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Differential D42823

Strip .note.gnu.build-id sections if --build-id is given.
ClosedPublic

Authored by ruiu on Feb 1 2018, 3:20 PM.

Details

Reviewers
• rafael
Commits
rGf46d3d1be9cd: Strip .note.gnu.build-id sections if --build-id is given.
rL324146: Strip .note.gnu.build-id sections if --build-id is given.
rLLD324146: Strip .note.gnu.build-id sections if --build-id is given.
Summary

Fixes https://bugs.llvm.org/show_bug.cgi?id=36203

Diff Detail

Event Timeline

ruiu created this revision.Feb 1 2018, 3:20 PM
Herald added a subscriber: emaste. · View Herald TranscriptFeb 1 2018, 3:20 PM
Harbormaster completed remote builds in B14528: Diff 132488.Feb 1 2018, 3:20 PM
ruiu updated this revision to Diff 132494.Feb 1 2018, 3:44 PM
  • Add -r to produce a re-linkable object file.
Harbormaster completed remote builds in B14531: Diff 132494.Feb 1 2018, 3:44 PM
This revision was not accepted when it landed; it landed in state Needs Review.Feb 2 2018, 1:58 PM
Closed by commit rLLD324146: Strip .note.gnu.build-id sections if --build-id is given. (authored by ruiu). · Explain Why
This revision was automatically updated to reflect the committed changes.

Revision Contents

PathSize
lld/
ELF/
7 lines
test/
ELF/
12 lines

Diff 132494

lld/ELF/InputFiles.cpp

Show First 20 Lines • Show All 612 Lines • ▼ Show 20 LinesInputSectionBase *ObjFile<ELFT>::createInputSection(const Elf_Shdr &Sec) {
// The linkonce feature is a sort of proto-comdat. Some glibc i386 object // The linkonce feature is a sort of proto-comdat. Some glibc i386 object
// files contain definitions of symbol "__x86.get_pc_thunk.bx" in linkonce // files contain definitions of symbol "__x86.get_pc_thunk.bx" in linkonce
// sections. Drop those sections to avoid duplicate symbol errors. // sections. Drop those sections to avoid duplicate symbol errors.
// FIXME: This is glibc PR20543, we should remove this hack once that has been // FIXME: This is glibc PR20543, we should remove this hack once that has been
// fixed for a while. // fixed for a while.
if (Name.startswith(".gnu.linkonce.")) if (Name.startswith(".gnu.linkonce."))
return &InputSection::Discarded; return &InputSection::Discarded;
// If we are creating a new .build-id section, strip existing .build-id
// sections so that the output won't have more than one .build-id.
// Usually, input object files don't contain .build-id sections, but if you
// create them with "ld -r --build-id", they contain it.
if (Name == ".note.gnu.build-id" && Config->BuildId != BuildIdKind::None)
return &InputSection::Discarded;
// The linker merges EH (exception handling) frames and creates a // The linker merges EH (exception handling) frames and creates a
// .eh_frame_hdr section for runtime. So we handle them with a special // .eh_frame_hdr section for runtime. So we handle them with a special
// class. For relocatable outputs, they are just passed through. // class. For relocatable outputs, they are just passed through.
if (Name == ".eh_frame" && !Config->Relocatable) if (Name == ".eh_frame" && !Config->Relocatable)
return make<EhInputSection>(*this, Sec, Name); return make<EhInputSection>(*this, Sec, Name);
if (shouldMerge(Sec)) if (shouldMerge(Sec))
return make<MergeInputSection>(*this, Sec, Name); return make<MergeInputSection>(*this, Sec, Name);
▲ Show 20 Lines • Show All 560 Lines • Show Last 20 Lines

lld/test/ELF/relocatable-build-id.s

  • This file was added.
# REQUIRES: x86
# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t1.o
# RUN: ld.lld --build-id=0xcafebabe -o %t2.o %t1.o -r
# RUN: ld.lld --build-id=0xdeadbeef -o %t.exe %t2.o
# RUN: llvm-objdump -s %t.exe | FileCheck %s
# CHECK-NOT: cafebabe
# CHECK: deadbeef
.global _start
_start:
ret