ce45c95694
https://maskray.me/blog/2022-02-06-all-about-common-symbols#no-define-common In GNU ld, -dc only affects -r links and causes COMMON symbols to be allocated. --no-define-common is defined to make COMMON symbols undefined for -shared. AIUI --no-define-common is a workaround around glibc 2.1 time and not really useful. gold confuses --define-common with -d/FORCE_COMMON_ALLOCATION and implements --define-common with -d semantics. Its --no-define-common is incompatible with GNU ld. In ld.lld, b2a23cf3c08cee45614f27eb2c6d044e506aa6a6 fixed the default -r behavior for COMMON symbols but ported the incompatible gold --[no-]define-common. To the best of my knowledge, no project uses -dp --[no-]define-common. So just remove these options. -d/-dc are used by the following projects: * grub grub-core/genmod.sh.in uses -Wl,-r,-d (https://lists.gnu.org/archive/html/grub-devel/2022-02/msg00088.html) * FreeBSD crunchgen uses -Wl,-dc (https://reviews.freebsd.org/D34215) A no-op implementation works for them. Only when a program inspects relocatable output by itself and does not recognize COMMON symbols, there may be a problem. This is an extremely unlikely case. Reviewed By: peter.smith Differential Revision: https://reviews.llvm.org/D119108
17 lines
449 B
ArmAsm
17 lines
449 B
ArmAsm
# REQUIRES: x86
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# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t1.o
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# RUN: ld.lld -r %t1.o -o %t
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# RUN: llvm-readobj --symbols -r %t | FileCheck %s
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# CHECK: Symbol {
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# CHECK: Name: common
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# CHECK-NEXT: Value: 0x4
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# CHECK-NEXT: Size: 4
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# CHECK-NEXT: Binding: Global
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# CHECK-NEXT: Type: Object
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# CHECK-NEXT: Other: 0
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# CHECK-NEXT: Section: Common (0xFFF2)
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# CHECK-NEXT: }
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.comm common,4,4
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