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 uses Rel instead of RelA.
37 /*HasRelocationAddend*/ EMachine != ELF::EM_386) {}
39 X86ELFObjectWriter::~X86ELFObjectWriter()
42 enum X86_64RelType { RT64_64, RT64_32, RT64_32S, RT64_16, RT64_8 };
44 static X86_64RelType getType64(unsigned Kind,
45 MCSymbolRefExpr::VariantKind &Modifier,
49 llvm_unreachable("Unimplemented");
50 case X86::reloc_global_offset_table8:
51 Modifier = MCSymbolRefExpr::VK_GOT;
56 case X86::reloc_signed_4byte:
57 if (Modifier == MCSymbolRefExpr::VK_None && !IsPCRel)
60 case X86::reloc_global_offset_table:
61 Modifier = MCSymbolRefExpr::VK_GOT;
66 case X86::reloc_riprel_4byte:
67 case X86::reloc_riprel_4byte_movq_load:
78 static unsigned getRelocType64(MCSymbolRefExpr::VariantKind Modifier,
79 X86_64RelType Type, bool IsPCRel) {
82 llvm_unreachable("Unimplemented");
83 case MCSymbolRefExpr::VK_None:
86 return IsPCRel ? ELF::R_X86_64_PC64 : ELF::R_X86_64_64;
88 return IsPCRel ? ELF::R_X86_64_PC32 : ELF::R_X86_64_32;
90 return ELF::R_X86_64_32S;
92 return IsPCRel ? ELF::R_X86_64_PC16 : ELF::R_X86_64_16;
94 return IsPCRel ? ELF::R_X86_64_PC8 : ELF::R_X86_64_8;
96 case MCSymbolRefExpr::VK_GOT:
99 return IsPCRel ? ELF::R_X86_64_GOTPC64 : ELF::R_X86_64_GOT64;
101 return IsPCRel ? ELF::R_X86_64_GOTPC32 : ELF::R_X86_64_GOT32;
105 llvm_unreachable("Unimplemented");
107 case MCSymbolRefExpr::VK_GOTOFF:
108 assert(Type == RT64_64);
110 return ELF::R_X86_64_GOTOFF64;
111 case MCSymbolRefExpr::VK_TPOFF:
115 return ELF::R_X86_64_TPOFF64;
117 return ELF::R_X86_64_TPOFF32;
121 llvm_unreachable("Unimplemented");
123 case MCSymbolRefExpr::VK_DTPOFF:
127 return ELF::R_X86_64_DTPOFF64;
129 return ELF::R_X86_64_DTPOFF32;
133 llvm_unreachable("Unimplemented");
135 case MCSymbolRefExpr::VK_SIZE:
139 return ELF::R_X86_64_SIZE64;
141 return ELF::R_X86_64_SIZE32;
145 llvm_unreachable("Unimplemented");
147 case MCSymbolRefExpr::VK_TLSGD:
148 assert(Type == RT64_32);
149 return ELF::R_X86_64_TLSGD;
150 case MCSymbolRefExpr::VK_GOTTPOFF:
151 assert(Type == RT64_32);
152 return ELF::R_X86_64_GOTTPOFF;
153 case MCSymbolRefExpr::VK_TLSLD:
154 assert(Type == RT64_32);
155 return ELF::R_X86_64_TLSLD;
156 case MCSymbolRefExpr::VK_PLT:
157 assert(Type == RT64_32);
158 return ELF::R_X86_64_PLT32;
159 case MCSymbolRefExpr::VK_GOTPCREL:
160 assert(Type == RT64_32);
161 return ELF::R_X86_64_GOTPCREL;
165 enum X86_32RelType { RT32_32, RT32_16, RT32_8 };
167 static X86_32RelType getType32(X86_64RelType T) {
170 llvm_unreachable("Unimplemented");
179 llvm_unreachable("unexpected relocation type!");
182 static unsigned getRelocType32(MCSymbolRefExpr::VariantKind Modifier,
183 X86_32RelType Type, bool IsPCRel) {
186 llvm_unreachable("Unimplemented");
187 case MCSymbolRefExpr::VK_None:
190 return IsPCRel ? ELF::R_386_PC32 : ELF::R_386_32;
192 return IsPCRel ? ELF::R_386_PC16 : ELF::R_386_16;
194 return IsPCRel ? ELF::R_386_PC8 : ELF::R_386_8;
196 case MCSymbolRefExpr::VK_GOT:
197 assert(Type == RT32_32);
198 return IsPCRel ? ELF::R_386_GOTPC : ELF::R_386_GOT32;
199 case MCSymbolRefExpr::VK_GOTOFF:
200 assert(Type == RT32_32);
202 return ELF::R_386_GOTOFF;
203 case MCSymbolRefExpr::VK_TPOFF:
204 assert(Type == RT32_32);
206 return ELF::R_386_TLS_LE_32;
207 case MCSymbolRefExpr::VK_DTPOFF:
208 assert(Type == RT32_32);
210 return ELF::R_386_TLS_LDO_32;
211 case MCSymbolRefExpr::VK_TLSGD:
212 assert(Type == RT32_32);
214 return ELF::R_386_TLS_GD;
215 case MCSymbolRefExpr::VK_GOTTPOFF:
216 assert(Type == RT32_32);
218 return ELF::R_386_TLS_IE_32;
219 case MCSymbolRefExpr::VK_PLT:
220 assert(Type == RT32_32);
221 return ELF::R_386_PLT32;
222 case MCSymbolRefExpr::VK_INDNTPOFF:
223 assert(Type == RT32_32);
225 return ELF::R_386_TLS_IE;
226 case MCSymbolRefExpr::VK_NTPOFF:
227 assert(Type == RT32_32);
229 return ELF::R_386_TLS_LE;
230 case MCSymbolRefExpr::VK_GOTNTPOFF:
231 assert(Type == RT32_32);
233 return ELF::R_386_TLS_GOTIE;
234 case MCSymbolRefExpr::VK_TLSLDM:
235 assert(Type == RT32_32);
237 return ELF::R_386_TLS_LDM;
241 unsigned X86ELFObjectWriter::GetRelocType(const MCValue &Target,
242 const MCFixup &Fixup,
243 bool IsPCRel) const {
244 MCSymbolRefExpr::VariantKind Modifier = Target.getAccessVariant();
245 X86_64RelType Type = getType64(Fixup.getKind(), Modifier, IsPCRel);
246 if (getEMachine() == ELF::EM_X86_64)
247 return getRelocType64(Modifier, Type, IsPCRel);
249 assert(getEMachine() == ELF::EM_386 && "Unsupported ELF machine type.");
250 return getRelocType32(Modifier, getType32(Type), IsPCRel);
253 MCObjectWriter *llvm::createX86ELFObjectWriter(raw_pwrite_stream &OS,
254 bool IsELF64, uint8_t OSABI,
256 MCELFObjectTargetWriter *MOTW =
257 new X86ELFObjectWriter(IsELF64, OSABI, EMachine);
258 return createELFObjectWriter(MOTW, OS, /*IsLittleEndian=*/true);