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llvm-project/lld/test/ELF/comdat-discarded-reloc.s

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[ELF] - Add a test case for relocation pointing to deduplicated COMDAT. ELF spec doesn't allow a relocation to point to a deduplicated COMDAT section. Unfortunately this happens in practice (e.g. .eh_frame) We have a code in MarkLive.cpp for that and it was uncovered by any test case: https://github.com/llvm-mirror/lld/blob/master/ELF/MarkLive.cpp#L199 Patch adds a test. llvm-svn: 336259
2018-07-04 18:38:12 +08:00
# REQUIRES: x86
# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o
# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %p/Inputs/comdat-discarded-reloc.s -o %t2.o
Reland D61583 [ELF] Error on relocations to STT_SECTION symbols if the sections were discarded 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
2019-06-26 16:09:08 +08:00
# RUN: ld.lld -gc-sections --noinhibit-exec %t2.o %t.o -o /dev/null
# RUN: ld.lld -r %t2.o %t.o -o %t 2>&1 | FileCheck --check-prefix=WARN %s
# RUN: llvm-readobj -r %t | FileCheck --check-prefix=RELOC %s
[ELF] - Add a test case for relocation pointing to deduplicated COMDAT. ELF spec doesn't allow a relocation to point to a deduplicated COMDAT section. Unfortunately this happens in practice (e.g. .eh_frame) We have a code in MarkLive.cpp for that and it was uncovered by any test case: https://github.com/llvm-mirror/lld/blob/master/ELF/MarkLive.cpp#L199 Patch adds a test. llvm-svn: 336259
2018-07-04 18:38:12 +08:00
## ELF spec doesn't allow a relocation to point to a deduplicated
## COMDAT section. Unfortunately this happens in practice (e.g. .eh_frame)
## Test case checks we do not crash.
Reland D61583 [ELF] Error on relocations to STT_SECTION symbols if the sections were discarded 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
2019-06-26 16:09:08 +08:00
# WARN: warning: relocation refers to a discarded section: .text.bar1
# WARN-NEXT: >>> referenced by {{.*}}.o:(.rela.text.bar2+0x0)
# WARN-NOT: warning
[ELF] - Add a test case for relocation pointing to deduplicated COMDAT. ELF spec doesn't allow a relocation to point to a deduplicated COMDAT section. Unfortunately this happens in practice (e.g. .eh_frame) We have a code in MarkLive.cpp for that and it was uncovered by any test case: https://github.com/llvm-mirror/lld/blob/master/ELF/MarkLive.cpp#L199 Patch adds a test. llvm-svn: 336259
2018-07-04 18:38:12 +08:00
Reland D61583 [ELF] Error on relocations to STT_SECTION symbols if the sections were discarded 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
2019-06-26 16:09:08 +08:00
# RELOC: .rela.eh_frame {
# RELOC-NEXT: R_X86_64_NONE
# RELOC-NEXT: }
# RELOC-NEXT: .rela.debug_foo {
# RELOC-NEXT: R_X86_64_NONE
# RELOC-NEXT: }
# RELOC-NEXT: .rela.gcc_except_table {
# RELOC-NEXT: R_X86_64_NONE
# RELOC-NEXT: }
[ELF] - Add a test case for relocation pointing to deduplicated COMDAT. ELF spec doesn't allow a relocation to point to a deduplicated COMDAT section. Unfortunately this happens in practice (e.g. .eh_frame) We have a code in MarkLive.cpp for that and it was uncovered by any test case: https://github.com/llvm-mirror/lld/blob/master/ELF/MarkLive.cpp#L199 Patch adds a test. llvm-svn: 336259
2018-07-04 18:38:12 +08:00
Reland D61583 [ELF] Error on relocations to STT_SECTION symbols if the sections were discarded 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
2019-06-26 16:09:08 +08:00
.section .text.bar1,"aG",@progbits,group,comdat
## .text.bar1 in this file is discarded. Warn on the relocation.
.section .text.bar2,"ax"
.globl bar
bar:
.quad .text.bar1
## Don't warn on .eh_frame, .debug*, .zdebug*, or .gcc_except_table
.section .eh_frame,"a"
.quad .text.bar1
.section .debug_foo
.quad .text.bar1
.section .gcc_except_table,"a"
.quad .text.bar1