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(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 if (RelocM == Reloc::Static) { 176 StaticCtorSection = Ctx->getMachOSection("__TEXT", "__constructor", 0, 177 SectionKind::getData()); 178 StaticDtorSection = Ctx->getMachOSection("__TEXT", "__destructor", 0, 179 SectionKind::getData()); 180 } else { 181 StaticCtorSection = Ctx->getMachOSection("__DATA", "__mod_init_func", 182 MachO::S_MOD_INIT_FUNC_POINTERS, 183 SectionKind::getData()); 184 StaticDtorSection = Ctx->getMachOSection("__DATA", "__mod_term_func", 185 MachO::S_MOD_TERM_FUNC_POINTERS, 186 SectionKind::getData()); 187 } 188 189 // Exception Handling. 190 LSDASection = Ctx->getMachOSection("__TEXT", "__gcc_except_tab", 0, 191 SectionKind::getReadOnlyWithRel()); 192 193 COFFDebugSymbolsSection = nullptr; 194 195 if (useCompactUnwind(T)) { 196 CompactUnwindSection = 197 Ctx->getMachOSection("__LD", "__compact_unwind", MachO::S_ATTR_DEBUG, 198 SectionKind::getReadOnly()); 199 200 if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86) 201 CompactUnwindDwarfEHFrameOnly = 0x04000000; // UNWIND_X86_64_MODE_DWARF 202 else if (T.getArch() == Triple::aarch64) 203 CompactUnwindDwarfEHFrameOnly = 0x03000000; // UNWIND_ARM64_MODE_DWARF 204 else if (T.getArch() == Triple::arm || T.getArch() == Triple::thumb) 205 CompactUnwindDwarfEHFrameOnly = 0x04000000; // UNWIND_ARM_MODE_DWARF 206 } 207 208 // Debug Information. 209 DwarfAccelNamesSection = 210 Ctx->getMachOSection("__DWARF", "__apple_names", MachO::S_ATTR_DEBUG, 211 SectionKind::getMetadata(), "names_begin"); 212 DwarfAccelObjCSection = 213 Ctx->getMachOSection("__DWARF", "__apple_objc", MachO::S_ATTR_DEBUG, 214 SectionKind::getMetadata(), "objc_begin"); 215 // 16 character section limit... 216 DwarfAccelNamespaceSection = 217 Ctx->getMachOSection("__DWARF", "__apple_namespac", MachO::S_ATTR_DEBUG, 218 SectionKind::getMetadata(), "namespac_begin"); 219 DwarfAccelTypesSection = 220 Ctx->getMachOSection("__DWARF", "__apple_types", MachO::S_ATTR_DEBUG, 221 SectionKind::getMetadata(), "types_begin"); 222 223 DwarfAbbrevSection = 224 Ctx->getMachOSection("__DWARF", "__debug_abbrev", MachO::S_ATTR_DEBUG, 225 SectionKind::getMetadata(), "section_abbrev"); 226 DwarfInfoSection = 227 Ctx->getMachOSection("__DWARF", "__debug_info", MachO::S_ATTR_DEBUG, 228 SectionKind::getMetadata(), "section_info"); 229 DwarfLineSection = 230 Ctx->getMachOSection("__DWARF", "__debug_line", MachO::S_ATTR_DEBUG, 231 SectionKind::getMetadata(), "section_line"); 232 DwarfFrameSection = 233 Ctx->getMachOSection("__DWARF", "__debug_frame", MachO::S_ATTR_DEBUG, 234 SectionKind::getMetadata()); 235 DwarfPubNamesSection = 236 Ctx->getMachOSection("__DWARF", "__debug_pubnames", MachO::S_ATTR_DEBUG, 237 SectionKind::getMetadata()); 238 DwarfPubTypesSection = 239 Ctx->getMachOSection("__DWARF", "__debug_pubtypes", MachO::S_ATTR_DEBUG, 240 SectionKind::getMetadata()); 241 DwarfGnuPubNamesSection = 242 Ctx->getMachOSection("__DWARF", "__debug_gnu_pubn", MachO::S_ATTR_DEBUG, 243 SectionKind::getMetadata()); 244 DwarfGnuPubTypesSection = 245 Ctx->getMachOSection("__DWARF", "__debug_gnu_pubt", MachO::S_ATTR_DEBUG, 246 SectionKind::getMetadata()); 247 DwarfStrSection = 248 Ctx->getMachOSection("__DWARF", "__debug_str", MachO::S_ATTR_DEBUG, 249 SectionKind::getMetadata(), "info_string"); 250 DwarfLocSection = 251 Ctx->getMachOSection("__DWARF", "__debug_loc", MachO::S_ATTR_DEBUG, 252 SectionKind::getMetadata(), "section_debug_loc"); 253 DwarfARangesSection = 254 Ctx->getMachOSection("__DWARF", "__debug_aranges", MachO::S_ATTR_DEBUG, 255 SectionKind::getMetadata()); 256 DwarfRangesSection = 257 Ctx->getMachOSection("__DWARF", "__debug_ranges", MachO::S_ATTR_DEBUG, 258 SectionKind::getMetadata(), "debug_range"); 259 DwarfMacinfoSection = 260 Ctx->getMachOSection("__DWARF", "__debug_macinfo", MachO::S_ATTR_DEBUG, 261 SectionKind::getMetadata()); 262 DwarfDebugInlineSection = 263 Ctx->getMachOSection("__DWARF", "__debug_inlined", MachO::S_ATTR_DEBUG, 264 SectionKind::getMetadata()); 265 DwarfCUIndexSection = 266 Ctx->getMachOSection("__DWARF", "__debug_cu_index", MachO::S_ATTR_DEBUG, 267 SectionKind::getMetadata()); 268 DwarfTUIndexSection = 269 Ctx->getMachOSection("__DWARF", "__debug_tu_index", MachO::S_ATTR_DEBUG, 270 SectionKind::getMetadata()); 271 StackMapSection = Ctx->getMachOSection("__LLVM_STACKMAPS", "__llvm_stackmaps", 272 0, SectionKind::getMetadata()); 273 274 FaultMapSection = Ctx->getMachOSection("__LLVM_FAULTMAPS", "__llvm_faultmaps", 275 0, SectionKind::getMetadata()); 276 277 TLSExtraDataSection = TLSTLVSection; 278 } 279 280 void MCObjectFileInfo::initELFMCObjectFileInfo(Triple T) { 281 switch (T.getArch()) { 282 case Triple::mips: 283 case Triple::mipsel: 284 FDECFIEncoding = dwarf::DW_EH_PE_sdata4; 285 break; 286 case Triple::mips64: 287 case Triple::mips64el: 288 FDECFIEncoding = dwarf::DW_EH_PE_sdata8; 289 break; 290 case Triple::x86_64: 291 FDECFIEncoding = dwarf::DW_EH_PE_pcrel | 292 ((CMModel == CodeModel::Large) ? dwarf::DW_EH_PE_sdata8 293 : dwarf::DW_EH_PE_sdata4); 294 break; 295 default: 296 FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 297 break; 298 } 299 300 switch (T.getArch()) { 301 case Triple::arm: 302 case Triple::armeb: 303 case Triple::thumb: 304 case Triple::thumbeb: 305 if (Ctx->getAsmInfo()->getExceptionHandlingType() == ExceptionHandling::ARM) 306 break; 307 // Fallthrough if not using EHABI 308 case Triple::ppc: 309 case Triple::x86: 310 PersonalityEncoding = (RelocM == Reloc::PIC_) 311 ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4 312 : dwarf::DW_EH_PE_absptr; 313 LSDAEncoding = (RelocM == Reloc::PIC_) 314 ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4 315 : dwarf::DW_EH_PE_absptr; 316 TTypeEncoding = (RelocM == Reloc::PIC_) 317 ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4 318 : dwarf::DW_EH_PE_absptr; 319 break; 320 case Triple::x86_64: 321 if (RelocM == Reloc::PIC_) { 322 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 323 ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium) 324 ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8); 325 LSDAEncoding = dwarf::DW_EH_PE_pcrel | 326 (CMModel == CodeModel::Small 327 ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8); 328 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 329 ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium) 330 ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8); 331 } else { 332 PersonalityEncoding = 333 (CMModel == CodeModel::Small || CMModel == CodeModel::Medium) 334 ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr; 335 LSDAEncoding = (CMModel == CodeModel::Small) 336 ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr; 337 TTypeEncoding = (CMModel == CodeModel::Small) 338 ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr; 339 } 340 break; 341 case Triple::aarch64: 342 case Triple::aarch64_be: 343 // The small model guarantees static code/data size < 4GB, but not where it 344 // will be in memory. Most of these could end up >2GB away so even a signed 345 // pc-relative 32-bit address is insufficient, theoretically. 346 if (RelocM == Reloc::PIC_) { 347 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 348 dwarf::DW_EH_PE_sdata8; 349 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8; 350 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 351 dwarf::DW_EH_PE_sdata8; 352 } else { 353 PersonalityEncoding = dwarf::DW_EH_PE_absptr; 354 LSDAEncoding = dwarf::DW_EH_PE_absptr; 355 TTypeEncoding = dwarf::DW_EH_PE_absptr; 356 } 357 break; 358 case Triple::mips: 359 case Triple::mipsel: 360 case Triple::mips64: 361 case Triple::mips64el: 362 // MIPS uses indirect pointer to refer personality functions and types, so 363 // that the eh_frame section can be read-only. DW.ref.personality will be 364 // generated for relocation. 365 PersonalityEncoding = dwarf::DW_EH_PE_indirect; 366 // FIXME: The N64 ABI probably ought to use DW_EH_PE_sdata8 but we can't 367 // identify N64 from just a triple. 368 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 369 dwarf::DW_EH_PE_sdata4; 370 // We don't support PC-relative LSDA references in GAS so we use the default 371 // DW_EH_PE_absptr for those. 372 break; 373 case Triple::ppc64: 374 case Triple::ppc64le: 375 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 376 dwarf::DW_EH_PE_udata8; 377 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8; 378 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 379 dwarf::DW_EH_PE_udata8; 380 break; 381 case Triple::sparcel: 382 case Triple::sparc: 383 if (RelocM == Reloc::PIC_) { 384 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 385 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 386 dwarf::DW_EH_PE_sdata4; 387 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 388 dwarf::DW_EH_PE_sdata4; 389 } else { 390 LSDAEncoding = dwarf::DW_EH_PE_absptr; 391 PersonalityEncoding = dwarf::DW_EH_PE_absptr; 392 TTypeEncoding = dwarf::DW_EH_PE_absptr; 393 } 394 break; 395 case Triple::sparcv9: 396 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 397 if (RelocM == Reloc::PIC_) { 398 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 399 dwarf::DW_EH_PE_sdata4; 400 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 401 dwarf::DW_EH_PE_sdata4; 402 } else { 403 PersonalityEncoding = dwarf::DW_EH_PE_absptr; 404 TTypeEncoding = dwarf::DW_EH_PE_absptr; 405 } 406 break; 407 case Triple::systemz: 408 // All currently-defined code models guarantee that 4-byte PC-relative 409 // values will be in range. 410 if (RelocM == Reloc::PIC_) { 411 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 412 dwarf::DW_EH_PE_sdata4; 413 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 414 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 415 dwarf::DW_EH_PE_sdata4; 416 } else { 417 PersonalityEncoding = dwarf::DW_EH_PE_absptr; 418 LSDAEncoding = dwarf::DW_EH_PE_absptr; 419 TTypeEncoding = dwarf::DW_EH_PE_absptr; 420 } 421 break; 422 default: 423 break; 424 } 425 426 unsigned EHSectionType = T.getArch() == Triple::x86_64 427 ? ELF::SHT_X86_64_UNWIND 428 : ELF::SHT_PROGBITS; 429 430 // Solaris requires different flags for .eh_frame to seemingly every other 431 // platform. 432 unsigned EHSectionFlags = ELF::SHF_ALLOC; 433 if (T.isOSSolaris() && T.getArch() != Triple::x86_64) 434 EHSectionFlags |= ELF::SHF_WRITE; 435 436 // ELF 437 BSSSection = Ctx->getELFSection(".bss", ELF::SHT_NOBITS, 438 ELF::SHF_WRITE | ELF::SHF_ALLOC); 439 440 TextSection = Ctx->getELFSection(".text", ELF::SHT_PROGBITS, 441 ELF::SHF_EXECINSTR | ELF::SHF_ALLOC); 442 443 DataSection = Ctx->getELFSection(".data", ELF::SHT_PROGBITS, 444 ELF::SHF_WRITE | ELF::SHF_ALLOC); 445 446 ReadOnlySection = 447 Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS, ELF::SHF_ALLOC); 448 449 TLSDataSection = 450 Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS, 451 ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE); 452 453 TLSBSSSection = Ctx->getELFSection( 454 ".tbss", ELF::SHT_NOBITS, ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE); 455 456 DataRelROSection = Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS, 457 ELF::SHF_ALLOC | ELF::SHF_WRITE); 458 459 MergeableConst4Section = 460 Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS, 461 ELF::SHF_ALLOC | ELF::SHF_MERGE, 4, ""); 462 463 MergeableConst8Section = 464 Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS, 465 ELF::SHF_ALLOC | ELF::SHF_MERGE, 8, ""); 466 467 MergeableConst16Section = 468 Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS, 469 ELF::SHF_ALLOC | ELF::SHF_MERGE, 16, ""); 470 471 StaticCtorSection = Ctx->getELFSection(".ctors", ELF::SHT_PROGBITS, 472 ELF::SHF_ALLOC | ELF::SHF_WRITE); 473 474 StaticDtorSection = Ctx->getELFSection(".dtors", ELF::SHT_PROGBITS, 475 ELF::SHF_ALLOC | ELF::SHF_WRITE); 476 477 // Exception Handling Sections. 478 479 // FIXME: We're emitting LSDA info into a readonly section on ELF, even though 480 // it contains relocatable pointers. In PIC mode, this is probably a big 481 // runtime hit for C++ apps. Either the contents of the LSDA need to be 482 // adjusted or this should be a data section. 483 LSDASection = Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS, 484 ELF::SHF_ALLOC); 485 486 COFFDebugSymbolsSection = nullptr; 487 488 // Debug Info Sections. 489 DwarfAbbrevSection = Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0, 490 "section_abbrev"); 491 DwarfInfoSection = 492 Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0, "section_info"); 493 DwarfLineSection = Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0); 494 DwarfFrameSection = Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0); 495 DwarfPubNamesSection = 496 Ctx->getELFSection(".debug_pubnames", ELF::SHT_PROGBITS, 0); 497 DwarfPubTypesSection = 498 Ctx->getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0); 499 DwarfGnuPubNamesSection = 500 Ctx->getELFSection(".debug_gnu_pubnames", ELF::SHT_PROGBITS, 0); 501 DwarfGnuPubTypesSection = 502 Ctx->getELFSection(".debug_gnu_pubtypes", ELF::SHT_PROGBITS, 0); 503 DwarfStrSection = 504 Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS, 505 ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, ""); 506 DwarfLocSection = Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0); 507 DwarfARangesSection = 508 Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0); 509 DwarfRangesSection = 510 Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0, "debug_range"); 511 DwarfMacinfoSection = 512 Ctx->getELFSection(".debug_macinfo", ELF::SHT_PROGBITS, 0); 513 514 // DWARF5 Experimental Debug Info 515 516 // Accelerator Tables 517 DwarfAccelNamesSection = 518 Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0, "names_begin"); 519 DwarfAccelObjCSection = 520 Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0, "objc_begin"); 521 DwarfAccelNamespaceSection = Ctx->getELFSection( 522 ".apple_namespaces", ELF::SHT_PROGBITS, 0, "namespac_begin"); 523 DwarfAccelTypesSection = 524 Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0, "types_begin"); 525 526 // Fission Sections 527 DwarfInfoDWOSection = 528 Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0); 529 DwarfTypesDWOSection = 530 Ctx->getELFSection(".debug_types.dwo", ELF::SHT_PROGBITS, 0); 531 DwarfAbbrevDWOSection = 532 Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0); 533 DwarfStrDWOSection = 534 Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS, 535 ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, ""); 536 DwarfLineDWOSection = 537 Ctx->getELFSection(".debug_line.dwo", ELF::SHT_PROGBITS, 0); 538 DwarfLocDWOSection = 539 Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0, "skel_loc"); 540 DwarfStrOffDWOSection = 541 Ctx->getELFSection(".debug_str_offsets.dwo", ELF::SHT_PROGBITS, 0); 542 DwarfAddrSection = 543 Ctx->getELFSection(".debug_addr", ELF::SHT_PROGBITS, 0, "addr_sec"); 544 545 // DWP Sections 546 DwarfCUIndexSection = 547 Ctx->getELFSection(".debug_cu_index", ELF::SHT_PROGBITS, 0); 548 DwarfTUIndexSection = 549 Ctx->getELFSection(".debug_tu_index", ELF::SHT_PROGBITS, 0); 550 551 StackMapSection = 552 Ctx->getELFSection(".llvm_stackmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC); 553 554 FaultMapSection = 555 Ctx->getELFSection(".llvm_faultmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC); 556 557 EHFrameSection = 558 Ctx->getELFSection(".eh_frame", EHSectionType, EHSectionFlags); 559 } 560 561 void MCObjectFileInfo::initCOFFMCObjectFileInfo(Triple T) { 562 EHFrameSection = Ctx->getCOFFSection( 563 ".eh_frame", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 564 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE, 565 SectionKind::getData()); 566 567 bool IsWoA = T.getArch() == Triple::arm || T.getArch() == Triple::thumb; 568 569 CommDirectiveSupportsAlignment = true; 570 571 // COFF 572 BSSSection = Ctx->getCOFFSection( 573 ".bss", COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA | 574 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE, 575 SectionKind::getBSS()); 576 TextSection = Ctx->getCOFFSection( 577 ".text", 578 (IsWoA ? COFF::IMAGE_SCN_MEM_16BIT : (COFF::SectionCharacteristics)0) | 579 COFF::IMAGE_SCN_CNT_CODE | COFF::IMAGE_SCN_MEM_EXECUTE | 580 COFF::IMAGE_SCN_MEM_READ, 581 SectionKind::getText()); 582 DataSection = Ctx->getCOFFSection( 583 ".data", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ | 584 COFF::IMAGE_SCN_MEM_WRITE, 585 SectionKind::getData()); 586 ReadOnlySection = Ctx->getCOFFSection( 587 ".rdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 588 SectionKind::getReadOnly()); 589 590 if (T.isKnownWindowsMSVCEnvironment() || T.isWindowsItaniumEnvironment()) { 591 StaticCtorSection = 592 Ctx->getCOFFSection(".CRT$XCU", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 593 COFF::IMAGE_SCN_MEM_READ, 594 SectionKind::getReadOnly()); 595 StaticDtorSection = 596 Ctx->getCOFFSection(".CRT$XTX", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 597 COFF::IMAGE_SCN_MEM_READ, 598 SectionKind::getReadOnly()); 599 } else { 600 StaticCtorSection = Ctx->getCOFFSection( 601 ".ctors", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 602 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE, 603 SectionKind::getData()); 604 StaticDtorSection = Ctx->getCOFFSection( 605 ".dtors", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 606 COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE, 607 SectionKind::getData()); 608 } 609 610 // FIXME: We're emitting LSDA info into a readonly section on COFF, even 611 // though it contains relocatable pointers. In PIC mode, this is probably a 612 // big runtime hit for C++ apps. Either the contents of the LSDA need to be 613 // adjusted or this should be a data section. 614 if (T.getArch() == Triple::x86_64) { 615 // On Windows 64 with SEH, the LSDA is emitted into the .xdata section 616 LSDASection = nullptr; 617 } else { 618 LSDASection = Ctx->getCOFFSection(".gcc_except_table", 619 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 620 COFF::IMAGE_SCN_MEM_READ, 621 SectionKind::getReadOnly()); 622 } 623 624 // Debug info. 625 COFFDebugSymbolsSection = 626 Ctx->getCOFFSection(".debug$S", COFF::IMAGE_SCN_MEM_DISCARDABLE | 627 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 628 COFF::IMAGE_SCN_MEM_READ, 629 SectionKind::getMetadata()); 630 631 DwarfAbbrevSection = Ctx->getCOFFSection( 632 ".debug_abbrev", 633 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 634 COFF::IMAGE_SCN_MEM_READ, 635 SectionKind::getMetadata(), "section_abbrev"); 636 DwarfInfoSection = Ctx->getCOFFSection( 637 ".debug_info", 638 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 639 COFF::IMAGE_SCN_MEM_READ, 640 SectionKind::getMetadata(), "section_info"); 641 DwarfLineSection = Ctx->getCOFFSection( 642 ".debug_line", 643 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 644 COFF::IMAGE_SCN_MEM_READ, 645 SectionKind::getMetadata(), "section_line"); 646 647 DwarfFrameSection = Ctx->getCOFFSection( 648 ".debug_frame", 649 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 650 COFF::IMAGE_SCN_MEM_READ, 651 SectionKind::getMetadata()); 652 DwarfPubNamesSection = Ctx->getCOFFSection( 653 ".debug_pubnames", 654 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 655 COFF::IMAGE_SCN_MEM_READ, 656 SectionKind::getMetadata()); 657 DwarfPubTypesSection = Ctx->getCOFFSection( 658 ".debug_pubtypes", 659 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 660 COFF::IMAGE_SCN_MEM_READ, 661 SectionKind::getMetadata()); 662 DwarfGnuPubNamesSection = Ctx->getCOFFSection( 663 ".debug_gnu_pubnames", 664 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 665 COFF::IMAGE_SCN_MEM_READ, 666 SectionKind::getMetadata()); 667 DwarfGnuPubTypesSection = Ctx->getCOFFSection( 668 ".debug_gnu_pubtypes", 669 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 670 COFF::IMAGE_SCN_MEM_READ, 671 SectionKind::getMetadata()); 672 DwarfStrSection = Ctx->getCOFFSection( 673 ".debug_str", 674 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 675 COFF::IMAGE_SCN_MEM_READ, 676 SectionKind::getMetadata(), "info_string"); 677 DwarfLocSection = Ctx->getCOFFSection( 678 ".debug_loc", 679 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 680 COFF::IMAGE_SCN_MEM_READ, 681 SectionKind::getMetadata(), "section_debug_loc"); 682 DwarfARangesSection = Ctx->getCOFFSection( 683 ".debug_aranges", 684 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 685 COFF::IMAGE_SCN_MEM_READ, 686 SectionKind::getMetadata()); 687 DwarfRangesSection = Ctx->getCOFFSection( 688 ".debug_ranges", 689 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 690 COFF::IMAGE_SCN_MEM_READ, 691 SectionKind::getMetadata(), "debug_range"); 692 DwarfMacinfoSection = Ctx->getCOFFSection( 693 ".debug_macinfo", 694 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 695 COFF::IMAGE_SCN_MEM_READ, 696 SectionKind::getMetadata()); 697 DwarfInfoDWOSection = Ctx->getCOFFSection( 698 ".debug_info.dwo", 699 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 700 COFF::IMAGE_SCN_MEM_READ, 701 SectionKind::getMetadata(), "section_info_dwo"); 702 DwarfTypesDWOSection = Ctx->getCOFFSection( 703 ".debug_types.dwo", 704 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 705 COFF::IMAGE_SCN_MEM_READ, 706 SectionKind::getMetadata(), "section_types_dwo"); 707 DwarfAbbrevDWOSection = Ctx->getCOFFSection( 708 ".debug_abbrev.dwo", 709 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 710 COFF::IMAGE_SCN_MEM_READ, 711 SectionKind::getMetadata(), "section_abbrev_dwo"); 712 DwarfStrDWOSection = Ctx->getCOFFSection( 713 ".debug_str.dwo", 714 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 715 COFF::IMAGE_SCN_MEM_READ, 716 SectionKind::getMetadata(), "skel_string"); 717 DwarfLineDWOSection = Ctx->getCOFFSection( 718 ".debug_line.dwo", 719 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 720 COFF::IMAGE_SCN_MEM_READ, 721 SectionKind::getMetadata()); 722 DwarfLocDWOSection = Ctx->getCOFFSection( 723 ".debug_loc.dwo", 724 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 725 COFF::IMAGE_SCN_MEM_READ, 726 SectionKind::getMetadata(), "skel_loc"); 727 DwarfStrOffDWOSection = Ctx->getCOFFSection( 728 ".debug_str_offsets.dwo", 729 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 730 COFF::IMAGE_SCN_MEM_READ, 731 SectionKind::getMetadata()); 732 DwarfAddrSection = Ctx->getCOFFSection( 733 ".debug_addr", 734 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 735 COFF::IMAGE_SCN_MEM_READ, 736 SectionKind::getMetadata(), "addr_sec"); 737 DwarfCUIndexSection = Ctx->getCOFFSection( 738 ".debug_cu_index", 739 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 740 COFF::IMAGE_SCN_MEM_READ, 741 SectionKind::getMetadata()); 742 DwarfTUIndexSection = Ctx->getCOFFSection( 743 ".debug_tu_index", 744 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 745 COFF::IMAGE_SCN_MEM_READ, 746 SectionKind::getMetadata()); 747 DwarfAccelNamesSection = Ctx->getCOFFSection( 748 ".apple_names", 749 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 750 COFF::IMAGE_SCN_MEM_READ, 751 SectionKind::getMetadata(), "names_begin"); 752 DwarfAccelNamespaceSection = Ctx->getCOFFSection( 753 ".apple_namespaces", 754 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 755 COFF::IMAGE_SCN_MEM_READ, 756 SectionKind::getMetadata(), "namespac_begin"); 757 DwarfAccelTypesSection = Ctx->getCOFFSection( 758 ".apple_types", 759 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 760 COFF::IMAGE_SCN_MEM_READ, 761 SectionKind::getMetadata(), "types_begin"); 762 DwarfAccelObjCSection = Ctx->getCOFFSection( 763 ".apple_objc", 764 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 765 COFF::IMAGE_SCN_MEM_READ, 766 SectionKind::getMetadata(), "objc_begin"); 767 768 DrectveSection = Ctx->getCOFFSection( 769 ".drectve", COFF::IMAGE_SCN_LNK_INFO | COFF::IMAGE_SCN_LNK_REMOVE, 770 SectionKind::getMetadata()); 771 772 PDataSection = Ctx->getCOFFSection( 773 ".pdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 774 SectionKind::getData()); 775 776 XDataSection = Ctx->getCOFFSection( 777 ".xdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 778 SectionKind::getData()); 779 780 SXDataSection = Ctx->getCOFFSection(".sxdata", COFF::IMAGE_SCN_LNK_INFO, 781 SectionKind::getMetadata()); 782 783 TLSDataSection = Ctx->getCOFFSection( 784 ".tls$", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ | 785 COFF::IMAGE_SCN_MEM_WRITE, 786 SectionKind::getData()); 787 788 StackMapSection = Ctx->getCOFFSection(".llvm_stackmaps", 789 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 790 COFF::IMAGE_SCN_MEM_READ, 791 SectionKind::getReadOnly()); 792 } 793 794 void MCObjectFileInfo::InitMCObjectFileInfo(const Triple &TheTriple, 795 Reloc::Model relocm, 796 CodeModel::Model cm, 797 MCContext &ctx) { 798 RelocM = relocm; 799 CMModel = cm; 800 Ctx = &ctx; 801 802 // Common. 803 CommDirectiveSupportsAlignment = true; 804 SupportsWeakOmittedEHFrame = true; 805 SupportsCompactUnwindWithoutEHFrame = false; 806 OmitDwarfIfHaveCompactUnwind = false; 807 808 PersonalityEncoding = LSDAEncoding = FDECFIEncoding = TTypeEncoding = 809 dwarf::DW_EH_PE_absptr; 810 811 CompactUnwindDwarfEHFrameOnly = 0; 812 813 EHFrameSection = nullptr; // Created on demand. 814 CompactUnwindSection = nullptr; // Used only by selected targets. 815 DwarfAccelNamesSection = nullptr; // Used only by selected targets. 816 DwarfAccelObjCSection = nullptr; // Used only by selected targets. 817 DwarfAccelNamespaceSection = nullptr; // Used only by selected targets. 818 DwarfAccelTypesSection = nullptr; // Used only by selected targets. 819 820 TT = TheTriple; 821 822 switch (TT.getObjectFormat()) { 823 case Triple::MachO: 824 Env = IsMachO; 825 initMachOMCObjectFileInfo(TT); 826 break; 827 case Triple::COFF: 828 if (!TT.isOSWindows()) 829 report_fatal_error( 830 "Cannot initialize MC for non-Windows COFF object files."); 831 832 Env = IsCOFF; 833 initCOFFMCObjectFileInfo(TT); 834 break; 835 case Triple::ELF: 836 Env = IsELF; 837 initELFMCObjectFileInfo(TT); 838 break; 839 case Triple::UnknownObjectFormat: 840 report_fatal_error("Cannot initialize MC for unknown object file format."); 841 break; 842 } 843 } 844 845 void MCObjectFileInfo::InitMCObjectFileInfo(StringRef TT, Reloc::Model RM, 846 CodeModel::Model CM, 847 MCContext &ctx) { 848 InitMCObjectFileInfo(Triple(TT), RM, CM, ctx); 849 } 850 851 MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const { 852 return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP, 853 0, utostr(Hash)); 854 } 855