| //===-- AsmPrinterDwarf.cpp - AsmPrinter Dwarf Support --------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements the Dwarf emissions parts of AsmPrinter. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "ByteStreamer.h" |
| #include "DwarfDebug.h" |
| #include "DwarfExpression.h" |
| #include "llvm/ADT/Twine.h" |
| #include "llvm/CodeGen/AsmPrinter.h" |
| #include "llvm/CodeGen/DIE.h" |
| #include "llvm/CodeGen/MachineFunction.h" |
| #include "llvm/CodeGen/MachineModuleInfo.h" |
| #include "llvm/IR/DataLayout.h" |
| #include "llvm/MC/MCAsmInfo.h" |
| #include "llvm/MC/MCRegisterInfo.h" |
| #include "llvm/MC/MCSection.h" |
| #include "llvm/MC/MCStreamer.h" |
| #include "llvm/MC/MCSymbol.h" |
| #include "llvm/MC/MachineLocation.h" |
| #include "llvm/Support/Dwarf.h" |
| #include "llvm/Support/ErrorHandling.h" |
| #include "llvm/Target/TargetLoweringObjectFile.h" |
| #include "llvm/Target/TargetMachine.h" |
| #include "llvm/Target/TargetSubtargetInfo.h" |
| using namespace llvm; |
| |
| #define DEBUG_TYPE "asm-printer" |
| |
| //===----------------------------------------------------------------------===// |
| // Dwarf Emission Helper Routines |
| //===----------------------------------------------------------------------===// |
| |
| /// EmitSLEB128 - emit the specified signed leb128 value. |
| void AsmPrinter::EmitSLEB128(int64_t Value, const char *Desc) const { |
| if (isVerbose() && Desc) |
| OutStreamer.AddComment(Desc); |
| |
| OutStreamer.EmitSLEB128IntValue(Value); |
| } |
| |
| /// EmitULEB128 - emit the specified signed leb128 value. |
| void AsmPrinter::EmitULEB128(uint64_t Value, const char *Desc, |
| unsigned PadTo) const { |
| if (isVerbose() && Desc) |
| OutStreamer.AddComment(Desc); |
| |
| OutStreamer.EmitULEB128IntValue(Value, PadTo); |
| } |
| |
| /// EmitCFAByte - Emit a .byte 42 directive for a DW_CFA_xxx value. |
| void AsmPrinter::EmitCFAByte(unsigned Val) const { |
| if (isVerbose()) { |
| if (Val >= dwarf::DW_CFA_offset && Val < dwarf::DW_CFA_offset + 64) |
| OutStreamer.AddComment("DW_CFA_offset + Reg (" + |
| Twine(Val - dwarf::DW_CFA_offset) + ")"); |
| else |
| OutStreamer.AddComment(dwarf::CallFrameString(Val)); |
| } |
| OutStreamer.EmitIntValue(Val, 1); |
| } |
| |
| static const char *DecodeDWARFEncoding(unsigned Encoding) { |
| switch (Encoding) { |
| case dwarf::DW_EH_PE_absptr: |
| return "absptr"; |
| case dwarf::DW_EH_PE_omit: |
| return "omit"; |
| case dwarf::DW_EH_PE_pcrel: |
| return "pcrel"; |
| case dwarf::DW_EH_PE_udata4: |
| return "udata4"; |
| case dwarf::DW_EH_PE_udata8: |
| return "udata8"; |
| case dwarf::DW_EH_PE_sdata4: |
| return "sdata4"; |
| case dwarf::DW_EH_PE_sdata8: |
| return "sdata8"; |
| case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata4: |
| return "pcrel udata4"; |
| case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4: |
| return "pcrel sdata4"; |
| case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8: |
| return "pcrel udata8"; |
| case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8: |
| return "pcrel sdata8"; |
| case dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata4 |
| : |
| return "indirect pcrel udata4"; |
| case dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4 |
| : |
| return "indirect pcrel sdata4"; |
| case dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8 |
| : |
| return "indirect pcrel udata8"; |
| case dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8 |
| : |
| return "indirect pcrel sdata8"; |
| } |
| |
| return "<unknown encoding>"; |
| } |
| |
| /// EmitEncodingByte - Emit a .byte 42 directive that corresponds to an |
| /// encoding. If verbose assembly output is enabled, we output comments |
| /// describing the encoding. Desc is an optional string saying what the |
| /// encoding is specifying (e.g. "LSDA"). |
| void AsmPrinter::EmitEncodingByte(unsigned Val, const char *Desc) const { |
| if (isVerbose()) { |
| if (Desc) |
| OutStreamer.AddComment(Twine(Desc) + " Encoding = " + |
| Twine(DecodeDWARFEncoding(Val))); |
| else |
| OutStreamer.AddComment(Twine("Encoding = ") + DecodeDWARFEncoding(Val)); |
| } |
| |
| OutStreamer.EmitIntValue(Val, 1); |
| } |
| |
| /// GetSizeOfEncodedValue - Return the size of the encoding in bytes. |
| unsigned AsmPrinter::GetSizeOfEncodedValue(unsigned Encoding) const { |
| if (Encoding == dwarf::DW_EH_PE_omit) |
| return 0; |
| |
| switch (Encoding & 0x07) { |
| default: |
| llvm_unreachable("Invalid encoded value."); |
| case dwarf::DW_EH_PE_absptr: |
| return TM.getDataLayout()->getPointerSize(); |
| case dwarf::DW_EH_PE_udata2: |
| return 2; |
| case dwarf::DW_EH_PE_udata4: |
| return 4; |
| case dwarf::DW_EH_PE_udata8: |
| return 8; |
| } |
| } |
| |
| void AsmPrinter::EmitTTypeReference(const GlobalValue *GV, |
| unsigned Encoding) const { |
| if (GV) { |
| const TargetLoweringObjectFile &TLOF = getObjFileLowering(); |
| |
| const MCExpr *Exp = |
| TLOF.getTTypeGlobalReference(GV, Encoding, *Mang, TM, MMI, OutStreamer); |
| OutStreamer.EmitValue(Exp, GetSizeOfEncodedValue(Encoding)); |
| } else |
| OutStreamer.EmitIntValue(0, GetSizeOfEncodedValue(Encoding)); |
| } |
| |
| /// EmitSectionOffset - Emit the 4-byte offset of Label from the start of its |
| /// section. This can be done with a special directive if the target supports |
| /// it (e.g. cygwin) or by emitting it as an offset from a label at the start |
| /// of the section. |
| /// |
| /// SectionLabel is a temporary label emitted at the start of the section that |
| /// Label lives in. |
| void AsmPrinter::emitSectionOffset(const MCSymbol *Label) const { |
| // On COFF targets, we have to emit the special .secrel32 directive. |
| if (MAI->needsDwarfSectionOffsetDirective()) { |
| OutStreamer.EmitCOFFSecRel32(Label); |
| return; |
| } |
| |
| // If the format uses relocations with dwarf, refer to the symbol directly. |
| if (MAI->doesDwarfUseRelocationsAcrossSections()) { |
| OutStreamer.EmitSymbolValue(Label, 4); |
| return; |
| } |
| |
| // Otherwise, emit it as a label difference from the start of the section. |
| EmitLabelDifference(Label, Label->getSection().getBeginSymbol(), 4); |
| } |
| |
| /// EmitDwarfRegOp - Emit dwarf register operation. |
| void AsmPrinter::EmitDwarfRegOp(ByteStreamer &Streamer, |
| const MachineLocation &MLoc) const { |
| DebugLocDwarfExpression Expr(*MF->getSubtarget().getRegisterInfo(), |
| getDwarfDebug()->getDwarfVersion(), Streamer); |
| const MCRegisterInfo *MRI = MMI->getContext().getRegisterInfo(); |
| int Reg = MRI->getDwarfRegNum(MLoc.getReg(), false); |
| if (Reg < 0) { |
| // We assume that pointers are always in an addressable register. |
| if (MLoc.isIndirect()) |
| // FIXME: We have no reasonable way of handling errors in here. The |
| // caller might be in the middle of a dwarf expression. We should |
| // probably assert that Reg >= 0 once debug info generation is more |
| // mature. |
| return Expr.EmitOp(dwarf::DW_OP_nop, |
| "nop (could not find a dwarf register number)"); |
| |
| // Attempt to find a valid super- or sub-register. |
| if (!Expr.AddMachineRegPiece(MLoc.getReg())) |
| Expr.EmitOp(dwarf::DW_OP_nop, |
| "nop (could not find a dwarf register number)"); |
| return; |
| } |
| |
| if (MLoc.isIndirect()) |
| Expr.AddRegIndirect(Reg, MLoc.getOffset()); |
| else |
| Expr.AddReg(Reg); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Dwarf Lowering Routines |
| //===----------------------------------------------------------------------===// |
| |
| void AsmPrinter::emitCFIInstruction(const MCCFIInstruction &Inst) const { |
| switch (Inst.getOperation()) { |
| default: |
| llvm_unreachable("Unexpected instruction"); |
| case MCCFIInstruction::OpDefCfaOffset: |
| OutStreamer.EmitCFIDefCfaOffset(Inst.getOffset()); |
| break; |
| case MCCFIInstruction::OpDefCfa: |
| OutStreamer.EmitCFIDefCfa(Inst.getRegister(), Inst.getOffset()); |
| break; |
| case MCCFIInstruction::OpDefCfaRegister: |
| OutStreamer.EmitCFIDefCfaRegister(Inst.getRegister()); |
| break; |
| case MCCFIInstruction::OpOffset: |
| OutStreamer.EmitCFIOffset(Inst.getRegister(), Inst.getOffset()); |
| break; |
| case MCCFIInstruction::OpRegister: |
| OutStreamer.EmitCFIRegister(Inst.getRegister(), Inst.getRegister2()); |
| break; |
| case MCCFIInstruction::OpWindowSave: |
| OutStreamer.EmitCFIWindowSave(); |
| break; |
| case MCCFIInstruction::OpSameValue: |
| OutStreamer.EmitCFISameValue(Inst.getRegister()); |
| break; |
| } |
| } |
| |
| void AsmPrinter::emitDwarfDIE(const DIE &Die) const { |
| // Get the abbreviation for this DIE. |
| const DIEAbbrev &Abbrev = Die.getAbbrev(); |
| |
| // Emit the code (index) for the abbreviation. |
| if (isVerbose()) |
| OutStreamer.AddComment("Abbrev [" + Twine(Abbrev.getNumber()) + |
| "] 0x" + Twine::utohexstr(Die.getOffset()) + |
| ":0x" + Twine::utohexstr(Die.getSize()) + " " + |
| dwarf::TagString(Abbrev.getTag())); |
| EmitULEB128(Abbrev.getNumber()); |
| |
| const SmallVectorImpl<DIEValue *> &Values = Die.getValues(); |
| const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData(); |
| |
| // Emit the DIE attribute values. |
| for (unsigned i = 0, N = Values.size(); i < N; ++i) { |
| dwarf::Attribute Attr = AbbrevData[i].getAttribute(); |
| dwarf::Form Form = AbbrevData[i].getForm(); |
| assert(Form && "Too many attributes for DIE (check abbreviation)"); |
| |
| if (isVerbose()) { |
| OutStreamer.AddComment(dwarf::AttributeString(Attr)); |
| if (Attr == dwarf::DW_AT_accessibility) |
| OutStreamer.AddComment(dwarf::AccessibilityString( |
| cast<DIEInteger>(Values[i])->getValue())); |
| } |
| |
| // Emit an attribute using the defined form. |
| Values[i]->EmitValue(this, Form); |
| } |
| |
| // Emit the DIE children if any. |
| if (Abbrev.hasChildren()) { |
| for (auto &Child : Die.getChildren()) |
| emitDwarfDIE(*Child); |
| |
| OutStreamer.AddComment("End Of Children Mark"); |
| EmitInt8(0); |
| } |
| } |
| |
| void |
| AsmPrinter::emitDwarfAbbrevs(const std::vector<DIEAbbrev *>& Abbrevs) const { |
| // For each abbrevation. |
| for (const DIEAbbrev *Abbrev : Abbrevs) { |
| // Emit the abbrevations code (base 1 index.) |
| EmitULEB128(Abbrev->getNumber(), "Abbreviation Code"); |
| |
| // Emit the abbreviations data. |
| Abbrev->Emit(this); |
| } |
| |
| // Mark end of abbreviations. |
| EmitULEB128(0, "EOM(3)"); |
| } |