cmake/CustomCompiler: optimize the code

especially, only create one temp file per language

Author: illwieckz

cmake/CustomCompiler.cmake

@@ -24,24 +24,13 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 # SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-function(detect_custom_clang lang)
-	set(C_EXT ".c")
-	set(CXX_EXT ".cpp")
-
-	string(RANDOM RANDOM_SUFFIX)
-
-	set(COMPILER_TEST_FILE "${PROJECT_BINARY_DIR}/test_compiler_${RANDOM_SUFFIX}${${lang}_EXT}")
-
-	file(TOUCH "${COMPILER_TEST_FILE}")
-
+function(detect_custom_clang_version lang file)
 	# Parse “<compiler> -E -dM <source file>”
-	execute_process(COMMAND "${CMAKE_${lang}_COMPILER}" ${CUSTOM_${lang}_COMPILER_SUBCOMMAND} -E -dM "${COMPILER_TEST_FILE}"
+	execute_process(COMMAND "${CMAKE_${lang}_COMPILER}" ${CUSTOM_${lang}_COMPILER_SUBCOMMAND} -E -dM "${file}"
 		OUTPUT_VARIABLE CUSTOM_${lang}_CLANG_OUTPUT
 		RESULT_VARIABLE CUSTOM_${lang}_RETURN_CODE
 		ERROR_QUIET)
 
-	file(REMOVE "${COMPILER_TEST_FILE}")
-
 	if (NOT CUSTOM_${lang}_RETURN_CODE) # Success
 		if ("${CUSTOM_${lang}_CLANG_OUTPUT}" MATCHES "\#define __clang_version__ ")
 			string(REGEX REPLACE ".*#define __clang_version__ \"([^ ]+)[\" ]*.*" "\\1" CUSTOM_${lang}_CLANG_VERSION "${CUSTOM_${lang}_CLANG_OUTPUT}")
@@ -50,7 +39,7 @@ function(detect_custom_clang lang)
 	endif()
 endfunction()
 
-function(detect_custom_gcc lang)
+function(detect_custom_gcc_version lang)
 	# This will only set the GCC version if the custom compiler is detected
 	# as GCC by CMake.
 	if(CUSTOM_${lang}_COMPILER_ID AND CMAKE_${lang}_COMPILER_ID STREQUAL "GNU")
@@ -59,24 +48,13 @@ function(detect_custom_gcc lang)
 	endif()
 endfunction()
 
-function(detect_custom_compiler lang)
-	set(C_EXT ".c")
-	set(CXX_EXT ".cpp")
-
-	string(RANDOM RANDOM_SUFFIX)
-
-	set(COMPILER_TEST_FILE "${PROJECT_BINARY_DIR}/test_compiler_${RANDOM_SUFFIX}${${lang}_EXT}")
-
-	file(TOUCH "${COMPILER_TEST_FILE}")
-
+function(detect_custom_compiler_id_version lang file)
 	# Parse “<compiler> -E -dM <source file>”
-	execute_process(COMMAND "${CMAKE_${lang}_COMPILER}" -E -dM "${COMPILER_TEST_FILE}"
+	execute_process(COMMAND "${CMAKE_${lang}_COMPILER}" -E -dM "${file}"
 		OUTPUT_VARIABLE CUSTOM_${lang}_COMPILER_OUTPUT
 		RESULT_VARIABLE CUSTOM_${lang}_RETURN_CODE
 		ERROR_QUIET)
 
-	file(REMOVE "${COMPILER_TEST_FILE}")
-
 	if (NOT CUSTOM_${lang}_RETURN_CODE) # Success
 		# PNaCL
 		if ("${CUSTOM_${lang}_COMPILER_OUTPUT}" MATCHES "\#define __pnacl__ 1")
@@ -161,11 +139,24 @@ function(detect_custom_compiler lang)
 	endif()
 endfunction()
 
-detect_custom_compiler("C")
-detect_custom_compiler("CXX")
+function(detect_custom_compiler lang)
+	set(C_EXT ".c")
+	set(CXX_EXT ".cpp")
 
-detect_custom_clang("C")
-detect_custom_clang("CXX")
+	string(RANDOM RANDOM_SUFFIX)
+	set(COMPILER_TEST_FILE "${PROJECT_BINARY_DIR}/test_compiler_${RANDOM_SUFFIX}${${lang}_EXT}")
+	file(TOUCH "${COMPILER_TEST_FILE}")
+
+	detect_custom_compiler_id_version("${lang}" "${COMPILER_TEST_FILE}")
+	detect_custom_clang_version("${lang}" "${COMPILER_TEST_FILE}")
+	detect_custom_gcc_version("${lang}")
 
-detect_custom_gcc("C")
-detect_custom_gcc("CXX")
+	file(REMOVE "${COMPILER_TEST_FILE}")
+
+	set(CUSTOM_${lang}_COMPILER_ID "${CUSTOM_${lang}_COMPILER_ID}" PARENT_SCOPE)
+	set(CUSTOM_${lang}_COMPILER_VERSION "${CUSTOM_${lang}_COMPILER_VERSION}" PARENT_SCOPE)
+	set(CUSTOM_${lang}_COMPILER_SUBCOMMAND "${CUSTOM_${lang}_COMPILER_SUBCOMMAND}" PARENT_SCOPE)
+
+	set(CUSTOM_${lang}_CLANG_VERSION "${CUSTOM_${lang}_CLANG_VERSION}" PARENT_SCOPE)
+	set(CUSTOM_${lang}_GCC_VERSION "${CUSTOM_${lang}_GCC_VERSION}" PARENT_SCOPE)
+endfunction()

cmake/DaemonCompiler.cmake

@@ -27,11 +27,11 @@
 include(CustomCompiler)
 
 function(detect_daemon_compiler lang)
+	detect_custom_compiler("${lang}")
+
 	set(C_NAME "C")
 	set(CXX_NAME "C++")
 
-	get_filename_component(DAEMON_${LANG}_COMPILER_BASENAME "${CMAKE_${lang}_COMPILER}" NAME)
-
 	if (CUSTOM_${lang}_COMPILER_ID)
 		set(DAEMON_${lang}_COMPILER_ID "${CUSTOM_${lang}_COMPILER_ID}")
 	elseif (CMAKE_${lang}_COMPILER_ID)
@@ -60,6 +60,8 @@ function(detect_daemon_compiler lang)
 		set(DAEMON_${lang}_COMPILER_VERSION "${DAEMON_${lang}_COMPILER_VERSION}/gcc-${CUSTOM_${lang}_GCC_VERSION}")
 	endif()
 
+	get_filename_component(DAEMON_${LANG}_COMPILER_BASENAME "${CMAKE_${lang}_COMPILER}" NAME)
+
 	set(DAEMON_${lang}_COMPILER_STRING "${DAEMON_${lang}_COMPILER_ID} ${DAEMON_${lang}_COMPILER_VERSION} ${DAEMON_${lang}_COMPILER_BASENAME}")
 	set(DAEMON_${lang}_COMPILER_STRING "${DAEMON_${lang}_COMPILER_STRING}" PARENT_SCOPE)
 
@@ -68,8 +70,9 @@ endfunction()
 
 message(STATUS "CMake generator: ${CMAKE_GENERATOR}")
 
-detect_daemon_compiler("C")
-detect_daemon_compiler("CXX")
+foreach(lang C;CXX)
+	detect_daemon_compiler("${lang}")
+endforeach()
 
 if (CMAKE_COMPILER_IS_GNUCXX)
 	set(DAEMON_COMPILER_IS_GNUCXX ON)