[MSYS2] CMake+Ninja Fix arm-none-eabi-ar: Argument list too long

This issue is related to the Arm toolchain for Windows which is available for x86 host architecture only (compatible with x86_64)

Windows (mingw-w64-i686) hosted cross toolchains
AArch32 bare-metal target (arm-none-eabi)

Issue
/bin/sh: line 1: /home/nuttx/nuttxnew/tools/gcc-arm-none-eabi/bin/arm-none-eabi-ar: Argument list too long

On Windows, arm-none-eabi-ar can only accept strings up to a maximum length of 32,768 characters.

We could suppress the 32K include string limitation by setting the CMake variable CMAKE_NINJA_FORCE_RESPONSE_FILE to ON.

This is unfortunately not enough!!! ): In the build phase this error comes out

$ cmake --build build
[2/1025] Building ASM object arch/CMakeFiles/arch.dir/arm/src/armv7-m/arm_exception.S.obj
FAILED: arch/CMakeFiles/arch.dir/arm/src/armv7-m/arm_exception.S.obj
/home/nuttx/nuttxnew/tools/gcc-arm-none-eabi/bin/arm-none-eabi-gcc.exe @arch/CMakeFiles/arch.dir/arm/src/armv7-m/arm_exception.S.obj.rsp -MD -MT arch/CMakeFiles/arch.dir/arm/src/armv7-m/arm_exception.S.obj -MF arch/CMakeFiles/arch.dir/arm/src/armv7-m/arm_exception.S.obj.d -o arch/CMakeFiles/arch.dir/arm/src/armv7-m/arm_exception.S.obj -c /home/nuttx/nxninja/nuttx/arch/arm/src/armv7-m/arm_exception.S
C:/msys64/home/nuttx/nxninja/nuttx/arch/arm/src/armv7-m/arm_exception.S:42:10: fatal error: nuttx/config.h: No such file or directory
   42 | #include <nuttx/config.h>
      |          ^~~~~~~~~~~~~~~~
compilation terminated.

The Workround I found to solve this problem is to overwrite
the responsible file flag CMAKE_${lang}_RESPONSE_FILE_FLAG with $DEFINES $INCLUDES $FLAGS

Maybe there is a better solution but this one it works. :)

.github/workflows/build.yml

@@ -328,7 +328,7 @@ jobs:
           git config --global --add safe.directory /github/workspace/sources/nuttx
           git config --global --add safe.directory /github/workspace/sources/apps
           cd sources/nuttx/tools/ci
-          ./cibuild.sh -g -i -A -C -R testlist/${{matrix.boards}}.dat
+          ./cibuild.sh -g -i -A -C -N -R testlist/${{matrix.boards}}.dat
 
       - uses: actions/upload-artifact@v4
         with:

CMakeLists.txt

@@ -337,13 +337,19 @@ if(NOT EXISTS ${CMAKE_BINARY_DIR}/.config OR NOT "${NUTTX_DEFCONFIG}" STREQUAL
       CACHE INTERNAL "Saved defconfig path" FORCE)
 
   # Print configuration choices
-  message(STATUS "  CMake   ${CMAKE_VERSION}")
+  message(STATUS "  CMake:  ${CMAKE_VERSION}")
   if(CMAKE_GENERATOR MATCHES "Ninja")
     execute_process(
       COMMAND ninja --version
       OUTPUT_VARIABLE ninja_version
       OUTPUT_STRIP_TRAILING_WHITESPACE)
-    message(STATUS "  Ninja   ${ninja_version}")
+    message(STATUS "  Ninja:  ${ninja_version}")
+
+    # Ninja generator does not yet know how to build archives in pieces, so
+    # response files must be used to deal with very long linker command lines.
+    set(CMAKE_NINJA_FORCE_RESPONSE_FILE
+        1
+        CACHE INTERNAL "")
   endif()
   message(STATUS "  Board:  ${NUTTX_BOARD}")
   message(STATUS "  Config: ${NUTTX_CONFIG}")

arch/arm/src/cmake/gcc.cmake

@@ -73,6 +73,14 @@ if(CONFIG_ARCH_TOOLCHAIN_GNU AND NOT CONFIG_ARCH_TOOLCHAIN_CLANG)
   endif()
 endif()
 
+# override the responsible file flag
+
+if(CMAKE_GENERATOR MATCHES "Ninja")
+  set(CMAKE_C_RESPONSE_FILE_FLAG "$DEFINES $INCLUDES $FLAGS @")
+  set(CMAKE_CXX_RESPONSE_FILE_FLAG "$DEFINES $INCLUDES $FLAGS @")
+  set(CMAKE_ASM_RESPONSE_FILE_FLAG "$DEFINES $INCLUDES $FLAGS @")
+endif()
+
 # override the ARCHIVE command
 
 set(CMAKE_ARCHIVE_COMMAND "<CMAKE_AR> rcs <TARGET> <LINK_FLAGS> <OBJECTS>")