src/llvm/lib/Target/X86/MCTargetDesc/X86MachORelocationInfo.cpp

   1 //===-- X86MachORelocationInfo.cpp ----------------------------------------===//
   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 "MCTargetDesc/X86MCTargetDesc.h"
  11 #include "llvm/MC/MCContext.h"
  12 #include "llvm/MC/MCExpr.h"
  13 #include "llvm/MC/MCInst.h"
  14 #include "llvm/MC/MCRelocationInfo.h"
  15 #include "llvm/MC/MCSymbol.h"
  16 #include "llvm/Object/MachO.h"
  17
  18 using namespace llvm;
  19 using namespace object;
  20 using namespace MachO;
  21
  22 namespace {
  23 class X86_64MachORelocationInfo : public MCRelocationInfo {
  24 public:
  25   X86_64MachORelocationInfo(MCContext &Ctx) : MCRelocationInfo(Ctx) {}
  26
  27   const MCExpr *createExprForRelocation(RelocationRef Rel) override {
  28     const MachOObjectFile *Obj = cast<MachOObjectFile>(Rel.getObjectFile());
  29
  30     uint64_t RelType; Rel.getType(RelType);
  31     symbol_iterator SymI = Rel.getSymbol();
  32
  33     StringRef SymName; SymI->getName(SymName);
  34     uint64_t  SymAddr; SymI->getAddress(SymAddr);
  35
  36     any_relocation_info RE = Obj->getRelocation(Rel.getRawDataRefImpl());
  37     bool isPCRel = Obj->getAnyRelocationPCRel(RE);
  38
  39     MCSymbol *Sym = Ctx.GetOrCreateSymbol(SymName);
  40     // FIXME: check that the value is actually the same.
  41     if (Sym->isVariable() == false)
  42       Sym->setVariableValue(MCConstantExpr::Create(SymAddr, Ctx));
  43     const MCExpr *Expr = nullptr;
  44
  45     switch(RelType) {
  46     case X86_64_RELOC_TLV:
  47       Expr = MCSymbolRefExpr::Create(Sym, MCSymbolRefExpr::VK_TLVP, Ctx);
  48       break;
  49     case X86_64_RELOC_SIGNED_4:
  50       Expr = MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Sym, Ctx),
  51                                      MCConstantExpr::Create(4, Ctx),
  52                                      Ctx);
  53       break;
  54     case X86_64_RELOC_SIGNED_2:
  55       Expr = MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Sym, Ctx),
  56                                      MCConstantExpr::Create(2, Ctx),
  57                                      Ctx);
  58       break;
  59     case X86_64_RELOC_SIGNED_1:
  60       Expr = MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Sym, Ctx),
  61                                      MCConstantExpr::Create(1, Ctx),
  62                                      Ctx);
  63       break;
  64     case X86_64_RELOC_GOT_LOAD:
  65       Expr = MCSymbolRefExpr::Create(Sym, MCSymbolRefExpr::VK_GOTPCREL, Ctx);
  66       break;
  67     case X86_64_RELOC_GOT:
  68       Expr = MCSymbolRefExpr::Create(Sym, isPCRel ?
  69                                      MCSymbolRefExpr::VK_GOTPCREL :
  70                                      MCSymbolRefExpr::VK_GOT,
  71                                      Ctx);
  72       break;
  73     case X86_64_RELOC_SUBTRACTOR:
  74       {
  75         Rel.moveNext();
  76         any_relocation_info RENext =
  77             Obj->getRelocation(Rel.getRawDataRefImpl());
  78
  79         // X86_64_SUBTRACTOR must be followed by a relocation of type
  80         // X86_64_RELOC_UNSIGNED.
  81         // NOTE: Scattered relocations don't exist on x86_64.
  82         unsigned RType = Obj->getAnyRelocationType(RENext);
  83         if (RType != X86_64_RELOC_UNSIGNED)
  84           report_fatal_error("Expected X86_64_RELOC_UNSIGNED after "
  85                              "X86_64_RELOC_SUBTRACTOR.");
  86
  87         const MCExpr *LHS = MCSymbolRefExpr::Create(Sym, Ctx);
  88
  89         symbol_iterator RSymI = Rel.getSymbol();
  90         uint64_t RSymAddr;
  91         RSymI->getAddress(RSymAddr);
  92         StringRef RSymName;
  93         RSymI->getName(RSymName);
  94
  95         MCSymbol *RSym = Ctx.GetOrCreateSymbol(RSymName);
  96         if (RSym->isVariable() == false)
  97           RSym->setVariableValue(MCConstantExpr::Create(RSymAddr, Ctx));
  98
  99         const MCExpr *RHS = MCSymbolRefExpr::Create(RSym, Ctx);
 100
 101         Expr = MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
 102         break;
 103       }
 104     default:
 105       Expr = MCSymbolRefExpr::Create(Sym, Ctx);
 106       break;
 107     }
 108     return Expr;
 109   }
 110 };
 111 } // End unnamed namespace
 112
 113 /// createX86_64MachORelocationInfo - Construct an X86-64 Mach-O RelocationInfo.
 114 MCRelocationInfo *llvm::createX86_64MachORelocationInfo(MCContext &Ctx) {
 115   return new X86_64MachORelocationInfo(Ctx);
 116 }