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//===- lib/MC/MCObjectWriter.cpp - MCObjectWriter implementation ----------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCObjectWriter.h"
#include "llvm/MC/MCSymbol.h"
using namespace llvm;
MCObjectWriter::~MCObjectWriter() {
}
/// Utility function to encode a SLEB128 value.
void MCObjectWriter::EncodeSLEB128(int64_t Value, raw_ostream &OS) {
bool More;
do {
uint8_t Byte = Value & 0x7f;
// NOTE: this assumes that this signed shift is an arithmetic right shift.
Value >>= 7;
More = !((((Value == 0 ) && ((Byte & 0x40) == 0)) ||
((Value == -1) && ((Byte & 0x40) != 0))));
if (More)
Byte |= 0x80; // Mark this byte that that more bytes will follow.
OS << char(Byte);
} while (More);
}
/// Utility function to encode a ULEB128 value.
void MCObjectWriter::EncodeULEB128(uint64_t Value, raw_ostream &OS) {
do {
uint8_t Byte = Value & 0x7f;
Value >>= 7;
if (Value != 0)
Byte |= 0x80; // Mark this byte that that more bytes will follow.
OS << char(Byte);
} while (Value != 0);
}
bool
MCObjectWriter::IsSymbolRefDifferenceFullyResolved(const MCAssembler &Asm,
const MCSymbolRefExpr *A,
const MCSymbolRefExpr *B,
bool InSet) const {
// Modified symbol references cannot be resolved.
if (A->getKind() != MCSymbolRefExpr::VK_None ||
B->getKind() != MCSymbolRefExpr::VK_None)
return false;
const MCSymbol &SA = A->getSymbol();
const MCSymbol &SB = B->getSymbol();
if (SA.AliasedSymbol().isUndefined() || SB.AliasedSymbol().isUndefined())
return false;
const MCSymbolData &DataA = Asm.getSymbolData(SA);
const MCSymbolData &DataB = Asm.getSymbolData(SB);
return IsSymbolRefDifferenceFullyResolvedImpl(Asm, DataA,
*DataB.getFragment(),
InSet,
false);
}
bool
MCObjectWriter::IsSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm,
const MCSymbolData &DataA,
const MCFragment &FB,
bool InSet,
bool IsPCRel) const {
const MCSection &SecA = DataA.getSymbol().AliasedSymbol().getSection();
const MCSection &SecB = FB.getParent()->getSection();
// On ELF and COFF A - B is absolute if A and B are in the same section.
return &SecA == &SecB;
}
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