1 //===-- MCObjectFileInfo.cpp - Object File Information --------------------===// 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 "llvm/MC/MCObjectFileInfo.h" 11 #include "llvm/ADT/StringExtras.h" 12 #include "llvm/ADT/Triple.h" 13 #include "llvm/MC/MCAsmInfo.h" 14 #include "llvm/MC/MCContext.h" 15 #include "llvm/MC/MCSection.h" 16 #include "llvm/MC/MCSectionCOFF.h" 17 #include "llvm/MC/MCSectionELF.h" 18 #include "llvm/MC/MCSectionMachO.h" 19 #include "llvm/Support/COFF.h" 20 21 using namespace llvm; 22 23 static bool useCompactUnwind(const Triple &T) { 24 // Only on darwin. 25 if (!T.isOSDarwin()) 26 return false; 27 28 // aarch64 always has it. 29 if (T.getArch() == Triple::aarch64) 30 return true; 31 32 // armv7k always has it. 33 if (T.isWatchABI()) 34 return true; 35 36 // Use it on newer version of OS X. 37 if (T.isMacOSX() && !T.isMacOSXVersionLT(10, 6)) 38 return true; 39 40 // And the iOS simulator. 41 if (T.isiOS() && 42 (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86)) 43 return true; 44 45 return false; 46 } 47 48 void MCObjectFileInfo::initMachOMCObjectFileInfo(const Triple &T) { 49 // MachO 50 SupportsWeakOmittedEHFrame = false; 51 52 EHFrameSection = Ctx->getMachOSection( 53 "__TEXT", "__eh_frame", 54 MachO::S_COALESCED | MachO::S_ATTR_NO_TOC | 55 MachO::S_ATTR_STRIP_STATIC_SYMS | MachO::S_ATTR_LIVE_SUPPORT, 56 SectionKind::getReadOnly()); 57 58 if (T.isOSDarwin() && T.getArch() == Triple::aarch64) 59 SupportsCompactUnwindWithoutEHFrame = true; 60 61 if (T.isWatchABI()) 62 OmitDwarfIfHaveCompactUnwind = true; 63 64 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel 65 | dwarf::DW_EH_PE_sdata4; 66 LSDAEncoding = FDECFIEncoding = dwarf::DW_EH_PE_pcrel; 67 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 68 dwarf::DW_EH_PE_sdata4; 69 70 // .comm doesn't support alignment before Leopard. 71 if (T.isMacOSX() && T.isMacOSXVersionLT(10, 5)) 72 CommDirectiveSupportsAlignment = false; 73 74 TextSection // .text 75 = Ctx->getMachOSection("__TEXT", "__text", 76 MachO::S_ATTR_PURE_INSTRUCTIONS, 77 SectionKind::getText()); 78 DataSection // .data 79 = Ctx->getMachOSection("__DATA", "__data", 0, SectionKind::getData()); 80 81 // BSSSection might not be expected initialized on msvc. 82 BSSSection = nullptr; 83 84 TLSDataSection // .tdata 85 = Ctx->getMachOSection("__DATA", "__thread_data", 86 MachO::S_THREAD_LOCAL_REGULAR, 87 SectionKind::getData()); 88 TLSBSSSection // .tbss 89 = Ctx->getMachOSection("__DATA", "__thread_bss", 90 MachO::S_THREAD_LOCAL_ZEROFILL, 91 SectionKind::getThreadBSS()); 92 93 // TODO: Verify datarel below. 94 TLSTLVSection // .tlv 95 = Ctx->getMachOSection("__DATA", "__thread_vars", 96 MachO::S_THREAD_LOCAL_VARIABLES, 97 SectionKind::getData()); 98 99 TLSThreadInitSection = Ctx->getMachOSection( 100 "__DATA", "__thread_init", MachO::S_THREAD_LOCAL_INIT_FUNCTION_POINTERS, 101 SectionKind::getData()); 102 103 CStringSection // .cstring 104 = Ctx->getMachOSection("__TEXT", "__cstring", 105 MachO::S_CSTRING_LITERALS, 106 SectionKind::getMergeable1ByteCString()); 107 UStringSection 108 = Ctx->getMachOSection("__TEXT","__ustring", 0, 109 SectionKind::getMergeable2ByteCString()); 110 FourByteConstantSection // .literal4 111 = Ctx->getMachOSection("__TEXT", "__literal4", 112 MachO::S_4BYTE_LITERALS, 113 SectionKind::getMergeableConst4()); 114 EightByteConstantSection // .literal8 115 = Ctx->getMachOSection("__TEXT", "__literal8", 116 MachO::S_8BYTE_LITERALS, 117 SectionKind::getMergeableConst8()); 118 119 SixteenByteConstantSection // .literal16 120 = Ctx->getMachOSection("__TEXT", "__literal16", 121 MachO::S_16BYTE_LITERALS, 122 SectionKind::getMergeableConst16()); 123 124 ReadOnlySection // .const 125 = Ctx->getMachOSection("__TEXT", "__const", 0, 126 SectionKind::getReadOnly()); 127 128 // If the target is not powerpc, map the coal sections to the non-coal 129 // sections. 130 // 131 // "__TEXT/__textcoal_nt" => section "__TEXT/__text" 132 // "__TEXT/__const_coal" => section "__TEXT/__const" 133 // "__DATA/__datacoal_nt" => section "__DATA/__data" 134 Triple::ArchType ArchTy = T.getArch(); 135 136 if (ArchTy == Triple::ppc || ArchTy == Triple::ppc64) { 137 TextCoalSection 138 = Ctx->getMachOSection("__TEXT", "__textcoal_nt", 139 MachO::S_COALESCED | 140 MachO::S_ATTR_PURE_INSTRUCTIONS, 141 SectionKind::getText()); 142 ConstTextCoalSection 143 = Ctx->getMachOSection("__TEXT", "__const_coal", 144 MachO::S_COALESCED, 145 SectionKind::getReadOnly()); 146 DataCoalSection = Ctx->getMachOSection( 147 "__DATA", "__datacoal_nt", MachO::S_COALESCED, SectionKind::getData()); 148 } else { 149 TextCoalSection = TextSection; 150 ConstTextCoalSection = ReadOnlySection; 151 DataCoalSection = DataSection; 152 } 153 154 ConstDataSection // .const_data 155 = Ctx->getMachOSection("__DATA", "__const", 0, 156 SectionKind::getReadOnlyWithRel()); 157 DataCommonSection 158 = Ctx->getMachOSection("__DATA","__common", 159 MachO::S_ZEROFILL, 160 SectionKind::getBSS()); 161 DataBSSSection 162 = Ctx->getMachOSection("__DATA","__bss", MachO::S_ZEROFILL, 163 SectionKind::getBSS()); 164 165 166 LazySymbolPointerSection 167 = Ctx->getMachOSection("__DATA", "__la_symbol_ptr", 168 MachO::S_LAZY_SYMBOL_POINTERS, 169 SectionKind::getMetadata()); 170 NonLazySymbolPointerSection 171 = Ctx->getMachOSection("__DATA", "__nl_symbol_ptr", 172 MachO::S_NON_LAZY_SYMBOL_POINTERS, 173 SectionKind::getMetadata()); 174 175 ThreadLocalPointerSection 176 = Ctx->getMachOSection("__DATA", "__thread_ptr", 177 MachO::S_THREAD_LOCAL_VARIABLE_POINTERS, 178 SectionKind::getMetadata()); 179 180 if (!PositionIndependent) { 181 StaticCtorSection = Ctx->getMachOSection("__TEXT", "__constructor", 0, 182 SectionKind::getData()); 183 StaticDtorSection = Ctx->getMachOSection("__TEXT", "__destructor", 0, 184 SectionKind::getData()); 185 } else { 186 StaticCtorSection = Ctx->getMachOSection("__DATA", "__mod_init_func", 187 MachO::S_MOD_INIT_FUNC_POINTERS, 188 SectionKind::getData()); 189 StaticDtorSection = Ctx->getMachOSection("__DATA", "__mod_term_func", 190 MachO::S_MOD_TERM_FUNC_POINTERS, 191 SectionKind::getData()); 192 } 193 194 // Exception Handling. 195 LSDASection = Ctx->getMachOSection("__TEXT", "__gcc_except_tab", 0, 196 SectionKind::getReadOnlyWithRel()); 197 198 COFFDebugSymbolsSection = nullptr; 199 COFFDebugTypesSection = nullptr; 200 201 if (useCompactUnwind(T)) { 202 CompactUnwindSection = 203 Ctx->getMachOSection("__LD", "__compact_unwind", MachO::S_ATTR_DEBUG, 204 SectionKind::getReadOnly()); 205 206 if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86) 207 CompactUnwindDwarfEHFrameOnly = 0x04000000; // UNWIND_X86_64_MODE_DWARF 208 else if (T.getArch() == Triple::aarch64) 209 CompactUnwindDwarfEHFrameOnly = 0x03000000; // UNWIND_ARM64_MODE_DWARF 210 else if (T.getArch() == Triple::arm || T.getArch() == Triple::thumb) 211 CompactUnwindDwarfEHFrameOnly = 0x04000000; // UNWIND_ARM_MODE_DWARF 212 } 213 214 // Debug Information. 215 DwarfAccelNamesSection = 216 Ctx->getMachOSection("__DWARF", "__apple_names", MachO::S_ATTR_DEBUG, 217 SectionKind::getMetadata(), "names_begin"); 218 DwarfAccelObjCSection = 219 Ctx->getMachOSection("__DWARF", "__apple_objc", MachO::S_ATTR_DEBUG, 220 SectionKind::getMetadata(), "objc_begin"); 221 // 16 character section limit... 222 DwarfAccelNamespaceSection = 223 Ctx->getMachOSection("__DWARF", "__apple_namespac", MachO::S_ATTR_DEBUG, 224 SectionKind::getMetadata(), "namespac_begin"); 225 DwarfAccelTypesSection = 226 Ctx->getMachOSection("__DWARF", "__apple_types", MachO::S_ATTR_DEBUG, 227 SectionKind::getMetadata(), "types_begin"); 228 229 DwarfAbbrevSection = 230 Ctx->getMachOSection("__DWARF", "__debug_abbrev", MachO::S_ATTR_DEBUG, 231 SectionKind::getMetadata(), "section_abbrev"); 232 DwarfInfoSection = 233 Ctx->getMachOSection("__DWARF", "__debug_info", MachO::S_ATTR_DEBUG, 234 SectionKind::getMetadata(), "section_info"); 235 DwarfLineSection = 236 Ctx->getMachOSection("__DWARF", "__debug_line", MachO::S_ATTR_DEBUG, 237 SectionKind::getMetadata(), "section_line"); 238 DwarfFrameSection = 239 Ctx->getMachOSection("__DWARF", "__debug_frame", MachO::S_ATTR_DEBUG, 240 SectionKind::getMetadata()); 241 DwarfPubNamesSection = 242 Ctx->getMachOSection("__DWARF", "__debug_pubnames", MachO::S_ATTR_DEBUG, 243 SectionKind::getMetadata()); 244 DwarfPubTypesSection = 245 Ctx->getMachOSection("__DWARF", "__debug_pubtypes", MachO::S_ATTR_DEBUG, 246 SectionKind::getMetadata()); 247 DwarfGnuPubNamesSection = 248 Ctx->getMachOSection("__DWARF", "__debug_gnu_pubn", MachO::S_ATTR_DEBUG, 249 SectionKind::getMetadata()); 250 DwarfGnuPubTypesSection = 251 Ctx->getMachOSection("__DWARF", "__debug_gnu_pubt", MachO::S_ATTR_DEBUG, 252 SectionKind::getMetadata()); 253 DwarfStrSection = 254 Ctx->getMachOSection("__DWARF", "__debug_str", MachO::S_ATTR_DEBUG, 255 SectionKind::getMetadata(), "info_string"); 256 DwarfLocSection = 257 Ctx->getMachOSection("__DWARF", "__debug_loc", MachO::S_ATTR_DEBUG, 258 SectionKind::getMetadata(), "section_debug_loc"); 259 DwarfARangesSection = 260 Ctx->getMachOSection("__DWARF", "__debug_aranges", MachO::S_ATTR_DEBUG, 261 SectionKind::getMetadata()); 262 DwarfRangesSection = 263 Ctx->getMachOSection("__DWARF", "__debug_ranges", MachO::S_ATTR_DEBUG, 264 SectionKind::getMetadata(), "debug_range"); 265 DwarfMacinfoSection = 266 Ctx->getMachOSection("__DWARF", "__debug_macinfo", MachO::S_ATTR_DEBUG, 267 SectionKind::getMetadata(), "debug_macinfo"); 268 DwarfDebugInlineSection = 269 Ctx->getMachOSection("__DWARF", "__debug_inlined", MachO::S_ATTR_DEBUG, 270 SectionKind::getMetadata()); 271 DwarfCUIndexSection = 272 Ctx->getMachOSection("__DWARF", "__debug_cu_index", MachO::S_ATTR_DEBUG, 273 SectionKind::getMetadata()); 274 DwarfTUIndexSection = 275 Ctx->getMachOSection("__DWARF", "__debug_tu_index", MachO::S_ATTR_DEBUG, 276 SectionKind::getMetadata()); 277 StackMapSection = Ctx->getMachOSection("__LLVM_STACKMAPS", "__llvm_stackmaps", 278 0, SectionKind::getMetadata()); 279 280 FaultMapSection = Ctx->getMachOSection("__LLVM_FAULTMAPS", "__llvm_faultmaps", 281 0, SectionKind::getMetadata()); 282 283 TLSExtraDataSection = TLSTLVSection; 284 } 285 286 void MCObjectFileInfo::initELFMCObjectFileInfo(const Triple &T) { 287 switch (T.getArch()) { 288 case Triple::mips: 289 case Triple::mipsel: 290 FDECFIEncoding = dwarf::DW_EH_PE_sdata4; 291 break; 292 case Triple::mips64: 293 case Triple::mips64el: 294 FDECFIEncoding = dwarf::DW_EH_PE_sdata8; 295 break; 296 case Triple::x86_64: 297 FDECFIEncoding = dwarf::DW_EH_PE_pcrel | 298 ((CMModel == CodeModel::Large) ? dwarf::DW_EH_PE_sdata8 299 : dwarf::DW_EH_PE_sdata4); 300 break; 301 default: 302 FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 303 break; 304 } 305 306 switch (T.getArch()) { 307 case Triple::arm: 308 case Triple::armeb: 309 case Triple::thumb: 310 case Triple::thumbeb: 311 if (Ctx->getAsmInfo()->getExceptionHandlingType() == ExceptionHandling::ARM) 312 break; 313 // Fallthrough if not using EHABI 314 case Triple::ppc: 315 case Triple::x86: 316 PersonalityEncoding = PositionIndependent 317 ? dwarf::DW_EH_PE_indirect | 318 dwarf::DW_EH_PE_pcrel | 319 dwarf::DW_EH_PE_sdata4 320 : dwarf::DW_EH_PE_absptr; 321 LSDAEncoding = PositionIndependent 322 ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4 323 : dwarf::DW_EH_PE_absptr; 324 TTypeEncoding = PositionIndependent 325 ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 326 dwarf::DW_EH_PE_sdata4 327 : dwarf::DW_EH_PE_absptr; 328 break; 329 case Triple::x86_64: 330 if (PositionIndependent) { 331 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 332 ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium) 333 ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8); 334 LSDAEncoding = dwarf::DW_EH_PE_pcrel | 335 (CMModel == CodeModel::Small 336 ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8); 337 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 338 ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium) 339 ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8); 340 } else { 341 PersonalityEncoding = 342 (CMModel == CodeModel::Small || CMModel == CodeModel::Medium) 343 ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr; 344 LSDAEncoding = (CMModel == CodeModel::Small) 345 ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr; 346 TTypeEncoding = (CMModel == CodeModel::Small) 347 ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr; 348 } 349 break; 350 case Triple::hexagon: 351 PersonalityEncoding = dwarf::DW_EH_PE_absptr; 352 LSDAEncoding = dwarf::DW_EH_PE_absptr; 353 FDECFIEncoding = dwarf::DW_EH_PE_absptr; 354 TTypeEncoding = dwarf::DW_EH_PE_absptr; 355 if (PositionIndependent) { 356 PersonalityEncoding |= dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel; 357 LSDAEncoding |= dwarf::DW_EH_PE_pcrel; 358 FDECFIEncoding |= dwarf::DW_EH_PE_pcrel; 359 TTypeEncoding |= dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel; 360 } 361 break; 362 case Triple::aarch64: 363 case Triple::aarch64_be: 364 // The small model guarantees static code/data size < 4GB, but not where it 365 // will be in memory. Most of these could end up >2GB away so even a signed 366 // pc-relative 32-bit address is insufficient, theoretically. 367 if (PositionIndependent) { 368 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 369 dwarf::DW_EH_PE_sdata8; 370 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8; 371 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 372 dwarf::DW_EH_PE_sdata8; 373 } else { 374 PersonalityEncoding = dwarf::DW_EH_PE_absptr; 375 LSDAEncoding = dwarf::DW_EH_PE_absptr; 376 TTypeEncoding = dwarf::DW_EH_PE_absptr; 377 } 378 break; 379 case Triple::lanai: 380 LSDAEncoding = dwarf::DW_EH_PE_absptr; 381 PersonalityEncoding = dwarf::DW_EH_PE_absptr; 382 TTypeEncoding = dwarf::DW_EH_PE_absptr; 383 break; 384 case Triple::mips: 385 case Triple::mipsel: 386 case Triple::mips64: 387 case Triple::mips64el: 388 // MIPS uses indirect pointer to refer personality functions and types, so 389 // that the eh_frame section can be read-only. DW.ref.personality will be 390 // generated for relocation. 391 PersonalityEncoding = dwarf::DW_EH_PE_indirect; 392 // FIXME: The N64 ABI probably ought to use DW_EH_PE_sdata8 but we can't 393 // identify N64 from just a triple. 394 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 395 dwarf::DW_EH_PE_sdata4; 396 // We don't support PC-relative LSDA references in GAS so we use the default 397 // DW_EH_PE_absptr for those. 398 break; 399 case Triple::ppc64: 400 case Triple::ppc64le: 401 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 402 dwarf::DW_EH_PE_udata8; 403 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8; 404 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 405 dwarf::DW_EH_PE_udata8; 406 break; 407 case Triple::sparcel: 408 case Triple::sparc: 409 if (PositionIndependent) { 410 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 411 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 412 dwarf::DW_EH_PE_sdata4; 413 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 414 dwarf::DW_EH_PE_sdata4; 415 } else { 416 LSDAEncoding = dwarf::DW_EH_PE_absptr; 417 PersonalityEncoding = dwarf::DW_EH_PE_absptr; 418 TTypeEncoding = dwarf::DW_EH_PE_absptr; 419 } 420 break; 421 case Triple::sparcv9: 422 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 423 if (PositionIndependent) { 424 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 425 dwarf::DW_EH_PE_sdata4; 426 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 427 dwarf::DW_EH_PE_sdata4; 428 } else { 429 PersonalityEncoding = dwarf::DW_EH_PE_absptr; 430 TTypeEncoding = dwarf::DW_EH_PE_absptr; 431 } 432 break; 433 case Triple::systemz: 434 // All currently-defined code models guarantee that 4-byte PC-relative 435 // values will be in range. 436 if (PositionIndependent) { 437 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 438 dwarf::DW_EH_PE_sdata4; 439 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 440 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 441 dwarf::DW_EH_PE_sdata4; 442 } else { 443 PersonalityEncoding = dwarf::DW_EH_PE_absptr; 444 LSDAEncoding = dwarf::DW_EH_PE_absptr; 445 TTypeEncoding = dwarf::DW_EH_PE_absptr; 446 } 447 break; 448 default: 449 break; 450 } 451 452 unsigned EHSectionType = T.getArch() == Triple::x86_64 453 ? ELF::SHT_X86_64_UNWIND 454 : ELF::SHT_PROGBITS; 455 456 // Solaris requires different flags for .eh_frame to seemingly every other 457 // platform. 458 unsigned EHSectionFlags = ELF::SHF_ALLOC; 459 if (T.isOSSolaris() && T.getArch() != Triple::x86_64) 460 EHSectionFlags |= ELF::SHF_WRITE; 461 462 // ELF 463 BSSSection = Ctx->getELFSection(".bss", ELF::SHT_NOBITS, 464 ELF::SHF_WRITE | ELF::SHF_ALLOC); 465 466 TextSection = Ctx->getELFSection(".text", ELF::SHT_PROGBITS, 467 ELF::SHF_EXECINSTR | ELF::SHF_ALLOC); 468 469 DataSection = Ctx->getELFSection(".data", ELF::SHT_PROGBITS, 470 ELF::SHF_WRITE | ELF::SHF_ALLOC); 471 472 ReadOnlySection = 473 Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS, ELF::SHF_ALLOC); 474 475 TLSDataSection = 476 Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS, 477 ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE); 478 479 TLSBSSSection = Ctx->getELFSection( 480 ".tbss", ELF::SHT_NOBITS, ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE); 481 482 DataRelROSection = Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS, 483 ELF::SHF_ALLOC | ELF::SHF_WRITE); 484 485 MergeableConst4Section = 486 Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS, 487 ELF::SHF_ALLOC | ELF::SHF_MERGE, 4, ""); 488 489 MergeableConst8Section = 490 Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS, 491 ELF::SHF_ALLOC | ELF::SHF_MERGE, 8, ""); 492 493 MergeableConst16Section = 494 Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS, 495 ELF::SHF_ALLOC | ELF::SHF_MERGE, 16, ""); 496 497 MergeableConst32Section = 498 Ctx->getELFSection(".rodata.cst32", ELF::SHT_PROGBITS, 499 ELF::SHF_ALLOC | ELF::SHF_MERGE, 32, ""); 500 501 StaticCtorSection = Ctx->getELFSection(".ctors", ELF::SHT_PROGBITS, 502 ELF::SHF_ALLOC | ELF::SHF_WRITE); 503 504 StaticDtorSection = Ctx->getELFSection(".dtors", ELF::SHT_PROGBITS, 505 ELF::SHF_ALLOC | ELF::SHF_WRITE); 506 507 // Exception Handling Sections. 508 509 // FIXME: We're emitting LSDA info into a readonly section on ELF, even though 510 // it contains relocatable pointers. In PIC mode, this is probably a big 511 // runtime hit for C++ apps. Either the contents of the LSDA need to be 512 // adjusted or this should be a data section. 513 LSDASection = Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS, 514 ELF::SHF_ALLOC); 515 516 COFFDebugSymbolsSection = nullptr; 517 COFFDebugTypesSection = nullptr; 518 519 // Debug Info Sections. 520 DwarfAbbrevSection = Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0, 521 "section_abbrev"); 522 DwarfInfoSection = 523 Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0, "section_info"); 524 DwarfLineSection = Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0); 525 DwarfFrameSection = Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0); 526 DwarfPubNamesSection = 527 Ctx->getELFSection(".debug_pubnames", ELF::SHT_PROGBITS, 0); 528 DwarfPubTypesSection = 529 Ctx->getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0); 530 DwarfGnuPubNamesSection = 531 Ctx->getELFSection(".debug_gnu_pubnames", ELF::SHT_PROGBITS, 0); 532 DwarfGnuPubTypesSection = 533 Ctx->getELFSection(".debug_gnu_pubtypes", ELF::SHT_PROGBITS, 0); 534 DwarfStrSection = 535 Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS, 536 ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, ""); 537 DwarfLocSection = Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0); 538 DwarfARangesSection = 539 Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0); 540 DwarfRangesSection = 541 Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0, "debug_range"); 542 DwarfMacinfoSection = Ctx->getELFSection(".debug_macinfo", ELF::SHT_PROGBITS, 543 0, "debug_macinfo"); 544 545 // DWARF5 Experimental Debug Info 546 547 // Accelerator Tables 548 DwarfAccelNamesSection = 549 Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0, "names_begin"); 550 DwarfAccelObjCSection = 551 Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0, "objc_begin"); 552 DwarfAccelNamespaceSection = Ctx->getELFSection( 553 ".apple_namespaces", ELF::SHT_PROGBITS, 0, "namespac_begin"); 554 DwarfAccelTypesSection = 555 Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0, "types_begin"); 556 557 // Fission Sections 558 DwarfInfoDWOSection = 559 Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0); 560 DwarfTypesDWOSection = 561 Ctx->getELFSection(".debug_types.dwo", ELF::SHT_PROGBITS, 0); 562 DwarfAbbrevDWOSection = 563 Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0); 564 DwarfStrDWOSection = 565 Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS, 566 ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, ""); 567 DwarfLineDWOSection = 568 Ctx->getELFSection(".debug_line.dwo", ELF::SHT_PROGBITS, 0); 569 DwarfLocDWOSection = 570 Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0, "skel_loc"); 571 DwarfStrOffDWOSection = 572 Ctx->getELFSection(".debug_str_offsets.dwo", ELF::SHT_PROGBITS, 0); 573 DwarfAddrSection = 574 Ctx->getELFSection(".debug_addr", ELF::SHT_PROGBITS, 0, "addr_sec"); 575 576 // DWP Sections 577 DwarfCUIndexSection = 578 Ctx->getELFSection(".debug_cu_index", ELF::SHT_PROGBITS, 0); 579 DwarfTUIndexSection = 580 Ctx->getELFSection(".debug_tu_index", ELF::SHT_PROGBITS, 0); 581 582 StackMapSection = 583 Ctx->getELFSection(".llvm_stackmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC); 584 585 FaultMapSection = 586 Ctx->getELFSection(".llvm_faultmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC); 587 588 EHFrameSection = 589 Ctx->getELFSection(".eh_frame", EHSectionType, EHSectionFlags); 590 } 591 592 void MCObjectFileInfo::initCOFFMCObjectFileInfo(const Triple &T) { 593 EHFrameSection = Ctx->getCOFFSection( 594 ".eh_frame", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 595 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE, 596 SectionKind::getData()); 597 598 // Set the `IMAGE_SCN_MEM_16BIT` flag when compiling for thumb mode. This is 599 // used to indicate to the linker that the text segment contains thumb instructions 600 // and to set the ISA selection bit for calls accordingly. 601 const bool IsThumb = T.getArch() == Triple::thumb; 602 603 CommDirectiveSupportsAlignment = true; 604 605 // COFF 606 BSSSection = Ctx->getCOFFSection( 607 ".bss", COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA | 608 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE, 609 SectionKind::getBSS()); 610 TextSection = Ctx->getCOFFSection( 611 ".text", 612 (IsThumb ? COFF::IMAGE_SCN_MEM_16BIT : (COFF::SectionCharacteristics)0) | 613 COFF::IMAGE_SCN_CNT_CODE | COFF::IMAGE_SCN_MEM_EXECUTE | 614 COFF::IMAGE_SCN_MEM_READ, 615 SectionKind::getText()); 616 DataSection = Ctx->getCOFFSection( 617 ".data", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ | 618 COFF::IMAGE_SCN_MEM_WRITE, 619 SectionKind::getData()); 620 ReadOnlySection = Ctx->getCOFFSection( 621 ".rdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 622 SectionKind::getReadOnly()); 623 624 if (T.isKnownWindowsMSVCEnvironment() || T.isWindowsItaniumEnvironment()) { 625 StaticCtorSection = 626 Ctx->getCOFFSection(".CRT$XCU", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 627 COFF::IMAGE_SCN_MEM_READ, 628 SectionKind::getReadOnly()); 629 StaticDtorSection = 630 Ctx->getCOFFSection(".CRT$XTX", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 631 COFF::IMAGE_SCN_MEM_READ, 632 SectionKind::getReadOnly()); 633 } else { 634 StaticCtorSection = Ctx->getCOFFSection( 635 ".ctors", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 636 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE, 637 SectionKind::getData()); 638 StaticDtorSection = Ctx->getCOFFSection( 639 ".dtors", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 640 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE, 641 SectionKind::getData()); 642 } 643 644 // FIXME: We're emitting LSDA info into a readonly section on COFF, even 645 // though it contains relocatable pointers. In PIC mode, this is probably a 646 // big runtime hit for C++ apps. Either the contents of the LSDA need to be 647 // adjusted or this should be a data section. 648 if (T.getArch() == Triple::x86_64) { 649 // On Windows 64 with SEH, the LSDA is emitted into the .xdata section 650 LSDASection = nullptr; 651 } else { 652 LSDASection = Ctx->getCOFFSection(".gcc_except_table", 653 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 654 COFF::IMAGE_SCN_MEM_READ, 655 SectionKind::getReadOnly()); 656 } 657 658 // Debug info. 659 COFFDebugSymbolsSection = 660 Ctx->getCOFFSection(".debug$S", (COFF::IMAGE_SCN_MEM_DISCARDABLE | 661 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 662 COFF::IMAGE_SCN_MEM_READ), 663 SectionKind::getMetadata()); 664 COFFDebugTypesSection = 665 Ctx->getCOFFSection(".debug$T", (COFF::IMAGE_SCN_MEM_DISCARDABLE | 666 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 667 COFF::IMAGE_SCN_MEM_READ), 668 SectionKind::getMetadata()); 669 670 DwarfAbbrevSection = Ctx->getCOFFSection( 671 ".debug_abbrev", 672 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 673 COFF::IMAGE_SCN_MEM_READ, 674 SectionKind::getMetadata(), "section_abbrev"); 675 DwarfInfoSection = Ctx->getCOFFSection( 676 ".debug_info", 677 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 678 COFF::IMAGE_SCN_MEM_READ, 679 SectionKind::getMetadata(), "section_info"); 680 DwarfLineSection = Ctx->getCOFFSection( 681 ".debug_line", 682 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 683 COFF::IMAGE_SCN_MEM_READ, 684 SectionKind::getMetadata(), "section_line"); 685 686 DwarfFrameSection = Ctx->getCOFFSection( 687 ".debug_frame", 688 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 689 COFF::IMAGE_SCN_MEM_READ, 690 SectionKind::getMetadata()); 691 DwarfPubNamesSection = Ctx->getCOFFSection( 692 ".debug_pubnames", 693 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 694 COFF::IMAGE_SCN_MEM_READ, 695 SectionKind::getMetadata()); 696 DwarfPubTypesSection = Ctx->getCOFFSection( 697 ".debug_pubtypes", 698 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 699 COFF::IMAGE_SCN_MEM_READ, 700 SectionKind::getMetadata()); 701 DwarfGnuPubNamesSection = Ctx->getCOFFSection( 702 ".debug_gnu_pubnames", 703 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 704 COFF::IMAGE_SCN_MEM_READ, 705 SectionKind::getMetadata()); 706 DwarfGnuPubTypesSection = Ctx->getCOFFSection( 707 ".debug_gnu_pubtypes", 708 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 709 COFF::IMAGE_SCN_MEM_READ, 710 SectionKind::getMetadata()); 711 DwarfStrSection = Ctx->getCOFFSection( 712 ".debug_str", 713 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 714 COFF::IMAGE_SCN_MEM_READ, 715 SectionKind::getMetadata(), "info_string"); 716 DwarfLocSection = Ctx->getCOFFSection( 717 ".debug_loc", 718 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 719 COFF::IMAGE_SCN_MEM_READ, 720 SectionKind::getMetadata(), "section_debug_loc"); 721 DwarfARangesSection = Ctx->getCOFFSection( 722 ".debug_aranges", 723 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 724 COFF::IMAGE_SCN_MEM_READ, 725 SectionKind::getMetadata()); 726 DwarfRangesSection = Ctx->getCOFFSection( 727 ".debug_ranges", 728 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 729 COFF::IMAGE_SCN_MEM_READ, 730 SectionKind::getMetadata(), "debug_range"); 731 DwarfMacinfoSection = Ctx->getCOFFSection( 732 ".debug_macinfo", 733 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 734 COFF::IMAGE_SCN_MEM_READ, 735 SectionKind::getMetadata(), "debug_macinfo"); 736 DwarfInfoDWOSection = Ctx->getCOFFSection( 737 ".debug_info.dwo", 738 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 739 COFF::IMAGE_SCN_MEM_READ, 740 SectionKind::getMetadata(), "section_info_dwo"); 741 DwarfTypesDWOSection = Ctx->getCOFFSection( 742 ".debug_types.dwo", 743 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 744 COFF::IMAGE_SCN_MEM_READ, 745 SectionKind::getMetadata(), "section_types_dwo"); 746 DwarfAbbrevDWOSection = Ctx->getCOFFSection( 747 ".debug_abbrev.dwo", 748 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 749 COFF::IMAGE_SCN_MEM_READ, 750 SectionKind::getMetadata(), "section_abbrev_dwo"); 751 DwarfStrDWOSection = Ctx->getCOFFSection( 752 ".debug_str.dwo", 753 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 754 COFF::IMAGE_SCN_MEM_READ, 755 SectionKind::getMetadata(), "skel_string"); 756 DwarfLineDWOSection = Ctx->getCOFFSection( 757 ".debug_line.dwo", 758 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 759 COFF::IMAGE_SCN_MEM_READ, 760 SectionKind::getMetadata()); 761 DwarfLocDWOSection = Ctx->getCOFFSection( 762 ".debug_loc.dwo", 763 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 764 COFF::IMAGE_SCN_MEM_READ, 765 SectionKind::getMetadata(), "skel_loc"); 766 DwarfStrOffDWOSection = Ctx->getCOFFSection( 767 ".debug_str_offsets.dwo", 768 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 769 COFF::IMAGE_SCN_MEM_READ, 770 SectionKind::getMetadata()); 771 DwarfAddrSection = Ctx->getCOFFSection( 772 ".debug_addr", 773 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 774 COFF::IMAGE_SCN_MEM_READ, 775 SectionKind::getMetadata(), "addr_sec"); 776 DwarfCUIndexSection = Ctx->getCOFFSection( 777 ".debug_cu_index", 778 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 779 COFF::IMAGE_SCN_MEM_READ, 780 SectionKind::getMetadata()); 781 DwarfTUIndexSection = Ctx->getCOFFSection( 782 ".debug_tu_index", 783 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 784 COFF::IMAGE_SCN_MEM_READ, 785 SectionKind::getMetadata()); 786 DwarfAccelNamesSection = Ctx->getCOFFSection( 787 ".apple_names", 788 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 789 COFF::IMAGE_SCN_MEM_READ, 790 SectionKind::getMetadata(), "names_begin"); 791 DwarfAccelNamespaceSection = Ctx->getCOFFSection( 792 ".apple_namespaces", 793 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 794 COFF::IMAGE_SCN_MEM_READ, 795 SectionKind::getMetadata(), "namespac_begin"); 796 DwarfAccelTypesSection = Ctx->getCOFFSection( 797 ".apple_types", 798 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 799 COFF::IMAGE_SCN_MEM_READ, 800 SectionKind::getMetadata(), "types_begin"); 801 DwarfAccelObjCSection = Ctx->getCOFFSection( 802 ".apple_objc", 803 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 804 COFF::IMAGE_SCN_MEM_READ, 805 SectionKind::getMetadata(), "objc_begin"); 806 807 DrectveSection = Ctx->getCOFFSection( 808 ".drectve", COFF::IMAGE_SCN_LNK_INFO | COFF::IMAGE_SCN_LNK_REMOVE, 809 SectionKind::getMetadata()); 810 811 PDataSection = Ctx->getCOFFSection( 812 ".pdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 813 SectionKind::getData()); 814 815 XDataSection = Ctx->getCOFFSection( 816 ".xdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 817 SectionKind::getData()); 818 819 SXDataSection = Ctx->getCOFFSection(".sxdata", COFF::IMAGE_SCN_LNK_INFO, 820 SectionKind::getMetadata()); 821 822 TLSDataSection = Ctx->getCOFFSection( 823 ".tls$", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ | 824 COFF::IMAGE_SCN_MEM_WRITE, 825 SectionKind::getData()); 826 827 StackMapSection = Ctx->getCOFFSection(".llvm_stackmaps", 828 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 829 COFF::IMAGE_SCN_MEM_READ, 830 SectionKind::getReadOnly()); 831 } 832 833 void MCObjectFileInfo::InitMCObjectFileInfo(const Triple &TheTriple, bool PIC, 834 CodeModel::Model cm, 835 MCContext &ctx) { 836 PositionIndependent = PIC; 837 CMModel = cm; 838 Ctx = &ctx; 839 840 // Common. 841 CommDirectiveSupportsAlignment = true; 842 SupportsWeakOmittedEHFrame = true; 843 SupportsCompactUnwindWithoutEHFrame = false; 844 OmitDwarfIfHaveCompactUnwind = false; 845 846 PersonalityEncoding = LSDAEncoding = FDECFIEncoding = TTypeEncoding = 847 dwarf::DW_EH_PE_absptr; 848 849 CompactUnwindDwarfEHFrameOnly = 0; 850 851 EHFrameSection = nullptr; // Created on demand. 852 CompactUnwindSection = nullptr; // Used only by selected targets. 853 DwarfAccelNamesSection = nullptr; // Used only by selected targets. 854 DwarfAccelObjCSection = nullptr; // Used only by selected targets. 855 DwarfAccelNamespaceSection = nullptr; // Used only by selected targets. 856 DwarfAccelTypesSection = nullptr; // Used only by selected targets. 857 858 TT = TheTriple; 859 860 switch (TT.getObjectFormat()) { 861 case Triple::MachO: 862 Env = IsMachO; 863 initMachOMCObjectFileInfo(TT); 864 break; 865 case Triple::COFF: 866 if (!TT.isOSWindows()) 867 report_fatal_error( 868 "Cannot initialize MC for non-Windows COFF object files."); 869 870 Env = IsCOFF; 871 initCOFFMCObjectFileInfo(TT); 872 break; 873 case Triple::ELF: 874 Env = IsELF; 875 initELFMCObjectFileInfo(TT); 876 break; 877 case Triple::UnknownObjectFormat: 878 report_fatal_error("Cannot initialize MC for unknown object file format."); 879 break; 880 } 881 } 882 883 MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const { 884 return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP, 885 0, utostr(Hash)); 886 } 887
