Differential D4961 Diff 15519 cmake/modules/AddCompilerFlags.cmake

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cmake/modules/AddCompilerFlags.cmake

Show First 20 Lines • Show All 110 Lines • ▼ Show 20 Lines	function(add_compile_definitions_to_configuration CONFIGURATION)
endforeach()		endforeach()
endfunction()		endfunction()

# Note that CMake does not provide any facility to check that a linker flag is		# Note that CMake does not provide any facility to check that a linker flag is
# supported by the compiler.		# supported by the compiler.
# However since CMake 3.2 introduced the CMP0056 policy, the		# However since CMake 3.2 introduced the CMP0056 policy, the
# CMAKE_EXE_LINKER_FLAGS variable is used by the try_compile function, so there		# CMAKE_EXE_LINKER_FLAGS variable is used by the try_compile function, so there
# is a workaround that allow for testing the linker flags.		# is a workaround that allow for testing the linker flags.
function(add_linker_flags)		function(check_linker_flag RESULT FLAG)
foreach(f ${ARGN})
sanitize_c_cxx_definition("have_linker_" ${f} FLAG_IS_SUPPORTED)

# Some linkers (e.g.: Clang) will issue a -Wunused-command-line-argument		# Some linkers (e.g.: Clang) will issue a -Wunused-command-line-argument
# warning when an unknown linker flag is set.		# warning when an unknown linker flag is set.
# Using -Werror will promote these warnings to errors so		# Using -Werror will promote these warnings to errors so
# CHECK_CXX_COMPILER_FLAG() will return false, preventing the flag from		# CHECK_CXX_COMPILER_FLAG() will return false, preventing the flag from
# being set.		# being set.
add_compiler_flags_to_var(		add_compiler_flags_to_var(
CMAKE_REQUIRED_FLAGS		CMAKE_REQUIRED_FLAGS
CXX		CXX
"-Werror=unused-command-line-argument"		"-Werror=unused-command-line-argument"
)		)

# Save the current linker flags		# Save the current linker flags
set(SAVE_CMAKE_EXE_LINKERFLAGS ${CMAKE_EXE_LINKER_FLAGS})		set(SAVE_CMAKE_EXE_LINKERFLAGS ${CMAKE_EXE_LINKER_FLAGS})

# If the flag is already set, avoid duplicating it		# If the flag is already set, avoid duplicating it
string(FIND "${CMAKE_EXE_LINKER_FLAGS}" "${f}" FLAG_POSITION)		string(FIND "${CMAKE_EXE_LINKER_FLAGS}" "${FLAG}" FLAG_POSITION)
if(${FLAG_POSITION} LESS 0)		if(${FLAG_POSITION} LESS 0)
string(APPEND CMAKE_EXE_LINKER_FLAGS " ${f}")		string(APPEND CMAKE_EXE_LINKER_FLAGS " ${FLAG}")
endif()		endif()

# CHECK_CXX_COMPILER_FLAG calls CHECK_CXX_SOURCE_COMPILES which in turn		# CHECK_CXX_COMPILER_FLAG calls CHECK_CXX_SOURCE_COMPILES which in turn
# calls try_compile, so it will check our flag		# calls try_compile, so it will check our flag
CHECK_CXX_COMPILER_FLAG("" ${FLAG_IS_SUPPORTED})		CHECK_CXX_COMPILER_FLAG("" ${RESULT})

# Unset the -Werror=unused-command-line-argument flag if it is set.
remove_compiler_flags_from_var(
CMAKE_REQUIRED_FLAGS
"-Werror=unused-command-line-argument"
)

# If the flag is not supported restore CMAKE_EXE_LINKER_FLAGS		# Restore CMAKE_EXE_LINKER_FLAGS
if(NOT ${FLAG_IS_SUPPORTED})
set(CMAKE_EXE_LINKER_FLAGS ${SAVE_CMAKE_EXE_LINKERFLAGS})		set(CMAKE_EXE_LINKER_FLAGS ${SAVE_CMAKE_EXE_LINKERFLAGS})

		set(${RESULT} ${${RESULT}} PARENT_SCOPE)
		endfunction()

		function(add_linker_flags)
		foreach(f ${ARGN})
		sanitize_c_cxx_definition("have_linker_" ${f} FLAG_IS_SUPPORTED)

		check_linker_flag(${FLAG_IS_SUPPORTED} ${f})

		# If the flag is supported, add it to CMAKE_EXE_LINKER_FLAGS
		if(${${FLAG_IS_SUPPORTED}})
		set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${f}" PARENT_SCOPE)
endif()		endif()
endforeach()		endforeach()
set(CMAKE_EXE_LINKER_FLAGS ${CMAKE_EXE_LINKER_FLAGS} PARENT_SCOPE)
endfunction()		endfunction()