diff options
Diffstat (limited to 'cmake/QtFeature.cmake')
| -rw-r--r-- | cmake/QtFeature.cmake | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/cmake/QtFeature.cmake b/cmake/QtFeature.cmake index 3ade942f17..bca31660b9 100644 --- a/cmake/QtFeature.cmake +++ b/cmake/QtFeature.cmake @@ -1118,6 +1118,62 @@ function(qt_config_compiler_supports_flag_test name) set(TEST_${name} "${TEST_${name}}" CACHE INTERNAL "${label}") endfunction() +# gcc expects -fuse-ld=mold (no absolute path can be given) (gcc >= 12.1) +# or an 'ld' symlink to 'mold' in a dir that is passed via -B flag (gcc < 12.1) +# +# clang expects -fuse-ld=mold +# or -fuse-ld=<mold-abs-path> +# or --ldpath=<mold-abs-path> (clang >= 12) +# https://github.com/rui314/mold/#how-to-use +# TODO: In the gcc < 12.1 case, the qt_internal_check_if_linker_is_available(mold) check will +# always return TRUE because gcc will not error out if it is given a -B flag pointing to an +# invalid dir, as well as when the the symlink to the linker in the -B dir is not actually +# a valid linker. +# It would be nice to handle that case in a better way, but it's not that important +# given that gcc > 12.1 now supports -fuse-ld=mold +# NOTE: In comparison to clang, in the gcc < 12.1 case, we pass the full path to where mold is +# and that is recorded in PlatformCommonInternal's INTERFACE_LINK_OPTIONS target. +# Moving such a Qt to a different machine and trying to build another repo won't +# work because the recorded path will be invalid. This is not a problem with +# the gcc >= 12.1 case +function(qt_internal_get_mold_linker_flags out_var) + cmake_parse_arguments(PARSE_ARGV 1 arg "ERROR_IF_EMPTY" "" "") + + find_program(QT_INTERNAL_LINKER_MOLD mold) + + set(flag "") + if(QT_INTERNAL_LINKER_MOLD) + if(GCC) + if(CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL "12.1") + set(flag "-fuse-ld=mold") + else() + set(mold_linker_dir "${CMAKE_CURRENT_BINARY_DIR}/.qt_linker") + set(mold_linker_path "${mold_linker_dir}/ld") + if(NOT EXISTS "${mold_linker_dir}") + file(MAKE_DIRECTORY "${mold_linker_dir}") + endif() + if(NOT EXISTS "${mold_linker_path}") + file(CREATE_LINK + "${QT_INTERNAL_LINKER_MOLD}" + "${mold_linker_path}" + SYMBOLIC) + endif() + set(flag "-B${mold_linker_dir}") + endif() + elseif(CLANG) + if(CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL "12") + set(flag "--ld-path=mold") + else() + set(flag "-fuse-ld=mold") + endif() + endif() + endif() + if(arg_ERROR_IS_EMPTY AND NOT flag) + message(FATAL_ERROR "Could not determine the flags to use the mold linker.") + endif() + set(${out_var} "${flag}" PARENT_SCOPE) +endfunction() + function(qt_internal_get_active_linker_flags out_var) set(flags "") if(GCC OR CLANG) @@ -1127,6 +1183,9 @@ function(qt_internal_get_active_linker_flags out_var) list(APPEND flags "-fuse-ld=bfd") elseif(QT_FEATURE_use_lld_linker) list(APPEND flags "-fuse-ld=lld") + elseif(QT_FEATURE_use_mold_linker) + qt_internal_get_mold_linker_flags(mold_flags ERROR_IF_EMPTY) + list(APPEND flags "${mold_flags}") endif() endif() set(${out_var} "${flags}" PARENT_SCOPE) |