Merge pull request #2256 from akohlmey/cmake-use-alternate-linker (7d46aa61) · Commits · 郑智淋 / lammps

cmake/CMakeLists.txt

+6 −0

Original line number	Diff line number	Diff line
		@@ -747,6 +747,12 @@ if (${_index} GREATER -1)
		endif()
		message(STATUS "<<< Linker flags: >>>")
		message(STATUS "Executable name: ${LAMMPS_BINARY}")
		if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.13)
		get_target_property(OPTIONS lammps LINK_OPTIONS)
		if(OPTIONS)
		message(STATUS "Linker options: ${OPTIONS}")
		endif()
		endif()
		if(CMAKE_EXE_LINKER_FLAGS)
		message(STATUS "Executable linker flags: ${CMAKE_EXE_LINKER_FLAGS}")
		endif()

+27 −0

Original line number	Diff line number	Diff line
		@@ -16,6 +16,33 @@ if(ENABLE_TESTING)
		set(MEMORYCHECK_COMMAND "${VALGRIND_BINARY}" CACHE FILEPATH "Memory Check Command")
		set(MEMORYCHECK_COMMAND_OPTIONS "${VALGRIND_DEFAULT_OPTIONS}" CACHE STRING "Memory Check Command Options")

		# check if a faster linker is available.
		# only verified with GNU and Clang compilers and new CMake
		if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.13)
		if((${CMAKE_CXX_COMPILER_ID} STREQUAL "GNU")
		OR (${CMAKE_CXX_COMPILER_ID} STREQUAL "Clang"))
		include(CheckCXXCompilerFlag)
		set(CMAKE_CUSTOM_LINKER_DEFAULT default)
		check_cxx_compiler_flag(-fuse-ld=lld HAVE_LLD_LINKER)
		check_cxx_compiler_flag(-fuse-ld=gold HAVE_GOLD_LINKER)
		check_cxx_compiler_flag(-fuse-ld=bfd HAVE_BFD_LINKER)
		if(HAVE_LLD_LINKER)
		set(CMAKE_CUSTOM_LINKER_DEFAULT lld)
		elseif(HAVE_GOLD_LINKER)
		set(CMAKE_CUSTOM_LINKER_DEFAULT gold)
		elseif(HAVE_BFD_LINKER)
		set(CMAKE_CUSTOM_LINKER_DEFAULT bfd)
		endif()
		set(CMAKE_CUSTOM_LINKER_VALUES lld gold bfd default)
		set(CMAKE_CUSTOM_LINKER ${CMAKE_CUSTOM_LINKER_DEFAULT} CACHE STRING "Choose a custom linker for faster linking (lld, gold, bfd, default)")
		validate_option(CMAKE_CUSTOM_LINKER CMAKE_CUSTOM_LINKER_VALUES)
		mark_as_advanced(CMAKE_CUSTOM_LINKER)
		if(NOT "${CMAKE_CUSTOM_LINKER}" STREQUAL "default")
		target_link_options(lammps PUBLIC -fuse-ld=${CMAKE_CUSTOM_LINKER})
		endif()
		endif()
		endif()

		include(CTest)

		enable_testing()

+17 −0

Original line number	Diff line number	Diff line
		@@ -259,6 +259,23 @@ and working.
		of mis-compiled code (or an undesired large loss of precision due
		to significant reordering of operations and thus less error cancellation).

		Use custom linker for faster link times when ENABLE_TESTING is active
		^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

		When compiling LAMMPS with enabled tests, most test executables will
		need to be linked against the LAMMPS library. Since this can be a
		large with many C++ objects when many packages are enabled, link times
		can become very long on machines that use the GNU BFD linker (e.g.
		Linux systems). Alternatives like the ``lld`` linker of the LLVM project
		or the ``gold`` linker available with GNU binutils can speed up this step
		substantially. CMake will by default test if any of the two can be
		enabled and use it when ``ENABLE_TESTING`` is active. It can also be
		selected manually through the ``CMAKE_CUSTOM_LINKER`` CMake variable.
		Allowed values are ``lld``, ``gold``, ``bfd``, or ``default``. The
		``default`` option will use the system default linker otherwise, the
		linker is chosen explicitly. This option is only available for the
		GNU or Clang C++ compiler.

		Tests for other components and utility functions
		^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

+1 −0