1 //===-- PPCELFObjectWriter.cpp - PPC ELF Writer ---------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 #include "MCTargetDesc/PPCMCTargetDesc.h" 11 #include "MCTargetDesc/PPCFixupKinds.h" 12 #include "MCTargetDesc/PPCMCExpr.h" 13 #include "llvm/ADT/STLExtras.h" 14 #include "llvm/MC/MCELFObjectWriter.h" 15 #include "llvm/MC/MCExpr.h" 16 #include "llvm/MC/MCValue.h" 17 #include "llvm/Support/ErrorHandling.h" 18 19 using namespace llvm; 20 21 namespace { 22 class PPCELFObjectWriter : public MCELFObjectTargetWriter { 23 public: 24 PPCELFObjectWriter(bool Is64Bit, uint8_t OSABI); 25 26 virtual ~PPCELFObjectWriter(); 27 protected: 28 virtual unsigned getRelocTypeInner(const MCValue &Target, 29 const MCFixup &Fixup, 30 bool IsPCRel) const; 31 virtual unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup, 32 bool IsPCRel, bool IsRelocWithSymbol, 33 int64_t Addend) const; 34 virtual const MCSymbol *ExplicitRelSym(const MCAssembler &Asm, 35 const MCValue &Target, 36 const MCFragment &F, 37 const MCFixup &Fixup, 38 bool IsPCRel) const; 39 virtual const MCSymbol *undefinedExplicitRelSym(const MCValue &Target, 40 const MCFixup &Fixup, 41 bool IsPCRel) const; 42 }; 43 } 44 45 PPCELFObjectWriter::PPCELFObjectWriter(bool Is64Bit, uint8_t OSABI) 46 : MCELFObjectTargetWriter(Is64Bit, OSABI, 47 Is64Bit ? ELF::EM_PPC64 : ELF::EM_PPC, 48 /*HasRelocationAddend*/ true) {} 49 50 PPCELFObjectWriter::~PPCELFObjectWriter() { 51 } 52 53 static MCSymbolRefExpr::VariantKind getAccessVariant(const MCFixup &Fixup) { 54 const MCExpr *Expr = Fixup.getValue(); 55 56 if (Expr->getKind() != MCExpr::Target) 57 return Fixup.getAccessVariant(); 58 59 switch (cast<PPCMCExpr>(Expr)->getKind()) { 60 case PPCMCExpr::VK_PPC_None: 61 return MCSymbolRefExpr::VK_None; 62 case PPCMCExpr::VK_PPC_LO: 63 return MCSymbolRefExpr::VK_PPC_LO; 64 case PPCMCExpr::VK_PPC_HI: 65 return MCSymbolRefExpr::VK_PPC_HI; 66 case PPCMCExpr::VK_PPC_HA: 67 return MCSymbolRefExpr::VK_PPC_HA; 68 case PPCMCExpr::VK_PPC_HIGHERA: 69 return MCSymbolRefExpr::VK_PPC_HIGHERA; 70 case PPCMCExpr::VK_PPC_HIGHER: 71 return MCSymbolRefExpr::VK_PPC_HIGHER; 72 case PPCMCExpr::VK_PPC_HIGHEST: 73 return MCSymbolRefExpr::VK_PPC_HIGHEST; 74 case PPCMCExpr::VK_PPC_HIGHESTA: 75 return MCSymbolRefExpr::VK_PPC_HIGHESTA; 76 } 77 llvm_unreachable("unknown PPCMCExpr kind"); 78 } 79 80 unsigned PPCELFObjectWriter::getRelocTypeInner(const MCValue &Target, 81 const MCFixup &Fixup, 82 bool IsPCRel) const 83 { 84 MCSymbolRefExpr::VariantKind Modifier = getAccessVariant(Fixup); 85 86 // determine the type of the relocation 87 unsigned Type; 88 if (IsPCRel) { 89 switch ((unsigned)Fixup.getKind()) { 90 default: 91 llvm_unreachable("Unimplemented"); 92 case PPC::fixup_ppc_br24: 93 case PPC::fixup_ppc_br24abs: 94 Type = ELF::R_PPC_REL24; 95 break; 96 case PPC::fixup_ppc_brcond14: 97 case PPC::fixup_ppc_brcond14abs: 98 Type = ELF::R_PPC_REL14; 99 break; 100 case PPC::fixup_ppc_half16: 101 switch (Modifier) { 102 default: llvm_unreachable("Unsupported Modifier"); 103 case MCSymbolRefExpr::VK_None: 104 Type = ELF::R_PPC_REL16; 105 break; 106 case MCSymbolRefExpr::VK_PPC_LO: 107 Type = ELF::R_PPC_REL16_LO; 108 break; 109 case MCSymbolRefExpr::VK_PPC_HI: 110 Type = ELF::R_PPC_REL16_HI; 111 break; 112 case MCSymbolRefExpr::VK_PPC_HA: 113 Type = ELF::R_PPC_REL16_HA; 114 break; 115 } 116 break; 117 case FK_Data_4: 118 case FK_PCRel_4: 119 Type = ELF::R_PPC_REL32; 120 break; 121 case FK_Data_8: 122 case FK_PCRel_8: 123 Type = ELF::R_PPC64_REL64; 124 break; 125 } 126 } else { 127 switch ((unsigned)Fixup.getKind()) { 128 default: llvm_unreachable("invalid fixup kind!"); 129 case PPC::fixup_ppc_br24abs: 130 Type = ELF::R_PPC_ADDR24; 131 break; 132 case PPC::fixup_ppc_brcond14abs: 133 Type = ELF::R_PPC_ADDR14; // XXX: or BRNTAKEN?_ 134 break; 135 case PPC::fixup_ppc_half16: 136 switch (Modifier) { 137 default: llvm_unreachable("Unsupported Modifier"); 138 case MCSymbolRefExpr::VK_None: 139 Type = ELF::R_PPC_ADDR16; 140 break; 141 case MCSymbolRefExpr::VK_PPC_LO: 142 Type = ELF::R_PPC_ADDR16_LO; 143 break; 144 case MCSymbolRefExpr::VK_PPC_HI: 145 Type = ELF::R_PPC_ADDR16_HI; 146 break; 147 case MCSymbolRefExpr::VK_PPC_HA: 148 Type = ELF::R_PPC_ADDR16_HA; 149 break; 150 case MCSymbolRefExpr::VK_PPC_HIGHER: 151 Type = ELF::R_PPC64_ADDR16_HIGHER; 152 break; 153 case MCSymbolRefExpr::VK_PPC_HIGHERA: 154 Type = ELF::R_PPC64_ADDR16_HIGHERA; 155 break; 156 case MCSymbolRefExpr::VK_PPC_HIGHEST: 157 Type = ELF::R_PPC64_ADDR16_HIGHEST; 158 break; 159 case MCSymbolRefExpr::VK_PPC_HIGHESTA: 160 Type = ELF::R_PPC64_ADDR16_HIGHESTA; 161 break; 162 case MCSymbolRefExpr::VK_GOT: 163 Type = ELF::R_PPC_GOT16; 164 break; 165 case MCSymbolRefExpr::VK_PPC_GOT_LO: 166 Type = ELF::R_PPC_GOT16_LO; 167 break; 168 case MCSymbolRefExpr::VK_PPC_GOT_HI: 169 Type = ELF::R_PPC_GOT16_HI; 170 break; 171 case MCSymbolRefExpr::VK_PPC_GOT_HA: 172 Type = ELF::R_PPC_GOT16_HA; 173 break; 174 case MCSymbolRefExpr::VK_PPC_TOC: 175 Type = ELF::R_PPC64_TOC16; 176 break; 177 case MCSymbolRefExpr::VK_PPC_TOC_LO: 178 Type = ELF::R_PPC64_TOC16_LO; 179 break; 180 case MCSymbolRefExpr::VK_PPC_TOC_HI: 181 Type = ELF::R_PPC64_TOC16_HI; 182 break; 183 case MCSymbolRefExpr::VK_PPC_TOC_HA: 184 Type = ELF::R_PPC64_TOC16_HA; 185 break; 186 case MCSymbolRefExpr::VK_PPC_TPREL: 187 Type = ELF::R_PPC_TPREL16; 188 break; 189 case MCSymbolRefExpr::VK_PPC_TPREL_LO: 190 Type = ELF::R_PPC_TPREL16_LO; 191 break; 192 case MCSymbolRefExpr::VK_PPC_TPREL_HI: 193 Type = ELF::R_PPC_TPREL16_HI; 194 break; 195 case MCSymbolRefExpr::VK_PPC_TPREL_HA: 196 Type = ELF::R_PPC_TPREL16_HA; 197 break; 198 case MCSymbolRefExpr::VK_PPC_TPREL_HIGHER: 199 Type = ELF::R_PPC64_TPREL16_HIGHER; 200 break; 201 case MCSymbolRefExpr::VK_PPC_TPREL_HIGHERA: 202 Type = ELF::R_PPC64_TPREL16_HIGHERA; 203 break; 204 case MCSymbolRefExpr::VK_PPC_TPREL_HIGHEST: 205 Type = ELF::R_PPC64_TPREL16_HIGHEST; 206 break; 207 case MCSymbolRefExpr::VK_PPC_TPREL_HIGHESTA: 208 Type = ELF::R_PPC64_TPREL16_HIGHESTA; 209 break; 210 case MCSymbolRefExpr::VK_PPC_DTPREL: 211 Type = ELF::R_PPC64_DTPREL16; 212 break; 213 case MCSymbolRefExpr::VK_PPC_DTPREL_LO: 214 Type = ELF::R_PPC64_DTPREL16_LO; 215 break; 216 case MCSymbolRefExpr::VK_PPC_DTPREL_HI: 217 Type = ELF::R_PPC64_DTPREL16_HI; 218 break; 219 case MCSymbolRefExpr::VK_PPC_DTPREL_HA: 220 Type = ELF::R_PPC64_DTPREL16_HA; 221 break; 222 case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHER: 223 Type = ELF::R_PPC64_DTPREL16_HIGHER; 224 break; 225 case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHERA: 226 Type = ELF::R_PPC64_DTPREL16_HIGHERA; 227 break; 228 case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHEST: 229 Type = ELF::R_PPC64_DTPREL16_HIGHEST; 230 break; 231 case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHESTA: 232 Type = ELF::R_PPC64_DTPREL16_HIGHESTA; 233 break; 234 case MCSymbolRefExpr::VK_PPC_GOT_TLSGD: 235 Type = ELF::R_PPC64_GOT_TLSGD16; 236 break; 237 case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_LO: 238 Type = ELF::R_PPC64_GOT_TLSGD16_LO; 239 break; 240 case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_HI: 241 Type = ELF::R_PPC64_GOT_TLSGD16_HI; 242 break; 243 case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_HA: 244 Type = ELF::R_PPC64_GOT_TLSGD16_HA; 245 break; 246 case MCSymbolRefExpr::VK_PPC_GOT_TLSLD: 247 Type = ELF::R_PPC64_GOT_TLSLD16; 248 break; 249 case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_LO: 250 Type = ELF::R_PPC64_GOT_TLSLD16_LO; 251 break; 252 case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_HI: 253 Type = ELF::R_PPC64_GOT_TLSLD16_HI; 254 break; 255 case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_HA: 256 Type = ELF::R_PPC64_GOT_TLSLD16_HA; 257 break; 258 case MCSymbolRefExpr::VK_PPC_GOT_TPREL: 259 /* We don't have R_PPC64_GOT_TPREL16, but since GOT offsets 260 are always 4-aligned, we can use R_PPC64_GOT_TPREL16_DS. */ 261 Type = ELF::R_PPC64_GOT_TPREL16_DS; 262 break; 263 case MCSymbolRefExpr::VK_PPC_GOT_TPREL_LO: 264 /* We don't have R_PPC64_GOT_TPREL16_LO, but since GOT offsets 265 are always 4-aligned, we can use R_PPC64_GOT_TPREL16_LO_DS. */ 266 Type = ELF::R_PPC64_GOT_TPREL16_LO_DS; 267 break; 268 case MCSymbolRefExpr::VK_PPC_GOT_TPREL_HI: 269 Type = ELF::R_PPC64_GOT_TPREL16_HI; 270 break; 271 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL: 272 /* We don't have R_PPC64_GOT_DTPREL16, but since GOT offsets 273 are always 4-aligned, we can use R_PPC64_GOT_DTPREL16_DS. */ 274 Type = ELF::R_PPC64_GOT_DTPREL16_DS; 275 break; 276 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_LO: 277 /* We don't have R_PPC64_GOT_DTPREL16_LO, but since GOT offsets 278 are always 4-aligned, we can use R_PPC64_GOT_DTPREL16_LO_DS. */ 279 Type = ELF::R_PPC64_GOT_DTPREL16_LO_DS; 280 break; 281 case MCSymbolRefExpr::VK_PPC_GOT_TPREL_HA: 282 Type = ELF::R_PPC64_GOT_TPREL16_HA; 283 break; 284 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_HI: 285 Type = ELF::R_PPC64_GOT_DTPREL16_HI; 286 break; 287 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_HA: 288 Type = ELF::R_PPC64_GOT_DTPREL16_HA; 289 break; 290 } 291 break; 292 case PPC::fixup_ppc_half16ds: 293 switch (Modifier) { 294 default: llvm_unreachable("Unsupported Modifier"); 295 case MCSymbolRefExpr::VK_None: 296 Type = ELF::R_PPC64_ADDR16_DS; 297 break; 298 case MCSymbolRefExpr::VK_PPC_LO: 299 Type = ELF::R_PPC64_ADDR16_LO_DS; 300 break; 301 case MCSymbolRefExpr::VK_GOT: 302 Type = ELF::R_PPC64_GOT16_DS; 303 break; 304 case MCSymbolRefExpr::VK_PPC_GOT_LO: 305 Type = ELF::R_PPC64_GOT16_LO_DS; 306 break; 307 case MCSymbolRefExpr::VK_PPC_TOC: 308 Type = ELF::R_PPC64_TOC16_DS; 309 break; 310 case MCSymbolRefExpr::VK_PPC_TOC_LO: 311 Type = ELF::R_PPC64_TOC16_LO_DS; 312 break; 313 case MCSymbolRefExpr::VK_PPC_TPREL: 314 Type = ELF::R_PPC64_TPREL16_DS; 315 break; 316 case MCSymbolRefExpr::VK_PPC_TPREL_LO: 317 Type = ELF::R_PPC64_TPREL16_LO_DS; 318 break; 319 case MCSymbolRefExpr::VK_PPC_DTPREL: 320 Type = ELF::R_PPC64_DTPREL16_DS; 321 break; 322 case MCSymbolRefExpr::VK_PPC_DTPREL_LO: 323 Type = ELF::R_PPC64_DTPREL16_LO_DS; 324 break; 325 case MCSymbolRefExpr::VK_PPC_GOT_TPREL: 326 Type = ELF::R_PPC64_GOT_TPREL16_DS; 327 break; 328 case MCSymbolRefExpr::VK_PPC_GOT_TPREL_LO: 329 Type = ELF::R_PPC64_GOT_TPREL16_LO_DS; 330 break; 331 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL: 332 Type = ELF::R_PPC64_GOT_DTPREL16_DS; 333 break; 334 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_LO: 335 Type = ELF::R_PPC64_GOT_DTPREL16_LO_DS; 336 break; 337 } 338 break; 339 case PPC::fixup_ppc_nofixup: 340 switch (Modifier) { 341 default: llvm_unreachable("Unsupported Modifier"); 342 case MCSymbolRefExpr::VK_PPC_TLSGD: 343 Type = ELF::R_PPC64_TLSGD; 344 break; 345 case MCSymbolRefExpr::VK_PPC_TLSLD: 346 Type = ELF::R_PPC64_TLSLD; 347 break; 348 case MCSymbolRefExpr::VK_PPC_TLS: 349 Type = ELF::R_PPC64_TLS; 350 break; 351 } 352 break; 353 case FK_Data_8: 354 switch (Modifier) { 355 default: llvm_unreachable("Unsupported Modifier"); 356 case MCSymbolRefExpr::VK_PPC_TOCBASE: 357 Type = ELF::R_PPC64_TOC; 358 break; 359 case MCSymbolRefExpr::VK_None: 360 Type = ELF::R_PPC64_ADDR64; 361 break; 362 case MCSymbolRefExpr::VK_PPC_DTPMOD: 363 Type = ELF::R_PPC64_DTPMOD64; 364 break; 365 case MCSymbolRefExpr::VK_PPC_TPREL: 366 Type = ELF::R_PPC64_TPREL64; 367 break; 368 case MCSymbolRefExpr::VK_PPC_DTPREL: 369 Type = ELF::R_PPC64_DTPREL64; 370 break; 371 } 372 break; 373 case FK_Data_4: 374 Type = ELF::R_PPC_ADDR32; 375 break; 376 case FK_Data_2: 377 Type = ELF::R_PPC_ADDR16; 378 break; 379 } 380 } 381 return Type; 382 } 383 384 unsigned PPCELFObjectWriter::GetRelocType(const MCValue &Target, 385 const MCFixup &Fixup, 386 bool IsPCRel, 387 bool IsRelocWithSymbol, 388 int64_t Addend) const { 389 return getRelocTypeInner(Target, Fixup, IsPCRel); 390 } 391 392 const MCSymbol *PPCELFObjectWriter::ExplicitRelSym(const MCAssembler &Asm, 393 const MCValue &Target, 394 const MCFragment &F, 395 const MCFixup &Fixup, 396 bool IsPCRel) const { 397 assert(Target.getSymA() && "SymA cannot be 0"); 398 MCSymbolRefExpr::VariantKind Modifier = Fixup.getAccessVariant(); 399 400 bool EmitThisSym; 401 switch (Modifier) { 402 // GOT references always need a relocation, even if the 403 // target symbol is local. 404 case MCSymbolRefExpr::VK_GOT: 405 case MCSymbolRefExpr::VK_PPC_GOT_LO: 406 case MCSymbolRefExpr::VK_PPC_GOT_HI: 407 case MCSymbolRefExpr::VK_PPC_GOT_HA: 408 EmitThisSym = true; 409 break; 410 default: 411 EmitThisSym = false; 412 break; 413 } 414 415 if (EmitThisSym) 416 return &Target.getSymA()->getSymbol().AliasedSymbol(); 417 return NULL; 418 } 419 420 const MCSymbol *PPCELFObjectWriter::undefinedExplicitRelSym(const MCValue &Target, 421 const MCFixup &Fixup, 422 bool IsPCRel) const { 423 assert(Target.getSymA() && "SymA cannot be 0"); 424 const MCSymbol &Symbol = Target.getSymA()->getSymbol().AliasedSymbol(); 425 426 unsigned RelocType = getRelocTypeInner(Target, Fixup, IsPCRel); 427 428 // The .odp creation emits a relocation against the symbol ".TOC." which 429 // create a R_PPC64_TOC relocation. However the relocation symbol name 430 // in final object creation should be NULL, since the symbol does not 431 // really exist, it is just the reference to TOC base for the current 432 // object file. 433 bool EmitThisSym = RelocType != ELF::R_PPC64_TOC; 434 435 if (EmitThisSym && !Symbol.isTemporary()) 436 return &Symbol; 437 return NULL; 438 } 439 440 MCObjectWriter *llvm::createPPCELFObjectWriter(raw_ostream &OS, 441 bool Is64Bit, 442 bool IsLittleEndian, 443 uint8_t OSABI) { 444 MCELFObjectTargetWriter *MOTW = new PPCELFObjectWriter(Is64Bit, OSABI); 445 return createELFObjectWriter(MOTW, OS, IsLittleEndian); 446 } 447