cmake: Add clang-format support

This does not rely on the "integrated" clang-format, but instead uses a custom target to achieve the goal. Supports file filtering (to ensure that clang-format only affects supported files), automatic dependency by the project (always run before build), multiple targets and a global target.

Options are:
- TARGETS <target> ...: Targets to add clang-format support to.
- DEPENDENCY: Add a dependency to the given targets so that clang-format runs before building.
- REGEX: Filter out files of the given targets, defaults to '\.(h|hpp|c|cpp)'.
- GLOBAL: Add a global CLANG_FORMAT target.

CMakeLists.txt

@@ -16,8 +16,7 @@
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 
 # CMake Setup
-CMake_Minimum_Required(VERSION 3.8.0)
+cmake_minimum_required(VERSION 3.8.0)
-Include("cmake/util.cmake")
 
 # Automatic Versioning
 set(VERSION_MAJOR 0)
@@ -28,7 +27,7 @@ set(PROJECT_COMMIT "N/A")
 if(EXISTS "${CMAKE_CURRENT_LIST_DIR}/.git")
 	set(GIT_RESULT "")
 	set(GIT_OUTPUT "")
-	EXECUTE_PROCESS(
+	execute_process(
 		COMMAND git rev-list --count --topo-order ${VERSION_MAJOR}.${VERSION_MINOR}.${VERSION_PATCH}..HEAD
 		WORKING_DIRECTORY ${CMAKE_CURRENT_LIST_DIR}
 		RESULT_VARIABLE GIT_RESULT
@@ -38,7 +37,7 @@ if(EXISTS "${CMAKE_CURRENT_LIST_DIR}/.git")
 	if(GIT_RESULT EQUAL 0)
 		set(VERSION_TWEAK ${GIT_OUTPUT})
 	endif()
-	EXECUTE_PROCESS(
+	execute_process(
 		COMMAND git rev-parse HEAD
 		WORKING_DIRECTORY ${CMAKE_CURRENT_LIST_DIR}
 		RESULT_VARIABLE GIT_RESULT
@@ -51,7 +50,7 @@ if(EXISTS "${CMAKE_CURRENT_LIST_DIR}/.git")
 endif()
 
 # Define Project
-PROJECT(
+project(
 	obs-stream-effects
 	VERSION ${VERSION_MAJOR}.${VERSION_MINOR}.${VERSION_PATCH}.${VERSION_TWEAK}
 )
@@ -64,6 +63,13 @@ set(PROJECT_COPYRIGHT_YEARS "2018 - 2019")
 # Setup / Bootstrap
 ################################################################################
 
+# Search Path
+set(CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake/;${CMAKE_MODULE_PATH}")
+
+# CMake Modules
+include("util")
+include("ClangToolkit")
+
 # Detect Build Type
 if("${CMAKE_SOURCE_DIR}" STREQUAL "${PROJECT_SOURCE_DIR}")
 	set(PropertyPrefix "")
@@ -80,9 +86,6 @@ else()
 	set(ARCH "x64")
 endif()
 
-# Search Path
-set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/cmake/modules/")
-
 # All Warnings, Extra Warnings, Pedantic
 if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
 	# using Clang
@@ -199,7 +202,7 @@ endif()
 
 # CMake Modules
 if(${PropertyPrefix}OBS_DOWNLOAD)
-	include("cmake/DownloadProject.cmake")
+	include("DownloadProject")
 endif()
 
 # Load OBS Studio
@@ -264,6 +267,10 @@ set(PROJECT_LIBRARIES
 set(PROJECT_TEMPLATES
 	"${PROJECT_SOURCE_DIR}/cmake/version.hpp.in"
 	"${PROJECT_SOURCE_DIR}/cmake/module.cpp.in"
+	"${PROJECT_SOURCE_DIR}/cmake/ClangToolkit.cmake"
+	"${PROJECT_SOURCE_DIR}/cmake/DownloadProject.cmake"
+	"${PROJECT_SOURCE_DIR}/cmake/DownloadProject.CmakeLists.cmake.in"
+	"${PROJECT_SOURCE_DIR}/cmake/util.cmake"
 )
 if(WIN32)
 	list(APPEND PROJECT_TEMPLATES
@@ -412,6 +419,12 @@ add_library(${PROJECT_NAME} MODULE
 	${PROJECT_PRIVATE}
 )
 
+# Clang-Format
+clang_format(
+	TARGETS ${PROJECT_NAME}
+	DEPENDENCY
+)
+
 # Include Directories
 target_include_directories(${PROJECT_NAME}
 	PUBLIC

cmake/ClangToolkit.cmake

@@ -0,0 +1,71 @@
+set(CLANG_FORMAT_BIN "clang-format" CACHE PATH "Path (or name) of the clang-format binary")
+
+function(clang_format)
+	cmake_parse_arguments(
+		PARSE_ARGV 0
+		_CLANG_FORMAT
+		"DEPENDENCY;GLOBAL"
+		"REGEX"
+		"TARGETS"
+	)
+
+	if(NOT EXISTS ${CLANG_FORMAT_BIN})
+		find_program(clang_format_bin_tmp ${CLANG_FORMAT_BIN})
+		if(clang_format_bin_tmp)
+			set(CLANG_FORMAT_BIN "${clang_format_bin_tmp}" CACHE PATH "Path (or name) of the clang-format binary")
+			unset(clang_format_bin_tmp)
+		else()
+			message(FATAL_ERROR "Clang: Could not find clang-format at path '${CLANG_FORMAT_BIN}'.")
+		endif()
+	endif()
+
+	if(NOT _CLANG_FORMAT_FILTER)
+		set(_CLANG_FORMAT_FILTER "\.(h|hpp|c|cpp)$")
+	endif()
+
+	foreach(_target ${_CLANG_FORMAT_TARGETS})
+#		get_target_property(target_name ${_target} NAME)
+
+		get_target_property(target_sources_rel ${_target} SOURCES)
+		set(target_sources "")
+		foreach(source_relative ${target_sources_rel})
+			get_filename_component(source_absolute ${source_relative} ABSOLUTE)
+			list(APPEND target_sources ${source_absolute})
+		endforeach()
+		list(FILTER target_sources INCLUDE REGEX "${_CLANG_FORMAT_FILTER}")
+		unset(target_sources_rel)
+		
+		get_target_property(target_source_dir_rel ${_target} SOURCE_DIR)
+		get_filename_component(target_source_dir ${target_source_dir_rel} ABSOLUTE)
+		unset(target_source_dir_rel)
+
+		add_custom_target(${_target}_CLANG-FORMAT
+			COMMAND
+				${CLANG_FORMAT_BIN}
+				-style=file
+				-i
+				${target_sources}
+			COMMENT
+				"clang-format: Formatting ${_target}..."
+			WORKING_DIRECTORY
+				${target_source_dir_rel}
+		)
+
+		if(_CLANG_FORMAT_DEPENDENCY)
+			add_dependencies(${_target} ${_target}_CLANG-FORMAT)
+		endif()
+
+		if(_CLANG_FORMAT_GLOBAL)
+			if(TARGET CLANG-FORMAT)
+				add_dependencies(CLANG-FORMAT ${_target}_CLANG-FORMAT)
+			else()
+				add_custom_target(CLANG-FORMAT
+					DEPENDS
+						${_target}_CLANG-FORMAT
+					COMMENT
+						"clang-format: Formatting..."
+				)
+			endif()
+		endif()
+	endforeach()
+endfunction()