Test headers are kosher

Author: revmischa

.github/workflows/build_linux.yml

@@ -43,6 +43,27 @@ jobs:
           cmake --build "${{ github.workspace }}/cmake-build" --config "Debug" --target install
           cmake --build "${{ github.workspace }}/cmake-build" --config "Release" --target install
 
+      # appended to the end of the build-shared job steps:
+      - name: Check Installed Headers Compile Cleanly
+        run: |
+          mkdir -p header-check
+          cd header-check
+          cmake -S . -B build -DCMAKE_C_STANDARD=99 -DMYAPI_INCLUDE_DIR="${{ github.workspace }}/install/include" <<EOF
+          cmake_minimum_required(VERSION 3.15)
+          project(HeaderCheck C)
+          
+          file(GLOB PUBLIC_HEADERS "\${MYAPI_INCLUDE_DIR}/*.h")
+          
+          foreach(header IN LISTS PUBLIC_HEADERS)
+          get_filename_component(header_file "\${header}" NAME)
+          set(test_source "\${CMAKE_BINARY_DIR}/check_\${header_file}.c")
+          file(WRITE "\${test_source}" "#include <\${header_file}>\nint main(void) { return 0; }\n")
+          add_executable("check_\${header_file}" "\${test_source}")
+          target_include_directories("check_\${header_file}" PRIVATE "\${MYAPI_INCLUDE_DIR}")
+          endforeach()
+          EOF
+          cmake --build build --parallel
+
       - name: Upload Artifact
         uses: actions/upload-artifact@v4
         with: