Author: Sam James Date: 2022-11-10T17:04:34-08:00 New Revision: d75ae21044ad893572855cefb0c0898a771b2094
URL: https://github.com/llvm/llvm-project/commit/d75ae21044ad893572855cefb0c0898a771b2094 DIFF: https://github.com/llvm/llvm-project/commit/d75ae21044ad893572855cefb0c0898a771b2094.diff LOG: Set LLVM_ATOMIC_LIB variable for convenient linking against libatomic * Set LLVM_ATOMIC_LIB to keep track of when we need to link against libatomic. * Add detection of mold linker which is required for this. * Use --as-needed when linking against libatomic as a bonus. On some platforms, libatomic may be required only sometimes. Bug: https://bugs.gentoo.org/832675 Thanks-to: Arfrever Frehtes Taifersar Arahesis <arfre...@apache.org> Tested-by: erhar...@mailbox.org <erhar...@mailbox.org> Differential Revision: https://reviews.llvm.org/D136280 (cherry picked from commit fa981b541365190ae646d2dce575706cd0626cf7) Added: Modified: llvm/cmake/modules/AddLLVM.cmake llvm/cmake/modules/CheckAtomic.cmake llvm/lib/Support/CMakeLists.txt llvm/tools/dsymutil/CMakeLists.txt Removed: ################################################################################ diff --git a/llvm/cmake/modules/AddLLVM.cmake b/llvm/cmake/modules/AddLLVM.cmake index 057431208322e..1f0507f395cf6 100644 --- a/llvm/cmake/modules/AddLLVM.cmake +++ b/llvm/cmake/modules/AddLLVM.cmake @@ -212,6 +212,7 @@ if (NOT DEFINED LLVM_LINKER_DETECTED AND NOT WIN32) else() if("${stdout}" MATCHES "^mold") set(LLVM_LINKER_DETECTED YES CACHE INTERNAL "") + set(LLVM_LINKER_IS_MOLD YES CACHE INTERNAL "") message(STATUS "Linker detection: mold") elseif("${stdout}" MATCHES "GNU gold") set(LLVM_LINKER_DETECTED YES CACHE INTERNAL "") diff --git a/llvm/cmake/modules/CheckAtomic.cmake b/llvm/cmake/modules/CheckAtomic.cmake index 3c5ba72993a3a..f11cadf39ff6b 100644 --- a/llvm/cmake/modules/CheckAtomic.cmake +++ b/llvm/cmake/modules/CheckAtomic.cmake @@ -82,6 +82,19 @@ elseif(LLVM_COMPILER_IS_GCC_COMPATIBLE OR CMAKE_CXX_COMPILER_ID MATCHES "XL") endif() endif() +# Set variable LLVM_ATOMIC_LIB specifying flags for linking against libatomic. +if(HAVE_CXX_ATOMICS_WITH_LIB OR HAVE_CXX_ATOMICS64_WITH_LIB) + # Use options --push-state, --as-needed and --pop-state if linker is known to support them. + # Use single option -Wl of compiler driver to avoid incorrect re-ordering of options by CMake. + if(LLVM_LINKER_IS_GNULD OR LLVM_LINKER_IS_GOLD OR LLVM_LINKER_IS_LLD OR LLVM_LINKER_IS_MOLD) + set(LLVM_ATOMIC_LIB "-Wl,--push-state,--as-needed,-latomic,--pop-state") + else() + set(LLVM_ATOMIC_LIB "-latomic") + endif() +else() + set(LLVM_ATOMIC_LIB) +endif() + ## TODO: This define is only used for the legacy atomic operations in ## llvm's Atomic.h, which should be replaced. Other code simply ## assumes C++11 <atomic> works. diff --git a/llvm/lib/Support/CMakeLists.txt b/llvm/lib/Support/CMakeLists.txt index 806cbc884cc5d..ff23ec74df962 100644 --- a/llvm/lib/Support/CMakeLists.txt +++ b/llvm/lib/Support/CMakeLists.txt @@ -59,9 +59,7 @@ elseif( CMAKE_HOST_UNIX ) if( LLVM_ENABLE_TERMINFO ) set(imported_libs ${imported_libs} Terminfo::terminfo) endif() - if( LLVM_ENABLE_THREADS AND (HAVE_LIBATOMIC OR HAVE_CXX_LIBATOMICS64) ) - set(system_libs ${system_libs} atomic) - endif() + set(system_libs ${system_libs} ${LLVM_ATOMIC_LIB}) set(system_libs ${system_libs} ${LLVM_PTHREAD_LIB}) if( UNIX AND NOT (BEOS OR HAIKU) ) set(system_libs ${system_libs} m) diff --git a/llvm/tools/dsymutil/CMakeLists.txt b/llvm/tools/dsymutil/CMakeLists.txt index a255c1c5daf51..38028cd3d80a3 100644 --- a/llvm/tools/dsymutil/CMakeLists.txt +++ b/llvm/tools/dsymutil/CMakeLists.txt @@ -40,6 +40,4 @@ if(APPLE) target_link_libraries(dsymutil PRIVATE "-framework CoreFoundation") endif(APPLE) -if(HAVE_CXX_ATOMICS_WITH_LIB OR HAVE_CXX_ATOMICS64_WITH_LIB) - target_link_libraries(dsymutil PRIVATE atomic) -endif() +target_link_libraries(dsymutil PRIVATE ${LLVM_ATOMIC_LIB}) _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
