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 virtual unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup,
28 bool IsPCRel, bool IsRelocWithSymbol,
29 int64_t Addend) const;
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 unsigned X86ELFObjectWriter::GetRelocType(const MCValue &Target,
45 bool IsRelocWithSymbol,
46 int64_t Addend) const {
47 // determine the type of the relocation
49 MCSymbolRefExpr::VariantKind Modifier = Target.isAbsolute() ?
50 MCSymbolRefExpr::VK_None : Target.getSymA()->getKind();
52 if (getEMachine() == ELF::EM_X86_64) {
54 switch ((unsigned)Fixup.getKind()) {
55 default: llvm_unreachable("invalid fixup kind!");
57 case FK_Data_8: Type = ELF::R_X86_64_PC64; break;
58 case FK_Data_4: Type = ELF::R_X86_64_PC32; break;
59 case FK_Data_2: Type = ELF::R_X86_64_PC16; break;
62 assert(Modifier == MCSymbolRefExpr::VK_None);
63 Type = ELF::R_X86_64_PC64;
65 case X86::reloc_signed_4byte:
66 case X86::reloc_riprel_4byte_movq_load:
67 case X86::reloc_riprel_4byte:
71 llvm_unreachable("Unimplemented");
72 case MCSymbolRefExpr::VK_None:
73 Type = ELF::R_X86_64_PC32;
75 case MCSymbolRefExpr::VK_PLT:
76 Type = ELF::R_X86_64_PLT32;
78 case MCSymbolRefExpr::VK_GOTPCREL:
79 Type = ELF::R_X86_64_GOTPCREL;
81 case MCSymbolRefExpr::VK_GOTTPOFF:
82 Type = ELF::R_X86_64_GOTTPOFF;
84 case MCSymbolRefExpr::VK_TLSGD:
85 Type = ELF::R_X86_64_TLSGD;
87 case MCSymbolRefExpr::VK_TLSLD:
88 Type = ELF::R_X86_64_TLSLD;
93 assert(Modifier == MCSymbolRefExpr::VK_None);
94 Type = ELF::R_X86_64_PC16;
97 assert(Modifier == MCSymbolRefExpr::VK_None);
98 Type = ELF::R_X86_64_PC8;
102 switch ((unsigned)Fixup.getKind()) {
103 default: llvm_unreachable("invalid fixup kind!");
104 case FK_Data_8: Type = ELF::R_X86_64_64; break;
105 case X86::reloc_signed_4byte:
108 llvm_unreachable("Unimplemented");
109 case MCSymbolRefExpr::VK_None:
110 Type = ELF::R_X86_64_32S;
112 case MCSymbolRefExpr::VK_GOT:
113 Type = ELF::R_X86_64_GOT32;
115 case MCSymbolRefExpr::VK_GOTPCREL:
116 Type = ELF::R_X86_64_GOTPCREL;
118 case MCSymbolRefExpr::VK_TPOFF:
119 Type = ELF::R_X86_64_TPOFF32;
121 case MCSymbolRefExpr::VK_DTPOFF:
122 Type = ELF::R_X86_64_DTPOFF32;
127 Type = ELF::R_X86_64_32;
129 case FK_Data_2: Type = ELF::R_X86_64_16; break;
131 case FK_Data_1: Type = ELF::R_X86_64_8; break;
134 } else if (getEMachine() == ELF::EM_386) {
136 switch ((unsigned)Fixup.getKind()) {
137 default: llvm_unreachable("invalid fixup kind!");
139 case X86::reloc_global_offset_table:
140 Type = ELF::R_386_GOTPC;
143 case X86::reloc_signed_4byte:
148 llvm_unreachable("Unimplemented");
149 case MCSymbolRefExpr::VK_None:
150 Type = ELF::R_386_PC32;
152 case MCSymbolRefExpr::VK_PLT:
153 Type = ELF::R_386_PLT32;
159 switch ((unsigned)Fixup.getKind()) {
160 default: llvm_unreachable("invalid fixup kind!");
162 case X86::reloc_global_offset_table:
163 Type = ELF::R_386_GOTPC;
166 // FIXME: Should we avoid selecting reloc_signed_4byte in 32 bit mode
168 case X86::reloc_signed_4byte:
173 llvm_unreachable("Unimplemented");
174 case MCSymbolRefExpr::VK_None:
175 Type = ELF::R_386_32;
177 case MCSymbolRefExpr::VK_GOT:
178 Type = ELF::R_386_GOT32;
180 case MCSymbolRefExpr::VK_GOTOFF:
181 Type = ELF::R_386_GOTOFF;
183 case MCSymbolRefExpr::VK_TLSGD:
184 Type = ELF::R_386_TLS_GD;
186 case MCSymbolRefExpr::VK_TPOFF:
187 Type = ELF::R_386_TLS_LE_32;
189 case MCSymbolRefExpr::VK_INDNTPOFF:
190 Type = ELF::R_386_TLS_IE;
192 case MCSymbolRefExpr::VK_NTPOFF:
193 Type = ELF::R_386_TLS_LE;
195 case MCSymbolRefExpr::VK_GOTNTPOFF:
196 Type = ELF::R_386_TLS_GOTIE;
198 case MCSymbolRefExpr::VK_TLSLDM:
199 Type = ELF::R_386_TLS_LDM;
201 case MCSymbolRefExpr::VK_DTPOFF:
202 Type = ELF::R_386_TLS_LDO_32;
204 case MCSymbolRefExpr::VK_GOTTPOFF:
205 Type = ELF::R_386_TLS_IE_32;
209 case FK_Data_2: Type = ELF::R_386_16; break;
211 case FK_Data_1: Type = ELF::R_386_8; break;
215 llvm_unreachable("Unsupported ELF machine type.");
220 MCObjectWriter *llvm::createX86ELFObjectWriter(raw_ostream &OS,
224 MCELFObjectTargetWriter *MOTW =
225 new X86ELFObjectWriter(IsELF64, OSABI, EMachine);
226 return createELFObjectWriter(MOTW, OS, /*IsLittleEndian=*/true);