change to 32-bit local multilib build

.github/workflows/cmake-single-platform.yml

@@ -4,14 +4,13 @@ name: CMake on a single platform
 
 on:
   push:
-    branches: [ "master" ]
+    branches: [ "master", "test" ]
   pull_request:
     branches: [ "master" ]
 
 env:
   # Customize the CMake build type here (Release, Debug, RelWithDebInfo, etc.)
   BUILD_TYPE: Release
-  TOOLCHAIN_PATH: ${{ github.workspace }}/gcc-arm-none-eabi.cmake
 
 jobs:
   build:
@@ -23,20 +22,15 @@ jobs:
     steps:
     - uses: actions/checkout@v3
 
-    - name: Install ARM GCC toolchain
+    - name: Install 32-bit multilib toolchain
       run: |
         sudo apt update
-        sudo apt install -y gcc-arm-none-eabi
-
-    - name: Download gcc-arm-none-eabi.cmake from another repository
-      run: |
-        mkdir -p ${{ github.workspace }}
-        curl -sSL "https://raw.githubusercontent.com/jobroe/cmake-arm-embedded/35a969878d3e6a979a0c61f0bf07327bac3aad1e/toolchain-arm-none-eabi.cmake" > "${TOOLCHAIN_PATH}"
+        sudo apt install -y build-essential libc6-dev-i386 g++-multilib
 
     - name: Configure CMake
       # Configure CMake in a 'build' subdirectory. `CMAKE_BUILD_TYPE` is only required if you are using a single-configuration generator such as make.
       # See https://cmake.org/cmake/help/latest/variable/CMAKE_BUILD_TYPE.html?highlight=cmake_build_type
-      run: cmake -B ${{github.workspace}}/build -DCMAKE_BUILD_TYPE=${{env.BUILD_TYPE}} -DCMAKE_TOOLCHAIN_FILE=${TOOLCHAIN_PATH}
+      run: cmake -B ${{github.workspace}}/build -DCMAKE_BUILD_TYPE=${{env.BUILD_TYPE}}
 
     - name: Build
       # Build your program with the given configuration

CMakeLists.txt

@@ -14,6 +14,18 @@ add_subdirectory(${PROJECT_NAME})
 
 find_package(Git REQUIRED)
 
+
+# Check if the target platform is 64-bit
+if (CMAKE_SIZEOF_VOID_P EQUAL 8)
+    message(STATUS "64-bit detected, adding -m32 flag for 32-bit compilation")
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -m32")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -m32")
+    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -m32")
+    set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -m32")
+else()
+    message(STATUS "32-bit detected, no additional flags needed")
+endif()
+
 # fetch all submodules explicitly as there are nested ones
 execute_process(
     COMMAND ${GIT_EXECUTABLE} submodule update --init --recursive