lib/MC/MCObjectWriter.cpp

   1 //===- lib/MC/MCObjectWriter.cpp - MCObjectWriter implementation ----------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #include "llvm/MC/MCObjectWriter.h"
  11 #include "llvm/MC/MCAssembler.h"
  12 #include "llvm/MC/MCExpr.h"
  13 #include "llvm/MC/MCFragment.h"
  14 #include "llvm/MC/MCSymbol.h"
  15
  16 using namespace llvm;
  17
  18 MCObjectWriter::~MCObjectWriter() = default;
  19
  20 bool MCObjectWriter::isSymbolRefDifferenceFullyResolved(
  21     const MCAssembler &Asm, const MCSymbolRefExpr *A, const MCSymbolRefExpr *B,
  22     bool InSet) const {
  23   // Modified symbol references cannot be resolved.
  24   if (A->getKind() != MCSymbolRefExpr::VK_None ||
  25       B->getKind() != MCSymbolRefExpr::VK_None)
  26     return false;
  27
  28   const MCSymbol &SA = A->getSymbol();
  29   const MCSymbol &SB = B->getSymbol();
  30   if (SA.isUndefined() || SB.isUndefined())
  31     return false;
  32
  33   if (!SA.getFragment() || !SB.getFragment())
  34     return false;
  35
  36   return isSymbolRefDifferenceFullyResolvedImpl(Asm, SA, SB, InSet);
  37 }
  38
  39 bool MCObjectWriter::isSymbolRefDifferenceFullyResolvedImpl(
  40     const MCAssembler &Asm, const MCSymbol &A, const MCSymbol &B,
  41     bool InSet) const {
  42   return isSymbolRefDifferenceFullyResolvedImpl(Asm, A, *B.getFragment(), InSet,
  43                                                 false);
  44 }
  45
  46 bool MCObjectWriter::isSymbolRefDifferenceFullyResolvedImpl(
  47     const MCAssembler &Asm, const MCSymbol &SymA, const MCFragment &FB,
  48     bool InSet, bool IsPCRel) const {
  49   const MCSection &SecA = SymA.getSection();
  50   const MCSection &SecB = *FB.getParent();
  51   // On ELF and COFF  A - B is absolute if A and B are in the same section.
  52   return &SecA == &SecB;
  53 }