Add API header compile tests for C

This will enable any future changes to the header to be tested. These additional build checks are only executed if BUILD_TESTING is enabled (e.g. in our automated build checks) to speed up release builds.

Author: kblaschke

cmake/TestAPIHeaders.cmake

@@ -0,0 +1,51 @@
+cmake_minimum_required(VERSION 3.21 FATAL_ERROR)
+
+# Compile-test C API headers
+macro(TEST_API_HEADERS _target _include_dirs _includes)
+    set(_test_project_dir "${CMAKE_CURRENT_BINARY_DIR}/${_target}")
+    set(HEADER_TEST_OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/${_target}.done)
+
+    add_custom_command(OUTPUT ${HEADER_TEST_OUTPUT}
+            # Create test project directory
+            COMMAND ${CMAKE_COMMAND}
+            ARGS
+            -E make_directory "${_test_project_dir}"
+
+            # Copy project CMake file into it
+            COMMAND ${CMAKE_COMMAND}
+            ARGS
+            -E copy_if_different "${CMAKE_SOURCE_DIR}/cmake/TestAPIHeadersProject.cmake" "${_test_project_dir}/CMakeLists.txt"
+
+            # Delete any existing build dir to re-run all checks
+            COMMAND ${CMAKE_COMMAND}
+            ARGS
+            -E rm -Rf "${_test_project_dir}/build"
+
+            # Configure the test project
+            COMMAND ${CMAKE_COMMAND}
+            ARGS
+            -S ${_test_project_dir}
+            -B ${_test_project_dir}/build
+            -DCMAKE_TOOLCHAIN_FILE=${CMAKE_TOOLCHAIN_FILE}
+            -DCMAKE_C_FLAGS=${CMAKE_C_FLAGS}
+            -DCMAKE_VERBOSE_MAKEFILE=${CMAKE_VERBOSE_MAKEFILE}
+            "-DINCLUDE_FILES=${_includes}"
+            "-DINCLUDE_DIRS=${_include_dirs}"
+            -DOUTPUT_FILE=${HEADER_TEST_OUTPUT}
+
+            DEPENDS
+            ${CMAKE_SOURCE_DIR}/cmake/TestAPIHeaders.cmake
+            ${CMAKE_SOURCE_DIR}/cmake/TestAPIHeadersProject.cmake
+            ${_includes}
+
+            VERBATIM
+            COMMENT "Testing C API headers: ${_target}"
+            )
+
+    add_custom_target(${_target} ALL
+            DEPENDS ${HEADER_TEST_OUTPUT}
+            )
+
+    unset(_test_project_dir)
+
+endmacro()

cmake/TestAPIHeadersProject.cmake

@@ -0,0 +1,20 @@
+cmake_minimum_required(VERSION 3.21 FATAL_ERROR)
+
+project(TestAPIHeaders
+        LANGUAGES C
+        )
+
+include(CheckIncludeFile)
+
+set(CMAKE_REQUIRED_INCLUDES "${INCLUDE_DIRS}")
+
+foreach(INCLUDE_HEADER ${INCLUDE_FILES})
+    cmake_path(GET INCLUDE_HEADER FILENAME INCLUDE_FILENAME)
+    string(REPLACE "." "_" INCLUDE_FILENAME "${INCLUDE_FILENAME}")
+    check_include_file(${INCLUDE_HEADER} PROJECTM_${INCLUDE_FILENAME}_INCLUDE_OK)
+    if(NOT PROJECTM_${INCLUDE_FILENAME}_INCLUDE_OK)
+        message(FATAL_ERROR "projectM API include file ${INCLUDE_HEADER} does not compile on its own!\nSee logs in ${CMAKE_CURRENT_BINARY_DIR}/CMakeFiles/ for additional information.")
+    endif()
+endforeach()
+
+file(TOUCH ${OUTPUT_FILE})

tests/libprojectM/CMakeLists.txt

@@ -1,5 +1,31 @@
 find_package(GTest 1.10 REQUIRED NO_MODULE)
 
+# Compile-test C API headers
+set(INCLUDE_FILES
+        ${CMAKE_SOURCE_DIR}/src/api/include/projectM-4/types.h
+
+        ${CMAKE_SOURCE_DIR}/src/api/include/projectM-4/audio.h
+        ${CMAKE_SOURCE_DIR}/src/api/include/projectM-4/callbacks.h
+        ${CMAKE_SOURCE_DIR}/src/api/include/projectM-4/core.h
+        ${CMAKE_SOURCE_DIR}/src/api/include/projectM-4/debug.h
+        ${CMAKE_SOURCE_DIR}/src/api/include/projectM-4/memory.h
+        ${CMAKE_SOURCE_DIR}/src/api/include/projectM-4/parameters.h
+        ${CMAKE_SOURCE_DIR}/src/api/include/projectM-4/render_opengl.h
+        ${CMAKE_SOURCE_DIR}/src/api/include/projectM-4/touch.h
+        ${CMAKE_SOURCE_DIR}/src/api/include/projectM-4/user_sprites.h
+
+        # Convenience header last, so it doesn't obscure issues with a single header above.
+        ${CMAKE_SOURCE_DIR}/src/api/include/projectM-4/projectM.h
+        )
+
+get_target_property(API_HEADER_INCLUDE_DIRS libprojectM::API INTERFACE_INCLUDE_DIRECTORIES)
+
+include(TestAPIHeaders)
+test_api_headers(TestMainAPIHeaders
+        "${API_HEADER_INCLUDE_DIRS}"
+        "${INCLUDE_FILES}"
+        )
+
 add_executable(projectM-unittest
         WaveformAlignerTest.cpp
         PresetFileParserTest.cpp

tests/playlist/CMakeLists.txt

@@ -4,6 +4,30 @@ endif()
 
 find_package(GTest 1.10 REQUIRED NO_MODULE)
 
+# Compile-test C API headers
+set(INCLUDE_FILES
+        ${CMAKE_SOURCE_DIR}/src/playlist/api/projectM-4/playlist_types.h
+
+        ${CMAKE_SOURCE_DIR}/src/playlist/api/projectM-4/playlist_callbacks.h
+        ${CMAKE_SOURCE_DIR}/src/playlist/api/projectM-4/playlist_core.h
+        ${CMAKE_SOURCE_DIR}/src/playlist/api/projectM-4/playlist_filter.h
+        ${CMAKE_SOURCE_DIR}/src/playlist/api/projectM-4/playlist_items.h
+        ${CMAKE_SOURCE_DIR}/src/playlist/api/projectM-4/playlist_memory.h
+        ${CMAKE_SOURCE_DIR}/src/playlist/api/projectM-4/playlist_playback.h
+
+        # Convenience header last, so it doesn't obscure issues with a single header above.
+        ${CMAKE_SOURCE_DIR}/src/playlist/api/projectM-4/playlist.h
+        )
+
+get_target_property(API_HEADER_INCLUDE_DIRS_MAIN libprojectM::API INTERFACE_INCLUDE_DIRECTORIES)
+get_target_property(API_HEADER_INCLUDE_DIRS_PLAYLIST projectM_playlist_main INTERFACE_INCLUDE_DIRECTORIES)
+
+include(TestAPIHeaders)
+test_api_headers(TestPlaylistAPIHeaders
+        "${API_HEADER_INCLUDE_DIRS_MAIN};${API_HEADER_INCLUDE_DIRS_PLAYLIST}"
+        "${INCLUDE_FILES}"
+        )
+
 add_executable(projectM-playlist-unittest
         $<TARGET_OBJECTS:projectM_playlist_main>
         APITest.cpp