#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCCodeEmitter.h"
+#include "llvm/MC/MCExpr.h"
+#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 {
- MCAssembler Assembler;
+private:
+ MCAssembler Assembler;
MCSectionData *CurSectionData;
- DenseMap<const MCSection*, MCSectionData*> SectionMap;
-
- DenseMap<const MCSymbol*, MCSymbolData*> SymbolMap;
+ /// Track the current atom for each section.
+ DenseMap<const MCSectionData*, MCSymbolData*> CurrentAtomMap;
private:
MCFragment *getCurrentFragment() const {
return 0;
}
- MCSymbolData &getSymbolData(MCSymbol &Symbol) {
- MCSymbolData *&Entry = SymbolMap[&Symbol];
-
- if (!Entry)
- Entry = new MCSymbolData(Symbol, 0, 0, &Assembler);
+ /// 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;
+ }
- return *Entry;
+ /// Create a new data fragment in the current section.
+ MCDataFragment *createDataFragment() const {
+ MCDataFragment *DF = new MCDataFragment(CurSectionData);
+ DF->setAtom(CurrentAtomMap.lookup(CurSectionData));
+ return DF;
}
public:
- MCMachOStreamer(MCContext &Context, raw_ostream &_OS)
- : MCStreamer(Context), Assembler(_OS), CurSectionData(0) {}
+ MCMachOStreamer(MCContext &Context, TargetAsmBackend &TAB,
+ raw_ostream &_OS, MCCodeEmitter *_Emitter)
+ : MCStreamer(Context), Assembler(Context, TAB, *_Emitter, _OS),
+ CurSectionData(0) {}
~MCMachOStreamer() {}
- /// @name MCStreamer Interface
- /// @{
-
- virtual void SwitchSection(const MCSection *Section);
-
- virtual void EmitLabel(MCSymbol *Symbol);
-
- virtual void EmitAssemblerFlag(AssemblerFlag Flag);
+ MCAssembler &getAssembler() { return Assembler; }
- virtual void EmitAssignment(MCSymbol *Symbol, const MCValue &Value,
- bool MakeAbsolute = false);
-
- virtual void EmitSymbolAttribute(MCSymbol *Symbol, SymbolAttr Attribute);
-
- virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue);
+ const MCExpr *AddValueSymbols(const MCExpr *Value) {
+ switch (Value->getKind()) {
+ case MCExpr::Target: assert(0 && "Can't handle target exprs yet!");
+ case MCExpr::Constant:
+ break;
- virtual void EmitLocalSymbol(MCSymbol *Symbol, const MCValue &Value);
+ case MCExpr::Binary: {
+ const MCBinaryExpr *BE = cast<MCBinaryExpr>(Value);
+ AddValueSymbols(BE->getLHS());
+ AddValueSymbols(BE->getRHS());
+ break;
+ }
- virtual void EmitCommonSymbol(MCSymbol *Symbol, unsigned Size,
- unsigned Pow2Alignment, bool IsLocal);
+ case MCExpr::SymbolRef:
+ Assembler.getOrCreateSymbolData(
+ cast<MCSymbolRefExpr>(Value)->getSymbol());
+ break;
- virtual void EmitZerofill(MCSection *Section, MCSymbol *Symbol = NULL,
- unsigned Size = 0, unsigned Pow2Alignment = 0);
+ case MCExpr::Unary:
+ AddValueSymbols(cast<MCUnaryExpr>(Value)->getSubExpr());
+ break;
+ }
- virtual void EmitBytes(const StringRef &Data);
+ return Value;
+ }
- virtual void EmitValue(const MCValue &Value, unsigned Size);
+ /// @name MCStreamer Interface
+ /// @{
+ virtual void SwitchSection(const MCSection *Section);
+ virtual void EmitLabel(MCSymbol *Symbol);
+ virtual void EmitAssemblerFlag(MCAssemblerFlag Flag);
+ virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value);
+ virtual void EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute);
+ 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 EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size) {
+ 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 EmitBytes(StringRef Data, unsigned AddrSpace);
+ virtual void EmitValue(const MCExpr *Value, unsigned Size,unsigned AddrSpace);
+ virtual void EmitGPRel32Value(const MCExpr *Value) {
+ assert(0 && "macho doesn't support this directive");
+ }
virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
unsigned ValueSize = 1,
unsigned MaxBytesToEmit = 0);
-
- virtual void EmitValueToOffset(const MCValue &Offset,
+ virtual void EmitCodeAlignment(unsigned ByteAlignment,
+ 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";
+ }
+ virtual void EmitDwarfFileDirective(unsigned FileNo, StringRef Filename) {
+ errs() << "FIXME: MCMachoStreamer:EmitDwarfFileDirective not implemented\n";
+ }
+
virtual void EmitInstruction(const MCInst &Inst);
-
virtual void Finish();
/// @}
// If already in this section, then this is a noop.
if (Section == CurSection) return;
-
- CurSection = Section;
- MCSectionData *&Entry = SectionMap[Section];
-
- if (!Entry)
- Entry = new MCSectionData(*Section, &Assembler);
- CurSectionData = Entry;
+ CurSection = Section;
+ CurSectionData = &Assembler.getOrCreateSectionData(*Section);
}
void MCMachOStreamer::EmitLabel(MCSymbol *Symbol) {
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);
+
+ // Update the current atom map, if necessary.
+ bool MustCreateFragment = false;
+ if (Assembler.isSymbolLinkerVisible(&SD)) {
+ CurrentAtomMap[CurSectionData] = &SD;
- MCDataFragment *F = dyn_cast_or_null<MCDataFragment>(getCurrentFragment());
- if (!F)
- F = new MCDataFragment(CurSectionData);
+ // We have to create a new fragment, fragments cannot span atoms.
+ MustCreateFragment = true;
+ }
- MCSymbolData &SD = getSymbolData(*Symbol);
+ // 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));
Symbol->setSection(*CurSection);
}
-void MCMachOStreamer::EmitAssemblerFlag(AssemblerFlag Flag) {
- llvm_unreachable("FIXME: Not yet implemented!");
-}
+void MCMachOStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
+ switch (Flag) {
+ case MCAF_SubsectionsViaSymbols:
+ Assembler.setSubsectionsViaSymbols(true);
+ return;
+ }
-void MCMachOStreamer::EmitAssignment(MCSymbol *Symbol,
- const MCValue &Value,
- bool MakeAbsolute) {
- // Only absolute symbols can be redefined.
- assert((Symbol->isUndefined() || Symbol->isAbsolute()) &&
- "Cannot define a symbol twice!");
+ assert(0 && "invalid assembler flag!");
+}
- llvm_unreachable("FIXME: Not yet implemented!");
+void MCMachOStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
+ // FIXME: Lift context changes into super class.
+ Symbol->setVariableValue(AddValueSymbols(Value));
}
void MCMachOStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
- SymbolAttr Attribute) {
+ MCSymbolAttr Attribute) {
+ // Indirect symbols are handled differently, to match how 'as' handles
+ // them. This makes writing matching .o files easier.
+ if (Attribute == MCSA_IndirectSymbol) {
+ // Note that we intentionally cannot use the symbol data here; this is
+ // important for matching the string table that 'as' generates.
+ IndirectSymbolData ISD;
+ ISD.Symbol = Symbol;
+ ISD.SectionData = CurSectionData;
+ Assembler.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);
+
+ // 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
+ // remove flags, but 'as' allows this (in particular, see .desc).
+ //
+ // In the future it might be worth trying to make these operations more well
+ // defined.
switch (Attribute) {
- default:
- llvm_unreachable("FIXME: Not yet implemented!");
+ case MCSA_Invalid:
+ case MCSA_ELF_TypeFunction:
+ case MCSA_ELF_TypeIndFunction:
+ case MCSA_ELF_TypeObject:
+ case MCSA_ELF_TypeTLS:
+ case MCSA_ELF_TypeCommon:
+ case MCSA_ELF_TypeNoType:
+ case MCSA_IndirectSymbol:
+ case MCSA_Hidden:
+ case MCSA_Internal:
+ case MCSA_Protected:
+ case MCSA_Weak:
+ case MCSA_Local:
+ assert(0 && "Invalid symbol attribute for Mach-O!");
+ break;
+
+ case MCSA_Global:
+ SD.setExternal(true);
+ break;
+
+ case MCSA_LazyReference:
+ // FIXME: This requires -dynamic.
+ SD.setFlags(SD.getFlags() | SF_NoDeadStrip);
+ if (Symbol->isUndefined())
+ SD.setFlags(SD.getFlags() | SF_ReferenceTypeUndefinedLazy);
+ break;
+
+ // Since .reference sets the no dead strip bit, it is equivalent to
+ // .no_dead_strip in practice.
+ case MCSA_Reference:
+ case MCSA_NoDeadStrip:
+ SD.setFlags(SD.getFlags() | SF_NoDeadStrip);
+ break;
- case MCStreamer::Global:
- getSymbolData(*Symbol).setExternal(true);
+ case MCSA_PrivateExtern:
+ SD.setExternal(true);
+ SD.setPrivateExtern(true);
+ break;
+
+ case MCSA_WeakReference:
+ // FIXME: This requires -dynamic.
+ if (Symbol->isUndefined())
+ SD.setFlags(SD.getFlags() | SF_WeakReference);
+ break;
+
+ case MCSA_WeakDefinition:
+ // FIXME: 'as' enforces that this is defined and global. The manual claims
+ // it has to be in a coalesced section, but this isn't enforced.
+ SD.setFlags(SD.getFlags() | SF_WeakDefinition);
break;
}
}
void MCMachOStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
- llvm_unreachable("FIXME: Not yet implemented!");
+ // Encode the 'desc' value into the lowest implementation defined bits.
+ assert(DescValue == (DescValue & SF_DescFlagsMask) &&
+ "Invalid .desc value!");
+ Assembler.getOrCreateSymbolData(*Symbol).setFlags(DescValue&SF_DescFlagsMask);
}
-void MCMachOStreamer::EmitLocalSymbol(MCSymbol *Symbol, const MCValue &Value) {
- llvm_unreachable("FIXME: Not yet implemented!");
-}
+void MCMachOStreamer::EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
+ unsigned ByteAlignment) {
+ // FIXME: Darwin 'as' does appear to allow redef of a .comm by itself.
+ assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
-void MCMachOStreamer::EmitCommonSymbol(MCSymbol *Symbol, unsigned Size,
- unsigned Pow2Alignment,
- bool IsLocal) {
- llvm_unreachable("FIXME: Not yet implemented!");
+ MCSymbolData &SD = Assembler.getOrCreateSymbolData(*Symbol);
+ SD.setExternal(true);
+ SD.setCommon(Size, ByteAlignment);
}
-void MCMachOStreamer::EmitZerofill(MCSection *Section, MCSymbol *Symbol,
- unsigned Size, unsigned Pow2Alignment) {
- llvm_unreachable("FIXME: Not yet implemented!");
+void MCMachOStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
+ unsigned Size, unsigned ByteAlignment) {
+ MCSectionData &SectData = Assembler.getOrCreateSectionData(*Section);
+
+ // The symbol may not be present, which only creates the section.
+ if (!Symbol)
+ return;
+
+ // FIXME: Assert that this section has the zerofill type.
+
+ assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
+
+ MCSymbolData &SD = Assembler.getOrCreateSymbolData(*Symbol);
+
+ MCFragment *F = new MCZeroFillFragment(Size, ByteAlignment, &SectData);
+ SD.setFragment(F);
+ if (Assembler.isSymbolLinkerVisible(&SD))
+ F->setAtom(&SD);
+
+ Symbol->setSection(*Section);
+
+ // Update the maximum alignment on the zero fill section if necessary.
+ if (ByteAlignment > SectData.getAlignment())
+ SectData.setAlignment(ByteAlignment);
}
-void MCMachOStreamer::EmitBytes(const StringRef &Data) {
- MCDataFragment *DF = dyn_cast_or_null<MCDataFragment>(getCurrentFragment());
- if (!DF)
- DF = new MCDataFragment(CurSectionData);
- DF->getContents().append(Data.begin(), Data.end());
+void MCMachOStreamer::EmitBytes(StringRef Data, unsigned AddrSpace) {
+ getOrCreateDataFragment()->getContents().append(Data.begin(), Data.end());
}
-void MCMachOStreamer::EmitValue(const MCValue &Value, unsigned Size) {
- new MCFillFragment(Value, Size, 1, CurSectionData);
+void MCMachOStreamer::EmitValue(const MCExpr *Value, unsigned Size,
+ unsigned AddrSpace) {
+ MCDataFragment *DF = getOrCreateDataFragment();
+
+ // Avoid fixups when possible.
+ int64_t AbsValue;
+ if (AddValueSymbols(Value)->EvaluateAsAbsolute(AbsValue)) {
+ // FIXME: Endianness assumption.
+ 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->getContents().resize(DF->getContents().size() + Size, 0);
+ }
}
void MCMachOStreamer::EmitValueToAlignment(unsigned ByteAlignment,
unsigned MaxBytesToEmit) {
if (MaxBytesToEmit == 0)
MaxBytesToEmit = ByteAlignment;
- new MCAlignFragment(ByteAlignment, Value, ValueSize, MaxBytesToEmit,
- CurSectionData);
+ MCFragment *F = new MCAlignFragment(ByteAlignment, Value, ValueSize,
+ MaxBytesToEmit, /*EmitNops=*/false,
+ CurSectionData);
+ F->setAtom(CurrentAtomMap.lookup(CurSectionData));
// Update the maximum alignment on the current section if necessary.
if (ByteAlignment > CurSectionData->getAlignment())
CurSectionData->setAlignment(ByteAlignment);
}
-void MCMachOStreamer::EmitValueToOffset(const MCValue &Offset,
+void MCMachOStreamer::EmitCodeAlignment(unsigned ByteAlignment,
+ unsigned MaxBytesToEmit) {
+ if (MaxBytesToEmit == 0)
+ MaxBytesToEmit = ByteAlignment;
+ MCFragment *F = new MCAlignFragment(ByteAlignment, 0, 1, MaxBytesToEmit,
+ /*EmitNops=*/true, CurSectionData);
+ F->setAtom(CurrentAtomMap.lookup(CurSectionData));
+
+ // Update the maximum alignment on the current section if necessary.
+ if (ByteAlignment > CurSectionData->getAlignment())
+ CurSectionData->setAlignment(ByteAlignment);
+}
+
+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) {
- llvm_unreachable("FIXME: Not yet implemented!");
+ // Scan for values.
+ for (unsigned i = 0; i != Inst.getNumOperands(); ++i)
+ if (Inst.getOperand(i).isExpr())
+ AddValueSymbols(Inst.getOperand(i).getExpr());
+
+ CurSectionData->setHasInstructions(true);
+
+ // FIXME-PERF: Common case is that we don't need to relax, encode directly
+ // onto the data fragments buffers.
+
+ SmallVector<MCFixup, 4> Fixups;
+ SmallString<256> Code;
+ raw_svector_ostream VecOS(Code);
+ Assembler.getEmitter().EncodeInstruction(Inst, VecOS, Fixups);
+ VecOS.flush();
+
+ // FIXME: Eliminate this copy.
+ SmallVector<MCAsmFixup, 4> AsmFixups;
+ for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
+ MCFixup &F = Fixups[i];
+ AsmFixups.push_back(MCAsmFixup(F.getOffset(), *F.getValue(),
+ F.getKind()));
+ }
+
+ // 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;
+
+ 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]);
+ }
+ DF->getContents().append(Code.begin(), Code.end());
}
void MCMachOStreamer::Finish() {
Assembler.Finish();
}
-MCStreamer *llvm::createMachOStreamer(MCContext &Context, raw_ostream &OS) {
- return new MCMachOStreamer(Context, OS);
+MCStreamer *llvm::createMachOStreamer(MCContext &Context, TargetAsmBackend &TAB,
+ 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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