#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCObjectWriter.h"
#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/Twine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
static void EmitSymbol(MCStreamer &streamer, const MCSymbol &symbol,
unsigned symbolEncoding) {
+ MCContext &context = streamer.getContext();
+ const MCAsmInfo &asmInfo = context.getAsmInfo();
+ const MCExpr *v = asmInfo.getExprForFDESymbol(&symbol,
+ symbolEncoding,
+ streamer);
unsigned size = getSizeForEncoding(streamer, symbolEncoding);
- unsigned application = symbolEncoding & 0x70;
- switch (application) {
- default:
- assert(0 && "Unknown Encoding");
- break;
- case 0:
- streamer.EmitSymbolValue(&symbol, size);
- break;
- case dwarf::DW_EH_PE_pcrel:
- streamer.EmitPCRelSymbolValue(&symbol, size);
- break;
- }
+ streamer.EmitAbsValue(v, size);
+}
+
+static void EmitPersonality(MCStreamer &streamer, const MCSymbol &symbol,
+ unsigned symbolEncoding) {
+ MCContext &context = streamer.getContext();
+ const MCAsmInfo &asmInfo = context.getAsmInfo();
+ const MCExpr *v = asmInfo.getExprForPersonalitySymbol(&symbol,
+ symbolEncoding,
+ streamer);
+ unsigned size = getSizeForEncoding(streamer, symbolEncoding);
+ streamer.EmitValue(v, size);
}
static const MachineLocation TranslateMachineLocation(
namespace {
class FrameEmitterImpl {
int CFAOffset;
+ int CIENum;
public:
- FrameEmitterImpl() : CFAOffset(0) {
+ FrameEmitterImpl() : CFAOffset(0), CIENum(0) {
}
const MCSymbol &EmitCIE(MCStreamer &streamer,
unsigned lsdaEncoding);
MCSymbol *EmitFDE(MCStreamer &streamer,
const MCSymbol &cieStart,
- const MCDwarfFrameInfo &frame);
+ const MCDwarfFrameInfo &frame,
+ bool forceLsda);
void EmitCFIInstructions(MCStreamer &streamer,
const std::vector<MCCFIInstruction> &Instrs,
MCSymbol *BaseLabel);
const TargetAsmInfo &asmInfo = context.getTargetAsmInfo();
const MCSection §ion = *asmInfo.getEHFrameSection();
streamer.SwitchSection(§ion);
- MCSymbol *sectionStart = streamer.getContext().CreateTempSymbol();
+
+ MCSymbol *sectionStart;
+ if (asmInfo.isFunctionEHFrameSymbolPrivate())
+ sectionStart = context.CreateTempSymbol();
+ else
+ sectionStart = context.GetOrCreateSymbol(Twine("EH_frame") + Twine(CIENum));
+
+ CIENum++;
+
MCSymbol *sectionEnd = streamer.getContext().CreateTempSymbol();
// Length
const MCExpr *Length = MakeStartMinusEndExpr(streamer, *sectionStart,
*sectionEnd, 4);
streamer.EmitLabel(sectionStart);
- streamer.EmitValue(Length, 4);
+ streamer.EmitAbsValue(Length, 4);
// CIE ID
streamer.EmitIntValue(0, 4);
streamer.EmitULEB128IntValue(asmInfo.getDwarfRARegNum(true));
// Augmentation Data Length (optional)
- MCSymbol *augmentationStart = streamer.getContext().CreateTempSymbol();
- MCSymbol *augmentationEnd = streamer.getContext().CreateTempSymbol();
- const MCExpr *augmentationLength = MakeStartMinusEndExpr(streamer,
- *augmentationStart,
- *augmentationEnd, 0);
- streamer.EmitULEB128Value(augmentationLength);
+
+ unsigned augmentationLength = 0;
+ if (personality) {
+ // Personality Encoding
+ augmentationLength += 1;
+ // Personality
+ augmentationLength += getSizeForEncoding(streamer, personalityEncoding);
+ }
+ if (lsda) {
+ augmentationLength += 1;
+ }
+ // Encoding of the FDE pointers
+ augmentationLength += 1;
+
+ streamer.EmitULEB128IntValue(augmentationLength);
// Augmentation Data (optional)
- streamer.EmitLabel(augmentationStart);
if (personality) {
// Personality Encoding
streamer.EmitIntValue(personalityEncoding, 1);
// Personality
- EmitSymbol(streamer, *personality, personalityEncoding);
+ EmitPersonality(streamer, *personality, personalityEncoding);
}
if (lsda) {
// LSDA Encoding
}
// Encoding of the FDE pointers
streamer.EmitIntValue(asmInfo.getFDEEncoding(), 1);
- streamer.EmitLabel(augmentationEnd);
// Initial Instructions
MCSymbol *FrameEmitterImpl::EmitFDE(MCStreamer &streamer,
const MCSymbol &cieStart,
- const MCDwarfFrameInfo &frame) {
+ const MCDwarfFrameInfo &frame,
+ bool forceLsda) {
MCContext &context = streamer.getContext();
MCSymbol *fdeStart = context.CreateTempSymbol();
MCSymbol *fdeEnd = context.CreateTempSymbol();
const TargetAsmInfo &asmInfo = context.getTargetAsmInfo();
+ if (!asmInfo.isFunctionEHFrameSymbolPrivate()) {
+ Twine EHName = frame.Function->getName() + Twine(".eh");
+ MCSymbol *EHSym = context.GetOrCreateSymbol(EHName);
+ streamer.EmitEHSymAttributes(frame.Function, EHSym);
+ streamer.EmitLabel(EHSym);
+ }
+
// Length
const MCExpr *Length = MakeStartMinusEndExpr(streamer, *fdeStart, *fdeEnd, 0);
- streamer.EmitValue(Length, 4);
+ streamer.EmitAbsValue(Length, 4);
streamer.EmitLabel(fdeStart);
// CIE Pointer
const MCExpr *offset = MakeStartMinusEndExpr(streamer, cieStart, *fdeStart,
0);
- streamer.EmitValue(offset, 4);
+ streamer.EmitAbsValue(offset, 4);
unsigned fdeEncoding = asmInfo.getFDEEncoding();
unsigned size = getSizeForEncoding(streamer, fdeEncoding);
// PC Begin
- streamer.EmitPCRelSymbolValue(frame.Begin, size);
+ EmitSymbol(streamer, *frame.Begin, fdeEncoding);
// PC Range
const MCExpr *Range = MakeStartMinusEndExpr(streamer, *frame.Begin,
*frame.End, 0);
- streamer.EmitValue(Range, size);
+ streamer.EmitAbsValue(Range, size);
// Augmentation Data Length
- MCSymbol *augmentationStart = streamer.getContext().CreateTempSymbol();
- MCSymbol *augmentationEnd = streamer.getContext().CreateTempSymbol();
- const MCExpr *augmentationLength = MakeStartMinusEndExpr(streamer,
- *augmentationStart,
- *augmentationEnd, 0);
- streamer.EmitULEB128Value(augmentationLength);
+ unsigned augmentationLength = 0;
+
+ if (frame.Lsda || forceLsda)
+ augmentationLength += getSizeForEncoding(streamer, frame.LsdaEncoding);
+
+ streamer.EmitULEB128IntValue(augmentationLength);
// Augmentation Data
- streamer.EmitLabel(augmentationStart);
+
+ // When running in "CodeGen compatibility mode" a FDE with no LSDA can be
+ // assigned to a CIE that requires one. In that case we output a 0 (as does
+ // CodeGen).
if (frame.Lsda)
EmitSymbol(streamer, *frame.Lsda, frame.LsdaEncoding);
- streamer.EmitLabel(augmentationEnd);
+ else if (forceLsda)
+ streamer.EmitIntValue(0, getSizeForEncoding(streamer, frame.LsdaEncoding));
+
// Call Frame Instructions
EmitCFIInstructions(streamer, frame.Instructions, frame.Begin);
// Padding
- streamer.EmitValueToAlignment(4);
+ streamer.EmitValueToAlignment(size);
return fdeEnd;
}
};
}
+// This is an implementation of CIE and FDE emission that is bug by bug
+// compatible with the one in CodeGen. It is useful during the transition
+// to make it easy to compare the outputs, but should probably be removed
+// afterwards.
+void MCDwarfFrameEmitter::EmitDarwin(MCStreamer &streamer) {
+ FrameEmitterImpl Emitter;
+ DenseMap<const MCSymbol*, const MCSymbol*> Personalities;
+ const MCSymbol *aCIE = NULL;
+ const MCDwarfFrameInfo *aFrame = NULL;
+
+ for (unsigned i = 0, n = streamer.getNumFrameInfos(); i < n; ++i) {
+ const MCDwarfFrameInfo &frame = streamer.getFrameInfo(i);
+ if (!frame.Personality)
+ continue;
+ if (Personalities.count(frame.Personality))
+ continue;
+
+ const MCSymbol *cieStart = &Emitter.EmitCIE(streamer, frame.Personality,
+ frame.PersonalityEncoding,
+ frame.Lsda,
+ frame.LsdaEncoding);
+ aCIE = cieStart;
+ aFrame = &frame;
+ Personalities[frame.Personality] = cieStart;
+ }
+
+ if (Personalities.empty()) {
+ const MCDwarfFrameInfo &frame = streamer.getFrameInfo(0);
+ aCIE = &Emitter.EmitCIE(streamer, frame.Personality,
+ frame.PersonalityEncoding, frame.Lsda,
+ frame.LsdaEncoding);
+ aFrame = &frame;
+ }
+
+ MCSymbol *fdeEnd = NULL;
+ for (unsigned i = 0, n = streamer.getNumFrameInfos(); i < n; ++i) {
+ const MCDwarfFrameInfo &frame = streamer.getFrameInfo(i);
+ const MCSymbol *cieStart = Personalities[frame.Personality];
+ bool hasLSDA;
+ if (!cieStart) {
+ cieStart = aCIE;
+ hasLSDA = aFrame->Lsda;
+ } else {
+ hasLSDA = true;
+ }
+
+ fdeEnd = Emitter.EmitFDE(streamer, *cieStart, frame,
+ hasLSDA);
+ if (i != n - 1)
+ streamer.EmitLabel(fdeEnd);
+ }
+
+ const MCContext &context = streamer.getContext();
+ const TargetAsmInfo &asmInfo = context.getTargetAsmInfo();
+ streamer.EmitValueToAlignment(asmInfo.getPointerSize());
+ if (fdeEnd)
+ streamer.EmitLabel(fdeEnd);
+}
+
void MCDwarfFrameEmitter::Emit(MCStreamer &streamer) {
const MCContext &context = streamer.getContext();
const TargetAsmInfo &asmInfo = context.getTargetAsmInfo();
+ if (!asmInfo.isFunctionEHFrameSymbolPrivate()) {
+ EmitDarwin(streamer);
+ return;
+ }
+
MCSymbol *fdeEnd = NULL;
DenseMap<CIEKey, const MCSymbol*> CIEStarts;
FrameEmitterImpl Emitter;
cieStart = &Emitter.EmitCIE(streamer, frame.Personality,
frame.PersonalityEncoding, frame.Lsda,
frame.LsdaEncoding);
- fdeEnd = Emitter.EmitFDE(streamer, *cieStart, frame);
+ fdeEnd = Emitter.EmitFDE(streamer, *cieStart, frame, false);
if (i != n - 1)
streamer.EmitLabel(fdeEnd);
}
uint64_t AddrDelta) {
SmallString<256> Tmp;
raw_svector_ostream OS(Tmp);
- MCDwarfFrameEmitter::EncodeAdvanceLoc(AddrDelta, OS);
+ const TargetAsmInfo &AsmInfo = Streamer.getContext().getTargetAsmInfo();
+ MCDwarfFrameEmitter::EncodeAdvanceLoc(AddrDelta, OS, AsmInfo);
Streamer.EmitBytes(OS.str(), /*AddrSpace=*/0);
}
void MCDwarfFrameEmitter::EncodeAdvanceLoc(uint64_t AddrDelta,
- raw_ostream &OS) {
+ raw_ostream &OS,
+ const TargetAsmInfo &AsmInfo) {
+ // This is a small hack to facilitate the transition to CFI on OS X. It
+ // relaxes all address advances which lets us produces identical output
+ // to the one produce by CodeGen.
+ const bool Relax = !AsmInfo.isFunctionEHFrameSymbolPrivate();
+
// FIXME: Assumes the code alignment factor is 1.
if (AddrDelta == 0) {
- } else if (isUIntN(6, AddrDelta)) {
+ } else if (isUIntN(6, AddrDelta) && !Relax) {
uint8_t Opcode = dwarf::DW_CFA_advance_loc | AddrDelta;
OS << Opcode;
- } else if (isUInt<8>(AddrDelta)) {
+ } else if (isUInt<8>(AddrDelta) && !Relax) {
OS << uint8_t(dwarf::DW_CFA_advance_loc1);
OS << uint8_t(AddrDelta);
- } else if (isUInt<16>(AddrDelta)) {
+ } else if (isUInt<16>(AddrDelta) && !Relax) {
// FIXME: check what is the correct behavior on a big endian machine.
OS << uint8_t(dwarf::DW_CFA_advance_loc2);
OS << uint8_t( AddrDelta & 0xff);
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