#include "llvm/MC/MCStreamer.h"
-#include "llvm/ADT/DenseMap.h"
#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCCodeEmitter.h"
+#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCSymbol.h"
-#include "llvm/MC/MCValue.h"
#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/raw_ostream.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;
+ MCCodeEmitter *Emitter;
+
MCSectionData *CurSectionData;
DenseMap<const MCSection*, MCSectionData*> SectionMap;
+
+ DenseMap<const MCSymbol*, MCSymbolData*> SymbolMap;
+
+private:
+ MCFragment *getCurrentFragment() const {
+ assert(CurSectionData && "No current section!");
+
+ if (!CurSectionData->empty())
+ return &CurSectionData->getFragmentList().back();
+
+ return 0;
+ }
+
+ MCSectionData &getSectionData(const MCSection &Section) {
+ MCSectionData *&Entry = SectionMap[&Section];
+
+ if (!Entry)
+ Entry = new MCSectionData(Section, &Assembler);
+
+ return *Entry;
+ }
+
+ MCSymbolData &getSymbolData(MCSymbol &Symbol) {
+ MCSymbolData *&Entry = SymbolMap[&Symbol];
+
+ if (!Entry)
+ Entry = new MCSymbolData(Symbol, 0, 0, &Assembler);
+
+ return *Entry;
+ }
public:
- MCMachOStreamer(MCContext &Context, raw_ostream &_OS)
- : MCStreamer(Context), Assembler(_OS), CurSectionData(0) {}
+ MCMachOStreamer(MCContext &Context, raw_ostream &_OS, MCCodeEmitter *_Emitter)
+ : MCStreamer(Context), Assembler(_OS), Emitter(_Emitter),
+ CurSectionData(0) {}
~MCMachOStreamer() {}
+ const MCValue &AddValueSymbols(const MCValue &Value) {
+ if (Value.getSymA())
+ getSymbolData(*const_cast<MCSymbol*>(Value.getSymA()));
+ if (Value.getSymB())
+ getSymbolData(*const_cast<MCSymbol*>(Value.getSymB()));
+ return Value;
+ }
+
/// @name MCStreamer Interface
/// @{
virtual void EmitLocalSymbol(MCSymbol *Symbol, const MCValue &Value);
virtual void EmitCommonSymbol(MCSymbol *Symbol, unsigned Size,
- unsigned Pow2Alignment, bool IsLocal);
+ unsigned Pow2Alignment);
- virtual void EmitZerofill(MCSection *Section, MCSymbol *Symbol = NULL,
+ virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
unsigned Size = 0, unsigned Pow2Alignment = 0);
virtual void EmitBytes(const StringRef &Data);
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;
- if (Section != CurSection) {
- CurSection = Section;
- MCSectionData *&Entry = SectionMap[Section];
-
- if (!Entry)
- Entry = new MCSectionData(*Section, &Assembler);
-
- CurSectionData = Entry;
- }
+ CurSection = Section;
+ CurSectionData = &getSectionData(*Section);
}
void MCMachOStreamer::EmitLabel(MCSymbol *Symbol) {
- assert(Symbol->getSection() == 0 && "Cannot emit a symbol twice!");
- assert(CurSection && "Cannot emit before setting section!");
- assert(!getContext().GetSymbolValue(Symbol) &&
- "Cannot emit symbol which was directly assigned to!");
-
- llvm_unreachable("FIXME: Not yet implemented!");
-
- Symbol->setSection(CurSection);
- Symbol->setExternal(false);
+ 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);
+
+ MCSymbolData &SD = getSymbolData(*Symbol);
+ 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!");
+ switch (Flag) {
+ case SubsectionsViaSymbols:
+ Assembler.setSubsectionsViaSymbols(true);
+ return;
+ }
+
+ assert(0 && "invalid assembler flag!");
}
void MCMachOStreamer::EmitAssignment(MCSymbol *Symbol,
const MCValue &Value,
bool MakeAbsolute) {
- assert(!Symbol->getSection() && "Cannot assign to a label!");
+ // Only absolute symbols can be redefined.
+ assert((Symbol->isUndefined() || Symbol->isAbsolute()) &&
+ "Cannot define a symbol twice!");
llvm_unreachable("FIXME: Not yet implemented!");
}
void MCMachOStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
SymbolAttr Attribute) {
- llvm_unreachable("FIXME: Not yet implemented!");
+ // Indirect symbols are handled differently, to match how 'as' handles
+ // them. This makes writing matching .o files easier.
+ if (Attribute == MCStreamer::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 getSymbolData here is to register the
+ // symbol with the assembler.
+ MCSymbolData &SD = getSymbolData(*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) {
+ case MCStreamer::IndirectSymbol:
+ case MCStreamer::Hidden:
+ case MCStreamer::Internal:
+ case MCStreamer::Protected:
+ case MCStreamer::Weak:
+ assert(0 && "Invalid symbol attribute for Mach-O!");
+ break;
+
+ case MCStreamer::Global:
+ SD.setExternal(true);
+ break;
+
+ case MCStreamer::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 MCStreamer::Reference:
+ case MCStreamer::NoDeadStrip:
+ SD.setFlags(SD.getFlags() | SF_NoDeadStrip);
+ break;
+
+ case MCStreamer::PrivateExtern:
+ SD.setExternal(true);
+ SD.setPrivateExtern(true);
+ break;
+
+ case MCStreamer::WeakReference:
+ // FIXME: This requires -dynamic.
+ if (Symbol->isUndefined())
+ SD.setFlags(SD.getFlags() | SF_WeakReference);
+ break;
+
+ case MCStreamer::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!");
+ getSymbolData(*Symbol).setFlags(DescValue & SF_DescFlagsMask);
}
void MCMachOStreamer::EmitLocalSymbol(MCSymbol *Symbol, const MCValue &Value) {
- llvm_unreachable("FIXME: Not yet implemented!");
+ // FIXME: Implement?
+ llvm_report_error("unsupported '.lsym' directive");
}
void MCMachOStreamer::EmitCommonSymbol(MCSymbol *Symbol, unsigned Size,
- unsigned Pow2Alignment,
- bool IsLocal) {
- llvm_unreachable("FIXME: Not yet implemented!");
+ unsigned Pow2Alignment) {
+ // FIXME: Darwin 'as' does appear to allow redef of a .comm by itself.
+ assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
+
+ MCSymbolData &SD = getSymbolData(*Symbol);
+ SD.setExternal(true);
+ SD.setCommon(Size, 1 << Pow2Alignment);
}
-void MCMachOStreamer::EmitZerofill(MCSection *Section, MCSymbol *Symbol,
+void MCMachOStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
unsigned Size, unsigned Pow2Alignment) {
- llvm_unreachable("FIXME: Not yet implemented!");
+ unsigned ByteAlignment = 1 << Pow2Alignment;
+ MCSectionData &SectData = getSectionData(*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 = getSymbolData(*Symbol);
+
+ MCFragment *F = new MCZeroFillFragment(Size, 1 << Pow2Alignment, &SectData);
+ SD.setFragment(F);
+
+ 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) {
- llvm_unreachable("FIXME: Not yet implemented!");
+ MCDataFragment *DF = dyn_cast_or_null<MCDataFragment>(getCurrentFragment());
+ if (!DF)
+ DF = new MCDataFragment(CurSectionData);
+ DF->getContents().append(Data.begin(), Data.end());
}
void MCMachOStreamer::EmitValue(const MCValue &Value, unsigned Size) {
- llvm_unreachable("FIXME: Not yet implemented!");
+ new MCFillFragment(AddValueSymbols(Value), Size, 1, CurSectionData);
}
void MCMachOStreamer::EmitValueToAlignment(unsigned ByteAlignment,
int64_t Value, unsigned ValueSize,
unsigned MaxBytesToEmit) {
- llvm_unreachable("FIXME: Not yet implemented!");
+ if (MaxBytesToEmit == 0)
+ MaxBytesToEmit = ByteAlignment;
+ new MCAlignFragment(ByteAlignment, Value, ValueSize, MaxBytesToEmit,
+ CurSectionData);
+
+ // Update the maximum alignment on the current section if necessary.
+ if (ByteAlignment > CurSectionData->getAlignment())
+ CurSectionData->setAlignment(ByteAlignment);
}
void MCMachOStreamer::EmitValueToOffset(const MCValue &Offset,
unsigned char Value) {
- llvm_unreachable("FIXME: Not yet implemented!");
+ new MCOrgFragment(AddValueSymbols(Offset), Value, 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).isMCValue())
+ AddValueSymbols(Inst.getOperand(i).getMCValue());
+
+ if (!Emitter)
+ llvm_unreachable("no code emitter available!");
+
+ // FIXME: Relocations!
+ SmallString<256> Code;
+ raw_svector_ostream VecOS(Code);
+ Emitter->EncodeInstruction(Inst, VecOS);
+ EmitBytes(VecOS.str());
}
void MCMachOStreamer::Finish() {
Assembler.Finish();
}
-MCStreamer *llvm::createMachOStreamer(MCContext &Context, raw_ostream &OS) {
- return new MCMachOStreamer(Context, OS);
+MCStreamer *llvm::createMachOStreamer(MCContext &Context, raw_ostream &OS,
+ MCCodeEmitter *CE) {
+ return new MCMachOStreamer(Context, OS, CE);
}
projects / oota-llvm.git / blobdiff