verifies toolchain preserves CMAKE_*_FLAGS in ExternalProject_Add context
+
 tools/test_apps/build_system/ld_non_contiguous_memory:
  disable:
    - if: SOC_MEM_NON_CONTIGUOUS_SRAM != 1  # TODO: IDF-13411, since P4 REV2, the SRAM is contiguous
@@ -0,0 +1,10 @@
+# The following lines of boilerplate have to be in your project's
+# CMakeLists in this exact order for cmake to work correctly
+cmake_minimum_required(VERSION 3.22)
+
+include($ENV{IDF_PATH}/tools/cmake/project.cmake)
+
+# Trim the build. Include the minimal set of components, main, and anything it depends on.
+set(COMPONENTS main)
+
+project(external_project)
@@ -0,0 +1,2 @@
+| Supported Targets | ESP32 | ESP32-C3 |
+| ----------------- | ----- | -------- |
@@ -0,0 +1,19 @@
+idf_component_register()
+
+include(ExternalProject)
+externalproject_add(ext_subproject
+    SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/subproject
+    CMAKE_ARGS
+        -DCMAKE_TOOLCHAIN_FILE=${CMAKE_TOOLCHAIN_FILE}
+        -DCMAKE_C_FLAGS=-DEXTERNAL_PROJECT_FLAG=1
+        -DCMAKE_CXX_FLAGS=-DEXTERNAL_PROJECT_CXX_FLAG=1
+        -DCMAKE_ASM_FLAGS=-DEXTERNAL_PROJECT_ASM_FLAG=1
+        -DCMAKE_EXE_LINKER_FLAGS=-Wl,--defsym=EXTERNAL_PROJECT_LINKER_CHECK=1
+    BINARY_DIR "${CMAKE_CURRENT_BINARY_DIR}/subproject"
+    INSTALL_COMMAND ""
+    BUILD_BYPRODUCTS "${CMAKE_CURRENT_BINARY_DIR}/subproject/libext_lib.a"
+)
+
+add_prebuilt_library(ext_lib "${CMAKE_CURRENT_BINARY_DIR}/subproject/libext_lib.a")
+
+target_link_libraries(${COMPONENT_LIB} INTERFACE ext_lib)
@@ -0,0 +1,6 @@
+cmake_minimum_required(VERSION 3.22)
+
+project(ext_subproject LANGUAGES C CXX ASM)
+add_library(ext_lib STATIC check_flag.c check_flag.cpp check_flag.S)
+add_executable(ext_link_test link_check.c)
+target_link_libraries(ext_link_test PRIVATE ext_lib)
@@ -0,0 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
+
+#ifndef EXTERNAL_PROJECT_ASM_FLAG
+#error "EXTERNAL_PROJECT_ASM_FLAG not defined - toolchain did not preserve CMAKE_ASM_FLAGS from ExternalProject_Add"
+#endif
@@ -0,0 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
+
+#ifndef EXTERNAL_PROJECT_FLAG
+#error "EXTERNAL_PROJECT_FLAG not defined - toolchain did not preserve CMAKE_C_FLAGS from ExternalProject_Add"
+#endif
@@ -0,0 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
+
+#ifndef EXTERNAL_PROJECT_CXX_FLAG
+#error "EXTERNAL_PROJECT_CXX_FLAG not defined - toolchain did not preserve CMAKE_CXX_FLAGS from ExternalProject_Add"
+#endif
@@ -0,0 +1,11 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
+extern char EXTERNAL_PROJECT_LINKER_CHECK;
+
+int _start(void)
+{
+    return (int)&EXTERNAL_PROJECT_LINKER_CHECK;
+}
@@ -0,0 +1,2 @@
+idf_component_register(SRCS "test_main.c"
+                       REQUIRES ext_component)
@@ -0,0 +1,12 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
+
+#include <stdio.h>
+
+void app_main(void)
+{
+    printf("external_project test OK\n");
+}