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When outputing a non-lazy pointer for a stub, we may need to fill in the value 

for the NLP because the object it's pointing to may be internal to the file.

This seems counter-intuitive, but bear with me. When we place the LSDA into the
TEXT section, the type info pointers need to be indirect and pc-rel. We
accomplish this by using NLPs. However, sometimes the types are local to the
file. GCC gets around this by not using a NLP in this case, but a "regular"
indirection like this:

GCC_except_tbl:
  .long Lfoo-.

__ZTIA:  @ This is local
  ...

Lfoo:
  .long __ZTIA

LLVM prefers NLPs on Darwin. In fact, it's more optimal for load performance to
use them.

llvm-svn: 98218
This commit is contained in:
Bill Wendling 2010-03-11 01:18:13 +00:00
parent f5e81aeba5
commit e8e79524d2
1 changed files with 5 additions and 4 deletions
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9
llvm/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp
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@ -1137,15 +1137,16 @@ void ARMAsmPrinter::EmitEndOfAsmFile(Module &M) {
// L_foo$stub:
OutStreamer.EmitLabel(Stubs[i].first);
// .indirect_symbol _foo
MCSymbol *MCSym = Stubs[i].second.getPointer();
OutStreamer.EmitSymbolAttribute(MCSym, MCSA_IndirectSymbol);
MachineModuleInfoImpl::StubValueTy &MCSym = Stubs[i].second;
OutStreamer.EmitSymbolAttribute(MCSym.getPointer(),MCSA_IndirectSymbol);
if (MCSym->isUndefined())
if (MCSym.getInt())
// External to current translation unit.
OutStreamer.EmitIntValue(0, 4/*size*/, 0/*addrspace*/);
else
// Internal to current translation unit.
OutStreamer.EmitValue(MCSymbolRefExpr::Create(MCSym, OutContext),
OutStreamer.EmitValue(MCSymbolRefExpr::Create(MCSym.getPointer(),
OutContext),
4/*size*/, 0/*addrspace*/);
}