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[cmake] Disable GCC lifetime DSE

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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.

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
This commit is contained in:
Sam James
2023-05-13 20:34:05 +01:00
parent 76b2915fdb
commit 94f7c961c7
1 changed files with 10 additions and 0 deletions
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10
llvm/cmake/modules/HandleLLVMOptions.cmake
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@@ -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})