#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCSymbol.h"
+#include "llvm/MC/MCMachOSymbolFlags.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
+#include "llvm/Target/TargetAsmBackend.h"
+
using namespace llvm;
namespace {
class MCMachOStreamer : public MCStreamer {
- /// SymbolFlags - We store the value for the 'desc' symbol field in the lowest
- /// 16 bits of the implementation defined flags.
- enum SymbolFlags { // See <mach-o/nlist.h>.
- SF_DescFlagsMask = 0xFFFF,
-
- // Reference type flags.
- SF_ReferenceTypeMask = 0x0007,
- SF_ReferenceTypeUndefinedNonLazy = 0x0000,
- SF_ReferenceTypeUndefinedLazy = 0x0001,
- SF_ReferenceTypeDefined = 0x0002,
- SF_ReferenceTypePrivateDefined = 0x0003,
- SF_ReferenceTypePrivateUndefinedNonLazy = 0x0004,
- SF_ReferenceTypePrivateUndefinedLazy = 0x0005,
-
- // Other 'desc' flags.
- SF_NoDeadStrip = 0x0020,
- SF_WeakReference = 0x0040,
- SF_WeakDefinition = 0x0080
- };
private:
MCAssembler Assembler;
MCSectionData *CurSectionData;
+ /// Track the current atom for each section.
+ DenseMap<const MCSectionData*, MCSymbolData*> CurrentAtomMap;
+
private:
MCFragment *getCurrentFragment() const {
assert(CurSectionData && "No current section!");
return 0;
}
+ /// Get a data fragment to write into, creating a new one if the current
+ /// fragment is not a data fragment.
+ MCDataFragment *getOrCreateDataFragment() const {
+ MCDataFragment *F = dyn_cast_or_null<MCDataFragment>(getCurrentFragment());
+ if (!F)
+ F = createDataFragment();
+ return F;
+ }
+
+ /// Create a new data fragment in the current section.
+ MCDataFragment *createDataFragment() const {
+ MCDataFragment *DF = new MCDataFragment(CurSectionData);
+ DF->setAtom(CurrentAtomMap.lookup(CurSectionData));
+ return DF;
+ }
+
+ void EmitInstToFragment(const MCInst &Inst);
+ void EmitInstToData(const MCInst &Inst);
+
public:
MCMachOStreamer(MCContext &Context, TargetAsmBackend &TAB,
raw_ostream &_OS, MCCodeEmitter *_Emitter)
CurSectionData(0) {}
~MCMachOStreamer() {}
+ MCAssembler &getAssembler() { return Assembler; }
+
const MCExpr *AddValueSymbols(const MCExpr *Value) {
switch (Value->getKind()) {
case MCExpr::Target: assert(0 && "Can't handle target exprs yet!");
virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue);
virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
unsigned ByteAlignment);
+ virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol) {
+ assert(0 && "macho doesn't support this directive");
+ }
+ virtual void EmitCOFFSymbolStorageClass(int StorageClass) {
+ assert(0 && "macho doesn't support this directive");
+ }
+ virtual void EmitCOFFSymbolType(int Type) {
+ assert(0 && "macho doesn't support this directive");
+ }
+ virtual void EndCOFFSymbolDef() {
+ assert(0 && "macho doesn't support this directive");
+ }
virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
assert(0 && "macho doesn't support this directive");
}
}
virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
unsigned Size = 0, unsigned ByteAlignment = 0);
+ virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
+ uint64_t Size, unsigned ByteAlignment = 0);
virtual void EmitBytes(StringRef Data, unsigned AddrSpace);
virtual void EmitValue(const MCExpr *Value, unsigned Size,unsigned AddrSpace);
virtual void EmitGPRel32Value(const MCExpr *Value) {
unsigned MaxBytesToEmit = 0);
virtual void EmitValueToOffset(const MCExpr *Offset,
unsigned char Value = 0);
-
+
virtual void EmitFileDirective(StringRef Filename) {
- errs() << "FIXME: MCMachoStreamer:EmitFileDirective not implemented\n";
+ report_fatal_error("unsupported directive: '.file'");
}
virtual void EmitDwarfFileDirective(unsigned FileNo, StringRef Filename) {
- errs() << "FIXME: MCMachoStreamer:EmitDwarfFileDirective not implemented\n";
+ report_fatal_error("unsupported directive: '.file'");
}
-
+
virtual void EmitInstruction(const MCInst &Inst);
virtual void Finish();
void MCMachOStreamer::SwitchSection(const MCSection *Section) {
assert(Section && "Cannot switch to a null section!");
-
+
// If already in this section, then this is a noop.
if (Section == CurSection) return;
void MCMachOStreamer::EmitLabel(MCSymbol *Symbol) {
assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
-
- // FIXME: We should also use offsets into Fill fragments.
- MCDataFragment *F = dyn_cast_or_null<MCDataFragment>(getCurrentFragment());
- if (!F)
- F = new MCDataFragment(CurSectionData);
+ assert(!Symbol->isVariable() && "Cannot emit a variable symbol!");
+ assert(CurSection && "Cannot emit before setting section!");
MCSymbolData &SD = Assembler.getOrCreateSymbolData(*Symbol);
+
+ // Update the current atom map, if necessary.
+ bool MustCreateFragment = false;
+ if (Assembler.isSymbolLinkerVisible(&SD)) {
+ CurrentAtomMap[CurSectionData] = &SD;
+
+ // We have to create a new fragment, fragments cannot span atoms.
+ MustCreateFragment = true;
+ }
+
+ // FIXME: This is wasteful, we don't necessarily need to create a data
+ // fragment. Instead, we should mark the symbol as pointing into the data
+ // fragment if it exists, otherwise we should just queue the label and set its
+ // fragment pointer when we emit the next fragment.
+ MCDataFragment *F =
+ MustCreateFragment ? createDataFragment() : getOrCreateDataFragment();
assert(!SD.getFragment() && "Unexpected fragment on symbol data!");
SD.setFragment(F);
SD.setOffset(F->getContents().size());
- // This causes the reference type and weak reference flags to be cleared.
- SD.setFlags(SD.getFlags() & ~(SF_WeakReference | SF_ReferenceTypeMask));
-
+ // This causes the reference type flag to be cleared. Darwin 'as' was "trying"
+ // to clear the weak reference and weak definition bits too, but the
+ // implementation was buggy. For now we just try to match 'as', for
+ // diffability.
+ //
+ // FIXME: Cleanup this code, these bits should be emitted based on semantic
+ // properties, not on the order of definition, etc.
+ SD.setFlags(SD.getFlags() & ~SF_ReferenceTypeMask);
+
Symbol->setSection(*CurSection);
}
}
void MCMachOStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
- // Only absolute symbols can be redefined.
- assert((Symbol->isUndefined() || Symbol->isAbsolute()) &&
- "Cannot define a symbol twice!");
-
// FIXME: Lift context changes into super class.
- // FIXME: Set associated section.
- Symbol->setValue(AddValueSymbols(Value));
+ Assembler.getOrCreateSymbolData(*Symbol);
+ Symbol->setVariableValue(AddValueSymbols(Value));
}
void MCMachOStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
case MCSA_Global:
SD.setExternal(true);
+ // This effectively clears the undefined lazy bit, in Darwin 'as', although
+ // it isn't very consistent because it implements this as part of symbol
+ // lookup.
+ //
+ // FIXME: Cleanup this code, these bits should be emitted based on semantic
+ // properties, not on the order of definition, etc.
+ SD.setFlags(SD.getFlags() & ~SF_ReferenceTypeUndefinedLazy);
break;
case MCSA_LazyReference:
void MCMachOStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
// Encode the 'desc' value into the lowest implementation defined bits.
- assert(DescValue == (DescValue & SF_DescFlagsMask) &&
+ assert(DescValue == (DescValue & SF_DescFlagsMask) &&
"Invalid .desc value!");
Assembler.getOrCreateSymbolData(*Symbol).setFlags(DescValue&SF_DescFlagsMask);
}
MCSymbolData &SD = Assembler.getOrCreateSymbolData(*Symbol);
- MCFragment *F = new MCZeroFillFragment(Size, ByteAlignment, &SectData);
+ // Emit an align fragment if necessary.
+ if (ByteAlignment != 1)
+ new MCAlignFragment(ByteAlignment, 0, 0, ByteAlignment, &SectData);
+
+ MCFragment *F = new MCFillFragment(0, 0, Size, &SectData);
SD.setFragment(F);
+ if (Assembler.isSymbolLinkerVisible(&SD))
+ F->setAtom(&SD);
Symbol->setSection(*Section);
SectData.setAlignment(ByteAlignment);
}
+// This should always be called with the thread local bss section. Like the
+// .zerofill directive this doesn't actually switch sections on us.
+void MCMachOStreamer::EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
+ uint64_t Size, unsigned ByteAlignment) {
+ EmitZerofill(Section, Symbol, Size, ByteAlignment);
+ return;
+}
+
void MCMachOStreamer::EmitBytes(StringRef Data, unsigned AddrSpace) {
- MCDataFragment *DF = dyn_cast_or_null<MCDataFragment>(getCurrentFragment());
- if (!DF)
- DF = new MCDataFragment(CurSectionData);
- DF->getContents().append(Data.begin(), Data.end());
+ getOrCreateDataFragment()->getContents().append(Data.begin(), Data.end());
}
void MCMachOStreamer::EmitValue(const MCExpr *Value, unsigned Size,
unsigned AddrSpace) {
- MCDataFragment *DF = dyn_cast_or_null<MCDataFragment>(getCurrentFragment());
- if (!DF)
- DF = new MCDataFragment(CurSectionData);
+ MCDataFragment *DF = getOrCreateDataFragment();
// Avoid fixups when possible.
int64_t AbsValue;
for (unsigned i = 0; i != Size; ++i)
DF->getContents().push_back(uint8_t(AbsValue >> (i * 8)));
} else {
- DF->addFixup(MCAsmFixup(DF->getContents().size(), *AddValueSymbols(Value),
- MCFixup::getKindForSize(Size)));
+ DF->addFixup(MCFixup::Create(DF->getContents().size(),
+ AddValueSymbols(Value),
+ MCFixup::getKindForSize(Size)));
DF->getContents().resize(DF->getContents().size() + Size, 0);
}
}
unsigned MaxBytesToEmit) {
if (MaxBytesToEmit == 0)
MaxBytesToEmit = ByteAlignment;
- new MCAlignFragment(ByteAlignment, Value, ValueSize, MaxBytesToEmit,
- false /* EmitNops */, CurSectionData);
+ MCFragment *F = new MCAlignFragment(ByteAlignment, Value, ValueSize,
+ MaxBytesToEmit, CurSectionData);
+ F->setAtom(CurrentAtomMap.lookup(CurSectionData));
// Update the maximum alignment on the current section if necessary.
if (ByteAlignment > CurSectionData->getAlignment())
unsigned MaxBytesToEmit) {
if (MaxBytesToEmit == 0)
MaxBytesToEmit = ByteAlignment;
- // FIXME the 0x90 is the default x86 1 byte nop opcode.
- new MCAlignFragment(ByteAlignment, 0x90, 1, MaxBytesToEmit,
- true /* EmitNops */, CurSectionData);
+ MCAlignFragment *F = new MCAlignFragment(ByteAlignment, 0, 1, MaxBytesToEmit,
+ CurSectionData);
+ F->setEmitNops(true);
+ F->setAtom(CurrentAtomMap.lookup(CurSectionData));
// Update the maximum alignment on the current section if necessary.
if (ByteAlignment > CurSectionData->getAlignment())
void MCMachOStreamer::EmitValueToOffset(const MCExpr *Offset,
unsigned char Value) {
- new MCOrgFragment(*Offset, Value, CurSectionData);
+ MCFragment *F = new MCOrgFragment(*Offset, Value, CurSectionData);
+ F->setAtom(CurrentAtomMap.lookup(CurSectionData));
}
-void MCMachOStreamer::EmitInstruction(const MCInst &Inst) {
- // Scan for values.
- for (unsigned i = 0; i != Inst.getNumOperands(); ++i)
- if (Inst.getOperand(i).isExpr())
- AddValueSymbols(Inst.getOperand(i).getExpr());
+void MCMachOStreamer::EmitInstToFragment(const MCInst &Inst) {
+ MCInstFragment *IF = new MCInstFragment(Inst, CurSectionData);
+ IF->setAtom(CurrentAtomMap.lookup(CurSectionData));
- CurSectionData->setHasInstructions(true);
+ // Add the fixups and data.
+ //
+ // FIXME: Revisit this design decision when relaxation is done, we may be
+ // able to get away with not storing any extra data in the MCInst.
+ SmallVector<MCFixup, 4> Fixups;
+ SmallString<256> Code;
+ raw_svector_ostream VecOS(Code);
+ Assembler.getEmitter().EncodeInstruction(Inst, VecOS, Fixups);
+ VecOS.flush();
+
+ IF->getCode() = Code;
+ IF->getFixups() = Fixups;
+}
+
+void MCMachOStreamer::EmitInstToData(const MCInst &Inst) {
+ MCDataFragment *DF = getOrCreateDataFragment();
SmallVector<MCFixup, 4> Fixups;
SmallString<256> Code;
VecOS.flush();
// Add the fixups and data.
- MCDataFragment *DF = dyn_cast_or_null<MCDataFragment>(getCurrentFragment());
- if (!DF)
- DF = new MCDataFragment(CurSectionData);
for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
- MCFixup &F = Fixups[i];
- DF->addFixup(MCAsmFixup(DF->getContents().size()+F.getOffset(),
- *F.getValue(), F.getKind()));
+ Fixups[i].setOffset(Fixups[i].getOffset() + DF->getContents().size());
+ DF->addFixup(Fixups[i]);
}
DF->getContents().append(Code.begin(), Code.end());
}
+void MCMachOStreamer::EmitInstruction(const MCInst &Inst) {
+ // Scan for values.
+ for (unsigned i = Inst.getNumOperands(); i--; )
+ if (Inst.getOperand(i).isExpr())
+ AddValueSymbols(Inst.getOperand(i).getExpr());
+
+ CurSectionData->setHasInstructions(true);
+
+ // If this instruction doesn't need relaxation, just emit it as data.
+ if (!Assembler.getBackend().MayNeedRelaxation(Inst)) {
+ EmitInstToData(Inst);
+ return;
+ }
+
+ // Otherwise, if we are relaxing everything, relax the instruction as much as
+ // possible and emit it as data.
+ if (Assembler.getRelaxAll()) {
+ MCInst Relaxed;
+ Assembler.getBackend().RelaxInstruction(Inst, Relaxed);
+ while (Assembler.getBackend().MayNeedRelaxation(Relaxed))
+ Assembler.getBackend().RelaxInstruction(Relaxed, Relaxed);
+ EmitInstToData(Relaxed);
+ return;
+ }
+
+ // Otherwise emit to a separate fragment.
+ EmitInstToFragment(Inst);
+}
+
void MCMachOStreamer::Finish() {
Assembler.Finish();
}
MCStreamer *llvm::createMachOStreamer(MCContext &Context, TargetAsmBackend &TAB,
- raw_ostream &OS, MCCodeEmitter *CE) {
- return new MCMachOStreamer(Context, TAB, OS, CE);
+ raw_ostream &OS, MCCodeEmitter *CE,
+ bool RelaxAll) {
+ MCMachOStreamer *S = new MCMachOStreamer(Context, TAB, OS, CE);
+ if (RelaxAll)
+ S->getAssembler().setRelaxAll(true);
+ return S;
}
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