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"
using namespace llvm;
namespace {
class MCMachOStreamer : public MCObjectStreamer {
private:
void EmitInstToFragment(const MCInst &Inst);
void EmitInstToData(const MCInst &Inst);
public:
MCMachOStreamer(MCContext &Context, TargetAsmBackend &TAB,
raw_ostream &OS, MCCodeEmitter *Emitter)
: MCObjectStreamer(Context, TAB, OS, Emitter, true) {}
virtual void InitSections();
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 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) {
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 EmitCodeAlignment(unsigned ByteAlignment,
unsigned MaxBytesToEmit = 0);
virtual void EmitValueToOffset(const MCExpr *Offset,
unsigned char Value = 0);
virtual void EmitFileDirective(StringRef Filename) {
}
virtual void EmitDwarfFileDirective(unsigned FileNo, StringRef Filename) {
}
virtual void EmitInstruction(const MCInst &Inst);
virtual void Finish();
};
}
void MCMachOStreamer::InitSections() {
SwitchSection(getContext().getMachOSection("__TEXT", "__text",
MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
0, SectionKind::getText()));
}
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!");
Symbol->setSection(*CurSection);
MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
if (getAssembler().isSymbolLinkerVisible(SD.getSymbol()))
new MCDataFragment(getCurrentSectionData());
MCDataFragment *F = getOrCreateDataFragment();
assert(!SD.getFragment() && "Unexpected fragment on symbol data!");
SD.setFragment(F);
SD.setOffset(F->getContents().size());
SD.setFlags(SD.getFlags() & ~SF_ReferenceTypeMask);
}
void MCMachOStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
switch (Flag) {
case MCAF_SubsectionsViaSymbols:
getAssembler().setSubsectionsViaSymbols(true);
return;
default:
llvm_unreachable("invalid assembler flag!");
}
}
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_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::EmitValue(const MCExpr *Value, unsigned Size,
unsigned AddrSpace) {
MCDataFragment *DF = getOrCreateDataFragment();
int64_t AbsValue;
if (AddValueSymbols(Value)->EvaluateAsAbsolute(AbsValue)) {
for (unsigned i = 0; i != Size; ++i)
DF->getContents().push_back(uint8_t(AbsValue >> (i * 8)));
} else {
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) {
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::EmitValueToOffset(const MCExpr *Offset,
unsigned char Value) {
new MCOrgFragment(*Offset, Value, getCurrentSectionData());
}
void MCMachOStreamer::EmitInstToFragment(const MCInst &Inst) {
MCInstFragment *IF = new MCInstFragment(Inst, getCurrentSectionData());
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;
}
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::EmitInstruction(const MCInst &Inst) {
for (unsigned i = Inst.getNumOperands(); i--; )
if (Inst.getOperand(i).isExpr())
AddValueSymbols(Inst.getOperand(i).getExpr());
getCurrentSectionData()->setHasInstructions(true);
MCLineEntry::Make(this, getCurrentSection());
if (!getAssembler().getBackend().MayNeedRelaxation(Inst)) {
EmitInstToData(Inst);
return;
}
if (getAssembler().getRelaxAll()) {
MCInst Relaxed;
getAssembler().getBackend().RelaxInstruction(Inst, Relaxed);
while (getAssembler().getBackend().MayNeedRelaxation(Relaxed))
getAssembler().getBackend().RelaxInstruction(Relaxed, Relaxed);
EmitInstToData(Relaxed);
return;
}
EmitInstToFragment(Inst);
}
void MCMachOStreamer::Finish() {
if (getContext().hasDwarfFiles()) {
const MCSection *DwarfLineSection = getContext().getMachOSection("__DWARF",
"__debug_line",
MCSectionMachO::S_ATTR_DEBUG,
0, SectionKind::getDataRelLocal());
MCDwarfFileTable::Emit(this, DwarfLineSection);
}
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;
}