From 47f5c54f997a59bb2c65abe6b8b811f6e7553456 Mon Sep 17 00:00:00 2001 From: Xi Ruoyao Date: Sun, 14 May 2023 03:42:45 +0100 Subject: [PATCH] [cmake] Disable GCC lifetime DSE LLVM data structures like llvm::User and llvm::MDNode rely on the value of object storage persisting beyond the lifetime of the object (#24952). This is not standard compliant and causes a runtime crash if LLVM is built with GCC and LTO enabled (#57740). Until these issues are fixed, we need to disable dead store eliminations eliminations based on object lifetime. The previous test issues are fixed by 626849c71e85d546a004cc91866beab610222194. Bug: https://github.com/llvm/llvm-project/issues/24952 Bug: https://github.com/llvm/llvm-project/issues/57740 Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106943 Reviewed By: MaskRay, thesamesam, nikic Differential Revision: https://reviews.llvm.org/D150505 --- llvm/cmake/modules/HandleLLVMOptions.cmake | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/llvm/cmake/modules/HandleLLVMOptions.cmake b/llvm/cmake/modules/HandleLLVMOptions.cmake index 578a316..52cb2ea 100644 --- a/llvm/cmake/modules/HandleLLVMOptions.cmake +++ b/llvm/cmake/modules/HandleLLVMOptions.cmake @@ -594,6 +594,16 @@ if ( LLVM_COMPILER_IS_GCC_COMPATIBLE OR CMAKE_CXX_COMPILER_ID MATCHES "XL" ) add_flag_if_supported("-Werror=unguarded-availability-new" WERROR_UNGUARDED_AVAILABILITY_NEW) endif( LLVM_COMPILER_IS_GCC_COMPATIBLE OR CMAKE_CXX_COMPILER_ID MATCHES "XL" ) +if ( LLVM_COMPILER_IS_GCC_COMPATIBLE ) + # LLVM data structures like llvm::User and llvm::MDNode rely on + # the value of object storage persisting beyond the lifetime of the + # object (#24952). This is not standard compliant and causes a runtime + # crash if LLVM is built with GCC and LTO enabled (#57740). Until + # these bugs are fixed, we need to disable dead store eliminations + # based on object lifetime. + add_flag_if_supported("-fno-lifetime-dse" CMAKE_CXX_FLAGS) +endif ( LLVM_COMPILER_IS_GCC_COMPATIBLE ) + # Modules enablement for GCC-compatible compilers: if ( LLVM_COMPILER_IS_GCC_COMPATIBLE AND LLVM_ENABLE_MODULES ) set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS}) -- 2.7.4