#include "llvm/MC/MCCodeEmitter.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCInst.h"
+#include "llvm/MC/MCObjectStreamer.h"
#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/MC/MCMachOSymbolFlags.h"
+#include "llvm/MC/MCSectionMachO.h"
+#include "llvm/MC/MCDwarf.h"
+#include "llvm/Support/Dwarf.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetAsmBackend.h"
namespace {
-class MCMachOStreamer : public MCStreamer {
-
+class MCMachOStreamer : public MCObjectStreamer {
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!");
-
- if (!CurSectionData->empty())
- return &CurSectionData->getFragmentList().back();
-
- 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)
- : MCStreamer(Context), Assembler(Context, TAB, *_Emitter, _OS),
- 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!");
- case MCExpr::Constant:
- break;
-
- case MCExpr::Binary: {
- const MCBinaryExpr *BE = cast<MCBinaryExpr>(Value);
- AddValueSymbols(BE->getLHS());
- AddValueSymbols(BE->getRHS());
- break;
- }
-
- case MCExpr::SymbolRef:
- Assembler.getOrCreateSymbolData(
- cast<MCSymbolRefExpr>(Value)->getSymbol());
- break;
-
- case MCExpr::Unary:
- AddValueSymbols(cast<MCUnaryExpr>(Value)->getSubExpr());
- break;
- }
-
- return Value;
- }
+ raw_ostream &OS, MCCodeEmitter *Emitter)
+ : MCObjectStreamer(Context, TAB, OS, Emitter, true) {}
/// @name MCStreamer Interface
/// @{
- virtual void SwitchSection(const MCSection *Section);
+ virtual void InitSections();
virtual void EmitLabel(MCSymbol *Symbol);
virtual void EmitAssemblerFlag(MCAssemblerFlag Flag);
virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value);
}
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";
+ // FIXME: Just ignore the .file; it isn't important enough to fail the
+ // entire assembly.
+
+ //report_fatal_error("unsupported directive: '.file'");
}
virtual void EmitDwarfFileDirective(unsigned FileNo, StringRef Filename) {
- errs() << "FIXME: MCMachoStreamer:EmitDwarfFileDirective not implemented\n";
+ // FIXME: Just ignore the .file; it isn't important enough to fail the
+ // entire assembly.
+
+ //report_fatal_error("unsupported directive: '.file'");
}
-
+
virtual void EmitInstruction(const MCInst &Inst);
+
virtual void Finish();
/// @}
} // end anonymous namespace.
-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::InitSections() {
+ SwitchSection(getContext().getMachOSection("__TEXT", "__text",
+ MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
+ 0, SectionKind::getText()));
- CurSection = Section;
- CurSectionData = &Assembler.getOrCreateSectionData(*Section);
}
void MCMachOStreamer::EmitLabel(MCSymbol *Symbol) {
+ // TODO: This is almost exactly the same as WinCOFFStreamer. Consider merging
+ // into MCObjectStreamer.
assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
assert(!Symbol->isVariable() && "Cannot emit a variable symbol!");
assert(CurSection && "Cannot emit before setting section!");
- MCSymbolData &SD = Assembler.getOrCreateSymbolData(*Symbol);
+ Symbol->setSection(*CurSection);
- // Update the current atom map, if necessary.
- bool MustCreateFragment = false;
- if (Assembler.isSymbolLinkerVisible(&SD)) {
- CurrentAtomMap[CurSectionData] = &SD;
+ MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
- // We have to create a new fragment, fragments cannot span atoms.
- MustCreateFragment = true;
- }
+ // We have to create a new fragment if this is an atom defining symbol,
+ // fragments cannot span atoms.
+ if (getAssembler().isSymbolLinkerVisible(SD.getSymbol()))
+ new MCDataFragment(getCurrentSectionData());
// 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();
+ MCDataFragment *F = 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));
-
- Symbol->setSection(*CurSection);
+ // 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);
}
void MCMachOStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
switch (Flag) {
case MCAF_SubsectionsViaSymbols:
- Assembler.setSubsectionsViaSymbols(true);
+ getAssembler().setSubsectionsViaSymbols(true);
return;
+ default:
+ llvm_unreachable("invalid assembler flag!");
}
-
- assert(0 && "invalid assembler flag!");
}
void MCMachOStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
+ // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
+ // MCObjectStreamer.
// FIXME: Lift context changes into super class.
+ getAssembler().getOrCreateSymbolData(*Symbol);
Symbol->setVariableValue(AddValueSymbols(Value));
}
// important for matching the string table that 'as' generates.
IndirectSymbolData ISD;
ISD.Symbol = Symbol;
- ISD.SectionData = CurSectionData;
- Assembler.getIndirectSymbols().push_back(ISD);
+ ISD.SectionData = getCurrentSectionData();
+ getAssembler().getIndirectSymbols().push_back(ISD);
return;
}
// Adding a symbol attribute always introduces the symbol, note that an
// important side effect of calling getOrCreateSymbolData here is to register
// the symbol with the assembler.
- MCSymbolData &SD = Assembler.getOrCreateSymbolData(*Symbol);
+ MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
// The implementation of symbol attributes is designed to match 'as', but it
// leaves much to desired. It doesn't really make sense to arbitrarily add and
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:
// it has to be in a coalesced section, but this isn't enforced.
SD.setFlags(SD.getFlags() | SF_WeakDefinition);
break;
+
+ case MCSA_WeakDefAutoPrivate:
+ SD.setFlags(SD.getFlags() | SF_WeakDefinition | SF_WeakReference);
+ break;
}
}
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);
+ getAssembler().getOrCreateSymbolData(*Symbol).setFlags(
+ DescValue & SF_DescFlagsMask);
}
void MCMachOStreamer::EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
// FIXME: Darwin 'as' does appear to allow redef of a .comm by itself.
assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
- MCSymbolData &SD = Assembler.getOrCreateSymbolData(*Symbol);
+ MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
SD.setExternal(true);
SD.setCommon(Size, ByteAlignment);
}
void MCMachOStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
unsigned Size, unsigned ByteAlignment) {
- MCSectionData &SectData = Assembler.getOrCreateSectionData(*Section);
+ MCSectionData &SectData = getAssembler().getOrCreateSectionData(*Section);
// The symbol may not be present, which only creates the section.
if (!Symbol)
assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
- MCSymbolData &SD = Assembler.getOrCreateSymbolData(*Symbol);
+ MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
// Emit an align fragment if necessary.
if (ByteAlignment != 1)
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) {
+ // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
+ // MCObjectStreamer.
getOrCreateDataFragment()->getContents().append(Data.begin(), Data.end());
}
void MCMachOStreamer::EmitValue(const MCExpr *Value, unsigned Size,
unsigned AddrSpace) {
+ // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
+ // MCObjectStreamer.
MCDataFragment *DF = getOrCreateDataFragment();
// Avoid fixups when possible.
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);
}
}
void MCMachOStreamer::EmitValueToAlignment(unsigned ByteAlignment,
int64_t Value, unsigned ValueSize,
unsigned MaxBytesToEmit) {
+ // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
+ // MCObjectStreamer.
if (MaxBytesToEmit == 0)
MaxBytesToEmit = ByteAlignment;
- MCFragment *F = new MCAlignFragment(ByteAlignment, Value, ValueSize,
- MaxBytesToEmit, CurSectionData);
- F->setAtom(CurrentAtomMap.lookup(CurSectionData));
+ new MCAlignFragment(ByteAlignment, Value, ValueSize, MaxBytesToEmit,
+ getCurrentSectionData());
// Update the maximum alignment on the current section if necessary.
- if (ByteAlignment > CurSectionData->getAlignment())
- CurSectionData->setAlignment(ByteAlignment);
+ if (ByteAlignment > getCurrentSectionData()->getAlignment())
+ getCurrentSectionData()->setAlignment(ByteAlignment);
}
void MCMachOStreamer::EmitCodeAlignment(unsigned ByteAlignment,
unsigned MaxBytesToEmit) {
+ // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
+ // MCObjectStreamer.
if (MaxBytesToEmit == 0)
MaxBytesToEmit = ByteAlignment;
MCAlignFragment *F = new MCAlignFragment(ByteAlignment, 0, 1, MaxBytesToEmit,
- CurSectionData);
+ getCurrentSectionData());
F->setEmitNops(true);
- F->setAtom(CurrentAtomMap.lookup(CurSectionData));
// Update the maximum alignment on the current section if necessary.
- if (ByteAlignment > CurSectionData->getAlignment())
- CurSectionData->setAlignment(ByteAlignment);
+ if (ByteAlignment > getCurrentSectionData()->getAlignment())
+ getCurrentSectionData()->setAlignment(ByteAlignment);
}
void MCMachOStreamer::EmitValueToOffset(const MCExpr *Offset,
unsigned char Value) {
- MCFragment *F = new MCOrgFragment(*Offset, Value, CurSectionData);
- F->setAtom(CurrentAtomMap.lookup(CurSectionData));
+ new MCOrgFragment(*Offset, Value, getCurrentSectionData());
}
-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, getCurrentSectionData());
- 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);
+ getAssembler().getEmitter().EncodeInstruction(Inst, VecOS, Fixups);
+ VecOS.flush();
+
+ IF->getCode() = Code;
+ IF->getFixups() = Fixups;
+}
- // FIXME-PERF: Common case is that we don't need to relax, encode directly
- // onto the data fragments buffers.
+void MCMachOStreamer::EmitInstToData(const MCInst &Inst) {
+ MCDataFragment *DF = getOrCreateDataFragment();
SmallVector<MCFixup, 4> Fixups;
SmallString<256> Code;
raw_svector_ostream VecOS(Code);
- Assembler.getEmitter().EncodeInstruction(Inst, VecOS, Fixups);
+ getAssembler().getEmitter().EncodeInstruction(Inst, VecOS, Fixups);
VecOS.flush();
- // FIXME: Eliminate this copy.
- SmallVector<MCAsmFixup, 4> AsmFixups;
+ // Add the fixups and data.
for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
- MCFixup &F = Fixups[i];
- AsmFixups.push_back(MCAsmFixup(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());
+}
- // See if we might need to relax this instruction, if so it needs its own
- // fragment.
- //
- // FIXME-PERF: Support target hook to do a fast path that avoids the encoder,
- // when we can immediately tell that we will get something which might need
- // relaxation (and compute its size).
- //
- // FIXME-PERF: We should also be smart about immediately relaxing instructions
- // which we can already show will never possibly fit (we can also do a very
- // good job of this before we do the first relaxation pass, because we have
- // total knowledge about undefined symbols at that point). Even now, though,
- // we can do a decent job, especially on Darwin where scattering means that we
- // are going to often know that we can never fully resolve a fixup.
- if (Assembler.getBackend().MayNeedRelaxation(Inst, AsmFixups)) {
- MCInstFragment *IF = new MCInstFragment(Inst, CurSectionData);
- IF->setAtom(CurrentAtomMap.lookup(CurSectionData));
-
- // 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.
- IF->getCode() = Code;
- IF->getFixups() = AsmFixups;
+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());
+
+ getCurrentSectionData()->setHasInstructions(true);
+ // Now that a machine instruction has been assembled into this section, make
+ // a line entry for any .loc directive that has been seen.
+ MCLineEntry::Make(this, getCurrentSection());
+
+ // If this instruction doesn't need relaxation, just emit it as data.
+ if (!getAssembler().getBackend().MayNeedRelaxation(Inst)) {
+ EmitInstToData(Inst);
return;
}
- // Add the fixups and data.
- MCDataFragment *DF = getOrCreateDataFragment();
- for (unsigned i = 0, e = AsmFixups.size(); i != e; ++i) {
- AsmFixups[i].Offset += DF->getContents().size();
- DF->addFixup(AsmFixups[i]);
+ // Otherwise, if we are relaxing everything, relax the instruction as much as
+ // possible and emit it as data.
+ if (getAssembler().getRelaxAll()) {
+ MCInst Relaxed;
+ getAssembler().getBackend().RelaxInstruction(Inst, Relaxed);
+ while (getAssembler().getBackend().MayNeedRelaxation(Relaxed))
+ getAssembler().getBackend().RelaxInstruction(Relaxed, Relaxed);
+ EmitInstToData(Relaxed);
+ return;
}
- DF->getContents().append(Code.begin(), Code.end());
+
+ // Otherwise emit to a separate fragment.
+ EmitInstToFragment(Inst);
}
void MCMachOStreamer::Finish() {
- Assembler.Finish();
+ // Dump out the dwarf file & directory tables and line tables.
+ if (getContext().hasDwarfFiles()) {
+ const MCSection *DwarfLineSection = getContext().getMachOSection("__DWARF",
+ "__debug_line",
+ MCSectionMachO::S_ATTR_DEBUG,
+ 0, SectionKind::getDataRelLocal());
+ MCDwarfFileTable::Emit(this, DwarfLineSection);
+ }
+
+ // We have to set the fragment atom associations so we can relax properly for
+ // Mach-O.
+
+ // First, scan the symbol table to build a lookup table from fragments to
+ // defining symbols.
+ DenseMap<const MCFragment*, MCSymbolData*> DefiningSymbolMap;
+ for (MCAssembler::symbol_iterator it = getAssembler().symbol_begin(),
+ ie = getAssembler().symbol_end(); it != ie; ++it) {
+ if (getAssembler().isSymbolLinkerVisible(it->getSymbol()) &&
+ it->getFragment()) {
+ // An atom defining symbol should never be internal to a fragment.
+ assert(it->getOffset() == 0 && "Invalid offset in atom defining symbol!");
+ DefiningSymbolMap[it->getFragment()] = it;
+ }
+ }
+
+ // Set the fragment atom associations by tracking the last seen atom defining
+ // symbol.
+ for (MCAssembler::iterator it = getAssembler().begin(),
+ ie = getAssembler().end(); it != ie; ++it) {
+ MCSymbolData *CurrentAtom = 0;
+ for (MCSectionData::iterator it2 = it->begin(),
+ ie2 = it->end(); it2 != ie2; ++it2) {
+ if (MCSymbolData *SD = DefiningSymbolMap.lookup(it2))
+ CurrentAtom = SD;
+ it2->setAtom(CurrentAtom);
+ }
+ }
+
+ this->MCObjectStreamer::Finish();
}
MCStreamer *llvm::createMachOStreamer(MCContext &Context, TargetAsmBackend &TAB,
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