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//===--- lib/CodeGen/DwarfPrinter.cpp - Dwarf Printer ---------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Emit general DWARF directives.
//
//===----------------------------------------------------------------------===//
#include "DwarfPrinter.h"
#include "llvm/Module.h"
#include "llvm/CodeGen/AsmPrinter.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/Support/Dwarf.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetFrameInfo.h"
#include "llvm/Target/TargetRegisterInfo.h"
using namespace llvm;
Dwarf::Dwarf(raw_ostream &OS, AsmPrinter *A, const MCAsmInfo *T,
const char *flavor)
: O(OS), Asm(A), TAI(T), TD(Asm->TM.getTargetData()),
RI(Asm->TM.getRegisterInfo()), M(NULL), MF(NULL), MMI(NULL),
SubprogramCount(0), Flavor(flavor), SetCounter(1) {}
void Dwarf::PrintRelDirective(bool Force32Bit, bool isInSection) const {
if (isInSection && TAI->getDwarfSectionOffsetDirective())
O << TAI->getDwarfSectionOffsetDirective();
else if (Force32Bit || TD->getPointerSize() == sizeof(int32_t))
O << TAI->getData32bitsDirective();
else
O << TAI->getData64bitsDirective();
}
/// PrintLabelName - Print label name in form used by Dwarf writer.
///
void Dwarf::PrintLabelName(const char *Tag, unsigned Number) const {
O << TAI->getPrivateGlobalPrefix() << Tag;
if (Number) O << Number;
}
void Dwarf::PrintLabelName(const char *Tag, unsigned Number,
const char *Suffix) const {
O << TAI->getPrivateGlobalPrefix() << Tag;
if (Number) O << Number;
O << Suffix;
}
/// EmitLabel - Emit location label for internal use by Dwarf.
///
void Dwarf::EmitLabel(const char *Tag, unsigned Number) const {
PrintLabelName(Tag, Number);
O << ":\n";
}
/// EmitReference - Emit a reference to a label.
///
void Dwarf::EmitReference(const char *Tag, unsigned Number,
bool IsPCRelative, bool Force32Bit) const {
PrintRelDirective(Force32Bit);
PrintLabelName(Tag, Number);
if (IsPCRelative) O << "-" << TAI->getPCSymbol();
}
void Dwarf::EmitReference(const std::string &Name, bool IsPCRelative,
bool Force32Bit) const {
PrintRelDirective(Force32Bit);
O << Name;
if (IsPCRelative) O << "-" << TAI->getPCSymbol();
}
/// EmitDifference - Emit the difference between two labels. Some assemblers do
/// not behave with absolute expressions with data directives, so there is an
/// option (needsSet) to use an intermediary set expression.
void Dwarf::EmitDifference(const char *TagHi, unsigned NumberHi,
const char *TagLo, unsigned NumberLo,
bool IsSmall) {
if (TAI->needsSet()) {
O << "\t.set\t";
PrintLabelName("set", SetCounter, Flavor);
O << ",";
PrintLabelName(TagHi, NumberHi);
O << "-";
PrintLabelName(TagLo, NumberLo);
O << "\n";
PrintRelDirective(IsSmall);
PrintLabelName("set", SetCounter, Flavor);
++SetCounter;
} else {
PrintRelDirective(IsSmall);
PrintLabelName(TagHi, NumberHi);
O << "-";
PrintLabelName(TagLo, NumberLo);
}
}
void Dwarf::EmitSectionOffset(const char* Label, const char* Section,
unsigned LabelNumber, unsigned SectionNumber,
bool IsSmall, bool isEH,
bool useSet) {
bool printAbsolute = false;
if (isEH)
printAbsolute = TAI->isAbsoluteEHSectionOffsets();
else
printAbsolute = TAI->isAbsoluteDebugSectionOffsets();
if (TAI->needsSet() && useSet) {
O << "\t.set\t";
PrintLabelName("set", SetCounter, Flavor);
O << ",";
PrintLabelName(Label, LabelNumber);
if (!printAbsolute) {
O << "-";
PrintLabelName(Section, SectionNumber);
}
O << "\n";
PrintRelDirective(IsSmall);
PrintLabelName("set", SetCounter, Flavor);
++SetCounter;
} else {
PrintRelDirective(IsSmall, true);
PrintLabelName(Label, LabelNumber);
if (!printAbsolute) {
O << "-";
PrintLabelName(Section, SectionNumber);
}
}
}
/// EmitFrameMoves - Emit frame instructions to describe the layout of the
/// frame.
void Dwarf::EmitFrameMoves(const char *BaseLabel, unsigned BaseLabelID,
const std::vector<MachineMove> &Moves, bool isEH) {
int stackGrowth =
Asm->TM.getFrameInfo()->getStackGrowthDirection() ==
TargetFrameInfo::StackGrowsUp ?
TD->getPointerSize() : -TD->getPointerSize();
bool IsLocal = BaseLabel && strcmp(BaseLabel, "label") == 0;
for (unsigned i = 0, N = Moves.size(); i < N; ++i) {
const MachineMove &Move = Moves[i];
unsigned LabelID = Move.getLabelID();
if (LabelID) {
LabelID = MMI->MappedLabel(LabelID);
// Throw out move if the label is invalid.
if (!LabelID) continue;
}
const MachineLocation &Dst = Move.getDestination();
const MachineLocation &Src = Move.getSource();
// Advance row if new location.
if (BaseLabel && LabelID && (BaseLabelID != LabelID || !IsLocal)) {
Asm->EmitInt8(dwarf::DW_CFA_advance_loc4);
Asm->EOL("DW_CFA_advance_loc4");
EmitDifference("label", LabelID, BaseLabel, BaseLabelID, true);
Asm->EOL();
BaseLabelID = LabelID;
BaseLabel = "label";
IsLocal = true;
}
// If advancing cfa.
if (Dst.isReg() && Dst.getReg() == MachineLocation::VirtualFP) {
if (!Src.isReg()) {
if (Src.getReg() == MachineLocation::VirtualFP) {
Asm->EmitInt8(dwarf::DW_CFA_def_cfa_offset);
Asm->EOL("DW_CFA_def_cfa_offset");
} else {
Asm->EmitInt8(dwarf::DW_CFA_def_cfa);
Asm->EOL("DW_CFA_def_cfa");
Asm->EmitULEB128Bytes(RI->getDwarfRegNum(Src.getReg(), isEH));
Asm->EOL("Register");
}
int Offset = -Src.getOffset();
Asm->EmitULEB128Bytes(Offset);
Asm->EOL("Offset");
} else {
llvm_unreachable("Machine move not supported yet.");
}
} else if (Src.isReg() &&
Src.getReg() == MachineLocation::VirtualFP) {
if (Dst.isReg()) {
Asm->EmitInt8(dwarf::DW_CFA_def_cfa_register);
Asm->EOL("DW_CFA_def_cfa_register");
Asm->EmitULEB128Bytes(RI->getDwarfRegNum(Dst.getReg(), isEH));
Asm->EOL("Register");
} else {
llvm_unreachable("Machine move not supported yet.");
}
} else {
unsigned Reg = RI->getDwarfRegNum(Src.getReg(), isEH);
int Offset = Dst.getOffset() / stackGrowth;
if (Offset < 0) {
Asm->EmitInt8(dwarf::DW_CFA_offset_extended_sf);
Asm->EOL("DW_CFA_offset_extended_sf");
Asm->EmitULEB128Bytes(Reg);
Asm->EOL("Reg");
Asm->EmitSLEB128Bytes(Offset);
Asm->EOL("Offset");
} else if (Reg < 64) {
Asm->EmitInt8(dwarf::DW_CFA_offset + Reg);
if (Asm->isVerbose())
Asm->EOL("DW_CFA_offset + Reg (" + utostr(Reg) + ")");
else
Asm->EOL();
Asm->EmitULEB128Bytes(Offset);
Asm->EOL("Offset");
} else {
Asm->EmitInt8(dwarf::DW_CFA_offset_extended);
Asm->EOL("DW_CFA_offset_extended");
Asm->EmitULEB128Bytes(Reg);
Asm->EOL("Reg");
Asm->EmitULEB128Bytes(Offset);
Asm->EOL("Offset");
}
}
}
}
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