cxx/cmake/Modules/HandleLibCXXABI.cmake
Eric Fiselier cb7e32c290 [libcxx] Redo adding support for building and testing with an ABI library not along linker paths
Summary:
This is the second attempt at allowing for the use of libraries that the linker cannot find. The first attempt used `CMAKE_LIBRARY_PATH` and `find_library` to select which ABI library should be used. There were a number of problems with this approach:

- `find_library` didn't work with cmake targets (ie in-tree libcxxabi build)
- It wasn't always possible to determine where `find_library` actually found your library.
- `target_link_libraries` inserted the path of the ABI library into libc++'s RPATH when `find_library` was used.
- Linking libc++ and it's ABI library is a special case. It's a lot easier to keep it simple. 

After discussion with @cbergstrum a new approach was decided upon.
This patch achieve the same ends by simply using `LIBCXX_CXX_ABI_LIBRARY_PATH` to specify where to find the library (if the linker won't find it). When this variable is defined it is simply added as a library search path when linking libc++. It is a lot easier to duplicate this behavior in LIT. It also prevents libc++ from being linked with an RPATH.






Reviewers: mclow.lists, cbergstrom, chandlerc, danalbert

Reviewed By: chandlerc, danalbert

Subscribers: chandlerc, cfe-commits

Differential Revision: http://reviews.llvm.org/D5860

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@220157 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-19 00:42:41 +00:00

98 lines
3.5 KiB
CMake

#===============================================================================
# Add an ABI library if appropriate
#===============================================================================
#
# _setup_abi: Set up the build to use an ABI library
#
# Parameters:
# abidefines: A list of defines needed to compile libc++ with the ABI library
# abilib : The ABI library to link against.
# abifiles : A list of files (which may be relative paths) to copy into the
# libc++ build tree for the build. These files will also be
# installed alongside the libc++ headers.
# abidirs : A list of relative paths to create under an include directory
# in the libc++ build directory.
#
macro(setup_abi_lib abipathvar abidefines abilib abifiles abidirs)
list(APPEND LIBCXX_CXX_FEATURE_FLAGS ${abidefines})
set(${abipathvar} "${${abipathvar}}"
CACHE PATH
"Paths to C++ ABI header directories separated by ';'." FORCE
)
set(LIBCXX_CXX_ABI_LIBRARY ${abilib})
set(LIBCXX_ABILIB_FILES ${abifiles})
file(MAKE_DIRECTORY "${CMAKE_BINARY_DIR}/include")
foreach(_d ${abidirs})
file(MAKE_DIRECTORY "${CMAKE_BINARY_DIR}/include/${_d}")
endforeach()
foreach(fpath ${LIBCXX_ABILIB_FILES})
set(found FALSE)
foreach(incpath ${${abipathvar}})
if (EXISTS "${incpath}/${fpath}")
set(found TRUE)
get_filename_component(dstdir ${fpath} PATH)
get_filename_component(ifile ${fpath} NAME)
file(COPY "${incpath}/${fpath}"
DESTINATION "${CMAKE_BINARY_DIR}/include/${dstdir}"
)
install(FILES "${CMAKE_BINARY_DIR}/include/${fpath}"
DESTINATION include/c++/v1/${dstdir}
PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
)
list(APPEND abilib_headers "${CMAKE_BINARY_DIR}/include/${fpath}")
endif()
endforeach()
if (NOT found)
message(FATAL_ERROR "Failed to find ${fpath}")
endif()
endforeach()
add_custom_target(LIBCXX_CXX_ABI_DEPS DEPENDS ${abilib_headers})
include_directories("${CMAKE_BINARY_DIR}/include")
endmacro()
if ("${LIBCXX_CXX_ABI_LIBNAME}" STREQUAL "libstdc++" OR
"${LIBCXX_CXX_ABI_LIBNAME}" STREQUAL "libsupc++")
set(_LIBSUPCXX_INCLUDE_FILES
cxxabi.h bits/c++config.h bits/os_defines.h bits/cpu_defines.h
bits/cxxabi_tweaks.h bits/cxxabi_forced.h
)
if ("${LIBCXX_CXX_ABI_LIBNAME}" STREQUAL "libstdc++")
set(_LIBSUPCXX_DEFINES "-DLIBSTDCXX")
set(_LIBSUPCXX_LIBNAME stdc++)
else()
set(_LIBSUPCXX_DEFINES "")
set(_LIBSUPCXX_LIBNAME supc++)
endif()
setup_abi_lib("LIBCXX_LIBSUPCXX_INCLUDE_PATHS"
"-D__GLIBCXX__ ${_LIBSUPCXX_DEFINES}"
"${_LIBSUPCXX_LIBNAME}" "${_LIBSUPCXX_INCLUDE_FILES}" "bits"
)
elseif ("${LIBCXX_CXX_ABI_LIBNAME}" STREQUAL "libcxxabi")
if (LIBCXX_CXX_ABI_INTREE)
# Link against just-built "cxxabi" target.
set(CXXABI_LIBNAME cxxabi)
else()
# Assume c++abi is installed in the system, rely on -lc++abi link flag.
set(CXXABI_LIBNAME "c++abi")
endif()
setup_abi_lib("LIBCXX_LIBCXXABI_INCLUDE_PATHS" ""
${CXXABI_LIBNAME} "cxxabi.h" ""
)
elseif ("${LIBCXX_CXX_ABI_LIBNAME}" STREQUAL "libcxxrt")
setup_abi_lib("LIBCXX_LIBCXXRT_INCLUDE_PATHS" "-DLIBCXXRT"
"cxxrt" "cxxabi.h;unwind.h;unwind-arm.h;unwind-itanium.h" ""
)
elseif (NOT "${LIBCXX_CXX_ABI_LIBNAME}" STREQUAL "none")
message(FATAL_ERROR
"Currently libstdc++, libsupc++, libcxxabi, libcxxrt and none are "
"supported for c++ abi."
)
endif ()