ba51fd5664
This restores r361830 "[ELF] Error on relocations to STT_SECTION symbols if the sections were discarded"
and dependent commits (r362218, r362497) which were reverted by r364321, with a fix of a --gdb-index issue.
.rela.debug_ranges contains relocations of range list entries:
// start address of a range list entry
// old: 0; after r361830: 0
00000000000033a0 R_X86_64_64 .text._ZN2v88internal7Isolate7factoryEv + 0
// end address of a range list entry
// old: 0xe; after r361830: 0
00000000000033a8 R_X86_64_64 .text._ZN2v88internal7Isolate7factoryEv + e
If both start and end addresses of a range list entry resolve to 0,
DWARFDebugRangeList::isEndOfListEntry() will return true, then the
.debug_range decoding loop will terminate prematurely:
while (true) {
decode StartAddress
decode EndAddress
if (Entry.isEndOfListEntry()) // prematurely
break;
Entries.push_back(Entry);
}
In lld/ELF/SyntheticSections.cpp, readAddressAreas() will read
incomplete address ranges and the resulting .gdb_index will be
incomplete. For files that gdb hasn't loaded their debug info, gdb uses
.gdb_index to map addresses to CUs. The absent entries make gdb fail to
symbolize some addresses.
To address this issue, we simply allow relocations to undefined symbols
in DWARF.cpp:findAux() and let RelocationResolver resolve them.
This patch should fix:
[1] http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20190603/659848.html
[2] https://bugs.chromium.org/p/chromium/issues/detail?id=978067
llvm-svn: 364391
29 lines
1.0 KiB
ArmAsm
29 lines
1.0 KiB
ArmAsm
# REQUIRES: x86
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# RUN: llvm-mc -filetype=obj -triple=x86_64 %s -o %t1.o
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# RUN: echo '.section .text.foo,"axG",@progbits,foo,comdat; .globl foo; foo:' |\
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# RUN: llvm-mc -filetype=obj -triple=x86_64 - -o %t2.o
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# RUN: echo '.section .text.foo,"axG",@progbits,foo,comdat; .globl bar; bar:' |\
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# RUN: llvm-mc -filetype=obj -triple=x86_64 - -o %t3.o
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# RUN: not ld.lld %t2.o %t3.o %t1.o -o /dev/null 2>&1 | FileCheck %s
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# CHECK: error: relocation refers to a symbol in a discarded section: bar
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# CHECK-NEXT: >>> defined in {{.*}}3.o
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# CHECK-NEXT: >>> section group signature: foo
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# CHECK-NEXT: >>> prevailing definition is in {{.*}}2.o
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# CHECK-NEXT: >>> referenced by {{.*}}1.o:(.text+0x1)
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# CHECK: error: relocation refers to a discarded section: .text.foo
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# CHECK-NEXT: >>> defined in {{.*}}1.o
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# CHECK-NEXT: >>> section group signature: foo
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# CHECK-NEXT: >>> prevailing definition is in {{.*}}2.o
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# CHECK-NEXT: >>> referenced by {{.*}}1.o:(.data+0x0)
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.globl _start
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_start:
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jmp bar
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.section .text.foo,"axG",@progbits,foo,comdat
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.data
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.quad .text.foo
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