1 //===-- MCELFObjectTargetWriter.cpp - ELF Target Writer Subclass ----------===//
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/ADT/STLExtras.h"
11 #include "llvm/MC/MCELFObjectWriter.h"
12 #include "llvm/MC/MCExpr.h"
13 #include "llvm/MC/MCValue.h"
14 
15 using namespace llvm;
16 
MCELFObjectTargetWriter(bool Is64Bit_,uint8_t OSABI_,uint16_t EMachine_,bool HasRelocationAddend_,bool IsN64_)17 MCELFObjectTargetWriter::MCELFObjectTargetWriter(bool Is64Bit_,
18                                                  uint8_t OSABI_,
19                                                  uint16_t EMachine_,
20                                                  bool HasRelocationAddend_,
21                                                  bool IsN64_)
22   : OSABI(OSABI_), EMachine(EMachine_),
23     HasRelocationAddend(HasRelocationAddend_), Is64Bit(Is64Bit_),
24     IsN64(IsN64_){
25 }
26 
needsRelocateWithSymbol(const MCSymbolData & SD,unsigned Type) const27 bool MCELFObjectTargetWriter::needsRelocateWithSymbol(const MCSymbolData &SD,
28                                                       unsigned Type) const {
29   return false;
30 }
31 
32 // ELF doesn't require relocations to be in any order. We sort by the Offset,
33 // just to match gnu as for easier comparison. The use type is an arbitrary way
34 // of making the sort deterministic.
cmpRel(const ELFRelocationEntry * AP,const ELFRelocationEntry * BP)35 static int cmpRel(const ELFRelocationEntry *AP, const ELFRelocationEntry *BP) {
36   const ELFRelocationEntry &A = *AP;
37   const ELFRelocationEntry &B = *BP;
38   if (A.Offset != B.Offset)
39     return B.Offset - A.Offset;
40   if (B.Type != A.Type)
41     return A.Type - B.Type;
42   //llvm_unreachable("ELFRelocs might be unstable!");
43   return 0;
44 }
45 
46 
47 void
sortRelocs(const MCAssembler & Asm,std::vector<ELFRelocationEntry> & Relocs)48 MCELFObjectTargetWriter::sortRelocs(const MCAssembler &Asm,
49                                     std::vector<ELFRelocationEntry> &Relocs) {
50   array_pod_sort(Relocs.begin(), Relocs.end(), cmpRel);
51 }
52