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/MCSymbolELF.h" 17#include "llvm/MC/MCValue.h" 18#include "llvm/Support/ErrorHandling.h" 19 20using namespace llvm; 21 22namespace { 23 class PPCELFObjectWriter : public MCELFObjectTargetWriter { 24 public: 25 PPCELFObjectWriter(bool Is64Bit, uint8_t OSABI); 26 27 protected: 28 unsigned getRelocType(MCContext &Ctx, const MCValue &Target, 29 const MCFixup &Fixup, bool IsPCRel) const override; 30 31 bool needsRelocateWithSymbol(const MCSymbol &Sym, 32 unsigned Type) const override; 33 }; 34} 35 36PPCELFObjectWriter::PPCELFObjectWriter(bool Is64Bit, uint8_t OSABI) 37 : MCELFObjectTargetWriter(Is64Bit, OSABI, 38 Is64Bit ? ELF::EM_PPC64 : ELF::EM_PPC, 39 /*HasRelocationAddend*/ true) {} 40 41static MCSymbolRefExpr::VariantKind getAccessVariant(const MCValue &Target, 42 const MCFixup &Fixup) { 43 const MCExpr *Expr = Fixup.getValue(); 44 45 if (Expr->getKind() != MCExpr::Target) 46 return Target.getAccessVariant(); 47 48 switch (cast<PPCMCExpr>(Expr)->getKind()) { 49 case PPCMCExpr::VK_PPC_None: 50 return MCSymbolRefExpr::VK_None; 51 case PPCMCExpr::VK_PPC_LO: 52 return MCSymbolRefExpr::VK_PPC_LO; 53 case PPCMCExpr::VK_PPC_HI: 54 return MCSymbolRefExpr::VK_PPC_HI; 55 case PPCMCExpr::VK_PPC_HA: 56 return MCSymbolRefExpr::VK_PPC_HA; 57 case PPCMCExpr::VK_PPC_HIGHERA: 58 return MCSymbolRefExpr::VK_PPC_HIGHERA; 59 case PPCMCExpr::VK_PPC_HIGHER: 60 return MCSymbolRefExpr::VK_PPC_HIGHER; 61 case PPCMCExpr::VK_PPC_HIGHEST: 62 return MCSymbolRefExpr::VK_PPC_HIGHEST; 63 case PPCMCExpr::VK_PPC_HIGHESTA: 64 return MCSymbolRefExpr::VK_PPC_HIGHESTA; 65 } 66 llvm_unreachable("unknown PPCMCExpr kind"); 67} 68 69unsigned PPCELFObjectWriter::getRelocType(MCContext &Ctx, const MCValue &Target, 70 const MCFixup &Fixup, 71 bool IsPCRel) const { 72 MCSymbolRefExpr::VariantKind Modifier = getAccessVariant(Target, Fixup); 73 74 // determine the type of the relocation 75 unsigned Type; 76 if (IsPCRel) { 77 switch ((unsigned)Fixup.getKind()) { 78 default: 79 llvm_unreachable("Unimplemented"); 80 case PPC::fixup_ppc_br24: 81 case PPC::fixup_ppc_br24abs: 82 switch (Modifier) { 83 default: llvm_unreachable("Unsupported Modifier"); 84 case MCSymbolRefExpr::VK_None: 85 Type = ELF::R_PPC_REL24; 86 break; 87 case MCSymbolRefExpr::VK_PLT: 88 Type = ELF::R_PPC_PLTREL24; 89 break; 90 case MCSymbolRefExpr::VK_PPC_LOCAL: 91 Type = ELF::R_PPC_LOCAL24PC; 92 break; 93 } 94 break; 95 case PPC::fixup_ppc_brcond14: 96 case PPC::fixup_ppc_brcond14abs: 97 Type = ELF::R_PPC_REL14; 98 break; 99 case PPC::fixup_ppc_half16: 100 switch (Modifier) { 101 default: llvm_unreachable("Unsupported Modifier"); 102 case MCSymbolRefExpr::VK_None: 103 Type = ELF::R_PPC_REL16; 104 break; 105 case MCSymbolRefExpr::VK_PPC_LO: 106 Type = ELF::R_PPC_REL16_LO; 107 break; 108 case MCSymbolRefExpr::VK_PPC_HI: 109 Type = ELF::R_PPC_REL16_HI; 110 break; 111 case MCSymbolRefExpr::VK_PPC_HA: 112 Type = ELF::R_PPC_REL16_HA; 113 break; 114 } 115 break; 116 case PPC::fixup_ppc_half16ds: 117 Target.print(errs()); 118 errs() << '\n'; 119 report_fatal_error("Invalid PC-relative half16ds relocation"); 120 case FK_Data_4: 121 case FK_PCRel_4: 122 Type = ELF::R_PPC_REL32; 123 break; 124 case FK_Data_8: 125 case FK_PCRel_8: 126 Type = ELF::R_PPC64_REL64; 127 break; 128 } 129 } else { 130 switch ((unsigned)Fixup.getKind()) { 131 default: llvm_unreachable("invalid fixup kind!"); 132 case PPC::fixup_ppc_br24abs: 133 Type = ELF::R_PPC_ADDR24; 134 break; 135 case PPC::fixup_ppc_brcond14abs: 136 Type = ELF::R_PPC_ADDR14; // XXX: or BRNTAKEN?_ 137 break; 138 case PPC::fixup_ppc_half16: 139 switch (Modifier) { 140 default: llvm_unreachable("Unsupported Modifier"); 141 case MCSymbolRefExpr::VK_None: 142 Type = ELF::R_PPC_ADDR16; 143 break; 144 case MCSymbolRefExpr::VK_PPC_LO: 145 Type = ELF::R_PPC_ADDR16_LO; 146 break; 147 case MCSymbolRefExpr::VK_PPC_HI: 148 Type = ELF::R_PPC_ADDR16_HI; 149 break; 150 case MCSymbolRefExpr::VK_PPC_HA: 151 Type = ELF::R_PPC_ADDR16_HA; 152 break; 153 case MCSymbolRefExpr::VK_PPC_HIGHER: 154 Type = ELF::R_PPC64_ADDR16_HIGHER; 155 break; 156 case MCSymbolRefExpr::VK_PPC_HIGHERA: 157 Type = ELF::R_PPC64_ADDR16_HIGHERA; 158 break; 159 case MCSymbolRefExpr::VK_PPC_HIGHEST: 160 Type = ELF::R_PPC64_ADDR16_HIGHEST; 161 break; 162 case MCSymbolRefExpr::VK_PPC_HIGHESTA: 163 Type = ELF::R_PPC64_ADDR16_HIGHESTA; 164 break; 165 case MCSymbolRefExpr::VK_GOT: 166 Type = ELF::R_PPC_GOT16; 167 break; 168 case MCSymbolRefExpr::VK_PPC_GOT_LO: 169 Type = ELF::R_PPC_GOT16_LO; 170 break; 171 case MCSymbolRefExpr::VK_PPC_GOT_HI: 172 Type = ELF::R_PPC_GOT16_HI; 173 break; 174 case MCSymbolRefExpr::VK_PPC_GOT_HA: 175 Type = ELF::R_PPC_GOT16_HA; 176 break; 177 case MCSymbolRefExpr::VK_PPC_TOC: 178 Type = ELF::R_PPC64_TOC16; 179 break; 180 case MCSymbolRefExpr::VK_PPC_TOC_LO: 181 Type = ELF::R_PPC64_TOC16_LO; 182 break; 183 case MCSymbolRefExpr::VK_PPC_TOC_HI: 184 Type = ELF::R_PPC64_TOC16_HI; 185 break; 186 case MCSymbolRefExpr::VK_PPC_TOC_HA: 187 Type = ELF::R_PPC64_TOC16_HA; 188 break; 189 case MCSymbolRefExpr::VK_TPREL: 190 Type = ELF::R_PPC_TPREL16; 191 break; 192 case MCSymbolRefExpr::VK_PPC_TPREL_LO: 193 Type = ELF::R_PPC_TPREL16_LO; 194 break; 195 case MCSymbolRefExpr::VK_PPC_TPREL_HI: 196 Type = ELF::R_PPC_TPREL16_HI; 197 break; 198 case MCSymbolRefExpr::VK_PPC_TPREL_HA: 199 Type = ELF::R_PPC_TPREL16_HA; 200 break; 201 case MCSymbolRefExpr::VK_PPC_TPREL_HIGHER: 202 Type = ELF::R_PPC64_TPREL16_HIGHER; 203 break; 204 case MCSymbolRefExpr::VK_PPC_TPREL_HIGHERA: 205 Type = ELF::R_PPC64_TPREL16_HIGHERA; 206 break; 207 case MCSymbolRefExpr::VK_PPC_TPREL_HIGHEST: 208 Type = ELF::R_PPC64_TPREL16_HIGHEST; 209 break; 210 case MCSymbolRefExpr::VK_PPC_TPREL_HIGHESTA: 211 Type = ELF::R_PPC64_TPREL16_HIGHESTA; 212 break; 213 case MCSymbolRefExpr::VK_DTPREL: 214 Type = ELF::R_PPC64_DTPREL16; 215 break; 216 case MCSymbolRefExpr::VK_PPC_DTPREL_LO: 217 Type = ELF::R_PPC64_DTPREL16_LO; 218 break; 219 case MCSymbolRefExpr::VK_PPC_DTPREL_HI: 220 Type = ELF::R_PPC64_DTPREL16_HI; 221 break; 222 case MCSymbolRefExpr::VK_PPC_DTPREL_HA: 223 Type = ELF::R_PPC64_DTPREL16_HA; 224 break; 225 case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHER: 226 Type = ELF::R_PPC64_DTPREL16_HIGHER; 227 break; 228 case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHERA: 229 Type = ELF::R_PPC64_DTPREL16_HIGHERA; 230 break; 231 case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHEST: 232 Type = ELF::R_PPC64_DTPREL16_HIGHEST; 233 break; 234 case MCSymbolRefExpr::VK_PPC_DTPREL_HIGHESTA: 235 Type = ELF::R_PPC64_DTPREL16_HIGHESTA; 236 break; 237 case MCSymbolRefExpr::VK_PPC_GOT_TLSGD: 238 if (is64Bit()) 239 Type = ELF::R_PPC64_GOT_TLSGD16; 240 else 241 Type = ELF::R_PPC_GOT_TLSGD16; 242 break; 243 case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_LO: 244 Type = ELF::R_PPC64_GOT_TLSGD16_LO; 245 break; 246 case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_HI: 247 Type = ELF::R_PPC64_GOT_TLSGD16_HI; 248 break; 249 case MCSymbolRefExpr::VK_PPC_GOT_TLSGD_HA: 250 Type = ELF::R_PPC64_GOT_TLSGD16_HA; 251 break; 252 case MCSymbolRefExpr::VK_PPC_GOT_TLSLD: 253 if (is64Bit()) 254 Type = ELF::R_PPC64_GOT_TLSLD16; 255 else 256 Type = ELF::R_PPC_GOT_TLSLD16; 257 break; 258 case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_LO: 259 Type = ELF::R_PPC64_GOT_TLSLD16_LO; 260 break; 261 case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_HI: 262 Type = ELF::R_PPC64_GOT_TLSLD16_HI; 263 break; 264 case MCSymbolRefExpr::VK_PPC_GOT_TLSLD_HA: 265 Type = ELF::R_PPC64_GOT_TLSLD16_HA; 266 break; 267 case MCSymbolRefExpr::VK_PPC_GOT_TPREL: 268 /* We don't have R_PPC64_GOT_TPREL16, but since GOT offsets 269 are always 4-aligned, we can use R_PPC64_GOT_TPREL16_DS. */ 270 Type = ELF::R_PPC64_GOT_TPREL16_DS; 271 break; 272 case MCSymbolRefExpr::VK_PPC_GOT_TPREL_LO: 273 /* We don't have R_PPC64_GOT_TPREL16_LO, but since GOT offsets 274 are always 4-aligned, we can use R_PPC64_GOT_TPREL16_LO_DS. */ 275 Type = ELF::R_PPC64_GOT_TPREL16_LO_DS; 276 break; 277 case MCSymbolRefExpr::VK_PPC_GOT_TPREL_HI: 278 Type = ELF::R_PPC64_GOT_TPREL16_HI; 279 break; 280 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL: 281 /* We don't have R_PPC64_GOT_DTPREL16, but since GOT offsets 282 are always 4-aligned, we can use R_PPC64_GOT_DTPREL16_DS. */ 283 Type = ELF::R_PPC64_GOT_DTPREL16_DS; 284 break; 285 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_LO: 286 /* We don't have R_PPC64_GOT_DTPREL16_LO, but since GOT offsets 287 are always 4-aligned, we can use R_PPC64_GOT_DTPREL16_LO_DS. */ 288 Type = ELF::R_PPC64_GOT_DTPREL16_LO_DS; 289 break; 290 case MCSymbolRefExpr::VK_PPC_GOT_TPREL_HA: 291 Type = ELF::R_PPC64_GOT_TPREL16_HA; 292 break; 293 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_HI: 294 Type = ELF::R_PPC64_GOT_DTPREL16_HI; 295 break; 296 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_HA: 297 Type = ELF::R_PPC64_GOT_DTPREL16_HA; 298 break; 299 } 300 break; 301 case PPC::fixup_ppc_half16ds: 302 switch (Modifier) { 303 default: llvm_unreachable("Unsupported Modifier"); 304 case MCSymbolRefExpr::VK_None: 305 Type = ELF::R_PPC64_ADDR16_DS; 306 break; 307 case MCSymbolRefExpr::VK_PPC_LO: 308 Type = ELF::R_PPC64_ADDR16_LO_DS; 309 break; 310 case MCSymbolRefExpr::VK_GOT: 311 Type = ELF::R_PPC64_GOT16_DS; 312 break; 313 case MCSymbolRefExpr::VK_PPC_GOT_LO: 314 Type = ELF::R_PPC64_GOT16_LO_DS; 315 break; 316 case MCSymbolRefExpr::VK_PPC_TOC: 317 Type = ELF::R_PPC64_TOC16_DS; 318 break; 319 case MCSymbolRefExpr::VK_PPC_TOC_LO: 320 Type = ELF::R_PPC64_TOC16_LO_DS; 321 break; 322 case MCSymbolRefExpr::VK_TPREL: 323 Type = ELF::R_PPC64_TPREL16_DS; 324 break; 325 case MCSymbolRefExpr::VK_PPC_TPREL_LO: 326 Type = ELF::R_PPC64_TPREL16_LO_DS; 327 break; 328 case MCSymbolRefExpr::VK_DTPREL: 329 Type = ELF::R_PPC64_DTPREL16_DS; 330 break; 331 case MCSymbolRefExpr::VK_PPC_DTPREL_LO: 332 Type = ELF::R_PPC64_DTPREL16_LO_DS; 333 break; 334 case MCSymbolRefExpr::VK_PPC_GOT_TPREL: 335 Type = ELF::R_PPC64_GOT_TPREL16_DS; 336 break; 337 case MCSymbolRefExpr::VK_PPC_GOT_TPREL_LO: 338 Type = ELF::R_PPC64_GOT_TPREL16_LO_DS; 339 break; 340 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL: 341 Type = ELF::R_PPC64_GOT_DTPREL16_DS; 342 break; 343 case MCSymbolRefExpr::VK_PPC_GOT_DTPREL_LO: 344 Type = ELF::R_PPC64_GOT_DTPREL16_LO_DS; 345 break; 346 } 347 break; 348 case PPC::fixup_ppc_nofixup: 349 switch (Modifier) { 350 default: llvm_unreachable("Unsupported Modifier"); 351 case MCSymbolRefExpr::VK_PPC_TLSGD: 352 if (is64Bit()) 353 Type = ELF::R_PPC64_TLSGD; 354 else 355 Type = ELF::R_PPC_TLSGD; 356 break; 357 case MCSymbolRefExpr::VK_PPC_TLSLD: 358 if (is64Bit()) 359 Type = ELF::R_PPC64_TLSLD; 360 else 361 Type = ELF::R_PPC_TLSLD; 362 break; 363 case MCSymbolRefExpr::VK_PPC_TLS: 364 if (is64Bit()) 365 Type = ELF::R_PPC64_TLS; 366 else 367 Type = ELF::R_PPC_TLS; 368 break; 369 } 370 break; 371 case FK_Data_8: 372 switch (Modifier) { 373 default: llvm_unreachable("Unsupported Modifier"); 374 case MCSymbolRefExpr::VK_PPC_TOCBASE: 375 Type = ELF::R_PPC64_TOC; 376 break; 377 case MCSymbolRefExpr::VK_None: 378 Type = ELF::R_PPC64_ADDR64; 379 break; 380 case MCSymbolRefExpr::VK_PPC_DTPMOD: 381 Type = ELF::R_PPC64_DTPMOD64; 382 break; 383 case MCSymbolRefExpr::VK_TPREL: 384 Type = ELF::R_PPC64_TPREL64; 385 break; 386 case MCSymbolRefExpr::VK_DTPREL: 387 Type = ELF::R_PPC64_DTPREL64; 388 break; 389 } 390 break; 391 case FK_Data_4: 392 Type = ELF::R_PPC_ADDR32; 393 break; 394 case FK_Data_2: 395 Type = ELF::R_PPC_ADDR16; 396 break; 397 } 398 } 399 return Type; 400} 401 402bool PPCELFObjectWriter::needsRelocateWithSymbol(const MCSymbol &Sym, 403 unsigned Type) const { 404 switch (Type) { 405 default: 406 return false; 407 408 case ELF::R_PPC_REL24: 409 // If the target symbol has a local entry point, we must keep the 410 // target symbol to preserve that information for the linker. 411 // The "other" values are stored in the last 6 bits of the second byte. 412 // The traditional defines for STO values assume the full byte and thus 413 // the shift to pack it. 414 unsigned Other = cast<MCSymbolELF>(Sym).getOther() << 2; 415 return (Other & ELF::STO_PPC64_LOCAL_MASK) != 0; 416 } 417} 418 419MCObjectWriter *llvm::createPPCELFObjectWriter(raw_pwrite_stream &OS, 420 bool Is64Bit, 421 bool IsLittleEndian, 422 uint8_t OSABI) { 423 MCELFObjectTargetWriter *MOTW = new PPCELFObjectWriter(Is64Bit, OSABI); 424 return createELFObjectWriter(MOTW, OS, IsLittleEndian); 425} 426