CMake/Modules/CMakeDetermineCCompiler.cmake

138 lines
5.6 KiB
CMake

# determine the compiler to use for C programs
# NOTE, a generator may set CMAKE_C_COMPILER before
# loading this file to force a compiler.
# use environment variable CC first if defined by user, next use
# the cmake variable CMAKE_GENERATOR_CC which can be defined by a generator
# as a default compiler
# If the internal cmake variable _CMAKE_TOOLCHAIN_PREFIX is set, this is used
# as prefix for the tools (e.g. arm-elf-gcc, arm-elf-ar etc.). This works
# currently with the GNU crosscompilers.
#
# Sets the following variables:
# CMAKE_C_COMPILER
# CMAKE_AR
# CMAKE_RANLIB
# CMAKE_COMPILER_IS_GNUCC
#
# If not already set before, it also sets
# _CMAKE_TOOLCHAIN_PREFIX
IF(NOT CMAKE_C_COMPILER)
SET(CMAKE_CXX_COMPILER_INIT NOTFOUND)
# prefer the environment variable CC
IF($ENV{CC} MATCHES ".+")
GET_FILENAME_COMPONENT(CMAKE_C_COMPILER_INIT $ENV{CC} PROGRAM PROGRAM_ARGS CMAKE_C_FLAGS_ENV_INIT)
IF(CMAKE_C_FLAGS_ENV_INIT)
SET(CMAKE_C_COMPILER_ARG1 "${CMAKE_C_FLAGS_ENV_INIT}" CACHE STRING "First argument to C compiler")
ENDIF(CMAKE_C_FLAGS_ENV_INIT)
IF(NOT EXISTS ${CMAKE_C_COMPILER_INIT})
MESSAGE(FATAL_ERROR "Could not find compiler set in environment variable CC:\n$ENV{CC}.")
ENDIF(NOT EXISTS ${CMAKE_C_COMPILER_INIT})
ENDIF($ENV{CC} MATCHES ".+")
# next try prefer the compiler specified by the generator
IF(CMAKE_GENERATOR_CC)
IF(NOT CMAKE_C_COMPILER_INIT)
SET(CMAKE_C_COMPILER_INIT ${CMAKE_GENERATOR_CC})
ENDIF(NOT CMAKE_C_COMPILER_INIT)
ENDIF(CMAKE_GENERATOR_CC)
# finally list compilers to try
IF(CMAKE_C_COMPILER_INIT)
SET(CMAKE_C_COMPILER_LIST ${CMAKE_C_COMPILER_INIT})
ELSE(CMAKE_C_COMPILER_INIT)
SET(CMAKE_C_COMPILER_LIST ${_CMAKE_TOOLCHAIN_PREFIX}gcc ${_CMAKE_TOOLCHAIN_PREFIX}cc cl bcc xlc)
ENDIF(CMAKE_C_COMPILER_INIT)
# Find the compiler.
IF (_CMAKE_USER_CXX_COMPILER_PATH)
FIND_PROGRAM(CMAKE_C_COMPILER NAMES ${CMAKE_C_COMPILER_LIST} PATHS ${_CMAKE_USER_CXX_COMPILER_PATH} DOC "C compiler" NO_DEFAULT_PATH)
ENDIF (_CMAKE_USER_CXX_COMPILER_PATH)
FIND_PROGRAM(CMAKE_C_COMPILER NAMES ${CMAKE_C_COMPILER_LIST} DOC "C compiler")
IF(CMAKE_C_COMPILER_INIT AND NOT CMAKE_C_COMPILER)
SET(CMAKE_C_COMPILER "${CMAKE_C_COMPILER_INIT}" CACHE FILEPATH "C compiler" FORCE)
ENDIF(CMAKE_C_COMPILER_INIT AND NOT CMAKE_C_COMPILER)
ELSE(NOT CMAKE_C_COMPILER)
# we only get here if CMAKE_C_COMPILER was specified using -D or a pre-made CMakeCache.txt
# (e.g. via ctest) or set in CMAKE_TOOLCHAIN_FILE
# if CMAKE_C_COMPILER is a list of length 2, use the first item as
# CMAKE_C_COMPILER and the 2nd one as CMAKE_C_COMPILER_ARG1
LIST(LENGTH CMAKE_C_COMPILER _CMAKE_C_COMPILER_LIST_LENGTH)
IF("${_CMAKE_C_COMPILER_LIST_LENGTH}" EQUAL 2)
LIST(GET CMAKE_C_COMPILER 1 CMAKE_C_COMPILER_ARG1)
LIST(GET CMAKE_C_COMPILER 0 CMAKE_C_COMPILER)
ENDIF("${_CMAKE_C_COMPILER_LIST_LENGTH}" EQUAL 2)
# if a compiler was specified by the user but without path,
# now try to find it with the full path
# if it is found, force it into the cache,
# if not, don't overwrite the setting (which was given by the user) with "NOTFOUND"
# if the C compiler already had a path, reuse it for searching the CXX compiler
GET_FILENAME_COMPONENT(_CMAKE_USER_C_COMPILER_PATH "${CMAKE_C_COMPILER}" PATH)
IF(NOT _CMAKE_USER_C_COMPILER_PATH)
FIND_PROGRAM(CMAKE_C_COMPILER_WITH_PATH NAMES ${CMAKE_C_COMPILER})
MARK_AS_ADVANCED(CMAKE_C_COMPILER_WITH_PATH)
IF(CMAKE_C_COMPILER_WITH_PATH)
SET(CMAKE_C_COMPILER ${CMAKE_C_COMPILER_WITH_PATH} CACHE STRING "C compiler" FORCE)
ENDIF(CMAKE_C_COMPILER_WITH_PATH)
ENDIF(NOT _CMAKE_USER_C_COMPILER_PATH)
ENDIF(NOT CMAKE_C_COMPILER)
MARK_AS_ADVANCED(CMAKE_C_COMPILER)
IF (NOT _CMAKE_TOOLCHAIN_LOCATION)
GET_FILENAME_COMPONENT(_CMAKE_TOOLCHAIN_LOCATION "${CMAKE_C_COMPILER}" PATH)
ENDIF (NOT _CMAKE_TOOLCHAIN_LOCATION)
# if we have a gcc cross compiler, they have usually some prefix, like
# e.g. powerpc-linux-gcc, arm-elf-gcc or i586-mingw32msvc-gcc
# the other tools of the toolchain usually have the same prefix
IF (NOT _CMAKE_TOOLCHAIN_PREFIX)
GET_FILENAME_COMPONENT(COMPILER_BASENAME "${CMAKE_C_COMPILER}" NAME_WE)
IF (COMPILER_BASENAME MATCHES "^(.+-)g?cc")
STRING(REGEX REPLACE "^(.+-)g?cc" "\\1" _CMAKE_TOOLCHAIN_PREFIX "${COMPILER_BASENAME}")
ENDIF (COMPILER_BASENAME MATCHES "^(.+-)g?cc")
ENDIF (NOT _CMAKE_TOOLCHAIN_PREFIX)
# Build a small source file to identify the compiler.
IF(${CMAKE_GENERATOR} MATCHES "Visual Studio")
SET(CMAKE_C_COMPILER_ID_RUN 1)
SET(CMAKE_C_PLATFORM_ID "Windows")
# TODO: Set the compiler id. It is probably MSVC but
# the user may be using an integrated Intel compiler.
# SET(CMAKE_C_COMPILER_ID "MSVC")
ENDIF(${CMAKE_GENERATOR} MATCHES "Visual Studio")
IF(NOT CMAKE_C_COMPILER_ID_RUN)
SET(CMAKE_C_COMPILER_ID_RUN 1)
# Try to identify the compiler.
SET(CMAKE_C_COMPILER_ID)
INCLUDE(${CMAKE_ROOT}/Modules/CMakeDetermineCompilerId.cmake)
CMAKE_DETERMINE_COMPILER_ID(C CFLAGS ${CMAKE_ROOT}/Modules/CMakeCCompilerId.c)
# Set old compiler and platform id variables.
IF("${CMAKE_C_COMPILER_ID}" MATCHES "GNU")
SET(CMAKE_COMPILER_IS_GNUCC 1)
ENDIF("${CMAKE_C_COMPILER_ID}" MATCHES "GNU")
IF("${CMAKE_C_PLATFORM_ID}" MATCHES "MinGW")
SET(CMAKE_COMPILER_IS_MINGW 1)
ELSEIF("${CMAKE_C_PLATFORM_ID}" MATCHES "Cygwin")
SET(CMAKE_COMPILER_IS_CYGWIN 1)
ENDIF("${CMAKE_C_PLATFORM_ID}" MATCHES "MinGW")
ENDIF(NOT CMAKE_C_COMPILER_ID_RUN)
INCLUDE(CMakeFindBinUtils)
# configure variables set in this file for fast reload later on
CONFIGURE_FILE(${CMAKE_ROOT}/Modules/CMakeCCompiler.cmake.in
"${CMAKE_PLATFORM_ROOT_BIN}/CMakeCCompiler.cmake" IMMEDIATE)
SET(CMAKE_C_COMPILER_ENV_VAR "CC")