8abf8d124a
A SHN_ABS symbol has never been considered for InputSection::relocateNonAlloc. Before #74686, the code did made it work in the absence of `-z dead-reloc-in-nonalloc=`. There is now a report about such SHN_ABS uses (https://github.com/llvm/llvm-project/pull/74686#issuecomment-1904101711) and I think it makes sense for non-SHF_ALLOC to support SHN_ABS, like SHF_ALLOC sections do. ``` // clang -g __attribute__((weak)) int symbol; int *foo() { return &symbol; } 0x00000023: DW_TAG_variable [2] (0x0000000c) ... DW_AT_location [DW_FORM_exprloc] (DW_OP_addrx 0x0) ``` .debug_addr references `symbol`, which can be redefined by a symbol assignment or --defsym to become a SHN_ABS symbol. The problem is that `!sym.getOutputSection()` cannot discern SHN_ABS from a symbol whose section has been discarded. Since commit 1981b1b6b92f7579a30c9ed32dbdf3bc749c1b40, a symbol relative to a discarded section is changed to `Undefined`, so the `SHN_ABS` check become trivial. We currently apply tombstone for a relocation referencing `SharedSymbol`. This patch does not change the behavior.
81 lines
3.1 KiB
ArmAsm
81 lines
3.1 KiB
ArmAsm
# REQUIRES: x86
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## Test an absolute relocation referencing an undefined or DSO symbol, relocating
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## a non-SHF_ALLOC section. Also test -z dead-reloc-in-nonalloc=.
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# RUN: llvm-mc -filetype=obj -triple=x86_64 %s -o %t.o
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# RUN: echo '.globl bar; bar = 42' | llvm-mc -filetype=obj -triple=x86_64 - -o %tabs.o
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# RUN: ld.lld --gc-sections -z dead-reloc-in-nonalloc=.debug_info=0xaaaaaaaa \
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# RUN: -z dead-reloc-in-nonalloc=.not_debug=0xbbbbbbbb %t.o %tabs.o -o %t
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# RUN: llvm-objdump -s %t | FileCheck %s --check-prefixes=COMMON,AA
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## 0xaaaaaaaa == 2863311530
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# RUN: ld.lld --gc-sections -z dead-reloc-in-nonalloc=.debug_info=2863311530 \
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# RUN: -z dead-reloc-in-nonalloc=.not_debug=0xbbbbbbbb %t.o %tabs.o -o - | cmp %t -
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# COMMON: Contents of section .debug_addr:
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# COMMON-NEXT: 0000 [[ADDR:[0-9a-f]+]] 00000000 00000000 00000000
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# AA: Contents of section .debug_info:
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# AA-NEXT: 0000 [[ADDR]] 00000000 aaaaaaaa 00000000
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# AA: Contents of section .not_debug:
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# AA-NEXT: 0000 bbbbbbbb 2a000000 00000000 .
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## Specifying zero can get a behavior similar to GNU ld.
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# RUN: ld.lld --icf=all -z dead-reloc-in-nonalloc=.debug_info=0 %t.o %tabs.o -o %tzero
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# RUN: llvm-objdump -s %tzero | FileCheck %s --check-prefixes=COMMON,ZERO
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# ZERO: Contents of section .debug_info:
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# ZERO-NEXT: 0000 {{[0-9a-f]+}}000 00000000 00000000 00000000
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## Glob works.
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# RUN: ld.lld --gc-sections -z dead-reloc-in-nonalloc='.debug_i*=0xaaaaaaaa' \
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# RUN: -z dead-reloc-in-nonalloc='[.]not_debug=0xbbbbbbbb' %t.o %tabs.o -o - | cmp %t -
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## If a section matches multiple option. The last option wins.
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# RUN: ld.lld --icf=all -z dead-reloc-in-nonalloc='.debug_info=1' \
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# RUN: -z dead-reloc-in-nonalloc='.debug_i*=0' %t.o %tabs.o -o - | cmp %tzero -
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# RUN: llvm-mc -filetype=obj -triple=x86_64 %S/Inputs/shared.s -o %t1.o
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# RUN: ld.lld -shared -soname=t1.so %t1.o -o %t1.so
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# RUN: ld.lld --gc-sections %t.o %t1.so -o %tso
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# RUN: llvm-objdump -s %tso | FileCheck %s --check-prefix=SHARED
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# SHARED: Contents of section .not_debug:
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# SHARED-NEXT: 0000 08000000 00000000 00000000 .
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## Test all possible invalid cases.
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# RUN: not ld.lld -z dead-reloc-in-nonalloc= 2>&1 | FileCheck %s --check-prefix=USAGE
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# RUN: not ld.lld -z dead-reloc-in-nonalloc=a= 2>&1 | FileCheck %s --check-prefix=USAGE
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# RUN: not ld.lld -z dead-reloc-in-nonalloc==0 2>&1 | FileCheck %s --check-prefix=USAGE
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# USAGE: error: -z dead-reloc-in-nonalloc=: expected <section_glob>=<value>
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# RUN: not ld.lld -z dead-reloc-in-nonalloc=a=-1 2>&1 | FileCheck %s --check-prefix=NON-INTEGER
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# NON-INTEGER: error: -z dead-reloc-in-nonalloc=: expected a non-negative integer, but got '-1'
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# RUN: not ld.lld -z dead-reloc-in-nonalloc='['=0 2>&1 | FileCheck %s --check-prefix=INVALID
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# INVALID: error: -z dead-reloc-in-nonalloc=: invalid glob pattern, unmatched '[': [
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.globl _start
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_start:
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ret
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## .text.1 will be folded by ICF or discarded by --gc-sections.
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.section .text.1,"ax"
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ret
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.section .debug_addr
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.quad .text+8
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.quad .text.1+8
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.section .debug_info
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.quad .text+8
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.quad .text.1+8
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## Test a non-.debug_ section.
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.section .not_debug
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.long .text.1+8
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.quad bar
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