llvm-toolchain-10/libcxx/cmake/Modules/DefineLinkerScript.cmake

53 lines
2.1 KiB
CMake

# This function defines a linker script in place of the symlink traditionally
# created for shared libraries.
#
# More specifically, this function goes through the PUBLIC and INTERFACE
# library dependencies of <target> and gathers them into a linker script,
# such that those libraries are linked against when the shared library for
# <target> is linked against.
#
# Arguments:
# <target>: A target representing a shared library. A linker script will be
# created in place of that target's TARGET_LINKER_FILE, which is
# the symlink pointing to the actual shared library (usually
# libFoo.so pointing to libFoo.so.1, which itself points to
# libFoo.so.1.0).
function(define_linker_script target)
if (NOT TARGET "${target}")
message(FATAL_ERROR "The provided target '${target}' is not actually a target.")
endif()
get_target_property(target_type "${target}" TYPE)
if (NOT "${target_type}" STREQUAL "SHARED_LIBRARY")
message(FATAL_ERROR "The provided target '${target}' is not a shared library (its type is '${target_type}').")
endif()
set(symlink "$<TARGET_LINKER_FILE:${target}>")
set(soname "$<TARGET_SONAME_FILE_NAME:${target}>")
get_target_property(interface_libs "${target}" INTERFACE_LINK_LIBRARIES)
set(link_libraries)
if (interface_libs)
foreach(lib IN LISTS interface_libs)
if (TARGET "${lib}" OR
(${lib} MATCHES "cxxabi(_static|_shared)?" AND HAVE_LIBCXXABI) OR
(${lib} MATCHES "unwind(_static|_shared)?" AND HAVE_LIBUNWIND))
list(APPEND link_libraries "${CMAKE_LINK_LIBRARY_FLAG}$<TARGET_PROPERTY:${lib},OUTPUT_NAME>")
else()
list(APPEND link_libraries "${CMAKE_LINK_LIBRARY_FLAG}${lib}")
endif()
endforeach()
endif()
string(REPLACE ";" " " link_libraries "${link_libraries}")
set(linker_script "INPUT(${soname} ${link_libraries})")
add_custom_command(TARGET "${target}" POST_BUILD
COMMAND "${CMAKE_COMMAND}" -E remove "${symlink}"
COMMAND "${CMAKE_COMMAND}" -E echo "${linker_script}" > "${symlink}"
COMMENT "Generating linker script: '${linker_script}' as file ${symlink}"
VERBATIM
)
endfunction()