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:
77 static unsigned getRelocType64(MCSymbolRefExpr::VariantKind Modifier,
78 X86_64RelType Type, bool IsPCRel) {
81 llvm_unreachable("Unimplemented");
82 case MCSymbolRefExpr::VK_None:
85 return IsPCRel ? ELF::R_X86_64_PC64 : ELF::R_X86_64_64;
87 return IsPCRel ? ELF::R_X86_64_PC32 : ELF::R_X86_64_32;
89 return ELF::R_X86_64_32S;
91 return IsPCRel ? ELF::R_X86_64_PC16 : ELF::R_X86_64_16;
93 return IsPCRel ? ELF::R_X86_64_PC8 : ELF::R_X86_64_8;
95 case MCSymbolRefExpr::VK_GOT:
98 return IsPCRel ? ELF::R_X86_64_GOTPC64 : ELF::R_X86_64_GOT64;
100 return IsPCRel ? ELF::R_X86_64_GOTPC32 : ELF::R_X86_64_GOT32;
104 llvm_unreachable("Unimplemented");
106 case MCSymbolRefExpr::VK_GOTOFF:
107 assert(Type == RT64_64);
109 return ELF::R_X86_64_GOTOFF64;
110 case MCSymbolRefExpr::VK_TPOFF:
114 return ELF::R_X86_64_TPOFF64;
116 return ELF::R_X86_64_TPOFF32;
120 llvm_unreachable("Unimplemented");
122 case MCSymbolRefExpr::VK_DTPOFF:
126 return ELF::R_X86_64_DTPOFF64;
128 return ELF::R_X86_64_DTPOFF32;
132 llvm_unreachable("Unimplemented");
134 case MCSymbolRefExpr::VK_SIZE:
138 return ELF::R_X86_64_SIZE64;
140 return ELF::R_X86_64_SIZE32;
144 llvm_unreachable("Unimplemented");
146 case MCSymbolRefExpr::VK_TLSGD:
147 assert(Type == RT64_32);
148 return ELF::R_X86_64_TLSGD;
149 case MCSymbolRefExpr::VK_GOTTPOFF:
150 assert(Type == RT64_32);
151 return ELF::R_X86_64_GOTTPOFF;
152 case MCSymbolRefExpr::VK_TLSLD:
153 assert(Type == RT64_32);
154 return ELF::R_X86_64_TLSLD;
155 case MCSymbolRefExpr::VK_PLT:
156 assert(Type == RT64_32);
157 return ELF::R_X86_64_PLT32;
158 case MCSymbolRefExpr::VK_GOTPCREL:
159 assert(Type == RT64_32);
160 return ELF::R_X86_64_GOTPCREL;
164 enum X86_32RelType { RT32_32, RT32_16, RT32_8 };
166 static X86_32RelType getType32(X86_64RelType T) {
169 llvm_unreachable("Unimplemented");
178 llvm_unreachable("unexpected relocation type!");
181 static unsigned getRelocType32(MCSymbolRefExpr::VariantKind Modifier,
182 X86_32RelType Type, bool IsPCRel) {
185 llvm_unreachable("Unimplemented");
186 case MCSymbolRefExpr::VK_None:
189 return IsPCRel ? ELF::R_386_PC32 : ELF::R_386_32;
191 return IsPCRel ? ELF::R_386_PC16 : ELF::R_386_16;
193 return IsPCRel ? ELF::R_386_PC8 : ELF::R_386_8;
195 case MCSymbolRefExpr::VK_GOT:
196 assert(Type == RT32_32);
197 return IsPCRel ? ELF::R_386_GOTPC : ELF::R_386_GOT32;
198 case MCSymbolRefExpr::VK_GOTOFF:
199 assert(Type == RT32_32);
201 return ELF::R_386_GOTOFF;
202 case MCSymbolRefExpr::VK_TPOFF:
203 assert(Type == RT32_32);
205 return ELF::R_386_TLS_LE_32;
206 case MCSymbolRefExpr::VK_DTPOFF:
207 assert(Type == RT32_32);
209 return ELF::R_386_TLS_LDO_32;
210 case MCSymbolRefExpr::VK_TLSGD:
211 assert(Type == RT32_32);
213 return ELF::R_386_TLS_GD;
214 case MCSymbolRefExpr::VK_GOTTPOFF:
215 assert(Type == RT32_32);
217 return ELF::R_386_TLS_IE_32;
218 case MCSymbolRefExpr::VK_PLT:
219 assert(Type == RT32_32);
220 return ELF::R_386_PLT32;
221 case MCSymbolRefExpr::VK_INDNTPOFF:
222 assert(Type == RT32_32);
224 return ELF::R_386_TLS_IE;
225 case MCSymbolRefExpr::VK_NTPOFF:
226 assert(Type == RT32_32);
228 return ELF::R_386_TLS_LE;
229 case MCSymbolRefExpr::VK_GOTNTPOFF:
230 assert(Type == RT32_32);
232 return ELF::R_386_TLS_GOTIE;
233 case MCSymbolRefExpr::VK_TLSLDM:
234 assert(Type == RT32_32);
236 return ELF::R_386_TLS_LDM;
240 unsigned X86ELFObjectWriter::GetRelocType(const MCValue &Target,
241 const MCFixup &Fixup,
242 bool IsPCRel) const {
243 MCSymbolRefExpr::VariantKind Modifier = Target.getAccessVariant();
244 X86_64RelType Type = getType64(Fixup.getKind(), Modifier, IsPCRel);
245 if (getEMachine() == ELF::EM_X86_64)
246 return getRelocType64(Modifier, Type, IsPCRel);
248 assert(getEMachine() == ELF::EM_386 && "Unsupported ELF machine type.");
249 return getRelocType32(Modifier, getType32(Type), IsPCRel);
252 MCObjectWriter *llvm::createX86ELFObjectWriter(raw_pwrite_stream &OS,
253 bool IsELF64, uint8_t OSABI,
255 MCELFObjectTargetWriter *MOTW =
256 new X86ELFObjectWriter(IsELF64, OSABI, EMachine);
257 return createELFObjectWriter(MOTW, OS, /*IsLittleEndian=*/true);