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 ~X86ELFObjectWriter() override;
28 unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup,
29 bool IsPCRel) const override;
33 X86ELFObjectWriter::X86ELFObjectWriter(bool IsELF64, uint8_t OSABI,
35 : MCELFObjectTargetWriter(IsELF64, OSABI, EMachine,
36 // Only i386 and IAMCU use Rel instead of RelA.
37 /*HasRelocationAddend*/
38 (EMachine != ELF::EM_386) &&
39 (EMachine != ELF::EM_IAMCU)) {}
41 X86ELFObjectWriter::~X86ELFObjectWriter()
44 enum X86_64RelType { RT64_64, RT64_32, RT64_32S, RT64_16, RT64_8 };
46 static X86_64RelType getType64(unsigned Kind,
47 MCSymbolRefExpr::VariantKind &Modifier,
51 llvm_unreachable("Unimplemented");
52 case X86::reloc_global_offset_table8:
53 Modifier = MCSymbolRefExpr::VK_GOT;
58 case X86::reloc_signed_4byte:
59 if (Modifier == MCSymbolRefExpr::VK_None && !IsPCRel)
62 case X86::reloc_global_offset_table:
63 Modifier = MCSymbolRefExpr::VK_GOT;
68 case X86::reloc_riprel_4byte:
69 case X86::reloc_riprel_4byte_movq_load:
80 static unsigned getRelocType64(MCSymbolRefExpr::VariantKind Modifier,
81 X86_64RelType Type, bool IsPCRel) {
84 llvm_unreachable("Unimplemented");
85 case MCSymbolRefExpr::VK_None:
88 return IsPCRel ? ELF::R_X86_64_PC64 : ELF::R_X86_64_64;
90 return IsPCRel ? ELF::R_X86_64_PC32 : ELF::R_X86_64_32;
92 return ELF::R_X86_64_32S;
94 return IsPCRel ? ELF::R_X86_64_PC16 : ELF::R_X86_64_16;
96 return IsPCRel ? ELF::R_X86_64_PC8 : ELF::R_X86_64_8;
98 case MCSymbolRefExpr::VK_GOT:
101 return IsPCRel ? ELF::R_X86_64_GOTPC64 : ELF::R_X86_64_GOT64;
103 return IsPCRel ? ELF::R_X86_64_GOTPC32 : ELF::R_X86_64_GOT32;
107 llvm_unreachable("Unimplemented");
109 case MCSymbolRefExpr::VK_GOTOFF:
110 assert(Type == RT64_64);
112 return ELF::R_X86_64_GOTOFF64;
113 case MCSymbolRefExpr::VK_TPOFF:
117 return ELF::R_X86_64_TPOFF64;
119 return ELF::R_X86_64_TPOFF32;
123 llvm_unreachable("Unimplemented");
125 case MCSymbolRefExpr::VK_DTPOFF:
129 return ELF::R_X86_64_DTPOFF64;
131 return ELF::R_X86_64_DTPOFF32;
135 llvm_unreachable("Unimplemented");
137 case MCSymbolRefExpr::VK_SIZE:
141 return ELF::R_X86_64_SIZE64;
143 return ELF::R_X86_64_SIZE32;
147 llvm_unreachable("Unimplemented");
149 case MCSymbolRefExpr::VK_TLSGD:
150 assert(Type == RT64_32);
151 return ELF::R_X86_64_TLSGD;
152 case MCSymbolRefExpr::VK_GOTTPOFF:
153 assert(Type == RT64_32);
154 return ELF::R_X86_64_GOTTPOFF;
155 case MCSymbolRefExpr::VK_TLSLD:
156 assert(Type == RT64_32);
157 return ELF::R_X86_64_TLSLD;
158 case MCSymbolRefExpr::VK_PLT:
159 assert(Type == RT64_32);
160 return ELF::R_X86_64_PLT32;
161 case MCSymbolRefExpr::VK_GOTPCREL:
162 assert(Type == RT64_32);
163 return ELF::R_X86_64_GOTPCREL;
167 enum X86_32RelType { RT32_32, RT32_16, RT32_8 };
169 static X86_32RelType getType32(X86_64RelType T) {
172 llvm_unreachable("Unimplemented");
181 llvm_unreachable("unexpected relocation type!");
184 static unsigned getRelocType32(MCSymbolRefExpr::VariantKind Modifier,
185 X86_32RelType Type, bool IsPCRel) {
188 llvm_unreachable("Unimplemented");
189 case MCSymbolRefExpr::VK_None:
192 return IsPCRel ? ELF::R_386_PC32 : ELF::R_386_32;
194 return IsPCRel ? ELF::R_386_PC16 : ELF::R_386_16;
196 return IsPCRel ? ELF::R_386_PC8 : ELF::R_386_8;
198 case MCSymbolRefExpr::VK_GOT:
199 assert(Type == RT32_32);
200 return IsPCRel ? ELF::R_386_GOTPC : ELF::R_386_GOT32;
201 case MCSymbolRefExpr::VK_GOTOFF:
202 assert(Type == RT32_32);
204 return ELF::R_386_GOTOFF;
205 case MCSymbolRefExpr::VK_TPOFF:
206 assert(Type == RT32_32);
208 return ELF::R_386_TLS_LE_32;
209 case MCSymbolRefExpr::VK_DTPOFF:
210 assert(Type == RT32_32);
212 return ELF::R_386_TLS_LDO_32;
213 case MCSymbolRefExpr::VK_TLSGD:
214 assert(Type == RT32_32);
216 return ELF::R_386_TLS_GD;
217 case MCSymbolRefExpr::VK_GOTTPOFF:
218 assert(Type == RT32_32);
220 return ELF::R_386_TLS_IE_32;
221 case MCSymbolRefExpr::VK_PLT:
222 assert(Type == RT32_32);
223 return ELF::R_386_PLT32;
224 case MCSymbolRefExpr::VK_INDNTPOFF:
225 assert(Type == RT32_32);
227 return ELF::R_386_TLS_IE;
228 case MCSymbolRefExpr::VK_NTPOFF:
229 assert(Type == RT32_32);
231 return ELF::R_386_TLS_LE;
232 case MCSymbolRefExpr::VK_GOTNTPOFF:
233 assert(Type == RT32_32);
235 return ELF::R_386_TLS_GOTIE;
236 case MCSymbolRefExpr::VK_TLSLDM:
237 assert(Type == RT32_32);
239 return ELF::R_386_TLS_LDM;
243 unsigned X86ELFObjectWriter::GetRelocType(const MCValue &Target,
244 const MCFixup &Fixup,
245 bool IsPCRel) const {
246 MCSymbolRefExpr::VariantKind Modifier = Target.getAccessVariant();
247 X86_64RelType Type = getType64(Fixup.getKind(), Modifier, IsPCRel);
248 if (getEMachine() == ELF::EM_X86_64)
249 return getRelocType64(Modifier, Type, IsPCRel);
251 assert((getEMachine() == ELF::EM_386 || getEMachine() == ELF::EM_IAMCU) &&
252 "Unsupported ELF machine type.");
253 return getRelocType32(Modifier, getType32(Type), IsPCRel);
256 MCObjectWriter *llvm::createX86ELFObjectWriter(raw_pwrite_stream &OS,
257 bool IsELF64, uint8_t OSABI,
259 MCELFObjectTargetWriter *MOTW =
260 new X86ELFObjectWriter(IsELF64, OSABI, EMachine);
261 return createELFObjectWriter(MOTW, OS, /*IsLittleEndian=*/true);