lib/Target/X86/X86ELFWriterInfo.h

   1 //===-- X86ELFWriterInfo.h - ELF Writer Info for X86 ------------*- C++ -*-===//
   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 // This file implements ELF writer information for the X86 backend.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #ifndef X86_ELF_WRITER_INFO_H
  15 #define X86_ELF_WRITER_INFO_H
  16
  17 #include "llvm/Target/TargetELFWriterInfo.h"
  18
  19 namespace llvm {
  20
  21   class X86ELFWriterInfo : public TargetELFWriterInfo {
  22
  23     // ELF Relocation types for X86
  24     enum X86RelocationType {
  25       R_386_NONE = 0,
  26       R_386_32   = 1,
  27       R_386_PC32 = 2
  28     };
  29
  30     // ELF Relocation types for X86_64
  31     enum X86_64RelocationType {
  32       R_X86_64_NONE = 0,
  33       R_X86_64_64   = 1,
  34       R_X86_64_PC32 = 2,
  35       R_X86_64_32   = 10,
  36       R_X86_64_32S  = 11,
  37       R_X86_64_PC64 = 24
  38     };
  39
  40   public:
  41     X86ELFWriterInfo(TargetMachine &TM);
  42     virtual ~X86ELFWriterInfo();
  43
  44     /// getRelocationType - Returns the target specific ELF Relocation type.
  45     /// 'MachineRelTy' contains the object code independent relocation type
  46     virtual unsigned getRelocationType(unsigned MachineRelTy) const;
  47
  48     /// hasRelocationAddend - True if the target uses an addend in the
  49     /// ELF relocation entry.
  50     virtual bool hasRelocationAddend() const { return is64Bit ? true : false; }
  51
  52     /// hasCustomJumpTableIndexRelTy - Returns true if the target has a
  53     /// specific relocation type for a jump table index.
  54     virtual bool hasCustomJumpTableIndexRelTy() const {
  55       return is64Bit ? true : false;
  56     }
  57
  58     /// getJumpTableIndexRelTy - Returns the target specific relocation type
  59     /// for a jump table index.
  60     virtual unsigned getJumpTableIndexRelTy() const { return R_X86_64_32S; }
  61
  62     /// getDefaultAddendForRelTy - Gets the default addend value for a
  63     /// relocation entry based on the target ELF relocation type.
  64     virtual long int getDefaultAddendForRelTy(unsigned RelTy) const;
  65
  66     /// getRelTySize - Returns the size of relocatable field in bits
  67     virtual unsigned getRelocationTySize(unsigned RelTy) const;
  68
  69     /// isPCRelativeRel - True if the relocation type is pc relative
  70     virtual bool isPCRelativeRel(unsigned RelTy) const;
  71
  72     /// getJumpTableRelocationTy - Returns the machine relocation type used
  73     /// to reference a jumptable.
  74     virtual unsigned getAbsoluteLabelMachineRelTy() const;
  75
  76     /// computeRelocation - Some relocatable fields could be relocated
  77     /// directly, avoiding the relocation symbol emission, compute the
  78     /// final relocation value for this symbol.
  79     virtual long int computeRelocation(unsigned SymOffset, unsigned RelOffset,
  80                                        unsigned RelTy) const;
  81   };
  82
  83 } // end llvm namespace
  84
  85 #endif // X86_ELF_WRITER_INFO_H