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
76 lines
2.4 KiB
Plaintext
76 lines
2.4 KiB
Plaintext
# REQUIRES: x86
|
|
# RUN: yaml2obj %s -o %t.o
|
|
# RUN: not ld.lld %t.o -o /dev/null
|
|
|
|
# The debug info has a broken relocation. Check that we don't crash.
|
|
|
|
# We used to dereference null Target in DWARF.cpp:findAux while reporting a duplicate symbol error,
|
|
# because Target wasn't initialized yet.
|
|
# RUN: not ld.lld %t.o %t.o -o /dev/null
|
|
|
|
--- !ELF
|
|
FileHeader:
|
|
Class: ELFCLASS64
|
|
Data: ELFDATA2LSB
|
|
Type: ET_REL
|
|
Machine: EM_X86_64
|
|
Sections:
|
|
- Name: .text
|
|
Type: SHT_PROGBITS
|
|
Flags: [ SHF_ALLOC, SHF_EXECINSTR ]
|
|
Content: '0000000000000000'
|
|
- Name: .rela.text
|
|
Type: SHT_RELA
|
|
AddressAlign: 8
|
|
Link: .symtab
|
|
Info: .text
|
|
Relocations:
|
|
- Offset: 0x0000000000000000
|
|
Symbol: bar
|
|
Type: R_X86_64_64
|
|
- Name: .debug_line
|
|
Type: SHT_PROGBITS
|
|
Content: 3300000002001C0000000101FB0E0D000101010100000001000001006162632E7300000000000009020000000000000000140208000101
|
|
- Name: .rela.debug_line
|
|
AddressAlign: 8
|
|
Type: SHT_RELA
|
|
Link: .symtab
|
|
Info: .debug_line
|
|
Relocations:
|
|
- Offset: 0x0000000000000029
|
|
Symbol: bar
|
|
Type: R_X86_64_64
|
|
- Name: .debug_info
|
|
Type: SHT_PROGBITS
|
|
AddressAlign: 0x0000000000000001
|
|
Content: 0C000000040000000000080100000000
|
|
- Name: .rela.debug_info
|
|
Type: SHT_RELA
|
|
Link: .symtab
|
|
AddressAlign: 0x0000000000000008
|
|
Info: .debug_info
|
|
Relocations:
|
|
- Offset: 0x0000000000000006
|
|
Symbol: .debug_abbrev
|
|
Type: R_X86_64_32
|
|
- Offset: 0x000000000000000C
|
|
Symbol: .debug_line
|
|
Type: R_X86_64_32
|
|
- Name: .debug_abbrev
|
|
Type: SHT_PROGBITS
|
|
AddressAlign: 0x0000000000000001
|
|
Content: '0111001017000000'
|
|
|
|
Symbols:
|
|
- Name: .debug_abbrev
|
|
Type: STT_SECTION
|
|
Section: .debug_abbrev
|
|
- Name: .debug_line
|
|
Type: STT_SECTION
|
|
Section: .debug_line
|
|
- Name: _start
|
|
Section: .text
|
|
Binding: STB_GLOBAL
|
|
- Name: bar
|
|
Binding: STB_GLOBAL
|