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[ELF] - Simplify removeUnusedSyntheticSections a bit. 

Previously`InX::Got` and InX::MipsGot synthetic sections
were not removed if ElfSym::GlobalOffsetTable was defined.
ElfSym::GlobalOffsetTable is a symbol for _GLOBAL_OFFSET_TABLE_.

Patch moves ElfSym::GlobalOffsetTable check out from removeUnusedSyntheticSections.
Also note that there was no point to check ElfSym::GlobalOffsetTable for MIPS case
because InX::MipsGot::empty() always returns false for non-relocatable case, and in case
of relocatable output we do not create special symbols anyways.

Differential revision: https://reviews.llvm.org/D37623

llvm-svn: 314099
This commit is contained in:
George Rimar 2017-09-25 09:46:33 +00:00
parent 347c70d782
commit 19d6ce9d8e
2 changed files with 4 additions and 5 deletions
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7
lld/ELF/SyntheticSections.cpp
View File

@ -656,9 +656,10 @@ uint64_t GotSection::getGlobalDynOffset(const SymbolBody &B) const {
void GotSection::finalizeContents() { Size = NumEntries * Config->Wordsize; }
bool GotSection::empty() const {
// If we have a relocation that is relative to GOT (such as GOTOFFREL),
// we need to emit a GOT even if it's empty.
return NumEntries == 0 && !HasGotOffRel;
// We need to emit a GOT even if it's empty if there's a relocation that is
// relative to GOT(such as GOTOFFREL) or there's a symbol that points to a GOT
// (i.e. _GLOBAL_OFFSET_TABLE_).
return NumEntries == 0 && !HasGotOffRel && !ElfSym::GlobalOffsetTable;
}
void GotSection::writeTo(uint8_t *Buf) {

2
lld/ELF/Writer.cpp
View File

@ -1187,8 +1187,6 @@ static void removeUnusedSyntheticSections() {
OutputSection *OS = SS->getParent();
if (!SS->empty() || !OS)
continue;
if ((SS == InX::Got || SS == InX::MipsGot) && ElfSym::GlobalOffsetTable)
continue;
std::vector<BaseCommand *>::iterator Empty = OS->Commands.end();
for (auto I = OS->Commands.begin(), E = OS->Commands.end(); I != E; ++I) {