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/MCELF.h" 15 #include "llvm/MC/MCELFObjectWriter.h" 16 #include "llvm/MC/MCExpr.h" 17 #include "llvm/MC/MCValue.h" 18 #include "llvm/Support/ErrorHandling.h" 19 20 using namespace llvm; 21 22 namespace { 23 class PPCELFObjectWriter : public MCELFObjectTargetWriter { 24 public: 25 PPCELFObjectWriter(bool Is64Bit, uint8_t OSABI); 26 27 virtual ~PPCELFObjectWriter(); 28 protected: 29 virtual unsigned getRelocTypeInner(const MCValue &Target, 30 const MCFixup &Fixup, 31 bool IsPCRel) const; 32 unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup, 33 bool IsPCRel) const override; 34 35 bool needsRelocateWithSymbol(const MCSymbolData &SD, 36 unsigned Type) const override; 37 }; 38 } 39 40 PPCELFObjectWriter::PPCELFObjectWriter(bool Is64Bit, uint8_t OSABI) 41 : MCELFObjectTargetWriter(Is64Bit, OSABI, 42 Is64Bit ? ELF::EM_PPC64 : ELF::EM_PPC, 43 /*HasRelocationAddend*/ true) {} 44 45 PPCELFObjectWriter::~PPCELFObjectWriter() { 46 } 47 48 static MCSymbolRefExpr::VariantKind getAccessVariant(const MCValue &Target, 49 const MCFixup &Fixup) { 50 const MCExpr *Expr = Fixup.getValue(); 51 52 if (Expr->getKind() != MCExpr::Target) 53 return Target.getAccessVariant(); 54 55 switch (cast<PPCMCExpr>(Expr)->getKind()) { 56 case PPCMCExpr::VK_PPC_None: 57 return MCSymbolRefExpr::VK_None; 58 case PPCMCExpr::VK_PPC_LO: 59 return MCSymbolRefExpr::VK_PPC_LO; 60 case PPCMCExpr::VK_PPC_HI: 61 return MCSymbolRefExpr::VK_PPC_HI; 62 case PPCMCExpr::VK_PPC_HA: 63 return MCSymbolRefExpr::VK_PPC_HA; 64 case PPCMCExpr::VK_PPC_HIGHERA: 65 return MCSymbolRefExpr::VK_PPC_HIGHERA; 66 case PPCMCExpr::VK_PPC_HIGHER: 67 return MCSymbolRefExpr::VK_PPC_HIGHER; 68 case PPCMCExpr::VK_PPC_HIGHEST: 69 return MCSymbolRefExpr::VK_PPC_HIGHEST; 70 case PPCMCExpr::VK_PPC_HIGHESTA: 71 return MCSymbolRefExpr::VK_PPC_HIGHESTA; 72 } 73 llvm_unreachable("unknown PPCMCExpr kind"); 74 } 75 76 unsigned PPCELFObjectWriter::getRelocTypeInner(const MCValue &Target, 77 const MCFixup &Fixup, 78 bool IsPCRel) const 79 { 80 MCSymbolRefExpr::VariantKind Modifier = getAccessVariant(Target, Fixup); 81 82 // determine the type of the relocation 83 unsigned Type; 84 if (IsPCRel) { 85 switch ((unsigned)Fixup.getKind()) { 86 default: 87 llvm_unreachable("Unimplemented"); 88 case PPC::fixup_ppc_br24: 89 case PPC::fixup_ppc_br24abs: 90 switch (Modifier) { 91 default: llvm_unreachable("Unsupported Modifier"); 92 case MCSymbolRefExpr::VK_None: 93 Type = ELF::R_PPC_REL24; 94 break; 95 case MCSymbolRefExpr::VK_PLT: 96 Type = ELF::R_PPC_PLTREL24; 97 break; 98 } 99 break; 100 case PPC::fixup_ppc_brcond14: 101 case PPC::fixup_ppc_brcond14abs: 102 Type = ELF::R_PPC_REL14; 103 break; 104 case PPC::fixup_ppc_half16: 105 switch (Modifier) { 106 default: llvm_unreachable("Unsupported Modifier"); 107 case MCSymbolRefExpr::VK_None: 108 Type = ELF::R_PPC_REL16; 109 break; 110 case MCSymbolRefExpr::VK_PPC_LO: 111 Type = ELF::R_PPC_REL16_LO; 112 break; 113 case MCSymbolRefExpr::VK_PPC_HI: 114 Type = ELF::R_PPC_REL16_HI; 115 break; 116 case MCSymbolRefExpr::VK_PPC_HA: 117 Type = ELF::R_PPC_REL16_HA; 118 break; 119 } 120 break; 121 case FK_Data_4: 122 case FK_PCRel_4: 123 Type = ELF::R_PPC_REL32; 124 break; 125 case FK_Data_8: 126 case FK_PCRel_8: 127 Type = ELF::R_PPC64_REL64; 128 break; 129 } 130 } else { 131 switch ((unsigned)Fixup.getKind()) { 132 default: llvm_unreachable("invalid fixup kind!"); 133 case PPC::fixup_ppc_br24abs: 134 Type = ELF::R_PPC_ADDR24; 135 break; 136 case PPC::fixup_ppc_brcond14abs: 137 Type = ELF::R_PPC_ADDR14; // XXX: or BRNTAKEN?_ 138 break; 139 case PPC::fixup_ppc_half16: 140 switch (Modifier) { 141 default: llvm_unreachable("Unsupported Modifier"); 142 case MCSymbolRefExpr::VK_None: 143 Type = ELF::R_PPC_ADDR16; 144 break; 145 case MCSymbolRefExpr::VK_PPC_LO: 146 Type = ELF::R_PPC_ADDR16_LO; 147 break; 148 case MCSymbolRefExpr::VK_PPC_HI: 149 Type = ELF::R_PPC_ADDR16_HI; 150 break; 151 case MCSymbolRefExpr::VK_PPC_HA: 152 Type = ELF::R_PPC_ADDR16_HA; 153 break; 154 case MCSymbolRefExpr::VK_PPC_HIGHER: 155 Type = ELF::R_PPC64_ADDR16_HIGHER; 156 break; 157 case MCSymbolRefExpr::VK_PPC_HIGHERA: 158 Type = ELF::R_PPC64_ADDR16_HIGHERA; 159 break; 160 case MCSymbolRefExpr::VK_PPC_HIGHEST: 161 Type = ELF::R_PPC64_ADDR16_HIGHEST; 162 break; 163 case MCSymbolRefExpr::VK_PPC_HIGHESTA: 164 Type = ELF::R_PPC64_ADDR16_HIGHESTA; 165 break; 166 case MCSymbolRefExpr::VK_GOT: 167 Type = ELF::R_PPC_GOT16; 168 break; 169 case MCSymbolRefExpr::VK_PPC_GOT_LO: 170 Type = ELF::R_PPC_GOT16_LO; 171 break; 172 case MCSymbolRefExpr::VK_PPC_GOT_HI: 173 Type = ELF::R_PPC_GOT16_HI; 174 break; 175 case MCSymbolRefExpr::VK_PPC_GOT_HA: 176 Type = ELF::R_PPC_GOT16_HA; 177 break; 178 case MCSymbolRefExpr::VK_PPC_TOC: 179 Type = ELF::R_PPC64_TOC16; 180 break; 181 case MCSymbolRefExpr::VK_PPC_TOC_LO: 182 Type = ELF::R_PPC64_TOC16_LO; 183 break; 184 case MCSymbolRefExpr::VK_PPC_TOC_HI: 185 Type = ELF::R_PPC64_TOC16_HI; 186 break; 187 case MCSymbolRefExpr::VK_PPC_TOC_HA: 188 Type = ELF::R_PPC64_TOC16_HA; 189 break; 190 case MCSymbolRefExpr::VK_PPC_TPREL: 191 Type = ELF::R_PPC_TPREL16; 192 break; 193 case MCSymbolRefExpr::VK_PPC_TPREL_LO: 194 Type = ELF::R_PPC_TPREL16_LO; 195 break; 196 case MCSymbolRefExpr::VK_PPC_TPREL_HI: 197 Type = ELF::R_PPC_TPREL16_HI; 198 break; 199 case MCSymbolRefExpr::VK_PPC_TPREL_HA: 200 Type = ELF::R_PPC_TPREL16_HA; 201 break; 202 case MCSymbolRefExpr::VK_PPC_TPREL_HIGHER: 203 Type = ELF::R_PPC64_TPREL16_HIGHER; 204 break; 205 case MCSymbolRefExpr::VK_PPC_TPREL_HIGHERA: 206 Type = ELF::R_PPC64_TPREL16_HIGHERA; 207 break; 208 case MCSymbolRefExpr::VK_PPC_TPREL_HIGHEST: 209 Type = ELF::R_PPC64_TPREL16_HIGHEST; 210 break; 211 case MCSymbolRefExpr::VK_PPC_TPREL_HIGHESTA: 212 Type = ELF::R_PPC64_TPREL16_HIGHESTA; 213 break; 214 case MCSymbolRefExpr::VK_PPC_DTPREL: 215 Type = ELF::R_PPC64_DTPREL16; 216 break; 217 case MCSymbolRefExpr::VK_PPC_DTPREL_LO: 218 Type = ELF::R_PPC64_DTPREL16_LO; 219 break; 220 case MCSymbolRefExpr::VK_PPC_DTPREL_HI: 221 Type = ELF::R_PPC64_DTPREL16_HI; 222 break; 223 case MCSymbolRefExpr::VK_PPC_DTPREL_HA: 224 Type = ELF::R_PPC64_DTPREL16_HA; 225 break; 226 case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHER: 227 Type = ELF::R_PPC64_DTPREL16_HIGHER; 228 break; 229 case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHERA: 230 Type = ELF::R_PPC64_DTPREL16_HIGHERA; 231 break; 232 case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHEST: 233 Type = ELF::R_PPC64_DTPREL16_HIGHEST; 234 break; 235 case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHESTA: 236 Type = ELF::R_PPC64_DTPREL16_HIGHESTA; 237 break; 238 case MCSymbolRefExpr::VK_PPC_GOT_TLSGD: 239 Type = ELF::R_PPC64_GOT_TLSGD16; 240 break; 241 case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_LO: 242 Type = ELF::R_PPC64_GOT_TLSGD16_LO; 243 break; 244 case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_HI: 245 Type = ELF::R_PPC64_GOT_TLSGD16_HI; 246 break; 247 case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_HA: 248 Type = ELF::R_PPC64_GOT_TLSGD16_HA; 249 break; 250 case MCSymbolRefExpr::VK_PPC_GOT_TLSLD: 251 Type = ELF::R_PPC64_GOT_TLSLD16; 252 break; 253 case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_LO: 254 Type = ELF::R_PPC64_GOT_TLSLD16_LO; 255 break; 256 case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_HI: 257 Type = ELF::R_PPC64_GOT_TLSLD16_HI; 258 break; 259 case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_HA: 260 Type = ELF::R_PPC64_GOT_TLSLD16_HA; 261 break; 262 case MCSymbolRefExpr::VK_PPC_GOT_TPREL: 263 /* We don't have R_PPC64_GOT_TPREL16, but since GOT offsets 264 are always 4-aligned, we can use R_PPC64_GOT_TPREL16_DS. */ 265 Type = ELF::R_PPC64_GOT_TPREL16_DS; 266 break; 267 case MCSymbolRefExpr::VK_PPC_GOT_TPREL_LO: 268 /* We don't have R_PPC64_GOT_TPREL16_LO, but since GOT offsets 269 are always 4-aligned, we can use R_PPC64_GOT_TPREL16_LO_DS. */ 270 Type = ELF::R_PPC64_GOT_TPREL16_LO_DS; 271 break; 272 case MCSymbolRefExpr::VK_PPC_GOT_TPREL_HI: 273 Type = ELF::R_PPC64_GOT_TPREL16_HI; 274 break; 275 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL: 276 /* We don't have R_PPC64_GOT_DTPREL16, but since GOT offsets 277 are always 4-aligned, we can use R_PPC64_GOT_DTPREL16_DS. */ 278 Type = ELF::R_PPC64_GOT_DTPREL16_DS; 279 break; 280 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_LO: 281 /* We don't have R_PPC64_GOT_DTPREL16_LO, but since GOT offsets 282 are always 4-aligned, we can use R_PPC64_GOT_DTPREL16_LO_DS. */ 283 Type = ELF::R_PPC64_GOT_DTPREL16_LO_DS; 284 break; 285 case MCSymbolRefExpr::VK_PPC_GOT_TPREL_HA: 286 Type = ELF::R_PPC64_GOT_TPREL16_HA; 287 break; 288 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_HI: 289 Type = ELF::R_PPC64_GOT_DTPREL16_HI; 290 break; 291 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_HA: 292 Type = ELF::R_PPC64_GOT_DTPREL16_HA; 293 break; 294 } 295 break; 296 case PPC::fixup_ppc_half16ds: 297 switch (Modifier) { 298 default: llvm_unreachable("Unsupported Modifier"); 299 case MCSymbolRefExpr::VK_None: 300 Type = ELF::R_PPC64_ADDR16_DS; 301 break; 302 case MCSymbolRefExpr::VK_PPC_LO: 303 Type = ELF::R_PPC64_ADDR16_LO_DS; 304 break; 305 case MCSymbolRefExpr::VK_GOT: 306 Type = ELF::R_PPC64_GOT16_DS; 307 break; 308 case MCSymbolRefExpr::VK_PPC_GOT_LO: 309 Type = ELF::R_PPC64_GOT16_LO_DS; 310 break; 311 case MCSymbolRefExpr::VK_PPC_TOC: 312 Type = ELF::R_PPC64_TOC16_DS; 313 break; 314 case MCSymbolRefExpr::VK_PPC_TOC_LO: 315 Type = ELF::R_PPC64_TOC16_LO_DS; 316 break; 317 case MCSymbolRefExpr::VK_PPC_TPREL: 318 Type = ELF::R_PPC64_TPREL16_DS; 319 break; 320 case MCSymbolRefExpr::VK_PPC_TPREL_LO: 321 Type = ELF::R_PPC64_TPREL16_LO_DS; 322 break; 323 case MCSymbolRefExpr::VK_PPC_DTPREL: 324 Type = ELF::R_PPC64_DTPREL16_DS; 325 break; 326 case MCSymbolRefExpr::VK_PPC_DTPREL_LO: 327 Type = ELF::R_PPC64_DTPREL16_LO_DS; 328 break; 329 case MCSymbolRefExpr::VK_PPC_GOT_TPREL: 330 Type = ELF::R_PPC64_GOT_TPREL16_DS; 331 break; 332 case MCSymbolRefExpr::VK_PPC_GOT_TPREL_LO: 333 Type = ELF::R_PPC64_GOT_TPREL16_LO_DS; 334 break; 335 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL: 336 Type = ELF::R_PPC64_GOT_DTPREL16_DS; 337 break; 338 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_LO: 339 Type = ELF::R_PPC64_GOT_DTPREL16_LO_DS; 340 break; 341 } 342 break; 343 case PPC::fixup_ppc_nofixup: 344 switch (Modifier) { 345 default: llvm_unreachable("Unsupported Modifier"); 346 case MCSymbolRefExpr::VK_PPC_TLSGD: 347 Type = ELF::R_PPC64_TLSGD; 348 break; 349 case MCSymbolRefExpr::VK_PPC_TLSLD: 350 Type = ELF::R_PPC64_TLSLD; 351 break; 352 case MCSymbolRefExpr::VK_PPC_TLS: 353 Type = ELF::R_PPC64_TLS; 354 break; 355 } 356 break; 357 case FK_Data_8: 358 switch (Modifier) { 359 default: llvm_unreachable("Unsupported Modifier"); 360 case MCSymbolRefExpr::VK_PPC_TOCBASE: 361 Type = ELF::R_PPC64_TOC; 362 break; 363 case MCSymbolRefExpr::VK_None: 364 Type = ELF::R_PPC64_ADDR64; 365 break; 366 case MCSymbolRefExpr::VK_PPC_DTPMOD: 367 Type = ELF::R_PPC64_DTPMOD64; 368 break; 369 case MCSymbolRefExpr::VK_PPC_TPREL: 370 Type = ELF::R_PPC64_TPREL64; 371 break; 372 case MCSymbolRefExpr::VK_PPC_DTPREL: 373 Type = ELF::R_PPC64_DTPREL64; 374 break; 375 } 376 break; 377 case FK_Data_4: 378 Type = ELF::R_PPC_ADDR32; 379 break; 380 case FK_Data_2: 381 Type = ELF::R_PPC_ADDR16; 382 break; 383 } 384 } 385 return Type; 386 } 387 388 unsigned PPCELFObjectWriter::GetRelocType(const MCValue &Target, 389 const MCFixup &Fixup, 390 bool IsPCRel) const { 391 return getRelocTypeInner(Target, Fixup, IsPCRel); 392 } 393 394 bool PPCELFObjectWriter::needsRelocateWithSymbol(const MCSymbolData &SD, 395 unsigned Type) const { 396 switch (Type) { 397 default: 398 return false; 399 400 case ELF::R_PPC_REL24: 401 // If the target symbol has a local entry point, we must keep the 402 // target symbol to preserve that information for the linker. 403 // The "other" values are stored in the last 6 bits of the second byte. 404 // The traditional defines for STO values assume the full byte and thus 405 // the shift to pack it. 406 unsigned Other = MCELF::getOther(SD) << 2; 407 return (Other & ELF::STO_PPC64_LOCAL_MASK) != 0; 408 } 409 } 410 411 MCObjectWriter *llvm::createPPCELFObjectWriter(raw_ostream &OS, 412 bool Is64Bit, 413 bool IsLittleEndian, 414 uint8_t OSABI) { 415 MCELFObjectTargetWriter *MOTW = new PPCELFObjectWriter(Is64Bit, OSABI); 416 return createELFObjectWriter(MOTW, OS, IsLittleEndian); 417 } 418