This is an archive of the discontinued LLVM Phabricator instance.

Differential D62725

[ELF] Replace a dead test in getSymVA() with assert()
ClosedPublic

Authored by MaskRay on May 31 2019, 2:36 AM.

Details

Reviewers
ruiu
• espindola
Commits
rG3f29cfd91545: [ELF] Replace a dead test in getSymVA() with assert()
rLLD362218: [ELF] Replace a dead test in getSymVA() with assert()
rL362218: [ELF] Replace a dead test in getSymVA() with assert()
Summary

Symbols relative to discarded comdat sections are Undefined instead of
Defined now (after D59649 and D61583). The == &InputSection::Discarded
test is now dead. I cannot find a test related to this behavior.

Diff Detail

Event Timeline

MaskRay created this revision.May 31 2019, 2:36 AM
Herald added a reviewer: • espindola. · View Herald TranscriptMay 31 2019, 2:36 AM
Herald added a project: Restricted Project. · View Herald Transcript
Herald added subscribers: llvm-commits, arichardson, emaste. · View Herald Transcript
Harbormaster completed remote builds in B32723: Diff 202401.May 31 2019, 2:37 AM
ruiu accepted this revision.May 31 2019, 2:40 AM

LGTM

Nice!

This revision is now accepted and ready to land.May 31 2019, 2:40 AM
Closed by commit rL362218: [ELF] Replace a dead test in getSymVA() with assert() (authored by MaskRay). · Explain WhyMay 31 2019, 3:10 AM
This revision was automatically updated to reflect the committed changes.

Revision Contents

PathSize
ELF/
8 lines

Diff 202401

ELF/Symbols.cpp

Show First 20 Lines • Show All 41 Lines • ▼ Show 20 Lines
Defined *ElfSym::TlsModuleBase; Defined *ElfSym::TlsModuleBase;
static uint64_t getSymVA(const Symbol &Sym, int64_t &Addend) { static uint64_t getSymVA(const Symbol &Sym, int64_t &Addend) {
switch (Sym.kind()) { switch (Sym.kind()) {
case Symbol::DefinedKind: { case Symbol::DefinedKind: {
auto &D = cast<Defined>(Sym); auto &D = cast<Defined>(Sym);
SectionBase *IS = D.Section; SectionBase *IS = D.Section;
// According to the ELF spec reference to a local symbol from outside
// the group are not allowed. Unfortunately .eh_frame breaks that rule
// and must be treated specially. For now we just replace the symbol with
// 0.
if (IS == &InputSection::Discarded)
return 0;
// This is an absolute symbol. // This is an absolute symbol.
if (!IS) if (!IS)
return D.Value; return D.Value;
assert(IS != &InputSection::Discarded);
IS = IS->Repl; IS = IS->Repl;
uint64_t Offset = D.Value; uint64_t Offset = D.Value;
// An object in an SHF_MERGE section might be referenced via a // An object in an SHF_MERGE section might be referenced via a
// section symbol (as a hack for reducing the number of local // section symbol (as a hack for reducing the number of local
// symbols). // symbols).
// Depending on the addend, the reference via a section symbol // Depending on the addend, the reference via a section symbol
▲ Show 20 Lines • Show All 578 Lines • Show Last 20 Lines