Mercurial > hg > Members > tobaru > cbc > CbC_llvm
diff lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp @ 0:95c75e76d11b
LLVM 3.4
author | Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> |
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date | Thu, 12 Dec 2013 13:56:28 +0900 |
parents | |
children | e4204d083e25 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp Thu Dec 12 13:56:28 2013 +0900 @@ -0,0 +1,195 @@ +//===-- 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. +// +//===----------------------------------------------------------------------===// + +#define DEBUG_TYPE "asm-printer" +#include "llvm/CodeGen/AsmPrinter.h" +#include "llvm/ADT/Twine.h" +#include "llvm/IR/DataLayout.h" +#include "llvm/MC/MCAsmInfo.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/TargetFrameLowering.h" +#include "llvm/Target/TargetLoweringObjectFile.h" +#include "llvm/Target/TargetMachine.h" +#include "llvm/Target/TargetRegisterInfo.h" +using namespace llvm; + +//===----------------------------------------------------------------------===// +// 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 != 0) + 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, Mang, MMI, Encoding, 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 MCSymbol *SectionLabel) const { + // On COFF targets, we have to emit the special .secrel32 directive. + if (MAI->needsDwarfSectionOffsetDirective()) { + OutStreamer.EmitCOFFSecRel32(Label); + return; + } + + // Get the section that we're referring to, based on SectionLabel. + const MCSection &Section = SectionLabel->getSection(); + + // If Label has already been emitted, verify that it is in the same section as + // section label for sanity. + assert((!Label->isInSection() || &Label->getSection() == &Section) && + "Section offset using wrong section base for label"); + + // If the section in question will end up with an address of 0 anyway, we can + // just emit an absolute reference to save a relocation. + if (Section.isBaseAddressKnownZero()) { + OutStreamer.EmitSymbolValue(Label, 4); + return; + } + + // Otherwise, emit it as a label difference from the start of the section. + EmitLabelDifference(Label, SectionLabel, 4); +} + +//===----------------------------------------------------------------------===// +// 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; + } +}