Don't call markLiveAt for non alloc sections.

We don't gc them anyway, so just use an early return in Enqueue.

llvm-svn: 284663
This commit is contained in:
Rafael Espindola 2016-10-19 23:13:40 +00:00
parent 7c1381a099
commit 116d83fbe0
3 changed files with 12 additions and 7 deletions

View File

@ -53,7 +53,8 @@ InputSectionBase<ELFT>::InputSectionBase(elf::ObjectFile<ELFT> *File,
const Elf_Shdr *Hdr, StringRef Name,
Kind SectionKind)
: InputSectionData(SectionKind, Name, getSectionContents(File, Hdr),
isCompressed<ELFT>(Hdr, Name), !Config->GcSections),
isCompressed<ELFT>(Hdr, Name),
!Config->GcSections || !(Hdr->sh_flags & SHF_ALLOC)),
Header(Hdr), File(File), Repl(this) {
// The ELF spec states that a value of 0 means the section has
// no alignment constraits.

View File

@ -167,7 +167,10 @@ public:
void splitIntoPieces();
// Mark the piece at a given offset live. Used by GC.
void markLiveAt(uintX_t Offset) { LiveOffsets.insert(Offset); }
void markLiveAt(uintX_t Offset) {
assert(this->getSectionHdr()->sh_flags & llvm::ELF::SHF_ALLOC);
LiveOffsets.insert(Offset);
}
// Translate an offset in the input section to an offset
// in the output section.

View File

@ -201,6 +201,10 @@ template <class ELFT> void elf::markLive() {
if (!R.Sec || R.Sec == &InputSection<ELFT>::Discarded)
return;
// We don't gc non alloc sections.
if (!(R.Sec->getSectionHdr()->sh_flags & SHF_ALLOC))
return;
// Usually, a whole section is marked as live or dead, but in mergeable
// (splittable) sections, each piece of data has independent liveness bit.
// So we explicitly tell it which offset is in use.
@ -210,12 +214,9 @@ template <class ELFT> void elf::markLive() {
if (R.Sec->Live)
return;
R.Sec->Live = true;
// Add input section to the queue. We don't want to consider relocations
// from non-allocatable input sections, because we can bring those
// allocatable sections to living which otherwise would be dead.
// Add input section to the queue.
if (InputSection<ELFT> *S = dyn_cast<InputSection<ELFT>>(R.Sec))
if (S->getSectionHdr()->sh_flags & SHF_ALLOC)
Q.push_back(S);
Q.push_back(S);
};
auto MarkSymbol = [&](const SymbolBody *Sym) {