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MC/Mach-O: Lift the fixup evaluation and application up (to the same place), and eliminate MCAsmFixup::FixedValue. 

llvm-svn: 98944
This commit is contained in:
Daniel Dunbar 2010-03-19 07:09:47 +00:00
parent d84d196a86
commit 3cab275783
2 changed files with 32 additions and 41 deletions
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7
llvm/include/llvm/MC/MCAssembler.h
View File

@ -45,14 +45,9 @@ struct MCAsmFixup {
/// Kind - The fixup kind.
MCFixupKind Kind;
/// FixedValue - The value to replace the fix up by.
//
// FIXME: This should not be here.
uint64_t FixedValue;
public:
MCAsmFixup(uint64_t _Offset, const MCExpr &_Value, MCFixupKind _Kind)
: Offset(_Offset), Value(&_Value), Kind(_Kind), FixedValue(0) {}
: Offset(_Offset), Value(&_Value), Kind(_Kind) {}
};
class MCFragment : public ilist_node<MCFragment> {

66
llvm/lib/MC/MCAssembler.cpp
View File

@ -609,19 +609,6 @@ public:
Relocations[Fragment.getParent()].push_back(MRE);
}
void ComputeRelocationInfo(MCAssembler &Asm, MCDataFragment &Fragment,
MCAsmFixup &Fixup) {
// FIXME: Share layout object.
MCAsmLayout Layout(Asm);
// Evaluate the fixup; if the value was resolved, no relocation is needed.
MCValue Target;
if (Asm.EvaluateFixup(Layout, Fixup, &Fragment, Target, Fixup.FixedValue))
return;
RecordRelocation(Asm, Fragment, Fixup, Target, Fixup.FixedValue);
}
void BindIndirectSymbols(MCAssembler &Asm) {
// This is the point where 'as' creates actual symbols for indirect symbols
// (in the following two passes). It would be easier for us to do this
@ -785,17 +772,6 @@ public:
// Compute symbol table information and bind symbol indices.
ComputeSymbolTable(Asm, StringTable, LocalSymbolData, ExternalSymbolData,
UndefinedSymbolData);
// Compute relocations.
for (MCAssembler::iterator it = Asm.begin(),
ie = Asm.end(); it != ie; ++it) {
MCSectionData &SD = *it;
for (MCSectionData::iterator it2 = SD.begin(),
ie2 = SD.end(); it2 != ie2; ++it2)
if (MCDataFragment *DF = dyn_cast<MCDataFragment>(&*it2))
for (unsigned i = 0, e = DF->fixup_size(); i != e; ++i)
ComputeRelocationInfo(Asm, *DF, DF->getFixups()[i]);
}
}
void WriteObject(const MCAssembler &Asm) {
@ -955,14 +931,15 @@ public:
}
}
void ApplyFixup(const MCAsmFixup &Fixup, MCDataFragment &DF) {
void ApplyFixup(const MCAsmFixup &Fixup, MCDataFragment &DF,
uint64_t FixedValue) {
unsigned Size = 1 << getFixupKindLog2Size(Fixup.Kind);
// FIXME: Endianness assumption.
assert(Fixup.Offset + Size <= DF.getContents().size() &&
"Invalid fixup offset!");
for (unsigned i = 0; i != Size; ++i)
DF.getContents()[Fixup.Offset + i] = uint8_t(Fixup.FixedValue >> (i * 8));
DF.getContents()[Fixup.Offset + i] = uint8_t(FixedValue >> (i * 8));
}
};
@ -1394,15 +1371,6 @@ static void WriteFileData(raw_ostream &OS, const MCFragment &F,
}
case MCFragment::FT_Data: {
MCDataFragment &DF = cast<MCDataFragment>(F);
// Apply the fixups.
//
// FIXME: Move elsewhere.
for (MCDataFragment::const_fixup_iterator it = DF.fixup_begin(),
ie = DF.fixup_end(); it != ie; ++it)
MOW.ApplyFixup(*it, DF);
OS << cast<MCDataFragment>(F).getContents().str();
break;
}
@ -1484,6 +1452,34 @@ void MCAssembler::Finish() {
// example, to set the index fields in the symbol data).
MOW.ExecutePostLayoutBinding(*this);
// Evaluate and apply the fixups, generating relocation entries as necessary.
MCAsmLayout Layout(*this);
for (MCAssembler::iterator it = begin(), ie = end(); it != ie; ++it) {
for (MCSectionData::iterator it2 = it->begin(),
ie2 = it->end(); it2 != ie2; ++it2) {
MCDataFragment *DF = dyn_cast<MCDataFragment>(it2);
if (!DF)
continue;
for (MCDataFragment::fixup_iterator it3 = DF->fixup_begin(),
ie3 = DF->fixup_end(); it3 != ie3; ++it3) {
MCAsmFixup &Fixup = *it3;
// Evaluate the fixup.
MCValue Target;
uint64_t FixedValue;
if (!EvaluateFixup(Layout, Fixup, DF, Target, FixedValue)) {
// The fixup was unresolved, we need a relocation. Inform the object
// writer of the relocation, and give it an opportunity to adjust the
// fixup value if need be.
MOW.RecordRelocation(*this, *DF, Fixup, Target, FixedValue);
}
MOW.ApplyFixup(Fixup, *DF, FixedValue);
}
}
}
// Write the object file.
MOW.WriteObject(*this);