#include "llvm/MC/MCDwarf.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCObjectFileInfo.h"
#include "llvm/MC/MCObjectWriter.h"
#include "llvm/MC/MCRegisterInfo.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Support/LEB128.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/ADT/Hashing.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Config/config.h"
using namespace llvm;
#define SPECIAL_ADDR(op) (((op) - DWARF2_LINE_OPCODE_BASE)/DWARF2_LINE_RANGE)
#define MAX_SPECIAL_ADDR_DELTA SPECIAL_ADDR(255)
#define DWARF2_LINE_OPCODE_BASE 13
#define DWARF2_LINE_BASE -5
#define DWARF2_LINE_RANGE 14
#define DWARF2_LINE_MIN_INSN_LENGTH 1
static inline uint64_t ScaleAddrDelta(uint64_t AddrDelta) {
if (DWARF2_LINE_MIN_INSN_LENGTH == 1)
return AddrDelta;
if (AddrDelta % DWARF2_LINE_MIN_INSN_LENGTH != 0) {
;
}
return AddrDelta / DWARF2_LINE_MIN_INSN_LENGTH;
}
void MCLineEntry::Make(MCStreamer *MCOS, const MCSection *Section) {
if (!MCOS->getContext().getDwarfLocSeen())
return;
MCSymbol *LineSym = MCOS->getContext().CreateTempSymbol();
MCOS->EmitLabel(LineSym);
const MCDwarfLoc &DwarfLoc = MCOS->getContext().getCurrentDwarfLoc();
MCLineEntry LineEntry(LineSym, DwarfLoc);
MCOS->getContext().ClearDwarfLocSeen();
const DenseMap<const MCSection *, MCLineSection *> &MCLineSections =
MCOS->getContext().getMCLineSections();
MCLineSection *LineSection = MCLineSections.lookup(Section);
if (!LineSection) {
LineSection = new MCLineSection;
MCOS->getContext().addMCLineSection(Section, LineSection);
}
LineSection->addLineEntry(LineEntry);
}
static inline const MCExpr *MakeStartMinusEndExpr(const MCStreamer &MCOS,
const MCSymbol &Start,
const MCSymbol &End,
int IntVal) {
MCSymbolRefExpr::VariantKind Variant = MCSymbolRefExpr::VK_None;
const MCExpr *Res =
MCSymbolRefExpr::Create(&End, Variant, MCOS.getContext());
const MCExpr *RHS =
MCSymbolRefExpr::Create(&Start, Variant, MCOS.getContext());
const MCExpr *Res1 =
MCBinaryExpr::Create(MCBinaryExpr::Sub, Res, RHS, MCOS.getContext());
const MCExpr *Res2 =
MCConstantExpr::Create(IntVal, MCOS.getContext());
const MCExpr *Res3 =
MCBinaryExpr::Create(MCBinaryExpr::Sub, Res1, Res2, MCOS.getContext());
return Res3;
}
static inline void EmitDwarfLineTable(MCStreamer *MCOS,
const MCSection *Section,
const MCLineSection *LineSection) {
unsigned FileNum = 1;
unsigned LastLine = 1;
unsigned Column = 0;
unsigned Flags = DWARF2_LINE_DEFAULT_IS_STMT ? DWARF2_FLAG_IS_STMT : 0;
unsigned Isa = 0;
MCSymbol *LastLabel = NULL;
for (MCLineSection::const_iterator
it = LineSection->getMCLineEntries()->begin(),
ie = LineSection->getMCLineEntries()->end(); it != ie; ++it) {
if (FileNum != it->getFileNum()) {
FileNum = it->getFileNum();
MCOS->EmitIntValue(dwarf::DW_LNS_set_file, 1);
MCOS->EmitULEB128IntValue(FileNum);
}
if (Column != it->getColumn()) {
Column = it->getColumn();
MCOS->EmitIntValue(dwarf::DW_LNS_set_column, 1);
MCOS->EmitULEB128IntValue(Column);
}
if (Isa != it->getIsa()) {
Isa = it->getIsa();
MCOS->EmitIntValue(dwarf::DW_LNS_set_isa, 1);
MCOS->EmitULEB128IntValue(Isa);
}
if ((it->getFlags() ^ Flags) & DWARF2_FLAG_IS_STMT) {
Flags = it->getFlags();
MCOS->EmitIntValue(dwarf::DW_LNS_negate_stmt, 1);
}
if (it->getFlags() & DWARF2_FLAG_BASIC_BLOCK)
MCOS->EmitIntValue(dwarf::DW_LNS_set_basic_block, 1);
if (it->getFlags() & DWARF2_FLAG_PROLOGUE_END)
MCOS->EmitIntValue(dwarf::DW_LNS_set_prologue_end, 1);
if (it->getFlags() & DWARF2_FLAG_EPILOGUE_BEGIN)
MCOS->EmitIntValue(dwarf::DW_LNS_set_epilogue_begin, 1);
int64_t LineDelta = static_cast<int64_t>(it->getLine()) - LastLine;
MCSymbol *Label = it->getLabel();
const MCAsmInfo &asmInfo = MCOS->getContext().getAsmInfo();
MCOS->EmitDwarfAdvanceLineAddr(LineDelta, LastLabel, Label,
asmInfo.getPointerSize());
LastLine = it->getLine();
LastLabel = Label;
}
MCOS->SwitchSection(Section);
MCContext &context = MCOS->getContext();
MCSymbol *SectionEnd = context.CreateTempSymbol();
MCOS->EmitLabel(SectionEnd);
MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfLineSection());
const MCAsmInfo &asmInfo = MCOS->getContext().getAsmInfo();
MCOS->EmitDwarfAdvanceLineAddr(INT64_MAX, LastLabel, SectionEnd,
asmInfo.getPointerSize());
}
const MCSymbol *MCDwarfFileTable::Emit(MCStreamer *MCOS) {
MCContext &context = MCOS->getContext();
MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfLineSection());
MCSymbol *LineStartSym = context.CreateTempSymbol();
MCOS->EmitLabel(LineStartSym);
MCSymbol *LineEndSym = context.CreateTempSymbol();
MCOS->EmitAbsValue(MakeStartMinusEndExpr(*MCOS, *LineStartSym, *LineEndSym,4),
4);
MCOS->EmitIntValue(2, 2);
MCSymbol *ProEndSym = context.CreateTempSymbol();
MCOS->EmitAbsValue(MakeStartMinusEndExpr(*MCOS, *LineStartSym, *ProEndSym,
(4 + 2 + 4)),
4, 0);
MCOS->EmitIntValue(DWARF2_LINE_MIN_INSN_LENGTH, 1);
MCOS->EmitIntValue(DWARF2_LINE_DEFAULT_IS_STMT, 1);
MCOS->EmitIntValue(DWARF2_LINE_BASE, 1);
MCOS->EmitIntValue(DWARF2_LINE_RANGE, 1);
MCOS->EmitIntValue(DWARF2_LINE_OPCODE_BASE, 1);
MCOS->EmitIntValue(0, 1); MCOS->EmitIntValue(1, 1); MCOS->EmitIntValue(1, 1); MCOS->EmitIntValue(1, 1); MCOS->EmitIntValue(1, 1); MCOS->EmitIntValue(0, 1); MCOS->EmitIntValue(0, 1); MCOS->EmitIntValue(0, 1); MCOS->EmitIntValue(1, 1); MCOS->EmitIntValue(0, 1); MCOS->EmitIntValue(0, 1); MCOS->EmitIntValue(1, 1);
const std::vector<StringRef> &MCDwarfDirs =
context.getMCDwarfDirs();
for (unsigned i = 0; i < MCDwarfDirs.size(); i++) {
MCOS->EmitBytes(MCDwarfDirs[i], 0); MCOS->EmitBytes(StringRef("\0", 1), 0); }
MCOS->EmitIntValue(0, 1);
const std::vector<MCDwarfFile *> &MCDwarfFiles =
MCOS->getContext().getMCDwarfFiles();
for (unsigned i = 1; i < MCDwarfFiles.size(); i++) {
MCOS->EmitBytes(MCDwarfFiles[i]->getName(), 0); MCOS->EmitBytes(StringRef("\0", 1), 0); MCOS->EmitULEB128IntValue(MCDwarfFiles[i]->getDirIndex());
MCOS->EmitIntValue(0, 1); MCOS->EmitIntValue(0, 1); }
MCOS->EmitIntValue(0, 1);
MCOS->EmitLabel(ProEndSym);
const DenseMap<const MCSection *, MCLineSection *> &MCLineSections =
MCOS->getContext().getMCLineSections();
const std::vector<const MCSection *> &MCLineSectionOrder =
MCOS->getContext().getMCLineSectionOrder();
for (std::vector<const MCSection*>::const_iterator it =
MCLineSectionOrder.begin(), ie = MCLineSectionOrder.end(); it != ie;
++it) {
const MCSection *Sec = *it;
const MCLineSection *Line = MCLineSections.lookup(Sec);
EmitDwarfLineTable(MCOS, Sec, Line);
delete Line;
}
if (MCOS->getContext().getAsmInfo().getLinkerRequiresNonEmptyDwarfLines()
&& MCLineSectionOrder.begin() == MCLineSectionOrder.end()) {
MCDwarfLineAddr::Emit(MCOS, INT64_MAX, 0);
}
MCOS->EmitLabel(LineEndSym);
return LineStartSym;
}
void MCDwarfLineAddr::Write(MCObjectWriter *OW, int64_t LineDelta,
uint64_t AddrDelta) {
SmallString<256> Tmp;
raw_svector_ostream OS(Tmp);
MCDwarfLineAddr::Encode(LineDelta, AddrDelta, OS);
OW->WriteBytes(OS.str());
}
void MCDwarfLineAddr::Emit(MCStreamer *MCOS, int64_t LineDelta,
uint64_t AddrDelta) {
SmallString<256> Tmp;
raw_svector_ostream OS(Tmp);
MCDwarfLineAddr::Encode(LineDelta, AddrDelta, OS);
MCOS->EmitBytes(OS.str(), 0);
}
void MCDwarfLineAddr::Encode(int64_t LineDelta, uint64_t AddrDelta,
raw_ostream &OS) {
uint64_t Temp, Opcode;
bool NeedCopy = false;
AddrDelta = ScaleAddrDelta(AddrDelta);
if (LineDelta == INT64_MAX) {
if (AddrDelta == MAX_SPECIAL_ADDR_DELTA)
OS << char(dwarf::DW_LNS_const_add_pc);
else {
OS << char(dwarf::DW_LNS_advance_pc);
encodeULEB128(AddrDelta, OS);
}
OS << char(dwarf::DW_LNS_extended_op);
OS << char(1);
OS << char(dwarf::DW_LNE_end_sequence);
return;
}
Temp = LineDelta - DWARF2_LINE_BASE;
if (Temp >= DWARF2_LINE_RANGE) {
OS << char(dwarf::DW_LNS_advance_line);
encodeSLEB128(LineDelta, OS);
LineDelta = 0;
Temp = 0 - DWARF2_LINE_BASE;
NeedCopy = true;
}
if (LineDelta == 0 && AddrDelta == 0) {
OS << char(dwarf::DW_LNS_copy);
return;
}
Temp += DWARF2_LINE_OPCODE_BASE;
if (AddrDelta < 256 + MAX_SPECIAL_ADDR_DELTA) {
Opcode = Temp + AddrDelta * DWARF2_LINE_RANGE;
if (Opcode <= 255) {
OS << char(Opcode);
return;
}
Opcode = Temp + (AddrDelta - MAX_SPECIAL_ADDR_DELTA) * DWARF2_LINE_RANGE;
if (Opcode <= 255) {
OS << char(dwarf::DW_LNS_const_add_pc);
OS << char(Opcode);
return;
}
}
OS << char(dwarf::DW_LNS_advance_pc);
encodeULEB128(AddrDelta, OS);
if (NeedCopy)
OS << char(dwarf::DW_LNS_copy);
else
OS << char(Temp);
}
void MCDwarfFile::print(raw_ostream &OS) const {
OS << '"' << getName() << '"';
}
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
void MCDwarfFile::dump() const {
print(dbgs());
}
#endif
static void EmitAbbrev(MCStreamer *MCOS, uint64_t Name, uint64_t Form) {
MCOS->EmitULEB128IntValue(Name);
MCOS->EmitULEB128IntValue(Form);
}
static void EmitGenDwarfAbbrev(MCStreamer *MCOS) {
MCContext &context = MCOS->getContext();
MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfAbbrevSection());
MCOS->EmitULEB128IntValue(1);
MCOS->EmitULEB128IntValue(dwarf::DW_TAG_compile_unit);
MCOS->EmitIntValue(dwarf::DW_CHILDREN_yes, 1);
EmitAbbrev(MCOS, dwarf::DW_AT_stmt_list, dwarf::DW_FORM_data4);
EmitAbbrev(MCOS, dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr);
EmitAbbrev(MCOS, dwarf::DW_AT_high_pc, dwarf::DW_FORM_addr);
EmitAbbrev(MCOS, dwarf::DW_AT_name, dwarf::DW_FORM_string);
EmitAbbrev(MCOS, dwarf::DW_AT_comp_dir, dwarf::DW_FORM_string);
StringRef DwarfDebugFlags = context.getDwarfDebugFlags();
if (!DwarfDebugFlags.empty())
EmitAbbrev(MCOS, dwarf::DW_AT_APPLE_flags, dwarf::DW_FORM_string);
EmitAbbrev(MCOS, dwarf::DW_AT_producer, dwarf::DW_FORM_string);
EmitAbbrev(MCOS, dwarf::DW_AT_language, dwarf::DW_FORM_data2);
EmitAbbrev(MCOS, 0, 0);
MCOS->EmitULEB128IntValue(2);
MCOS->EmitULEB128IntValue(dwarf::DW_TAG_label);
MCOS->EmitIntValue(dwarf::DW_CHILDREN_yes, 1);
EmitAbbrev(MCOS, dwarf::DW_AT_name, dwarf::DW_FORM_string);
EmitAbbrev(MCOS, dwarf::DW_AT_decl_file, dwarf::DW_FORM_data4);
EmitAbbrev(MCOS, dwarf::DW_AT_decl_line, dwarf::DW_FORM_data4);
EmitAbbrev(MCOS, dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr);
EmitAbbrev(MCOS, dwarf::DW_AT_prototyped, dwarf::DW_FORM_flag);
EmitAbbrev(MCOS, 0, 0);
MCOS->EmitULEB128IntValue(3);
MCOS->EmitULEB128IntValue(dwarf::DW_TAG_unspecified_parameters);
MCOS->EmitIntValue(dwarf::DW_CHILDREN_no, 1);
EmitAbbrev(MCOS, 0, 0);
MCOS->EmitIntValue(0, 1);
}
static void EmitGenDwarfAranges(MCStreamer *MCOS) {
MCContext &context = MCOS->getContext();
MCOS->SwitchSection(context.getGenDwarfSection());
MCSymbol *SectionEndSym = context.CreateTempSymbol();
MCOS->EmitLabel(SectionEndSym);
context.setGenDwarfSectionEndSym(SectionEndSym);
MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfARangesSection());
int Length = 4 + 2 + 4 + 1 + 1;
const MCAsmInfo &asmInfo = context.getAsmInfo();
int AddrSize = asmInfo.getPointerSize();
int Pad = 2 * AddrSize - (Length & (2 * AddrSize - 1));
if (Pad == 2 * AddrSize)
Pad = 0;
Length += Pad;
Length += 2 * AddrSize;
Length += 2 * AddrSize;
MCOS->EmitIntValue(Length - 4, 4);
MCOS->EmitIntValue(2, 2);
MCOS->EmitIntValue(0, 4);
MCOS->EmitIntValue(AddrSize, 1);
MCOS->EmitIntValue(0, 1);
for(int i = 0; i < Pad; i++)
MCOS->EmitIntValue(0, 1);
const MCExpr *Addr = MCSymbolRefExpr::Create(
context.getGenDwarfSectionStartSym(), MCSymbolRefExpr::VK_None, context);
const MCExpr *Size = MakeStartMinusEndExpr(*MCOS,
*context.getGenDwarfSectionStartSym(), *SectionEndSym, 0);
MCOS->EmitAbsValue(Addr, AddrSize);
MCOS->EmitAbsValue(Size, AddrSize);
MCOS->EmitIntValue(0, AddrSize);
MCOS->EmitIntValue(0, AddrSize);
}
static void EmitGenDwarfInfo(MCStreamer *MCOS,
const MCSymbol *AbbrevSectionSymbol,
const MCSymbol *LineSectionSymbol) {
MCContext &context = MCOS->getContext();
MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfInfoSection());
MCSymbol *InfoStart = context.CreateTempSymbol();
MCOS->EmitLabel(InfoStart);
MCSymbol *InfoEnd = context.CreateTempSymbol();
const MCExpr *Length = MakeStartMinusEndExpr(*MCOS, *InfoStart, *InfoEnd, 4);
MCOS->EmitAbsValue(Length, 4);
MCOS->EmitIntValue(2, 2);
if (AbbrevSectionSymbol) {
MCOS->EmitSymbolValue(AbbrevSectionSymbol, 4);
} else {
MCOS->EmitIntValue(0, 4);
}
const MCAsmInfo &asmInfo = context.getAsmInfo();
int AddrSize = asmInfo.getPointerSize();
MCOS->EmitIntValue(AddrSize, 1);
MCOS->EmitULEB128IntValue(1);
if (LineSectionSymbol) {
MCOS->EmitSymbolValue(LineSectionSymbol, 4);
} else {
MCOS->EmitIntValue(0, 4);
}
const MCExpr *Start = MCSymbolRefExpr::Create(
context.getGenDwarfSectionStartSym(), MCSymbolRefExpr::VK_None, context);
MCOS->EmitAbsValue(Start, AddrSize);
const MCExpr *End = MCSymbolRefExpr::Create(
context.getGenDwarfSectionEndSym(), MCSymbolRefExpr::VK_None, context);
MCOS->EmitAbsValue(End, AddrSize);
const std::vector<StringRef> &MCDwarfDirs =
context.getMCDwarfDirs();
if (MCDwarfDirs.size() > 0) {
MCOS->EmitBytes(MCDwarfDirs[0], 0);
MCOS->EmitBytes("/", 0);
}
const std::vector<MCDwarfFile *> &MCDwarfFiles =
MCOS->getContext().getMCDwarfFiles();
MCOS->EmitBytes(MCDwarfFiles[1]->getName(), 0);
MCOS->EmitIntValue(0, 1);
llvm::sys::Path CWD = llvm::sys::Path::GetCurrentDirectory();
MCOS->EmitBytes(StringRef(CWD.c_str()), 0);
MCOS->EmitIntValue(0, 1);
StringRef DwarfDebugFlags = context.getDwarfDebugFlags();
if (!DwarfDebugFlags.empty()){
MCOS->EmitBytes(DwarfDebugFlags, 0);
MCOS->EmitIntValue(0, 1); }
MCOS->EmitBytes(StringRef("llvm-mc (based on LLVM "), 0);
MCOS->EmitBytes(StringRef(PACKAGE_VERSION), 0);
MCOS->EmitBytes(StringRef(")"), 0);
MCOS->EmitIntValue(0, 1);
MCOS->EmitIntValue(dwarf::DW_LANG_Mips_Assembler, 2);
const std::vector<const MCGenDwarfLabelEntry *> &Entries =
MCOS->getContext().getMCGenDwarfLabelEntries();
for (std::vector<const MCGenDwarfLabelEntry *>::const_iterator it =
Entries.begin(), ie = Entries.end(); it != ie;
++it) {
const MCGenDwarfLabelEntry *Entry = *it;
MCOS->EmitULEB128IntValue(2);
MCOS->EmitBytes(Entry->getName(), 0);
MCOS->EmitIntValue(0, 1);
MCOS->EmitIntValue(Entry->getFileNumber(), 4);
MCOS->EmitIntValue(Entry->getLineNumber(), 4);
const MCExpr *AT_low_pc = MCSymbolRefExpr::Create(Entry->getLabel(),
MCSymbolRefExpr::VK_None, context);
MCOS->EmitAbsValue(AT_low_pc, AddrSize);
MCOS->EmitIntValue(0, 1);
MCOS->EmitULEB128IntValue(3);
MCOS->EmitIntValue(0, 1);
}
for (std::vector<const MCGenDwarfLabelEntry *>::const_iterator it =
Entries.begin(), ie = Entries.end(); it != ie;
++it) {
const MCGenDwarfLabelEntry *Entry = *it;
delete Entry;
}
MCOS->EmitIntValue(0, 1);
MCOS->EmitLabel(InfoEnd);
}
void MCGenDwarfInfo::Emit(MCStreamer *MCOS, const MCSymbol *LineSectionSymbol) {
MCContext &context = MCOS->getContext();
const MCAsmInfo &AsmInfo = context.getAsmInfo();
MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfInfoSection());
MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfAbbrevSection());
MCSymbol *AbbrevSectionSymbol;
if (AsmInfo.doesDwarfUseRelocationsAcrossSections()) {
AbbrevSectionSymbol = context.CreateTempSymbol();
MCOS->EmitLabel(AbbrevSectionSymbol);
} else {
AbbrevSectionSymbol = NULL;
LineSectionSymbol = NULL;
}
MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfARangesSection());
if (context.getMCLineSections().empty())
return;
EmitGenDwarfAranges(MCOS);
EmitGenDwarfAbbrev(MCOS);
EmitGenDwarfInfo(MCOS, AbbrevSectionSymbol, LineSectionSymbol);
}
void MCGenDwarfLabelEntry::Make(MCSymbol *Symbol, MCStreamer *MCOS,
SourceMgr &SrcMgr, SMLoc &Loc) {
if (Symbol->isTemporary())
return;
MCContext &context = MCOS->getContext();
if (context.getGenDwarfSection() != MCOS->getCurrentSection())
return;
StringRef Name = Symbol->getName();
if (Name.startswith("_"))
Name = Name.substr(1, Name.size()-1);
unsigned FileNumber = context.getGenDwarfFileNumber();
int CurBuffer = SrcMgr.FindBufferContainingLoc(Loc);
unsigned LineNumber = SrcMgr.FindLineNumber(Loc, CurBuffer);
MCSymbol *Label = context.CreateTempSymbol();
MCOS->EmitLabel(Label);
MCGenDwarfLabelEntry *Entry =
new MCGenDwarfLabelEntry(Name, FileNumber, LineNumber, Label);
MCOS->getContext().addMCGenDwarfLabelEntry(Entry);
}
static int getDataAlignmentFactor(MCStreamer &streamer) {
MCContext &context = streamer.getContext();
const MCAsmInfo &asmInfo = context.getAsmInfo();
int size = asmInfo.getPointerSize();
if (asmInfo.isStackGrowthDirectionUp())
return size;
else
return -size;
}
static unsigned getSizeForEncoding(MCStreamer &streamer,
unsigned symbolEncoding) {
MCContext &context = streamer.getContext();
unsigned format = symbolEncoding & 0x0f;
switch (format) {
default: llvm_unreachable("Unknown Encoding");
case dwarf::DW_EH_PE_absptr:
case dwarf::DW_EH_PE_signed:
return context.getAsmInfo().getPointerSize();
case dwarf::DW_EH_PE_udata2:
case dwarf::DW_EH_PE_sdata2:
return 2;
case dwarf::DW_EH_PE_udata4:
case dwarf::DW_EH_PE_sdata4:
return 4;
case dwarf::DW_EH_PE_udata8:
case dwarf::DW_EH_PE_sdata8:
return 8;
}
}
static void EmitSymbol(MCStreamer &streamer, const MCSymbol &symbol,
unsigned symbolEncoding, const char *comment = 0) {
MCContext &context = streamer.getContext();
const MCAsmInfo &asmInfo = context.getAsmInfo();
const MCExpr *v = asmInfo.getExprForFDESymbol(&symbol,
symbolEncoding,
streamer);
unsigned size = getSizeForEncoding(streamer, symbolEncoding);
if (streamer.isVerboseAsm() && comment) streamer.AddComment(comment);
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(
const MCRegisterInfo &MRI,
const MachineLocation &Loc) {
unsigned Reg = Loc.getReg() == MachineLocation::VirtualFP ?
MachineLocation::VirtualFP :
unsigned(MRI.getDwarfRegNum(Loc.getReg(), true));
const MachineLocation &NewLoc = Loc.isReg() ?
MachineLocation(Reg) : MachineLocation(Reg, Loc.getOffset());
return NewLoc;
}
namespace {
class FrameEmitterImpl {
int CFAOffset;
int CIENum;
bool UsingCFI;
bool IsEH;
const MCSymbol *SectionStart;
public:
FrameEmitterImpl(bool usingCFI, bool isEH)
: CFAOffset(0), CIENum(0), UsingCFI(usingCFI), IsEH(isEH),
SectionStart(0) {}
void setSectionStart(const MCSymbol *Label) { SectionStart = Label; }
bool EmitCompactUnwind(MCStreamer &streamer,
const MCDwarfFrameInfo &frame);
const MCSymbol &EmitCIE(MCStreamer &streamer,
const MCSymbol *personality,
unsigned personalityEncoding,
const MCSymbol *lsda,
bool IsSignalFrame,
unsigned lsdaEncoding);
MCSymbol *EmitFDE(MCStreamer &streamer,
const MCSymbol &cieStart,
const MCDwarfFrameInfo &frame);
void EmitCFIInstructions(MCStreamer &streamer,
const std::vector<MCCFIInstruction> &Instrs,
MCSymbol *BaseLabel);
void EmitCFIInstruction(MCStreamer &Streamer,
const MCCFIInstruction &Instr);
};
}
static void EmitEncodingByte(MCStreamer &Streamer, unsigned Encoding,
StringRef Prefix) {
if (Streamer.isVerboseAsm()) {
const char *EncStr;
switch (Encoding) {
default: EncStr = "<unknown encoding>"; break;
case dwarf::DW_EH_PE_absptr: EncStr = "absptr"; break;
case dwarf::DW_EH_PE_omit: EncStr = "omit"; break;
case dwarf::DW_EH_PE_pcrel: EncStr = "pcrel"; break;
case dwarf::DW_EH_PE_udata4: EncStr = "udata4"; break;
case dwarf::DW_EH_PE_udata8: EncStr = "udata8"; break;
case dwarf::DW_EH_PE_sdata4: EncStr = "sdata4"; break;
case dwarf::DW_EH_PE_sdata8: EncStr = "sdata8"; break;
case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata4:
EncStr = "pcrel udata4";
break;
case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4:
EncStr = "pcrel sdata4";
break;
case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8:
EncStr = "pcrel udata8";
break;
case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8:
EncStr = "screl sdata8";
break;
case dwarf::DW_EH_PE_indirect |dwarf::DW_EH_PE_pcrel|dwarf::DW_EH_PE_udata4:
EncStr = "indirect pcrel udata4";
break;
case dwarf::DW_EH_PE_indirect |dwarf::DW_EH_PE_pcrel|dwarf::DW_EH_PE_sdata4:
EncStr = "indirect pcrel sdata4";
break;
case dwarf::DW_EH_PE_indirect |dwarf::DW_EH_PE_pcrel|dwarf::DW_EH_PE_udata8:
EncStr = "indirect pcrel udata8";
break;
case dwarf::DW_EH_PE_indirect |dwarf::DW_EH_PE_pcrel|dwarf::DW_EH_PE_sdata8:
EncStr = "indirect pcrel sdata8";
break;
}
Streamer.AddComment(Twine(Prefix) + " = " + EncStr);
}
Streamer.EmitIntValue(Encoding, 1);
}
void FrameEmitterImpl::EmitCFIInstruction(MCStreamer &Streamer,
const MCCFIInstruction &Instr) {
int dataAlignmentFactor = getDataAlignmentFactor(Streamer);
bool VerboseAsm = Streamer.isVerboseAsm();
switch (Instr.getOperation()) {
case MCCFIInstruction::Move:
case MCCFIInstruction::RelMove: {
const MachineLocation &Dst = Instr.getDestination();
const MachineLocation &Src = Instr.getSource();
const bool IsRelative = Instr.getOperation() == MCCFIInstruction::RelMove;
if (Dst.isReg() && Dst.getReg() == MachineLocation::VirtualFP) {
if (Src.getReg() == MachineLocation::VirtualFP) {
if (VerboseAsm) Streamer.AddComment("DW_CFA_def_cfa_offset");
Streamer.EmitIntValue(dwarf::DW_CFA_def_cfa_offset, 1);
} else {
if (VerboseAsm) Streamer.AddComment("DW_CFA_def_cfa");
Streamer.EmitIntValue(dwarf::DW_CFA_def_cfa, 1);
if (VerboseAsm) Streamer.AddComment(Twine("Reg ") +
Twine(Src.getReg()));
Streamer.EmitULEB128IntValue(Src.getReg());
}
if (IsRelative)
CFAOffset += Src.getOffset();
else
CFAOffset = -Src.getOffset();
if (VerboseAsm) Streamer.AddComment(Twine("Offset " + Twine(CFAOffset)));
Streamer.EmitULEB128IntValue(CFAOffset);
return;
}
if (Src.isReg() && Src.getReg() == MachineLocation::VirtualFP) {
assert(Dst.isReg() && "Machine move not supported yet.");
if (VerboseAsm) Streamer.AddComment("DW_CFA_def_cfa_register");
Streamer.EmitIntValue(dwarf::DW_CFA_def_cfa_register, 1);
if (VerboseAsm) Streamer.AddComment(Twine("Reg ") + Twine(Dst.getReg()));
Streamer.EmitULEB128IntValue(Dst.getReg());
return;
}
unsigned Reg = Src.getReg();
int Offset = Dst.getOffset();
if (IsRelative)
Offset -= CFAOffset;
Offset = Offset / dataAlignmentFactor;
if (Offset < 0) {
if (VerboseAsm) Streamer.AddComment("DW_CFA_offset_extended_sf");
Streamer.EmitIntValue(dwarf::DW_CFA_offset_extended_sf, 1);
if (VerboseAsm) Streamer.AddComment(Twine("Reg ") + Twine(Reg));
Streamer.EmitULEB128IntValue(Reg);
if (VerboseAsm) Streamer.AddComment(Twine("Offset ") + Twine(Offset));
Streamer.EmitSLEB128IntValue(Offset);
} else if (Reg < 64) {
if (VerboseAsm) Streamer.AddComment(Twine("DW_CFA_offset + Reg(") +
Twine(Reg) + ")");
Streamer.EmitIntValue(dwarf::DW_CFA_offset + Reg, 1);
if (VerboseAsm) Streamer.AddComment(Twine("Offset ") + Twine(Offset));
Streamer.EmitULEB128IntValue(Offset);
} else {
if (VerboseAsm) Streamer.AddComment("DW_CFA_offset_extended");
Streamer.EmitIntValue(dwarf::DW_CFA_offset_extended, 1);
if (VerboseAsm) Streamer.AddComment(Twine("Reg ") + Twine(Reg));
Streamer.EmitULEB128IntValue(Reg);
if (VerboseAsm) Streamer.AddComment(Twine("Offset ") + Twine(Offset));
Streamer.EmitULEB128IntValue(Offset);
}
return;
}
case MCCFIInstruction::RememberState:
if (VerboseAsm) Streamer.AddComment("DW_CFA_remember_state");
Streamer.EmitIntValue(dwarf::DW_CFA_remember_state, 1);
return;
case MCCFIInstruction::RestoreState:
if (VerboseAsm) Streamer.AddComment("DW_CFA_restore_state");
Streamer.EmitIntValue(dwarf::DW_CFA_restore_state, 1);
return;
case MCCFIInstruction::SameValue: {
unsigned Reg = Instr.getDestination().getReg();
if (VerboseAsm) Streamer.AddComment("DW_CFA_same_value");
Streamer.EmitIntValue(dwarf::DW_CFA_same_value, 1);
if (VerboseAsm) Streamer.AddComment(Twine("Reg ") + Twine(Reg));
Streamer.EmitULEB128IntValue(Reg);
return;
}
case MCCFIInstruction::Restore: {
unsigned Reg = Instr.getDestination().getReg();
if (VerboseAsm) {
Streamer.AddComment("DW_CFA_restore");
Streamer.AddComment(Twine("Reg ") + Twine(Reg));
}
Streamer.EmitIntValue(dwarf::DW_CFA_restore | Reg, 1);
return;
}
case MCCFIInstruction::Escape:
if (VerboseAsm) Streamer.AddComment("Escape bytes");
Streamer.EmitBytes(Instr.getValues(), 0);
return;
}
llvm_unreachable("Unhandled case in switch");
}
void FrameEmitterImpl::EmitCFIInstructions(MCStreamer &streamer,
const std::vector<MCCFIInstruction> &Instrs,
MCSymbol *BaseLabel) {
for (unsigned i = 0, N = Instrs.size(); i < N; ++i) {
const MCCFIInstruction &Instr = Instrs[i];
MCSymbol *Label = Instr.getLabel();
if (Label && !Label->isDefined()) continue;
if (BaseLabel && Label) {
MCSymbol *ThisSym = Label;
if (ThisSym != BaseLabel) {
if (streamer.isVerboseAsm()) streamer.AddComment("DW_CFA_advance_loc4");
streamer.EmitDwarfAdvanceFrameAddr(BaseLabel, ThisSym);
BaseLabel = ThisSym;
}
}
EmitCFIInstruction(streamer, Instr);
}
}
bool FrameEmitterImpl::EmitCompactUnwind(MCStreamer &Streamer,
const MCDwarfFrameInfo &Frame) {
MCContext &Context = Streamer.getContext();
const MCObjectFileInfo *MOFI = Context.getObjectFileInfo();
bool VerboseAsm = Streamer.isVerboseAsm();
uint32_t Encoding = Frame.CompactUnwindEncoding;
if (!Encoding) return false;
if (Frame.Lsda)
Encoding |= 0x40000000;
Streamer.SwitchSection(MOFI->getCompactUnwindSection());
unsigned FDEEncoding = MOFI->getFDEEncoding(UsingCFI);
unsigned Size = getSizeForEncoding(Streamer, FDEEncoding);
if (VerboseAsm) Streamer.AddComment("Range Start");
Streamer.EmitSymbolValue(Frame.Function, Size);
const MCExpr *Range = MakeStartMinusEndExpr(Streamer, *Frame.Begin,
*Frame.End, 0);
if (VerboseAsm) Streamer.AddComment("Range Length");
Streamer.EmitAbsValue(Range, 4);
Size = getSizeForEncoding(Streamer, dwarf::DW_EH_PE_udata4);
if (VerboseAsm) Streamer.AddComment("Compact Unwind Encoding: 0x" +
Twine::utohexstr(Encoding));
Streamer.EmitIntValue(Encoding, Size);
Size = getSizeForEncoding(Streamer, dwarf::DW_EH_PE_absptr);
if (VerboseAsm) Streamer.AddComment("Personality Function");
if (Frame.Personality)
Streamer.EmitSymbolValue(Frame.Personality, Size);
else
Streamer.EmitIntValue(0, Size);
Size = getSizeForEncoding(Streamer, Frame.LsdaEncoding);
if (VerboseAsm) Streamer.AddComment("LSDA");
if (Frame.Lsda)
Streamer.EmitSymbolValue(Frame.Lsda, Size);
else
Streamer.EmitIntValue(0, Size);
return true;
}
const MCSymbol &FrameEmitterImpl::EmitCIE(MCStreamer &streamer,
const MCSymbol *personality,
unsigned personalityEncoding,
const MCSymbol *lsda,
bool IsSignalFrame,
unsigned lsdaEncoding) {
MCContext &context = streamer.getContext();
const MCRegisterInfo &MRI = context.getRegisterInfo();
const MCObjectFileInfo *MOFI = context.getObjectFileInfo();
bool verboseAsm = streamer.isVerboseAsm();
MCSymbol *sectionStart;
if (MOFI->isFunctionEHFrameSymbolPrivate() || !IsEH)
sectionStart = context.CreateTempSymbol();
else
sectionStart = context.GetOrCreateSymbol(Twine("EH_frame") + Twine(CIENum));
streamer.EmitLabel(sectionStart);
CIENum++;
MCSymbol *sectionEnd = context.CreateTempSymbol();
const MCExpr *Length = MakeStartMinusEndExpr(streamer, *sectionStart,
*sectionEnd, 4);
if (verboseAsm) streamer.AddComment("CIE Length");
streamer.EmitAbsValue(Length, 4);
unsigned CIE_ID = IsEH ? 0 : -1;
if (verboseAsm) streamer.AddComment("CIE ID Tag");
streamer.EmitIntValue(CIE_ID, 4);
if (verboseAsm) streamer.AddComment("DW_CIE_VERSION");
streamer.EmitIntValue(dwarf::DW_CIE_VERSION, 1);
SmallString<8> Augmentation;
if (IsEH) {
if (verboseAsm) streamer.AddComment("CIE Augmentation");
Augmentation += "z";
if (personality)
Augmentation += "P";
if (lsda)
Augmentation += "L";
Augmentation += "R";
if (IsSignalFrame)
Augmentation += "S";
streamer.EmitBytes(Augmentation.str(), 0);
}
streamer.EmitIntValue(0, 1);
if (verboseAsm) streamer.AddComment("CIE Code Alignment Factor");
streamer.EmitULEB128IntValue(1);
if (verboseAsm) streamer.AddComment("CIE Data Alignment Factor");
streamer.EmitSLEB128IntValue(getDataAlignmentFactor(streamer));
if (verboseAsm) streamer.AddComment("CIE Return Address Column");
streamer.EmitULEB128IntValue(MRI.getDwarfRegNum(MRI.getRARegister(), true));
unsigned augmentationLength = 0;
if (IsEH) {
if (personality) {
augmentationLength += 1;
augmentationLength += getSizeForEncoding(streamer, personalityEncoding);
}
if (lsda)
augmentationLength += 1;
augmentationLength += 1;
if (verboseAsm) streamer.AddComment("Augmentation Size");
streamer.EmitULEB128IntValue(augmentationLength);
if (personality) {
EmitEncodingByte(streamer, personalityEncoding,
"Personality Encoding");
if (verboseAsm) streamer.AddComment("Personality");
EmitPersonality(streamer, *personality, personalityEncoding);
}
if (lsda)
EmitEncodingByte(streamer, lsdaEncoding, "LSDA Encoding");
EmitEncodingByte(streamer, MOFI->getFDEEncoding(UsingCFI),
"FDE Encoding");
}
const MCAsmInfo &MAI = context.getAsmInfo();
const std::vector<MachineMove> &Moves = MAI.getInitialFrameState();
std::vector<MCCFIInstruction> Instructions;
for (int i = 0, n = Moves.size(); i != n; ++i) {
MCSymbol *Label = Moves[i].getLabel();
const MachineLocation &Dst =
TranslateMachineLocation(MRI, Moves[i].getDestination());
const MachineLocation &Src =
TranslateMachineLocation(MRI, Moves[i].getSource());
MCCFIInstruction Inst(Label, Dst, Src);
Instructions.push_back(Inst);
}
EmitCFIInstructions(streamer, Instructions, NULL);
streamer.EmitValueToAlignment(IsEH
? 4 : context.getAsmInfo().getPointerSize());
streamer.EmitLabel(sectionEnd);
return *sectionStart;
}
MCSymbol *FrameEmitterImpl::EmitFDE(MCStreamer &streamer,
const MCSymbol &cieStart,
const MCDwarfFrameInfo &frame) {
MCContext &context = streamer.getContext();
MCSymbol *fdeStart = context.CreateTempSymbol();
MCSymbol *fdeEnd = context.CreateTempSymbol();
const MCObjectFileInfo *MOFI = context.getObjectFileInfo();
bool verboseAsm = streamer.isVerboseAsm();
if (IsEH && frame.Function && !MOFI->isFunctionEHFrameSymbolPrivate()) {
MCSymbol *EHSym =
context.GetOrCreateSymbol(frame.Function->getName() + Twine(".eh"));
streamer.EmitEHSymAttributes(frame.Function, EHSym);
streamer.EmitLabel(EHSym);
}
const MCExpr *Length = MakeStartMinusEndExpr(streamer, *fdeStart, *fdeEnd, 0);
if (verboseAsm) streamer.AddComment("FDE Length");
streamer.EmitAbsValue(Length, 4);
streamer.EmitLabel(fdeStart);
const MCAsmInfo &asmInfo = context.getAsmInfo();
if (IsEH) {
const MCExpr *offset = MakeStartMinusEndExpr(streamer, cieStart, *fdeStart,
0);
if (verboseAsm) streamer.AddComment("FDE CIE Offset");
streamer.EmitAbsValue(offset, 4);
} else if (!asmInfo.doesDwarfUseRelocationsAcrossSections()) {
const MCExpr *offset = MakeStartMinusEndExpr(streamer, *SectionStart,
cieStart, 0);
streamer.EmitAbsValue(offset, 4);
} else {
streamer.EmitSymbolValue(&cieStart, 4);
}
unsigned PCEncoding = IsEH ? MOFI->getFDEEncoding(UsingCFI)
: (unsigned)dwarf::DW_EH_PE_absptr;
unsigned PCSize = getSizeForEncoding(streamer, PCEncoding);
EmitSymbol(streamer, *frame.Begin, PCEncoding, "FDE initial location");
const MCExpr *Range = MakeStartMinusEndExpr(streamer, *frame.Begin,
*frame.End, 0);
if (verboseAsm) streamer.AddComment("FDE address range");
streamer.EmitAbsValue(Range, PCSize);
if (IsEH) {
unsigned augmentationLength = 0;
if (frame.Lsda)
augmentationLength += getSizeForEncoding(streamer, frame.LsdaEncoding);
if (verboseAsm) streamer.AddComment("Augmentation size");
streamer.EmitULEB128IntValue(augmentationLength);
if (frame.Lsda)
EmitSymbol(streamer, *frame.Lsda, frame.LsdaEncoding,
"Language Specific Data Area");
}
EmitCFIInstructions(streamer, frame.Instructions, frame.Begin);
streamer.EmitValueToAlignment(PCSize);
return fdeEnd;
}
namespace {
struct CIEKey {
static const CIEKey getEmptyKey() { return CIEKey(0, 0, -1, false); }
static const CIEKey getTombstoneKey() { return CIEKey(0, -1, 0, false); }
CIEKey(const MCSymbol* Personality_, unsigned PersonalityEncoding_,
unsigned LsdaEncoding_, bool IsSignalFrame_) :
Personality(Personality_), PersonalityEncoding(PersonalityEncoding_),
LsdaEncoding(LsdaEncoding_), IsSignalFrame(IsSignalFrame_) {
}
const MCSymbol* Personality;
unsigned PersonalityEncoding;
unsigned LsdaEncoding;
bool IsSignalFrame;
};
}
namespace llvm {
template <>
struct DenseMapInfo<CIEKey> {
static CIEKey getEmptyKey() {
return CIEKey::getEmptyKey();
}
static CIEKey getTombstoneKey() {
return CIEKey::getTombstoneKey();
}
static unsigned getHashValue(const CIEKey &Key) {
return static_cast<unsigned>(hash_combine(Key.Personality,
Key.PersonalityEncoding,
Key.LsdaEncoding,
Key.IsSignalFrame));
}
static bool isEqual(const CIEKey &LHS,
const CIEKey &RHS) {
return LHS.Personality == RHS.Personality &&
LHS.PersonalityEncoding == RHS.PersonalityEncoding &&
LHS.LsdaEncoding == RHS.LsdaEncoding &&
LHS.IsSignalFrame == RHS.IsSignalFrame;
}
};
}
void MCDwarfFrameEmitter::Emit(MCStreamer &Streamer,
bool UsingCFI,
bool IsEH) {
MCContext &Context = Streamer.getContext();
MCObjectFileInfo *MOFI =
const_cast<MCObjectFileInfo*>(Context.getObjectFileInfo());
FrameEmitterImpl Emitter(UsingCFI, IsEH);
ArrayRef<MCDwarfFrameInfo> FrameArray = Streamer.getFrameInfos();
if (IsEH && MOFI->getCompactUnwindSection())
for (unsigned i = 0, n = Streamer.getNumFrameInfos(); i < n; ++i) {
const MCDwarfFrameInfo &Frame = Streamer.getFrameInfo(i);
if (Frame.CompactUnwindEncoding)
Emitter.EmitCompactUnwind(Streamer, Frame);
}
const MCSection &Section = IsEH ? *MOFI->getEHFrameSection() :
*MOFI->getDwarfFrameSection();
Streamer.SwitchSection(&Section);
MCSymbol *SectionStart = Context.CreateTempSymbol();
Streamer.EmitLabel(SectionStart);
Emitter.setSectionStart(SectionStart);
MCSymbol *FDEEnd = NULL;
DenseMap<CIEKey, const MCSymbol*> CIEStarts;
const MCSymbol *DummyDebugKey = NULL;
for (unsigned i = 0, n = FrameArray.size(); i < n; ++i) {
const MCDwarfFrameInfo &Frame = FrameArray[i];
CIEKey Key(Frame.Personality, Frame.PersonalityEncoding,
Frame.LsdaEncoding, Frame.IsSignalFrame);
const MCSymbol *&CIEStart = IsEH ? CIEStarts[Key] : DummyDebugKey;
if (!CIEStart)
CIEStart = &Emitter.EmitCIE(Streamer, Frame.Personality,
Frame.PersonalityEncoding, Frame.Lsda,
Frame.IsSignalFrame,
Frame.LsdaEncoding);
FDEEnd = Emitter.EmitFDE(Streamer, *CIEStart, Frame);
if (i != n - 1)
Streamer.EmitLabel(FDEEnd);
}
Streamer.EmitValueToAlignment(Context.getAsmInfo().getPointerSize());
if (FDEEnd)
Streamer.EmitLabel(FDEEnd);
}
void MCDwarfFrameEmitter::EmitAdvanceLoc(MCStreamer &Streamer,
uint64_t AddrDelta) {
SmallString<256> Tmp;
raw_svector_ostream OS(Tmp);
MCDwarfFrameEmitter::EncodeAdvanceLoc(AddrDelta, OS);
Streamer.EmitBytes(OS.str(), 0);
}
void MCDwarfFrameEmitter::EncodeAdvanceLoc(uint64_t AddrDelta,
raw_ostream &OS) {
if (AddrDelta == 0) {
} else if (isUIntN(6, AddrDelta)) {
uint8_t Opcode = dwarf::DW_CFA_advance_loc | AddrDelta;
OS << Opcode;
} else if (isUInt<8>(AddrDelta)) {
OS << uint8_t(dwarf::DW_CFA_advance_loc1);
OS << uint8_t(AddrDelta);
} else if (isUInt<16>(AddrDelta)) {
OS << uint8_t(dwarf::DW_CFA_advance_loc2);
OS << uint8_t( AddrDelta & 0xff);
OS << uint8_t((AddrDelta >> 8) & 0xff);
} else {
assert(isUInt<32>(AddrDelta));
OS << uint8_t(dwarf::DW_CFA_advance_loc4);
OS << uint8_t( AddrDelta & 0xff);
OS << uint8_t((AddrDelta >> 8) & 0xff);
OS << uint8_t((AddrDelta >> 16) & 0xff);
OS << uint8_t((AddrDelta >> 24) & 0xff);
}
}