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 // Exception Handling. 181 LSDASection = Ctx->getMachOSection("__TEXT", "__gcc_except_tab", 0, 182 SectionKind::getReadOnlyWithRel()); 183 184 COFFDebugSymbolsSection = nullptr; 185 COFFDebugTypesSection = nullptr; 186 187 if (useCompactUnwind(T)) { 188 CompactUnwindSection = 189 Ctx->getMachOSection("__LD", "__compact_unwind", MachO::S_ATTR_DEBUG, 190 SectionKind::getReadOnly()); 191 192 if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86) 193 CompactUnwindDwarfEHFrameOnly = 0x04000000; // UNWIND_X86_64_MODE_DWARF 194 else if (T.getArch() == Triple::aarch64) 195 CompactUnwindDwarfEHFrameOnly = 0x03000000; // UNWIND_ARM64_MODE_DWARF 196 else if (T.getArch() == Triple::arm || T.getArch() == Triple::thumb) 197 CompactUnwindDwarfEHFrameOnly = 0x04000000; // UNWIND_ARM_MODE_DWARF 198 } 199 200 // Debug Information. 201 DwarfAccelNamesSection = 202 Ctx->getMachOSection("__DWARF", "__apple_names", MachO::S_ATTR_DEBUG, 203 SectionKind::getMetadata(), "names_begin"); 204 DwarfAccelObjCSection = 205 Ctx->getMachOSection("__DWARF", "__apple_objc", MachO::S_ATTR_DEBUG, 206 SectionKind::getMetadata(), "objc_begin"); 207 // 16 character section limit... 208 DwarfAccelNamespaceSection = 209 Ctx->getMachOSection("__DWARF", "__apple_namespac", MachO::S_ATTR_DEBUG, 210 SectionKind::getMetadata(), "namespac_begin"); 211 DwarfAccelTypesSection = 212 Ctx->getMachOSection("__DWARF", "__apple_types", MachO::S_ATTR_DEBUG, 213 SectionKind::getMetadata(), "types_begin"); 214 215 DwarfAbbrevSection = 216 Ctx->getMachOSection("__DWARF", "__debug_abbrev", MachO::S_ATTR_DEBUG, 217 SectionKind::getMetadata(), "section_abbrev"); 218 DwarfInfoSection = 219 Ctx->getMachOSection("__DWARF", "__debug_info", MachO::S_ATTR_DEBUG, 220 SectionKind::getMetadata(), "section_info"); 221 DwarfLineSection = 222 Ctx->getMachOSection("__DWARF", "__debug_line", MachO::S_ATTR_DEBUG, 223 SectionKind::getMetadata(), "section_line"); 224 DwarfFrameSection = 225 Ctx->getMachOSection("__DWARF", "__debug_frame", MachO::S_ATTR_DEBUG, 226 SectionKind::getMetadata()); 227 DwarfPubNamesSection = 228 Ctx->getMachOSection("__DWARF", "__debug_pubnames", MachO::S_ATTR_DEBUG, 229 SectionKind::getMetadata()); 230 DwarfPubTypesSection = 231 Ctx->getMachOSection("__DWARF", "__debug_pubtypes", MachO::S_ATTR_DEBUG, 232 SectionKind::getMetadata()); 233 DwarfGnuPubNamesSection = 234 Ctx->getMachOSection("__DWARF", "__debug_gnu_pubn", MachO::S_ATTR_DEBUG, 235 SectionKind::getMetadata()); 236 DwarfGnuPubTypesSection = 237 Ctx->getMachOSection("__DWARF", "__debug_gnu_pubt", MachO::S_ATTR_DEBUG, 238 SectionKind::getMetadata()); 239 DwarfStrSection = 240 Ctx->getMachOSection("__DWARF", "__debug_str", MachO::S_ATTR_DEBUG, 241 SectionKind::getMetadata(), "info_string"); 242 DwarfLocSection = 243 Ctx->getMachOSection("__DWARF", "__debug_loc", MachO::S_ATTR_DEBUG, 244 SectionKind::getMetadata(), "section_debug_loc"); 245 DwarfARangesSection = 246 Ctx->getMachOSection("__DWARF", "__debug_aranges", MachO::S_ATTR_DEBUG, 247 SectionKind::getMetadata()); 248 DwarfRangesSection = 249 Ctx->getMachOSection("__DWARF", "__debug_ranges", MachO::S_ATTR_DEBUG, 250 SectionKind::getMetadata(), "debug_range"); 251 DwarfMacinfoSection = 252 Ctx->getMachOSection("__DWARF", "__debug_macinfo", MachO::S_ATTR_DEBUG, 253 SectionKind::getMetadata(), "debug_macinfo"); 254 DwarfDebugInlineSection = 255 Ctx->getMachOSection("__DWARF", "__debug_inlined", MachO::S_ATTR_DEBUG, 256 SectionKind::getMetadata()); 257 DwarfCUIndexSection = 258 Ctx->getMachOSection("__DWARF", "__debug_cu_index", MachO::S_ATTR_DEBUG, 259 SectionKind::getMetadata()); 260 DwarfTUIndexSection = 261 Ctx->getMachOSection("__DWARF", "__debug_tu_index", MachO::S_ATTR_DEBUG, 262 SectionKind::getMetadata()); 263 StackMapSection = Ctx->getMachOSection("__LLVM_STACKMAPS", "__llvm_stackmaps", 264 0, SectionKind::getMetadata()); 265 266 FaultMapSection = Ctx->getMachOSection("__LLVM_FAULTMAPS", "__llvm_faultmaps", 267 0, SectionKind::getMetadata()); 268 269 TLSExtraDataSection = TLSTLVSection; 270 } 271 272 void MCObjectFileInfo::initELFMCObjectFileInfo(const Triple &T) { 273 switch (T.getArch()) { 274 case Triple::mips: 275 case Triple::mipsel: 276 FDECFIEncoding = dwarf::DW_EH_PE_sdata4; 277 break; 278 case Triple::mips64: 279 case Triple::mips64el: 280 FDECFIEncoding = dwarf::DW_EH_PE_sdata8; 281 break; 282 case Triple::x86_64: 283 FDECFIEncoding = dwarf::DW_EH_PE_pcrel | 284 ((CMModel == CodeModel::Large) ? dwarf::DW_EH_PE_sdata8 285 : dwarf::DW_EH_PE_sdata4); 286 break; 287 default: 288 FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 289 break; 290 } 291 292 switch (T.getArch()) { 293 case Triple::arm: 294 case Triple::armeb: 295 case Triple::thumb: 296 case Triple::thumbeb: 297 if (Ctx->getAsmInfo()->getExceptionHandlingType() == ExceptionHandling::ARM) 298 break; 299 // Fallthrough if not using EHABI 300 LLVM_FALLTHROUGH; 301 case Triple::ppc: 302 case Triple::x86: 303 PersonalityEncoding = PositionIndependent 304 ? dwarf::DW_EH_PE_indirect | 305 dwarf::DW_EH_PE_pcrel | 306 dwarf::DW_EH_PE_sdata4 307 : dwarf::DW_EH_PE_absptr; 308 LSDAEncoding = PositionIndependent 309 ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4 310 : dwarf::DW_EH_PE_absptr; 311 TTypeEncoding = PositionIndependent 312 ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 313 dwarf::DW_EH_PE_sdata4 314 : dwarf::DW_EH_PE_absptr; 315 break; 316 case Triple::x86_64: 317 if (PositionIndependent) { 318 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 319 ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium) 320 ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8); 321 LSDAEncoding = dwarf::DW_EH_PE_pcrel | 322 (CMModel == CodeModel::Small 323 ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8); 324 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 325 ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium) 326 ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8); 327 } else { 328 PersonalityEncoding = 329 (CMModel == CodeModel::Small || CMModel == CodeModel::Medium) 330 ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr; 331 LSDAEncoding = (CMModel == CodeModel::Small) 332 ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr; 333 TTypeEncoding = (CMModel == CodeModel::Small) 334 ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr; 335 } 336 break; 337 case Triple::hexagon: 338 PersonalityEncoding = dwarf::DW_EH_PE_absptr; 339 LSDAEncoding = dwarf::DW_EH_PE_absptr; 340 FDECFIEncoding = dwarf::DW_EH_PE_absptr; 341 TTypeEncoding = dwarf::DW_EH_PE_absptr; 342 if (PositionIndependent) { 343 PersonalityEncoding |= dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel; 344 LSDAEncoding |= dwarf::DW_EH_PE_pcrel; 345 FDECFIEncoding |= dwarf::DW_EH_PE_pcrel; 346 TTypeEncoding |= dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel; 347 } 348 break; 349 case Triple::aarch64: 350 case Triple::aarch64_be: 351 // The small model guarantees static code/data size < 4GB, but not where it 352 // will be in memory. Most of these could end up >2GB away so even a signed 353 // pc-relative 32-bit address is insufficient, theoretically. 354 if (PositionIndependent) { 355 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 356 dwarf::DW_EH_PE_sdata8; 357 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8; 358 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 359 dwarf::DW_EH_PE_sdata8; 360 } else { 361 PersonalityEncoding = dwarf::DW_EH_PE_absptr; 362 LSDAEncoding = dwarf::DW_EH_PE_absptr; 363 TTypeEncoding = dwarf::DW_EH_PE_absptr; 364 } 365 break; 366 case Triple::lanai: 367 LSDAEncoding = dwarf::DW_EH_PE_absptr; 368 PersonalityEncoding = dwarf::DW_EH_PE_absptr; 369 TTypeEncoding = dwarf::DW_EH_PE_absptr; 370 break; 371 case Triple::mips: 372 case Triple::mipsel: 373 case Triple::mips64: 374 case Triple::mips64el: 375 // MIPS uses indirect pointer to refer personality functions and types, so 376 // that the eh_frame section can be read-only. DW.ref.personality will be 377 // generated for relocation. 378 PersonalityEncoding = dwarf::DW_EH_PE_indirect; 379 // FIXME: The N64 ABI probably ought to use DW_EH_PE_sdata8 but we can't 380 // identify N64 from just a triple. 381 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 382 dwarf::DW_EH_PE_sdata4; 383 // We don't support PC-relative LSDA references in GAS so we use the default 384 // DW_EH_PE_absptr for those. 385 386 // FreeBSD must be explicit about the data size and using pcrel since it's 387 // assembler/linker won't do the automatic conversion that the Linux tools 388 // do. 389 if (T.isOSFreeBSD()) { 390 PersonalityEncoding |= dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 391 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 392 } 393 break; 394 case Triple::ppc64: 395 case Triple::ppc64le: 396 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 397 dwarf::DW_EH_PE_udata8; 398 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8; 399 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 400 dwarf::DW_EH_PE_udata8; 401 break; 402 case Triple::sparcel: 403 case Triple::sparc: 404 if (PositionIndependent) { 405 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 406 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 407 dwarf::DW_EH_PE_sdata4; 408 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 409 dwarf::DW_EH_PE_sdata4; 410 } else { 411 LSDAEncoding = dwarf::DW_EH_PE_absptr; 412 PersonalityEncoding = dwarf::DW_EH_PE_absptr; 413 TTypeEncoding = dwarf::DW_EH_PE_absptr; 414 } 415 break; 416 case Triple::sparcv9: 417 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 418 if (PositionIndependent) { 419 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 420 dwarf::DW_EH_PE_sdata4; 421 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 422 dwarf::DW_EH_PE_sdata4; 423 } else { 424 PersonalityEncoding = dwarf::DW_EH_PE_absptr; 425 TTypeEncoding = dwarf::DW_EH_PE_absptr; 426 } 427 break; 428 case Triple::systemz: 429 // All currently-defined code models guarantee that 4-byte PC-relative 430 // values will be in range. 431 if (PositionIndependent) { 432 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 433 dwarf::DW_EH_PE_sdata4; 434 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 435 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 436 dwarf::DW_EH_PE_sdata4; 437 } else { 438 PersonalityEncoding = dwarf::DW_EH_PE_absptr; 439 LSDAEncoding = dwarf::DW_EH_PE_absptr; 440 TTypeEncoding = dwarf::DW_EH_PE_absptr; 441 } 442 break; 443 default: 444 break; 445 } 446 447 unsigned EHSectionType = T.getArch() == Triple::x86_64 448 ? ELF::SHT_X86_64_UNWIND 449 : ELF::SHT_PROGBITS; 450 451 // Solaris requires different flags for .eh_frame to seemingly every other 452 // platform. 453 unsigned EHSectionFlags = ELF::SHF_ALLOC; 454 if (T.isOSSolaris() && T.getArch() != Triple::x86_64) 455 EHSectionFlags |= ELF::SHF_WRITE; 456 457 // ELF 458 BSSSection = Ctx->getELFSection(".bss", ELF::SHT_NOBITS, 459 ELF::SHF_WRITE | ELF::SHF_ALLOC); 460 461 TextSection = Ctx->getELFSection(".text", ELF::SHT_PROGBITS, 462 ELF::SHF_EXECINSTR | ELF::SHF_ALLOC); 463 464 DataSection = Ctx->getELFSection(".data", ELF::SHT_PROGBITS, 465 ELF::SHF_WRITE | ELF::SHF_ALLOC); 466 467 ReadOnlySection = 468 Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS, ELF::SHF_ALLOC); 469 470 TLSDataSection = 471 Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS, 472 ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE); 473 474 TLSBSSSection = Ctx->getELFSection( 475 ".tbss", ELF::SHT_NOBITS, ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE); 476 477 DataRelROSection = Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS, 478 ELF::SHF_ALLOC | ELF::SHF_WRITE); 479 480 MergeableConst4Section = 481 Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS, 482 ELF::SHF_ALLOC | ELF::SHF_MERGE, 4, ""); 483 484 MergeableConst8Section = 485 Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS, 486 ELF::SHF_ALLOC | ELF::SHF_MERGE, 8, ""); 487 488 MergeableConst16Section = 489 Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS, 490 ELF::SHF_ALLOC | ELF::SHF_MERGE, 16, ""); 491 492 MergeableConst32Section = 493 Ctx->getELFSection(".rodata.cst32", ELF::SHT_PROGBITS, 494 ELF::SHF_ALLOC | ELF::SHF_MERGE, 32, ""); 495 496 // Exception Handling Sections. 497 498 // FIXME: We're emitting LSDA info into a readonly section on ELF, even though 499 // it contains relocatable pointers. In PIC mode, this is probably a big 500 // runtime hit for C++ apps. Either the contents of the LSDA need to be 501 // adjusted or this should be a data section. 502 LSDASection = Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS, 503 ELF::SHF_ALLOC); 504 505 COFFDebugSymbolsSection = nullptr; 506 COFFDebugTypesSection = nullptr; 507 508 // Debug Info Sections. 509 DwarfAbbrevSection = 510 Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0); 511 DwarfInfoSection = Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0); 512 DwarfLineSection = Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0); 513 DwarfFrameSection = Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0); 514 DwarfPubNamesSection = 515 Ctx->getELFSection(".debug_pubnames", ELF::SHT_PROGBITS, 0); 516 DwarfPubTypesSection = 517 Ctx->getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0); 518 DwarfGnuPubNamesSection = 519 Ctx->getELFSection(".debug_gnu_pubnames", ELF::SHT_PROGBITS, 0); 520 DwarfGnuPubTypesSection = 521 Ctx->getELFSection(".debug_gnu_pubtypes", ELF::SHT_PROGBITS, 0); 522 DwarfStrSection = 523 Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS, 524 ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, ""); 525 DwarfLocSection = Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0); 526 DwarfARangesSection = 527 Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0); 528 DwarfRangesSection = 529 Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0); 530 DwarfMacinfoSection = 531 Ctx->getELFSection(".debug_macinfo", ELF::SHT_PROGBITS, 0); 532 533 // DWARF5 Experimental Debug Info 534 535 // Accelerator Tables 536 DwarfAccelNamesSection = 537 Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0); 538 DwarfAccelObjCSection = 539 Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0); 540 DwarfAccelNamespaceSection = 541 Ctx->getELFSection(".apple_namespaces", ELF::SHT_PROGBITS, 0); 542 DwarfAccelTypesSection = 543 Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0); 544 545 // Fission Sections 546 DwarfInfoDWOSection = 547 Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0); 548 DwarfTypesDWOSection = 549 Ctx->getELFSection(".debug_types.dwo", ELF::SHT_PROGBITS, 0); 550 DwarfAbbrevDWOSection = 551 Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0); 552 DwarfStrDWOSection = 553 Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS, 554 ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, ""); 555 DwarfLineDWOSection = 556 Ctx->getELFSection(".debug_line.dwo", ELF::SHT_PROGBITS, 0); 557 DwarfLocDWOSection = 558 Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0); 559 DwarfStrOffDWOSection = 560 Ctx->getELFSection(".debug_str_offsets.dwo", ELF::SHT_PROGBITS, 0); 561 DwarfAddrSection = Ctx->getELFSection(".debug_addr", ELF::SHT_PROGBITS, 0); 562 563 // DWP Sections 564 DwarfCUIndexSection = 565 Ctx->getELFSection(".debug_cu_index", ELF::SHT_PROGBITS, 0); 566 DwarfTUIndexSection = 567 Ctx->getELFSection(".debug_tu_index", ELF::SHT_PROGBITS, 0); 568 569 StackMapSection = 570 Ctx->getELFSection(".llvm_stackmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC); 571 572 FaultMapSection = 573 Ctx->getELFSection(".llvm_faultmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC); 574 575 EHFrameSection = 576 Ctx->getELFSection(".eh_frame", EHSectionType, EHSectionFlags); 577 } 578 579 void MCObjectFileInfo::initCOFFMCObjectFileInfo(const Triple &T) { 580 EHFrameSection = Ctx->getCOFFSection( 581 ".eh_frame", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 582 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE, 583 SectionKind::getData()); 584 585 // Set the `IMAGE_SCN_MEM_16BIT` flag when compiling for thumb mode. This is 586 // used to indicate to the linker that the text segment contains thumb instructions 587 // and to set the ISA selection bit for calls accordingly. 588 const bool IsThumb = T.getArch() == Triple::thumb; 589 590 CommDirectiveSupportsAlignment = true; 591 592 // COFF 593 BSSSection = Ctx->getCOFFSection( 594 ".bss", COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA | 595 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE, 596 SectionKind::getBSS()); 597 TextSection = Ctx->getCOFFSection( 598 ".text", 599 (IsThumb ? COFF::IMAGE_SCN_MEM_16BIT : (COFF::SectionCharacteristics)0) | 600 COFF::IMAGE_SCN_CNT_CODE | COFF::IMAGE_SCN_MEM_EXECUTE | 601 COFF::IMAGE_SCN_MEM_READ, 602 SectionKind::getText()); 603 DataSection = Ctx->getCOFFSection( 604 ".data", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ | 605 COFF::IMAGE_SCN_MEM_WRITE, 606 SectionKind::getData()); 607 ReadOnlySection = Ctx->getCOFFSection( 608 ".rdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 609 SectionKind::getReadOnly()); 610 611 // FIXME: We're emitting LSDA info into a readonly section on COFF, even 612 // though it contains relocatable pointers. In PIC mode, this is probably a 613 // big runtime hit for C++ apps. Either the contents of the LSDA need to be 614 // adjusted or this should be a data section. 615 if (T.getArch() == Triple::x86_64) { 616 // On Windows 64 with SEH, the LSDA is emitted into the .xdata section 617 LSDASection = nullptr; 618 } else { 619 LSDASection = Ctx->getCOFFSection(".gcc_except_table", 620 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 621 COFF::IMAGE_SCN_MEM_READ, 622 SectionKind::getReadOnly()); 623 } 624 625 // Debug info. 626 COFFDebugSymbolsSection = 627 Ctx->getCOFFSection(".debug$S", (COFF::IMAGE_SCN_MEM_DISCARDABLE | 628 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 629 COFF::IMAGE_SCN_MEM_READ), 630 SectionKind::getMetadata()); 631 COFFDebugTypesSection = 632 Ctx->getCOFFSection(".debug$T", (COFF::IMAGE_SCN_MEM_DISCARDABLE | 633 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 634 COFF::IMAGE_SCN_MEM_READ), 635 SectionKind::getMetadata()); 636 637 DwarfAbbrevSection = Ctx->getCOFFSection( 638 ".debug_abbrev", 639 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 640 COFF::IMAGE_SCN_MEM_READ, 641 SectionKind::getMetadata(), "section_abbrev"); 642 DwarfInfoSection = Ctx->getCOFFSection( 643 ".debug_info", 644 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 645 COFF::IMAGE_SCN_MEM_READ, 646 SectionKind::getMetadata(), "section_info"); 647 DwarfLineSection = Ctx->getCOFFSection( 648 ".debug_line", 649 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 650 COFF::IMAGE_SCN_MEM_READ, 651 SectionKind::getMetadata(), "section_line"); 652 653 DwarfFrameSection = Ctx->getCOFFSection( 654 ".debug_frame", 655 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 656 COFF::IMAGE_SCN_MEM_READ, 657 SectionKind::getMetadata()); 658 DwarfPubNamesSection = Ctx->getCOFFSection( 659 ".debug_pubnames", 660 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 661 COFF::IMAGE_SCN_MEM_READ, 662 SectionKind::getMetadata()); 663 DwarfPubTypesSection = Ctx->getCOFFSection( 664 ".debug_pubtypes", 665 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 666 COFF::IMAGE_SCN_MEM_READ, 667 SectionKind::getMetadata()); 668 DwarfGnuPubNamesSection = Ctx->getCOFFSection( 669 ".debug_gnu_pubnames", 670 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 671 COFF::IMAGE_SCN_MEM_READ, 672 SectionKind::getMetadata()); 673 DwarfGnuPubTypesSection = Ctx->getCOFFSection( 674 ".debug_gnu_pubtypes", 675 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 676 COFF::IMAGE_SCN_MEM_READ, 677 SectionKind::getMetadata()); 678 DwarfStrSection = Ctx->getCOFFSection( 679 ".debug_str", 680 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 681 COFF::IMAGE_SCN_MEM_READ, 682 SectionKind::getMetadata(), "info_string"); 683 DwarfLocSection = Ctx->getCOFFSection( 684 ".debug_loc", 685 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 686 COFF::IMAGE_SCN_MEM_READ, 687 SectionKind::getMetadata(), "section_debug_loc"); 688 DwarfARangesSection = Ctx->getCOFFSection( 689 ".debug_aranges", 690 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 691 COFF::IMAGE_SCN_MEM_READ, 692 SectionKind::getMetadata()); 693 DwarfRangesSection = Ctx->getCOFFSection( 694 ".debug_ranges", 695 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 696 COFF::IMAGE_SCN_MEM_READ, 697 SectionKind::getMetadata(), "debug_range"); 698 DwarfMacinfoSection = Ctx->getCOFFSection( 699 ".debug_macinfo", 700 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 701 COFF::IMAGE_SCN_MEM_READ, 702 SectionKind::getMetadata(), "debug_macinfo"); 703 DwarfInfoDWOSection = Ctx->getCOFFSection( 704 ".debug_info.dwo", 705 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 706 COFF::IMAGE_SCN_MEM_READ, 707 SectionKind::getMetadata(), "section_info_dwo"); 708 DwarfTypesDWOSection = Ctx->getCOFFSection( 709 ".debug_types.dwo", 710 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 711 COFF::IMAGE_SCN_MEM_READ, 712 SectionKind::getMetadata(), "section_types_dwo"); 713 DwarfAbbrevDWOSection = Ctx->getCOFFSection( 714 ".debug_abbrev.dwo", 715 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 716 COFF::IMAGE_SCN_MEM_READ, 717 SectionKind::getMetadata(), "section_abbrev_dwo"); 718 DwarfStrDWOSection = Ctx->getCOFFSection( 719 ".debug_str.dwo", 720 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 721 COFF::IMAGE_SCN_MEM_READ, 722 SectionKind::getMetadata(), "skel_string"); 723 DwarfLineDWOSection = Ctx->getCOFFSection( 724 ".debug_line.dwo", 725 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 726 COFF::IMAGE_SCN_MEM_READ, 727 SectionKind::getMetadata()); 728 DwarfLocDWOSection = Ctx->getCOFFSection( 729 ".debug_loc.dwo", 730 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 731 COFF::IMAGE_SCN_MEM_READ, 732 SectionKind::getMetadata(), "skel_loc"); 733 DwarfStrOffDWOSection = Ctx->getCOFFSection( 734 ".debug_str_offsets.dwo", 735 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 736 COFF::IMAGE_SCN_MEM_READ, 737 SectionKind::getMetadata()); 738 DwarfAddrSection = Ctx->getCOFFSection( 739 ".debug_addr", 740 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 741 COFF::IMAGE_SCN_MEM_READ, 742 SectionKind::getMetadata(), "addr_sec"); 743 DwarfCUIndexSection = Ctx->getCOFFSection( 744 ".debug_cu_index", 745 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 746 COFF::IMAGE_SCN_MEM_READ, 747 SectionKind::getMetadata()); 748 DwarfTUIndexSection = Ctx->getCOFFSection( 749 ".debug_tu_index", 750 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 751 COFF::IMAGE_SCN_MEM_READ, 752 SectionKind::getMetadata()); 753 DwarfAccelNamesSection = Ctx->getCOFFSection( 754 ".apple_names", 755 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 756 COFF::IMAGE_SCN_MEM_READ, 757 SectionKind::getMetadata(), "names_begin"); 758 DwarfAccelNamespaceSection = Ctx->getCOFFSection( 759 ".apple_namespaces", 760 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 761 COFF::IMAGE_SCN_MEM_READ, 762 SectionKind::getMetadata(), "namespac_begin"); 763 DwarfAccelTypesSection = Ctx->getCOFFSection( 764 ".apple_types", 765 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 766 COFF::IMAGE_SCN_MEM_READ, 767 SectionKind::getMetadata(), "types_begin"); 768 DwarfAccelObjCSection = Ctx->getCOFFSection( 769 ".apple_objc", 770 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 771 COFF::IMAGE_SCN_MEM_READ, 772 SectionKind::getMetadata(), "objc_begin"); 773 774 DrectveSection = Ctx->getCOFFSection( 775 ".drectve", COFF::IMAGE_SCN_LNK_INFO | COFF::IMAGE_SCN_LNK_REMOVE, 776 SectionKind::getMetadata()); 777 778 PDataSection = Ctx->getCOFFSection( 779 ".pdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 780 SectionKind::getData()); 781 782 XDataSection = Ctx->getCOFFSection( 783 ".xdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 784 SectionKind::getData()); 785 786 SXDataSection = Ctx->getCOFFSection(".sxdata", COFF::IMAGE_SCN_LNK_INFO, 787 SectionKind::getMetadata()); 788 789 TLSDataSection = Ctx->getCOFFSection( 790 ".tls$", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ | 791 COFF::IMAGE_SCN_MEM_WRITE, 792 SectionKind::getData()); 793 794 StackMapSection = Ctx->getCOFFSection(".llvm_stackmaps", 795 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 796 COFF::IMAGE_SCN_MEM_READ, 797 SectionKind::getReadOnly()); 798 } 799 800 void MCObjectFileInfo::InitMCObjectFileInfo(const Triple &TheTriple, bool PIC, 801 CodeModel::Model cm, 802 MCContext &ctx) { 803 PositionIndependent = PIC; 804 CMModel = cm; 805 Ctx = &ctx; 806 807 // Common. 808 CommDirectiveSupportsAlignment = true; 809 SupportsWeakOmittedEHFrame = true; 810 SupportsCompactUnwindWithoutEHFrame = false; 811 OmitDwarfIfHaveCompactUnwind = false; 812 813 PersonalityEncoding = LSDAEncoding = FDECFIEncoding = TTypeEncoding = 814 dwarf::DW_EH_PE_absptr; 815 816 CompactUnwindDwarfEHFrameOnly = 0; 817 818 EHFrameSection = nullptr; // Created on demand. 819 CompactUnwindSection = nullptr; // Used only by selected targets. 820 DwarfAccelNamesSection = nullptr; // Used only by selected targets. 821 DwarfAccelObjCSection = nullptr; // Used only by selected targets. 822 DwarfAccelNamespaceSection = nullptr; // Used only by selected targets. 823 DwarfAccelTypesSection = nullptr; // Used only by selected targets. 824 825 TT = TheTriple; 826 827 switch (TT.getObjectFormat()) { 828 case Triple::MachO: 829 Env = IsMachO; 830 initMachOMCObjectFileInfo(TT); 831 break; 832 case Triple::COFF: 833 if (!TT.isOSWindows()) 834 report_fatal_error( 835 "Cannot initialize MC for non-Windows COFF object files."); 836 837 Env = IsCOFF; 838 initCOFFMCObjectFileInfo(TT); 839 break; 840 case Triple::ELF: 841 Env = IsELF; 842 initELFMCObjectFileInfo(TT); 843 break; 844 case Triple::Wasm: 845 report_fatal_error("Cannot initialize MC for wasm object file format yet."); 846 break; 847 case Triple::UnknownObjectFormat: 848 report_fatal_error("Cannot initialize MC for unknown object file format."); 849 break; 850 } 851 } 852 853 MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const { 854 return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP, 855 0, utostr(Hash)); 856 } 857