MCMachOStreamer.cpp [plain text]
#include "llvm/MC/MCStreamer.h"
#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/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"
#include "llvm/Target/TargetAsmInfo.h"
using namespace llvm;
namespace {
class MCMachOStreamer : public MCObjectStreamer {
private:
virtual void EmitInstToData(const MCInst &Inst);
public:
MCMachOStreamer(MCContext &Context, TargetAsmBackend &TAB,
raw_ostream &OS, MCCodeEmitter *Emitter)
: MCObjectStreamer(Context, TAB, OS, Emitter) {}
virtual void InitSections();
virtual void EmitLabel(MCSymbol *Symbol);
virtual void EmitEHSymAttributes(const MCSymbol *Symbol,
MCSymbol *EHSymbol);
virtual void EmitAssemblerFlag(MCAssemblerFlag Flag);
virtual void EmitThumbFunc(MCSymbol *Func);
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 EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
uint64_t Size, unsigned ByteAlignment = 0);
virtual void EmitBytes(StringRef Data, unsigned AddrSpace);
virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
unsigned ValueSize = 1,
unsigned MaxBytesToEmit = 0);
virtual void EmitCodeAlignment(unsigned ByteAlignment,
unsigned MaxBytesToEmit = 0);
virtual void EmitFileDirective(StringRef Filename) {
}
virtual void Finish();
};
}
void MCMachOStreamer::InitSections() {
SwitchSection(getContext().getMachOSection("__TEXT", "__text",
MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
0, SectionKind::getText()));
}
void MCMachOStreamer::EmitEHSymAttributes(const MCSymbol *Symbol,
MCSymbol *EHSymbol) {
MCSymbolData &SD =
getAssembler().getOrCreateSymbolData(*Symbol);
if (SD.isExternal())
EmitSymbolAttribute(EHSymbol, MCSA_Global);
if (SD.getFlags() & SF_WeakDefinition)
EmitSymbolAttribute(EHSymbol, MCSA_WeakDefinition);
if (SD.isPrivateExtern())
EmitSymbolAttribute(EHSymbol, MCSA_PrivateExtern);
}
void MCMachOStreamer::EmitLabel(MCSymbol *Symbol) {
assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
Symbol->setSection(*getCurrentSection());
if (getAssembler().isSymbolLinkerVisible(*Symbol))
new MCDataFragment(getCurrentSectionData());
MCObjectStreamer::EmitLabel(Symbol);
MCSymbolData &SD = getAssembler().getSymbolData(*Symbol);
SD.setFlags(SD.getFlags() & ~SF_ReferenceTypeMask);
}
void MCMachOStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
getAssembler().getBackend().HandleAssemblerFlag(Flag);
switch (Flag) {
case MCAF_SyntaxUnified: return; case MCAF_Code16: return; case MCAF_Code32: return; case MCAF_SubsectionsViaSymbols:
getAssembler().setSubsectionsViaSymbols(true);
return;
default:
llvm_unreachable("invalid assembler flag!");
}
}
void MCMachOStreamer::EmitThumbFunc(MCSymbol *Symbol) {
getAssembler().setIsThumbFunc(Symbol);
MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
SD.setFlags(SD.getFlags() | SF_ThumbFunc);
}
void MCMachOStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
getAssembler().getOrCreateSymbolData(*Symbol);
Symbol->setVariableValue(AddValueSymbols(Value));
}
void MCMachOStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
MCSymbolAttr Attribute) {
if (Attribute == MCSA_IndirectSymbol) {
IndirectSymbolData ISD;
ISD.Symbol = Symbol;
ISD.SectionData = getCurrentSectionData();
getAssembler().getIndirectSymbols().push_back(ISD);
return;
}
MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
switch (Attribute) {
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_ELF_TypeGnuUniqueObject:
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);
SD.setFlags(SD.getFlags() & ~SF_ReferenceTypeUndefinedLazy);
break;
case MCSA_LazyReference:
SD.setFlags(SD.getFlags() | SF_NoDeadStrip);
if (Symbol->isUndefined())
SD.setFlags(SD.getFlags() | SF_ReferenceTypeUndefinedLazy);
break;
case MCSA_Reference:
case MCSA_NoDeadStrip:
SD.setFlags(SD.getFlags() | SF_NoDeadStrip);
break;
case MCSA_SymbolResolver:
SD.setFlags(SD.getFlags() | SF_SymbolResolver);
break;
case MCSA_PrivateExtern:
SD.setExternal(true);
SD.setPrivateExtern(true);
break;
case MCSA_WeakReference:
if (Symbol->isUndefined())
SD.setFlags(SD.getFlags() | SF_WeakReference);
break;
case MCSA_WeakDefinition:
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) {
assert(DescValue == (DescValue & SF_DescFlagsMask) &&
"Invalid .desc value!");
getAssembler().getOrCreateSymbolData(*Symbol).setFlags(
DescValue & SF_DescFlagsMask);
}
void MCMachOStreamer::EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
unsigned ByteAlignment) {
assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
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 = getAssembler().getOrCreateSectionData(*Section);
if (!Symbol)
return;
assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
if (ByteAlignment != 1)
new MCAlignFragment(ByteAlignment, 0, 0, ByteAlignment, &SectData);
MCFragment *F = new MCFillFragment(0, 0, Size, &SectData);
SD.setFragment(F);
Symbol->setSection(*Section);
if (ByteAlignment > SectData.getAlignment())
SectData.setAlignment(ByteAlignment);
}
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) {
getOrCreateDataFragment()->getContents().append(Data.begin(), Data.end());
}
void MCMachOStreamer::EmitValueToAlignment(unsigned ByteAlignment,
int64_t Value, unsigned ValueSize,
unsigned MaxBytesToEmit) {
if (MaxBytesToEmit == 0)
MaxBytesToEmit = ByteAlignment;
new MCAlignFragment(ByteAlignment, Value, ValueSize, MaxBytesToEmit,
getCurrentSectionData());
if (ByteAlignment > getCurrentSectionData()->getAlignment())
getCurrentSectionData()->setAlignment(ByteAlignment);
}
void MCMachOStreamer::EmitCodeAlignment(unsigned ByteAlignment,
unsigned MaxBytesToEmit) {
if (MaxBytesToEmit == 0)
MaxBytesToEmit = ByteAlignment;
MCAlignFragment *F = new MCAlignFragment(ByteAlignment, 0, 1, MaxBytesToEmit,
getCurrentSectionData());
F->setEmitNops(true);
if (ByteAlignment > getCurrentSectionData()->getAlignment())
getCurrentSectionData()->setAlignment(ByteAlignment);
}
void MCMachOStreamer::EmitInstToData(const MCInst &Inst) {
MCDataFragment *DF = getOrCreateDataFragment();
SmallVector<MCFixup, 4> Fixups;
SmallString<256> Code;
raw_svector_ostream VecOS(Code);
getAssembler().getEmitter().EncodeInstruction(Inst, VecOS, Fixups);
VecOS.flush();
for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
Fixups[i].setOffset(Fixups[i].getOffset() + DF->getContents().size());
DF->addFixup(Fixups[i]);
}
DF->getContents().append(Code.begin(), Code.end());
}
void MCMachOStreamer::Finish() {
if (getNumFrameInfos())
MCDwarfFrameEmitter::Emit(*this, true);
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()) {
assert(it->getOffset() == 0 && "Invalid offset in atom defining symbol!");
DefiningSymbolMap[it->getFragment()] = it;
}
}
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,
raw_ostream &OS, MCCodeEmitter *CE,
bool RelaxAll) {
MCMachOStreamer *S = new MCMachOStreamer(Context, TAB, OS, CE);
if (RelaxAll)
S->getAssembler().setRelaxAll(true);
return S;
}