llvm-mirror/cmake/modules/HandleLLVMStdlib.cmake
Erich Keane 8d0fafd361 Add support in CMake to statically link the C++ standard library.
It is sometimes useful to have the C++ standard library linked into the
assembly when compiling clang, particularly when distributing a compiler
onto systems that don't have a copy of stdlibc++ or libc++ installed.

This functionality should work with either GCC or Clang as the host
compiler, though statically linking libc++ (as may be required for
licensing purposes) is only possible if the host compiler is Clang with
a copy of libc++ available.

Differential Revision: https://reviews.llvm.org/D65603

llvm-svn: 368907
2019-08-14 19:55:59 +00:00

55 lines
1.8 KiB
CMake

# This CMake module is responsible for setting the standard library to libc++
# if the user has requested it.
include(DetermineGCCCompatible)
if(NOT DEFINED LLVM_STDLIB_HANDLED)
set(LLVM_STDLIB_HANDLED ON)
function(append value)
foreach(variable ${ARGN})
set(${variable} "${${variable}} ${value}" PARENT_SCOPE)
endforeach(variable)
endfunction()
include(CheckCXXCompilerFlag)
include(CheckLinkerFlag)
set(LLVM_LIBCXX_USED 0)
if(LLVM_ENABLE_LIBCXX)
if(LLVM_COMPILER_IS_GCC_COMPATIBLE)
check_cxx_compiler_flag("-stdlib=libc++" CXX_COMPILER_SUPPORTS_STDLIB)
check_linker_flag("-stdlib=libc++" CXX_LINKER_SUPPORTS_STDLIB)
if(CXX_COMPILER_SUPPORTS_STDLIB AND CXX_LINKER_SUPPORTS_STDLIB)
append("-stdlib=libc++"
CMAKE_CXX_FLAGS CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS
CMAKE_MODULE_LINKER_FLAGS)
set(LLVM_LIBCXX_USED 1)
else()
message(WARNING "Can't specify libc++ with '-stdlib='")
endif()
else()
message(WARNING "Not sure how to specify libc++ for this compiler")
endif()
endif()
if(LLVM_STATIC_LINK_CXX_STDLIB)
if(LLVM_COMPILER_IS_GCC_COMPATIBLE)
check_cxx_compiler_flag("-static-libstdc++"
CXX_COMPILER_SUPPORTS_STATIC_STDLIB)
check_linker_flag("-static-libstdc++" CXX_LINKER_SUPPORTS_STATIC_STDLIB)
if(CXX_COMPILER_SUPPORTS_STATIC_STDLIB AND
CXX_LINKER_SUPPORTS_STATIC_STDLIB)
append("-static-libstdc++"
CMAKE_EXE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS
CMAKE_MODULE_LINKER_FLAGS)
else()
message(WARNING
"Can't specify static linking for the C++ standard library")
endif()
else()
message(WARNING "Not sure how to specify static linking of C++ standard "
"library for this compiler")
endif()
endif()
endif()