llvm-6502/lib/CodeGen/AsmPrinter/DwarfPrinter.cpp
Chris Lattner 57578766aa simplify EmitSectionOffset to always use .set if it is
available, the only thing this affects is that we produce
.set in one case we didn't before, which shouldn't harm
anything.  Make EmitSectionOffset call EmitDifference
instead of duplicating it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98005 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-08 23:23:25 +00:00

374 lines
13 KiB
C++

//===--- 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/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetFrameInfo.h"
#include "llvm/Target/TargetLoweringObjectFile.h"
#include "llvm/Target/TargetRegisterInfo.h"
#include "llvm/Support/Dwarf.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/ADT/SmallString.h"
using namespace llvm;
DwarfPrinter::DwarfPrinter(raw_ostream &OS, AsmPrinter *A, const MCAsmInfo *T,
const char *flavor)
: O(OS), Asm(A), MAI(T), TD(Asm->TM.getTargetData()),
RI(Asm->TM.getRegisterInfo()), M(NULL), MF(NULL), MMI(NULL),
SubprogramCount(0), Flavor(flavor), SetCounter(1) {}
/// getDWLabel - Return the MCSymbol corresponding to the assembler temporary
/// label with the specified stem and unique ID.
MCSymbol *DwarfPrinter::getDWLabel(const char *Name, unsigned ID) const {
// FIXME: REMOVE this. However, there is stuff in EH that passes counters in
// here that can be zero.
//assert(ID && "Should use getTempLabel if no ID");
if (ID == 0) return getTempLabel(Name);
return Asm->OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix())
+ Twine(Name) + Twine(ID));
}
/// getTempLabel - Return the MCSymbol corresponding to the assembler temporary
/// label with the specified name.
MCSymbol *DwarfPrinter::getTempLabel(const char *Name) const {
return Asm->OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix())
+ Name);
}
/// SizeOfEncodedValue - Return the size of the encoding in bytes.
unsigned DwarfPrinter::SizeOfEncodedValue(unsigned Encoding) const {
if (Encoding == dwarf::DW_EH_PE_omit)
return 0;
switch (Encoding & 0x07) {
case dwarf::DW_EH_PE_absptr:
return TD->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;
}
assert(0 && "Invalid encoded value.");
return 0;
}
void DwarfPrinter::PrintRelDirective(bool Force32Bit, bool isInSection) const {
if (isInSection && MAI->getDwarfSectionOffsetDirective())
O << MAI->getDwarfSectionOffsetDirective();
else if (Force32Bit || TD->getPointerSize() == sizeof(int32_t))
O << MAI->getData32bitsDirective();
else
O << MAI->getData64bitsDirective();
}
void DwarfPrinter::PrintRelDirective(unsigned Encoding) const {
unsigned Size = SizeOfEncodedValue(Encoding);
assert((Size == 4 || Size == 8) && "Do not support other types or rels!");
O << (Size == 4 ?
MAI->getData32bitsDirective() : MAI->getData64bitsDirective());
}
/// EOL - Print a newline character to asm stream. If a comment is present
/// then it will be printed first. Comments should not contain '\n'.
void DwarfPrinter::EOL(const Twine &Comment) const {
if (Asm->VerboseAsm && !Comment.isTriviallyEmpty()) {
Asm->O.PadToColumn(MAI->getCommentColumn());
Asm->O << Asm->MAI->getCommentString() << ' ' << Comment;
}
Asm->O << '\n';
}
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 DwarfPrinter::EmitEncodingByte(unsigned Val, const char *Desc) {
if (Asm->VerboseAsm) {
if (Desc != 0)
Asm->OutStreamer.AddComment(Twine(Desc)+" Encoding = " +
Twine(DecodeDWARFEncoding(Val)));
else
Asm->OutStreamer.AddComment(Twine("Encoding = ") +
DecodeDWARFEncoding(Val));
}
Asm->OutStreamer.EmitIntValue(Val, 1, 0/*addrspace*/);
}
/// EmitCFAByte - Emit a .byte 42 directive for a DW_CFA_xxx value.
void DwarfPrinter::EmitCFAByte(unsigned Val) {
if (Asm->VerboseAsm) {
if (Val >= dwarf::DW_CFA_offset && Val < dwarf::DW_CFA_offset+64)
Asm->OutStreamer.AddComment("DW_CFA_offset + Reg (" +
Twine(Val-dwarf::DW_CFA_offset) + ")");
else
Asm->OutStreamer.AddComment(dwarf::CallFrameString(Val));
}
Asm->OutStreamer.EmitIntValue(Val, 1, 0/*addrspace*/);
}
/// EmitSLEB128 - emit the specified signed leb128 value.
void DwarfPrinter::EmitSLEB128(int Value, const char *Desc) const {
if (Asm->VerboseAsm && Desc)
Asm->OutStreamer.AddComment(Desc);
if (MAI->hasLEB128()) {
O << "\t.sleb128\t" << Value;
Asm->OutStreamer.AddBlankLine();
return;
}
// If we don't have .sleb128, emit as .bytes.
int Sign = Value >> (8 * sizeof(Value) - 1);
bool IsMore;
do {
unsigned char Byte = static_cast<unsigned char>(Value & 0x7f);
Value >>= 7;
IsMore = Value != Sign || ((Byte ^ Sign) & 0x40) != 0;
if (IsMore) Byte |= 0x80;
Asm->OutStreamer.EmitIntValue(Byte, 1, /*addrspace*/0);
} while (IsMore);
}
/// EmitULEB128 - emit the specified signed leb128 value.
void DwarfPrinter::EmitULEB128(unsigned Value, const char *Desc,
unsigned PadTo) const {
if (Asm->VerboseAsm && Desc)
Asm->OutStreamer.AddComment(Desc);
if (MAI->hasLEB128() && PadTo == 0) {
O << "\t.uleb128\t" << Value;
Asm->OutStreamer.AddBlankLine();
return;
}
// If we don't have .uleb128 or we want to emit padding, emit as .bytes.
do {
unsigned char Byte = static_cast<unsigned char>(Value & 0x7f);
Value >>= 7;
if (Value || PadTo != 0) Byte |= 0x80;
Asm->OutStreamer.EmitIntValue(Byte, 1, /*addrspace*/0);
} while (Value);
if (PadTo) {
if (PadTo > 1)
Asm->OutStreamer.EmitFill(PadTo - 1, 0x80/*fillval*/, 0/*addrspace*/);
Asm->OutStreamer.EmitFill(1, 0/*fillval*/, 0/*addrspace*/);
}
}
/// PrintLabelName - Print label name in form used by Dwarf writer.
///
void DwarfPrinter::PrintLabelName(const MCSymbol *Label) const {
// FIXME: REMOVE.
O << Label->getName();
}
void DwarfPrinter::PrintLabelName(const char *Tag, unsigned Number,
const char *Suffix) const {
// FIXME: REMOVE.
O << MAI->getPrivateGlobalPrefix() << Tag;
if (Number) O << Number;
O << Suffix;
}
/// EmitReference - Emit a reference to a label.
///
void DwarfPrinter::EmitReference(const MCSymbol *Sym, bool IsPCRelative,
bool Force32Bit) const {
PrintRelDirective(Force32Bit);
O << *Sym;
if (IsPCRelative) O << "-" << MAI->getPCSymbol();
}
void DwarfPrinter::EmitReference(const MCSymbol *Sym, unsigned Encoding) const {
const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
PrintRelDirective(Encoding);
O << *TLOF.getSymbolForDwarfReference(Sym, Asm->MMI, Encoding);;
}
void DwarfPrinter::EmitReference(const GlobalValue *GV, unsigned Encoding)const {
const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
PrintRelDirective(Encoding);
O << *TLOF.getSymbolForDwarfGlobalReference(GV, Asm->Mang,
Asm->MMI, Encoding);
}
/// EmitDifference - Emit the difference between two labels. If this assembler
/// supports .set, we emit a .set of a temporary and then use it in the .word.
void DwarfPrinter::EmitDifference(const MCSymbol *TagHi, const MCSymbol *TagLo,
bool IsSmall) {
if (MAI->hasSetDirective()) {
// FIXME: switch to OutStreamer.EmitAssignment.
O << "\t.set\t";
PrintLabelName("set", SetCounter, Flavor);
O << ",";
PrintLabelName(TagHi);
O << "-";
PrintLabelName(TagLo);
O << "\n";
PrintRelDirective(IsSmall);
PrintLabelName("set", SetCounter, Flavor);
++SetCounter;
} else {
PrintRelDirective(IsSmall);
PrintLabelName(TagHi);
O << "-";
PrintLabelName(TagLo);
}
}
void DwarfPrinter::EmitSectionOffset(const MCSymbol *Label,
const MCSymbol *Section,
bool IsSmall, bool isEH) {
bool printAbsolute = false;
if (isEH)
printAbsolute = MAI->isAbsoluteEHSectionOffsets();
else
printAbsolute = MAI->isAbsoluteDebugSectionOffsets();
if (!printAbsolute)
return EmitDifference(Label, Section, IsSmall);
PrintRelDirective(IsSmall, true);
PrintLabelName(Label);
}
/// EmitFrameMoves - Emit frame instructions to describe the layout of the
/// frame.
void DwarfPrinter::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)) {
EmitCFAByte(dwarf::DW_CFA_advance_loc4);
EmitDifference(getDWLabel("label", LabelID),
getDWLabel(BaseLabel, BaseLabelID), true);
Asm->O << '\n';
BaseLabelID = LabelID;
BaseLabel = "label";
IsLocal = true;
}
// If advancing cfa.
if (Dst.isReg() && Dst.getReg() == MachineLocation::VirtualFP) {
if (!Src.isReg()) {
if (Src.getReg() == MachineLocation::VirtualFP) {
EmitCFAByte(dwarf::DW_CFA_def_cfa_offset);
} else {
EmitCFAByte(dwarf::DW_CFA_def_cfa);
EmitULEB128(RI->getDwarfRegNum(Src.getReg(), isEH), "Register");
}
int Offset = -Src.getOffset();
EmitULEB128(Offset, "Offset");
} else {
llvm_unreachable("Machine move not supported yet.");
}
} else if (Src.isReg() &&
Src.getReg() == MachineLocation::VirtualFP) {
if (Dst.isReg()) {
EmitCFAByte(dwarf::DW_CFA_def_cfa_register);
EmitULEB128(RI->getDwarfRegNum(Dst.getReg(), isEH), "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) {
EmitCFAByte(dwarf::DW_CFA_offset_extended_sf);
EmitULEB128(Reg, "Reg");
EmitSLEB128(Offset, "Offset");
} else if (Reg < 64) {
EmitCFAByte(dwarf::DW_CFA_offset + Reg);
EmitULEB128(Offset, "Offset");
} else {
EmitCFAByte(dwarf::DW_CFA_offset_extended);
EmitULEB128(Reg, "Reg");
EmitULEB128(Offset, "Offset");
}
}
}
}