llvm/tools/llvm-shlib/CMakeLists.txt
Sylvestre Ledru cd789d8cfe Add a linker script to version LLVM symbols
Summary:
This patch adds a very simple linker script to version the lib's symbols
and thus trying to avoid crashes if an application loads two different
LLVM versions (as long as they do not share data between them).

Note that we deliberately *don't* make LLVM_5.0 depend on LLVM_4.0:
they're incompatible and the whole point of this patch is
to tell the linker that.


Avoid unexpected crashes when two LLVM versions are used in the same process.

Author: Rebecca N. Palmer <rebecca_palmer@zoho.com>
Author: Lisandro Damían Nicanor Pérez Meyer <lisandro@debian.org>
Author: Sylvestre Ledru <sylvestre@debian.org>
Bug-Debian:  https://bugs.debian.org/848368


Reviewers: beanz, rnk

Reviewed By: rnk

Subscribers: mgorny, llvm-commits

Differential Revision: https://reviews.llvm.org/D31524

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300496 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-17 20:51:50 +00:00

98 lines
3.8 KiB
CMake

# This tool creates a shared library from the LLVM libraries. Generating this
# library is enabled by setting LLVM_BUILD_LLVM_DYLIB=yes on the CMake
# commandline. By default the shared library only exports the LLVM C API.
set(SOURCES
libllvm.cpp
)
llvm_map_components_to_libnames(LIB_NAMES ${LLVM_DYLIB_COMPONENTS})
if(LLVM_LINK_LLVM_DYLIB AND LLVM_DYLIB_EXPORTED_SYMBOL_FILE)
message(WARNING "Using LLVM_LINK_LLVM_DYLIB with LLVM_DYLIB_EXPORTED_SYMBOL_FILE may not work. Use at your own risk.")
endif()
# libLLVM.so should not have any dependencies on any other LLVM
# shared libraries. When using the "all" pseudo-component,
# LLVM_AVAILABLE_LIBS is added to the dependencies, which may
# contain shared libraries (e.g. libLTO).
#
# Also exclude libLLVMTableGen for the following reasons:
# - it is only used by internal *-tblgen utilities;
# - it pollutes the global options space.
foreach(lib ${LIB_NAMES})
get_target_property(t ${lib} TYPE)
if("${lib}" STREQUAL "LLVMTableGen")
elseif("x${t}" STREQUAL "xSTATIC_LIBRARY")
list(APPEND FILTERED_LIB_NAMES ${lib})
endif()
endforeach()
set(LIB_NAMES ${FILTERED_LIB_NAMES})
if(LLVM_DYLIB_EXPORTED_SYMBOL_FILE)
set(LLVM_EXPORTED_SYMBOL_FILE ${LLVM_DYLIB_EXPORTED_SYMBOL_FILE})
add_custom_target(libLLVMExports DEPENDS ${LLVM_EXPORTED_SYMBOL_FILE})
endif()
add_llvm_library(LLVM SHARED DISABLE_LLVM_LINK_LLVM_DYLIB SONAME ${SOURCES})
list(REMOVE_DUPLICATES LIB_NAMES)
if(("${CMAKE_SYSTEM_NAME}" STREQUAL "Linux") OR (MINGW) OR ("${CMAKE_SYSTEM_NAME}" STREQUAL "FreeBSD") OR ("${CMAKE_SYSTEM_NAME}" STREQUAL "DragonFly")) # FIXME: It should be "GNU ld for elf"
configure_file(
${CMAKE_CURRENT_SOURCE_DIR}/simple_version_script.map.in
${LLVM_LIBRARY_DIR}/tools/llvm-shlib/simple_version_script.map)
# GNU ld doesn't resolve symbols in the version script.
set(LIB_NAMES -Wl,--version-script,${LLVM_LIBRARY_DIR}/tools/llvm-shlib/simple_version_script.map -Wl,--whole-archive ${LIB_NAMES} -Wl,--no-whole-archive)
elseif("${CMAKE_SYSTEM_NAME}" STREQUAL "Darwin")
set(LIB_NAMES -Wl,-all_load ${LIB_NAMES})
endif()
target_link_libraries(LLVM PRIVATE ${LIB_NAMES})
if (APPLE)
set_property(TARGET LLVM APPEND_STRING PROPERTY
LINK_FLAGS
" -compatibility_version 1 -current_version ${LLVM_VERSION_MAJOR}.${LLVM_VERSION_MINOR}.${LLVM_VERSION_PATCH}")
endif()
if(TARGET libLLVMExports)
add_dependencies(LLVM libLLVMExports)
endif()
if(LLVM_BUILD_LLVM_C_DYLIB)
# To get the export list for a single llvm library:
# nm ${LIB_PATH} | awk "/T _LLVM/ { print $3 }" | sort -u | sed -e "s/^_//g" > ${LIB_PATH}.exports
if(NOT APPLE)
message(FATAL_ERROR "Generating libLLVM-c is only supported on Darwin")
endif()
set(LLVM_EXPORTED_SYMBOL_FILE ${CMAKE_BINARY_DIR}/libllvm-c.exports)
set(LIB_DIR ${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/lib${LLVM_LIBDIR_SUFFIX})
set(LIB_NAME ${LIB_DIR}/${CMAKE_SHARED_LIBRARY_PREFIX}LLVM)
set(LIB_PATH ${LIB_NAME}${CMAKE_SHARED_LIBRARY_SUFFIX})
set(LIB_EXPORTS_PATH ${LIB_NAME}.exports)
list(APPEND LLVM_DYLIB_REQUIRED_EXPORTS ${LIB_EXPORTS_PATH})
add_custom_command(OUTPUT ${LLVM_EXPORTED_SYMBOL_FILE}
COMMAND nm ${LIB_PATH} | awk "/T _LLVM/ || /T LLVM/ { print $3 }" | sort -u | sed -e "s/^_//g" > ${LLVM_EXPORTED_SYMBOL_FILE}
WORKING_DIRECTORY ${LIB_DIR}
DEPENDS LLVM
COMMENT "Generating Export list for LLVM..."
VERBATIM )
add_custom_target(libLLVMCExports DEPENDS ${LLVM_EXPORTED_SYMBOL_FILE})
add_llvm_library(LLVM-C SHARED ${SOURCES})
target_link_libraries(LLVM-C PUBLIC LLVM)
add_dependencies(LLVM-C libLLVMCExports)
set_property(TARGET LLVM-C APPEND_STRING PROPERTY
LINK_FLAGS
" -compatibility_version 1 -current_version ${LLVM_VERSION_MAJOR}.${LLVM_VERSION_MINOR}.${LLVM_VERSION_PATCH} -Wl,-reexport_library ${LIB_PATH}")
endif()