1 //===-- X86ELFObjectWriter.cpp - X86 ELF Writer ---------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #include "MCTargetDesc/X86FixupKinds.h"
11 #include "MCTargetDesc/X86MCTargetDesc.h"
12 #include "llvm/MC/MCELFObjectWriter.h"
13 #include "llvm/MC/MCExpr.h"
14 #include "llvm/MC/MCValue.h"
15 #include "llvm/Support/ELF.h"
16 #include "llvm/Support/ErrorHandling.h"
21 class X86ELFObjectWriter : public MCELFObjectTargetWriter {
23 X86ELFObjectWriter(bool IsELF64, uint8_t OSABI, uint16_t EMachine);
25 virtual ~X86ELFObjectWriter();
27 unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup,
28 bool IsPCRel) const override;
32 X86ELFObjectWriter::X86ELFObjectWriter(bool IsELF64, uint8_t OSABI,
34 : MCELFObjectTargetWriter(IsELF64, OSABI, EMachine,
35 // Only i386 uses Rel instead of RelA.
36 /*HasRelocationAddend*/ EMachine != ELF::EM_386) {}
38 X86ELFObjectWriter::~X86ELFObjectWriter()
41 enum X86_64RelType { RT64_64, RT64_32, RT64_32S, RT64_16, RT64_8 };
43 static X86_64RelType getType64(unsigned Kind,
44 MCSymbolRefExpr::VariantKind &Modifier,
48 llvm_unreachable("Unimplemented");
49 case X86::reloc_global_offset_table8:
50 Modifier = MCSymbolRefExpr::VK_GOT;
55 case X86::reloc_signed_4byte:
56 if (Modifier == MCSymbolRefExpr::VK_None && !IsPCRel)
59 case X86::reloc_global_offset_table:
60 Modifier = MCSymbolRefExpr::VK_GOT;
65 case X86::reloc_riprel_4byte:
66 case X86::reloc_riprel_4byte_movq_load:
76 static unsigned getRelocType64(MCSymbolRefExpr::VariantKind Modifier,
77 X86_64RelType Type, bool IsPCRel) {
80 llvm_unreachable("Unimplemented");
81 case MCSymbolRefExpr::VK_None:
84 return IsPCRel ? ELF::R_X86_64_PC64 : ELF::R_X86_64_64;
86 return IsPCRel ? ELF::R_X86_64_PC32 : ELF::R_X86_64_32;
88 return ELF::R_X86_64_32S;
90 return IsPCRel ? ELF::R_X86_64_PC16 : ELF::R_X86_64_16;
92 return IsPCRel ? ELF::R_X86_64_PC8 : ELF::R_X86_64_8;
94 case MCSymbolRefExpr::VK_GOT:
97 return IsPCRel ? ELF::R_X86_64_GOTPC64 : ELF::R_X86_64_GOT64;
99 return IsPCRel ? ELF::R_X86_64_GOTPC32 : ELF::R_X86_64_GOT32;
103 llvm_unreachable("Unimplemented");
105 case MCSymbolRefExpr::VK_GOTOFF:
106 assert(Type == RT64_64);
108 return ELF::R_X86_64_GOTOFF64;
109 case MCSymbolRefExpr::VK_TPOFF:
113 return ELF::R_X86_64_TPOFF64;
115 return ELF::R_X86_64_TPOFF32;
119 llvm_unreachable("Unimplemented");
121 case MCSymbolRefExpr::VK_DTPOFF:
125 return ELF::R_X86_64_DTPOFF64;
127 return ELF::R_X86_64_DTPOFF32;
131 llvm_unreachable("Unimplemented");
133 case MCSymbolRefExpr::VK_SIZE:
137 return ELF::R_X86_64_SIZE64;
139 return ELF::R_X86_64_SIZE32;
143 llvm_unreachable("Unimplemented");
145 case MCSymbolRefExpr::VK_TLSGD:
146 assert(Type == RT64_32);
147 return ELF::R_X86_64_TLSGD;
148 case MCSymbolRefExpr::VK_GOTTPOFF:
149 assert(Type == RT64_32);
150 return ELF::R_X86_64_GOTTPOFF;
151 case MCSymbolRefExpr::VK_TLSLD:
152 assert(Type == RT64_32);
153 return ELF::R_X86_64_TLSLD;
154 case MCSymbolRefExpr::VK_PLT:
155 assert(Type == RT64_32);
156 return ELF::R_X86_64_PLT32;
157 case MCSymbolRefExpr::VK_GOTPCREL:
158 assert(Type == RT64_32);
159 return ELF::R_X86_64_GOTPCREL;
163 enum X86_32RelType { RT32_32, RT32_16, RT32_8 };
165 static X86_32RelType getType32(X86_64RelType T) {
169 llvm_unreachable("Unimplemented");
180 static unsigned getRelocType32(MCSymbolRefExpr::VariantKind Modifier,
181 X86_32RelType Type, bool IsPCRel) {
184 llvm_unreachable("Unimplemented");
185 case MCSymbolRefExpr::VK_None:
188 return IsPCRel ? ELF::R_386_PC32 : ELF::R_386_32;
190 return IsPCRel ? ELF::R_386_PC16 : ELF::R_386_16;
192 return IsPCRel ? ELF::R_386_PC8 : ELF::R_386_8;
194 case MCSymbolRefExpr::VK_GOT:
195 assert(Type == RT32_32);
196 return IsPCRel ? ELF::R_386_GOTPC : ELF::R_386_GOT32;
197 case MCSymbolRefExpr::VK_GOTOFF:
198 assert(Type == RT32_32);
200 return ELF::R_386_GOTOFF;
201 case MCSymbolRefExpr::VK_TPOFF:
202 assert(Type == RT32_32);
204 return ELF::R_386_TLS_LE_32;
205 case MCSymbolRefExpr::VK_DTPOFF:
206 assert(Type == RT32_32);
208 return ELF::R_386_TLS_LDO_32;
209 case MCSymbolRefExpr::VK_TLSGD:
210 assert(Type == RT32_32);
212 return ELF::R_386_TLS_GD;
213 case MCSymbolRefExpr::VK_GOTTPOFF:
214 assert(Type == RT32_32);
216 return ELF::R_386_TLS_IE_32;
217 case MCSymbolRefExpr::VK_PLT:
218 assert(Type == RT32_32);
219 return ELF::R_386_PLT32;
220 case MCSymbolRefExpr::VK_INDNTPOFF:
221 assert(Type == RT32_32);
223 return ELF::R_386_TLS_IE;
224 case MCSymbolRefExpr::VK_NTPOFF:
225 assert(Type == RT32_32);
227 return ELF::R_386_TLS_LE;
228 case MCSymbolRefExpr::VK_GOTNTPOFF:
229 assert(Type == RT32_32);
231 return ELF::R_386_TLS_GOTIE;
232 case MCSymbolRefExpr::VK_TLSLDM:
233 assert(Type == RT32_32);
235 return ELF::R_386_TLS_LDM;
239 unsigned X86ELFObjectWriter::GetRelocType(const MCValue &Target,
240 const MCFixup &Fixup,
241 bool IsPCRel) const {
242 MCSymbolRefExpr::VariantKind Modifier = Target.getAccessVariant();
243 X86_64RelType Type = getType64(Fixup.getKind(), Modifier, IsPCRel);
244 if (getEMachine() == ELF::EM_X86_64)
245 return getRelocType64(Modifier, Type, IsPCRel);
247 assert(getEMachine() == ELF::EM_386 && "Unsupported ELF machine type.");
248 return getRelocType32(Modifier, getType32(Type), IsPCRel);
251 MCObjectWriter *llvm::createX86ELFObjectWriter(raw_ostream &OS,
255 MCELFObjectTargetWriter *MOTW =
256 new X86ELFObjectWriter(IsELF64, OSABI, EMachine);
257 return createELFObjectWriter(MOTW, OS, /*IsLittleEndian=*/true);