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//===-- 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/MC/MCAsmInfo.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetLoweringObjectFile.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Support/Dwarf.h"
using namespace llvm;
/// EmitSLEB128 - emit the specified signed leb128 value.
void AsmPrinter::EmitSLEB128(int Value, const char *Desc) const {
if (isVerbose() && Desc)
OutStreamer.AddComment(Desc);
if (MAI->hasLEB128()) {
// FIXME: MCize.
OutStreamer.EmitRawText("\t.sleb128\t" + Twine(Value));
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;
OutStreamer.EmitIntValue(Byte, 1, /*addrspace*/0);
} while (IsMore);
}
/// EmitULEB128 - emit the specified signed leb128 value.
void AsmPrinter::EmitULEB128(unsigned Value, const char *Desc,
unsigned PadTo) const {
if (isVerbose() && Desc)
OutStreamer.AddComment(Desc);
if (MAI->hasLEB128() && PadTo == 0) {
// FIXME: MCize.
OutStreamer.EmitRawText("\t.uleb128\t" + Twine(Value));
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;
OutStreamer.EmitIntValue(Byte, 1, /*addrspace*/0);
} while (Value);
if (PadTo) {
if (PadTo > 1)
OutStreamer.EmitFill(PadTo - 1, 0x80/*fillval*/, 0/*addrspace*/);
OutStreamer.EmitFill(1, 0/*fillval*/, 0/*addrspace*/);
}
}
/// 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, 0/*addrspace*/);
}
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) {
if (isVerbose()) {
if (Desc != 0)
OutStreamer.AddComment(Twine(Desc)+" Encoding = " +
Twine(DecodeDWARFEncoding(Val)));
else
OutStreamer.AddComment(Twine("Encoding = ") +
DecodeDWARFEncoding(Val));
}
OutStreamer.EmitIntValue(Val, 1, 0/*addrspace*/);
}
/// 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: assert(0 && "Invalid encoded value.");
case dwarf::DW_EH_PE_absptr: return TM.getTargetData()->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::EmitReference(const MCSymbol *Sym, unsigned Encoding) const {
const TargetLoweringObjectFile &TLOF = getObjFileLowering();
const MCExpr *Exp =
TLOF.getExprForDwarfReference(Sym, Mang, MMI, Encoding, OutStreamer);
OutStreamer.EmitValue(Exp, GetSizeOfEncodedValue(Encoding), /*addrspace*/0);
}
void AsmPrinter::EmitReference(const GlobalValue *GV, unsigned Encoding)const{
const TargetLoweringObjectFile &TLOF = getObjFileLowering();
const MCExpr *Exp =
TLOF.getExprForDwarfGlobalReference(GV, Mang, MMI, Encoding, OutStreamer);
OutStreamer.EmitValue(Exp, GetSizeOfEncodedValue(Encoding), /*addrspace*/0);
}
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