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MC/Mach-O: Factor out doesSymbolRequireExternRelocation. 

llvm-svn: 103442
This commit is contained in:
Daniel Dunbar 2010-05-10 23:15:13 +00:00
parent ffb9f18dfe
commit 7de3106a89
1 changed files with 20 additions and 10 deletions
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30
llvm/lib/MC/MachObjectWriter.cpp
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@ -59,6 +59,20 @@ static bool isFixupKindRIPRel(unsigned Kind) {
Kind == X86::reloc_riprel_4byte_movq_load;
}
static bool doesSymbolRequireExternRelocation(MCSymbolData *SD) {
// Undefined symbols are always extern.
if (SD->Symbol->isUndefined())
return true;
// References to weak definitions require external relocation entries; the
// definition may not always be the one in the same object file.
if (SD->getFlags() & SF_WeakDefinition)
return true;
// Otherwise, we can use an internal relocation.
return false;
}
namespace {
class MachObjectWriterImpl {
@ -754,18 +768,14 @@ public:
const MCSymbol *Symbol = &Target.getSymA()->getSymbol();
MCSymbolData *SD = &Asm.getSymbolData(*Symbol);
// Both references to undefined symbols and references to Weak Definitions
// get external relocation entries. This is so the static and then the
// the dynamic linker can resolve them to the actual definition that will
// be used. And in the case of Weak Definitions a reference to one will
// not always be to the definition in the same object file.
if (Symbol->isUndefined() || (SD->getFlags() & SF_WeakDefinition)) {
// Check whether we need an external or internal relocation.
if (doesSymbolRequireExternRelocation(SD)) {
IsExtern = 1;
Index = SD->getIndex();
// In the case of a Weak Definition the FixedValue needs to be set to
// to not have the address of the symbol. In the case of an undefined
// symbol you can't call getSymbolAddress().
if (SD->getFlags() & SF_WeakDefinition)
// For external relocations, make sure to offset the fixup value to
// compensate for the addend of the symbol address, if it was
// undefined. This occurs with weak definitions, for example.
if (!SD->Symbol->isUndefined())
FixedValue -= Layout.getSymbolAddress(SD);
Value = 0;
} else {