1 //===-- MObjectFileInfo.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.isWatchOS()) 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.isWatchOS()) 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, 80 SectionKind::getDataRel()); 81 82 // BSSSection might not be expected initialized on msvc. 83 BSSSection = nullptr; 84 85 TLSDataSection // .tdata 86 = Ctx->getMachOSection("__DATA", "__thread_data", 87 MachO::S_THREAD_LOCAL_REGULAR, 88 SectionKind::getDataRel()); 89 TLSBSSSection // .tbss 90 = Ctx->getMachOSection("__DATA", "__thread_bss", 91 MachO::S_THREAD_LOCAL_ZEROFILL, 92 SectionKind::getThreadBSS()); 93 94 // TODO: Verify datarel below. 95 TLSTLVSection // .tlv 96 = Ctx->getMachOSection("__DATA", "__thread_vars", 97 MachO::S_THREAD_LOCAL_VARIABLES, 98 SectionKind::getDataRel()); 99 100 TLSThreadInitSection 101 = Ctx->getMachOSection("__DATA", "__thread_init", 102 MachO::S_THREAD_LOCAL_INIT_FUNCTION_POINTERS, 103 SectionKind::getDataRel()); 104 105 CStringSection // .cstring 106 = Ctx->getMachOSection("__TEXT", "__cstring", 107 MachO::S_CSTRING_LITERALS, 108 SectionKind::getMergeable1ByteCString()); 109 UStringSection 110 = Ctx->getMachOSection("__TEXT","__ustring", 0, 111 SectionKind::getMergeable2ByteCString()); 112 FourByteConstantSection // .literal4 113 = Ctx->getMachOSection("__TEXT", "__literal4", 114 MachO::S_4BYTE_LITERALS, 115 SectionKind::getMergeableConst4()); 116 EightByteConstantSection // .literal8 117 = Ctx->getMachOSection("__TEXT", "__literal8", 118 MachO::S_8BYTE_LITERALS, 119 SectionKind::getMergeableConst8()); 120 121 SixteenByteConstantSection // .literal16 122 = Ctx->getMachOSection("__TEXT", "__literal16", 123 MachO::S_16BYTE_LITERALS, 124 SectionKind::getMergeableConst16()); 125 126 ReadOnlySection // .const 127 = Ctx->getMachOSection("__TEXT", "__const", 0, 128 SectionKind::getReadOnly()); 129 130 // If the target is not powerpc, map the coal sections to the non-coal 131 // sections. 132 // 133 // "__TEXT/__textcoal_nt" => section "__TEXT/__text" 134 // "__TEXT/__const_coal" => section "__TEXT/__const" 135 // "__DATA/__datacoal_nt" => section "__DATA/__data" 136 Triple::ArchType ArchTy = T.getArch(); 137 138 if (ArchTy == Triple::ppc || ArchTy == Triple::ppc64) { 139 TextCoalSection 140 = Ctx->getMachOSection("__TEXT", "__textcoal_nt", 141 MachO::S_COALESCED | 142 MachO::S_ATTR_PURE_INSTRUCTIONS, 143 SectionKind::getText()); 144 ConstTextCoalSection 145 = Ctx->getMachOSection("__TEXT", "__const_coal", 146 MachO::S_COALESCED, 147 SectionKind::getReadOnly()); 148 DataCoalSection 149 = Ctx->getMachOSection("__DATA","__datacoal_nt", 150 MachO::S_COALESCED, 151 SectionKind::getDataRel()); 152 } else { 153 TextCoalSection = TextSection; 154 ConstTextCoalSection = ReadOnlySection; 155 DataCoalSection = DataSection; 156 } 157 158 ConstDataSection // .const_data 159 = Ctx->getMachOSection("__DATA", "__const", 0, 160 SectionKind::getReadOnlyWithRel()); 161 DataCommonSection 162 = Ctx->getMachOSection("__DATA","__common", 163 MachO::S_ZEROFILL, 164 SectionKind::getBSS()); 165 DataBSSSection 166 = Ctx->getMachOSection("__DATA","__bss", MachO::S_ZEROFILL, 167 SectionKind::getBSS()); 168 169 170 LazySymbolPointerSection 171 = Ctx->getMachOSection("__DATA", "__la_symbol_ptr", 172 MachO::S_LAZY_SYMBOL_POINTERS, 173 SectionKind::getMetadata()); 174 NonLazySymbolPointerSection 175 = Ctx->getMachOSection("__DATA", "__nl_symbol_ptr", 176 MachO::S_NON_LAZY_SYMBOL_POINTERS, 177 SectionKind::getMetadata()); 178 179 if (RelocM == Reloc::Static) { 180 StaticCtorSection 181 = Ctx->getMachOSection("__TEXT", "__constructor", 0, 182 SectionKind::getDataRel()); 183 StaticDtorSection 184 = Ctx->getMachOSection("__TEXT", "__destructor", 0, 185 SectionKind::getDataRel()); 186 } else { 187 StaticCtorSection 188 = Ctx->getMachOSection("__DATA", "__mod_init_func", 189 MachO::S_MOD_INIT_FUNC_POINTERS, 190 SectionKind::getDataRel()); 191 StaticDtorSection 192 = Ctx->getMachOSection("__DATA", "__mod_term_func", 193 MachO::S_MOD_TERM_FUNC_POINTERS, 194 SectionKind::getDataRel()); 195 } 196 197 // Exception Handling. 198 LSDASection = Ctx->getMachOSection("__TEXT", "__gcc_except_tab", 0, 199 SectionKind::getReadOnlyWithRel()); 200 201 COFFDebugSymbolsSection = nullptr; 202 203 if (useCompactUnwind(T)) { 204 CompactUnwindSection = 205 Ctx->getMachOSection("__LD", "__compact_unwind", MachO::S_ATTR_DEBUG, 206 SectionKind::getReadOnly()); 207 208 if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86) 209 CompactUnwindDwarfEHFrameOnly = 0x04000000; // UNWIND_X86_64_MODE_DWARF 210 else if (T.getArch() == Triple::aarch64) 211 CompactUnwindDwarfEHFrameOnly = 0x03000000; // UNWIND_ARM64_MODE_DWARF 212 else if (T.getArch() == Triple::arm || T.getArch() == Triple::thumb) 213 CompactUnwindDwarfEHFrameOnly = 0x04000000; // UNWIND_ARM_MODE_DWARF 214 } 215 216 // Debug Information. 217 DwarfAccelNamesSection = 218 Ctx->getMachOSection("__DWARF", "__apple_names", MachO::S_ATTR_DEBUG, 219 SectionKind::getMetadata(), "names_begin"); 220 DwarfAccelObjCSection = 221 Ctx->getMachOSection("__DWARF", "__apple_objc", MachO::S_ATTR_DEBUG, 222 SectionKind::getMetadata(), "objc_begin"); 223 // 16 character section limit... 224 DwarfAccelNamespaceSection = 225 Ctx->getMachOSection("__DWARF", "__apple_namespac", MachO::S_ATTR_DEBUG, 226 SectionKind::getMetadata(), "namespac_begin"); 227 DwarfAccelTypesSection = 228 Ctx->getMachOSection("__DWARF", "__apple_types", MachO::S_ATTR_DEBUG, 229 SectionKind::getMetadata(), "types_begin"); 230 231 DwarfAbbrevSection = 232 Ctx->getMachOSection("__DWARF", "__debug_abbrev", MachO::S_ATTR_DEBUG, 233 SectionKind::getMetadata(), "section_abbrev"); 234 DwarfInfoSection = 235 Ctx->getMachOSection("__DWARF", "__debug_info", MachO::S_ATTR_DEBUG, 236 SectionKind::getMetadata(), "section_info"); 237 DwarfLineSection = 238 Ctx->getMachOSection("__DWARF", "__debug_line", MachO::S_ATTR_DEBUG, 239 SectionKind::getMetadata(), "section_line"); 240 DwarfFrameSection = 241 Ctx->getMachOSection("__DWARF", "__debug_frame", MachO::S_ATTR_DEBUG, 242 SectionKind::getMetadata()); 243 DwarfPubNamesSection = 244 Ctx->getMachOSection("__DWARF", "__debug_pubnames", MachO::S_ATTR_DEBUG, 245 SectionKind::getMetadata()); 246 DwarfPubTypesSection = 247 Ctx->getMachOSection("__DWARF", "__debug_pubtypes", MachO::S_ATTR_DEBUG, 248 SectionKind::getMetadata()); 249 DwarfGnuPubNamesSection = 250 Ctx->getMachOSection("__DWARF", "__debug_gnu_pubn", MachO::S_ATTR_DEBUG, 251 SectionKind::getMetadata()); 252 DwarfGnuPubTypesSection = 253 Ctx->getMachOSection("__DWARF", "__debug_gnu_pubt", MachO::S_ATTR_DEBUG, 254 SectionKind::getMetadata()); 255 DwarfStrSection = 256 Ctx->getMachOSection("__DWARF", "__debug_str", MachO::S_ATTR_DEBUG, 257 SectionKind::getMetadata(), "info_string"); 258 DwarfLocSection = 259 Ctx->getMachOSection("__DWARF", "__debug_loc", MachO::S_ATTR_DEBUG, 260 SectionKind::getMetadata(), "section_debug_loc"); 261 DwarfARangesSection = 262 Ctx->getMachOSection("__DWARF", "__debug_aranges", MachO::S_ATTR_DEBUG, 263 SectionKind::getMetadata()); 264 DwarfRangesSection = 265 Ctx->getMachOSection("__DWARF", "__debug_ranges", MachO::S_ATTR_DEBUG, 266 SectionKind::getMetadata(), "debug_range"); 267 DwarfDebugInlineSection = 268 Ctx->getMachOSection("__DWARF", "__debug_inlined", MachO::S_ATTR_DEBUG, 269 SectionKind::getMetadata()); 270 StackMapSection = Ctx->getMachOSection("__LLVM_STACKMAPS", "__llvm_stackmaps", 271 0, SectionKind::getMetadata()); 272 273 FaultMapSection = Ctx->getMachOSection("__LLVM_FAULTMAPS", "__llvm_faultmaps", 274 0, SectionKind::getMetadata()); 275 276 TLSExtraDataSection = TLSTLVSection; 277 } 278 279 void MCObjectFileInfo::initELFMCObjectFileInfo(Triple T) { 280 switch (T.getArch()) { 281 case Triple::mips: 282 case Triple::mipsel: 283 FDECFIEncoding = dwarf::DW_EH_PE_sdata4; 284 break; 285 case Triple::mips64: 286 case Triple::mips64el: 287 FDECFIEncoding = dwarf::DW_EH_PE_sdata8; 288 break; 289 case Triple::x86_64: 290 FDECFIEncoding = dwarf::DW_EH_PE_pcrel | 291 ((CMModel == CodeModel::Large) ? dwarf::DW_EH_PE_sdata8 292 : dwarf::DW_EH_PE_sdata4); 293 break; 294 default: 295 FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 296 break; 297 } 298 299 switch (T.getArch()) { 300 case Triple::arm: 301 case Triple::armeb: 302 case Triple::thumb: 303 case Triple::thumbeb: 304 if (Ctx->getAsmInfo()->getExceptionHandlingType() == ExceptionHandling::ARM) 305 break; 306 // Fallthrough if not using EHABI 307 case Triple::ppc: 308 case Triple::x86: 309 PersonalityEncoding = (RelocM == Reloc::PIC_) 310 ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4 311 : dwarf::DW_EH_PE_absptr; 312 LSDAEncoding = (RelocM == Reloc::PIC_) 313 ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4 314 : dwarf::DW_EH_PE_absptr; 315 TTypeEncoding = (RelocM == Reloc::PIC_) 316 ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4 317 : dwarf::DW_EH_PE_absptr; 318 break; 319 case Triple::x86_64: 320 if (RelocM == Reloc::PIC_) { 321 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 322 ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium) 323 ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8); 324 LSDAEncoding = dwarf::DW_EH_PE_pcrel | 325 (CMModel == CodeModel::Small 326 ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8); 327 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 328 ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium) 329 ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8); 330 } else { 331 PersonalityEncoding = 332 (CMModel == CodeModel::Small || CMModel == CodeModel::Medium) 333 ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr; 334 LSDAEncoding = (CMModel == CodeModel::Small) 335 ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr; 336 TTypeEncoding = (CMModel == CodeModel::Small) 337 ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr; 338 } 339 break; 340 case Triple::aarch64: 341 case Triple::aarch64_be: 342 // The small model guarantees static code/data size < 4GB, but not where it 343 // will be in memory. Most of these could end up >2GB away so even a signed 344 // pc-relative 32-bit address is insufficient, theoretically. 345 if (RelocM == Reloc::PIC_) { 346 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 347 dwarf::DW_EH_PE_sdata8; 348 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8; 349 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 350 dwarf::DW_EH_PE_sdata8; 351 } else { 352 PersonalityEncoding = dwarf::DW_EH_PE_absptr; 353 LSDAEncoding = dwarf::DW_EH_PE_absptr; 354 TTypeEncoding = dwarf::DW_EH_PE_absptr; 355 } 356 break; 357 case Triple::mips: 358 case Triple::mipsel: 359 case Triple::mips64: 360 case Triple::mips64el: 361 // MIPS uses indirect pointer to refer personality functions and types, so 362 // that the eh_frame section can be read-only. DW.ref.personality will be 363 // generated for relocation. 364 PersonalityEncoding = dwarf::DW_EH_PE_indirect; 365 // FIXME: The N64 ABI probably ought to use DW_EH_PE_sdata8 but we can't 366 // identify N64 from just a triple. 367 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 368 dwarf::DW_EH_PE_sdata4; 369 // We don't support PC-relative LSDA references in GAS so we use the default 370 // DW_EH_PE_absptr for those. 371 break; 372 case Triple::ppc64: 373 case Triple::ppc64le: 374 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 375 dwarf::DW_EH_PE_udata8; 376 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8; 377 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 378 dwarf::DW_EH_PE_udata8; 379 break; 380 case Triple::sparcel: 381 case Triple::sparc: 382 if (RelocM == Reloc::PIC_) { 383 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 384 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 385 dwarf::DW_EH_PE_sdata4; 386 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 387 dwarf::DW_EH_PE_sdata4; 388 } else { 389 LSDAEncoding = dwarf::DW_EH_PE_absptr; 390 PersonalityEncoding = dwarf::DW_EH_PE_absptr; 391 TTypeEncoding = dwarf::DW_EH_PE_absptr; 392 } 393 break; 394 case Triple::sparcv9: 395 LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4; 396 if (RelocM == Reloc::PIC_) { 397 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 398 dwarf::DW_EH_PE_sdata4; 399 TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 400 dwarf::DW_EH_PE_sdata4; 401 } else { 402 PersonalityEncoding = dwarf::DW_EH_PE_absptr; 403 TTypeEncoding = dwarf::DW_EH_PE_absptr; 404 } 405 break; 406 case Triple::systemz: 407 // All currently-defined code models guarantee that 4-byte PC-relative 408 // values will be in range. 409 if (RelocM == Reloc::PIC_) { 410 PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | 411 dwarf::DW_EH_PE_sdata4; 412 LSDAEncoding = dwarf::DW_EH_PE_pcrel | 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 PersonalityEncoding = dwarf::DW_EH_PE_absptr; 417 LSDAEncoding = dwarf::DW_EH_PE_absptr; 418 TTypeEncoding = dwarf::DW_EH_PE_absptr; 419 } 420 break; 421 default: 422 break; 423 } 424 425 unsigned EHSectionType = T.getArch() == Triple::x86_64 426 ? ELF::SHT_X86_64_UNWIND 427 : ELF::SHT_PROGBITS; 428 429 // Solaris requires different flags for .eh_frame to seemingly every other 430 // platform. 431 unsigned EHSectionFlags = ELF::SHF_ALLOC; 432 if (T.isOSSolaris() && T.getArch() != Triple::x86_64) 433 EHSectionFlags |= ELF::SHF_WRITE; 434 435 // ELF 436 BSSSection = Ctx->getELFSection(".bss", ELF::SHT_NOBITS, 437 ELF::SHF_WRITE | ELF::SHF_ALLOC); 438 439 TextSection = Ctx->getELFSection(".text", ELF::SHT_PROGBITS, 440 ELF::SHF_EXECINSTR | ELF::SHF_ALLOC); 441 442 DataSection = Ctx->getELFSection(".data", ELF::SHT_PROGBITS, 443 ELF::SHF_WRITE | ELF::SHF_ALLOC); 444 445 ReadOnlySection = 446 Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS, ELF::SHF_ALLOC); 447 448 TLSDataSection = 449 Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS, 450 ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE); 451 452 TLSBSSSection = Ctx->getELFSection( 453 ".tbss", ELF::SHT_NOBITS, ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE); 454 455 DataRelSection = Ctx->getELFSection(".data.rel", ELF::SHT_PROGBITS, 456 ELF::SHF_ALLOC | ELF::SHF_WRITE); 457 458 DataRelLocalSection = Ctx->getELFSection(".data.rel.local", ELF::SHT_PROGBITS, 459 ELF::SHF_ALLOC | ELF::SHF_WRITE); 460 461 DataRelROSection = Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS, 462 ELF::SHF_ALLOC | ELF::SHF_WRITE); 463 464 DataRelROLocalSection = Ctx->getELFSection( 465 ".data.rel.ro.local", ELF::SHT_PROGBITS, ELF::SHF_ALLOC | ELF::SHF_WRITE); 466 467 MergeableConst4Section = 468 Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS, 469 ELF::SHF_ALLOC | ELF::SHF_MERGE, 4, ""); 470 471 MergeableConst8Section = 472 Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS, 473 ELF::SHF_ALLOC | ELF::SHF_MERGE, 8, ""); 474 475 MergeableConst16Section = 476 Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS, 477 ELF::SHF_ALLOC | ELF::SHF_MERGE, 16, ""); 478 479 StaticCtorSection = Ctx->getELFSection(".ctors", ELF::SHT_PROGBITS, 480 ELF::SHF_ALLOC | ELF::SHF_WRITE); 481 482 StaticDtorSection = Ctx->getELFSection(".dtors", ELF::SHT_PROGBITS, 483 ELF::SHF_ALLOC | ELF::SHF_WRITE); 484 485 // Exception Handling Sections. 486 487 // FIXME: We're emitting LSDA info into a readonly section on ELF, even though 488 // it contains relocatable pointers. In PIC mode, this is probably a big 489 // runtime hit for C++ apps. Either the contents of the LSDA need to be 490 // adjusted or this should be a data section. 491 LSDASection = Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS, 492 ELF::SHF_ALLOC); 493 494 COFFDebugSymbolsSection = nullptr; 495 496 // Debug Info Sections. 497 DwarfAbbrevSection = Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0, 498 "section_abbrev"); 499 DwarfInfoSection = 500 Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0, "section_info"); 501 DwarfLineSection = Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0); 502 DwarfFrameSection = Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0); 503 DwarfPubNamesSection = 504 Ctx->getELFSection(".debug_pubnames", ELF::SHT_PROGBITS, 0); 505 DwarfPubTypesSection = 506 Ctx->getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0); 507 DwarfGnuPubNamesSection = 508 Ctx->getELFSection(".debug_gnu_pubnames", ELF::SHT_PROGBITS, 0); 509 DwarfGnuPubTypesSection = 510 Ctx->getELFSection(".debug_gnu_pubtypes", ELF::SHT_PROGBITS, 0); 511 DwarfStrSection = 512 Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS, 513 ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, ""); 514 DwarfLocSection = Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0); 515 DwarfARangesSection = 516 Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0); 517 DwarfRangesSection = 518 Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0, "debug_range"); 519 520 // DWARF5 Experimental Debug Info 521 522 // Accelerator Tables 523 DwarfAccelNamesSection = 524 Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0, "names_begin"); 525 DwarfAccelObjCSection = 526 Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0, "objc_begin"); 527 DwarfAccelNamespaceSection = Ctx->getELFSection( 528 ".apple_namespaces", ELF::SHT_PROGBITS, 0, "namespac_begin"); 529 DwarfAccelTypesSection = 530 Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0, "types_begin"); 531 532 // Fission Sections 533 DwarfInfoDWOSection = 534 Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0); 535 DwarfTypesDWOSection = 536 Ctx->getELFSection(".debug_types.dwo", ELF::SHT_PROGBITS, 0); 537 DwarfAbbrevDWOSection = 538 Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0); 539 DwarfStrDWOSection = 540 Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS, 541 ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, ""); 542 DwarfLineDWOSection = 543 Ctx->getELFSection(".debug_line.dwo", ELF::SHT_PROGBITS, 0); 544 DwarfLocDWOSection = 545 Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0, "skel_loc"); 546 DwarfStrOffDWOSection = 547 Ctx->getELFSection(".debug_str_offsets.dwo", ELF::SHT_PROGBITS, 0); 548 DwarfAddrSection = 549 Ctx->getELFSection(".debug_addr", ELF::SHT_PROGBITS, 0, "addr_sec"); 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::getDataRel()); 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::getDataRel()); 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::getDataRel()); 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::getDataRel()); 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 assert(T.isOSWindows() && "Windows is the only supported COFF target"); 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()); 631 632 DwarfAbbrevSection = Ctx->getCOFFSection( 633 ".debug_abbrev", 634 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 635 COFF::IMAGE_SCN_MEM_READ, 636 SectionKind::getMetadata(), "section_abbrev"); 637 DwarfInfoSection = Ctx->getCOFFSection( 638 ".debug_info", 639 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 640 COFF::IMAGE_SCN_MEM_READ, 641 SectionKind::getMetadata(), "section_info"); 642 DwarfLineSection = Ctx->getCOFFSection( 643 ".debug_line", 644 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 645 COFF::IMAGE_SCN_MEM_READ, 646 SectionKind::getMetadata(), "section_line"); 647 648 DwarfFrameSection = Ctx->getCOFFSection( 649 ".debug_frame", 650 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 651 COFF::IMAGE_SCN_MEM_READ, 652 SectionKind::getMetadata()); 653 DwarfPubNamesSection = Ctx->getCOFFSection( 654 ".debug_pubnames", 655 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 656 COFF::IMAGE_SCN_MEM_READ, 657 SectionKind::getMetadata()); 658 DwarfPubTypesSection = Ctx->getCOFFSection( 659 ".debug_pubtypes", 660 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 661 COFF::IMAGE_SCN_MEM_READ, 662 SectionKind::getMetadata()); 663 DwarfGnuPubNamesSection = Ctx->getCOFFSection( 664 ".debug_gnu_pubnames", 665 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 666 COFF::IMAGE_SCN_MEM_READ, 667 SectionKind::getMetadata()); 668 DwarfGnuPubTypesSection = Ctx->getCOFFSection( 669 ".debug_gnu_pubtypes", 670 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 671 COFF::IMAGE_SCN_MEM_READ, 672 SectionKind::getMetadata()); 673 DwarfStrSection = Ctx->getCOFFSection( 674 ".debug_str", 675 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 676 COFF::IMAGE_SCN_MEM_READ, 677 SectionKind::getMetadata(), "info_string"); 678 DwarfLocSection = Ctx->getCOFFSection( 679 ".debug_loc", 680 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 681 COFF::IMAGE_SCN_MEM_READ, 682 SectionKind::getMetadata(), "section_debug_loc"); 683 DwarfARangesSection = Ctx->getCOFFSection( 684 ".debug_aranges", 685 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 686 COFF::IMAGE_SCN_MEM_READ, 687 SectionKind::getMetadata()); 688 DwarfRangesSection = Ctx->getCOFFSection( 689 ".debug_ranges", 690 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 691 COFF::IMAGE_SCN_MEM_READ, 692 SectionKind::getMetadata(), "debug_range"); 693 DwarfInfoDWOSection = Ctx->getCOFFSection( 694 ".debug_info.dwo", 695 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 696 COFF::IMAGE_SCN_MEM_READ, 697 SectionKind::getMetadata(), "section_info_dwo"); 698 DwarfTypesDWOSection = Ctx->getCOFFSection( 699 ".debug_types.dwo", 700 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 701 COFF::IMAGE_SCN_MEM_READ, 702 SectionKind::getMetadata(), "section_types_dwo"); 703 DwarfAbbrevDWOSection = Ctx->getCOFFSection( 704 ".debug_abbrev.dwo", 705 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 706 COFF::IMAGE_SCN_MEM_READ, 707 SectionKind::getMetadata(), "section_abbrev_dwo"); 708 DwarfStrDWOSection = Ctx->getCOFFSection( 709 ".debug_str.dwo", 710 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 711 COFF::IMAGE_SCN_MEM_READ, 712 SectionKind::getMetadata(), "skel_string"); 713 DwarfLineDWOSection = Ctx->getCOFFSection( 714 ".debug_line.dwo", 715 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 716 COFF::IMAGE_SCN_MEM_READ, 717 SectionKind::getMetadata()); 718 DwarfLocDWOSection = Ctx->getCOFFSection( 719 ".debug_loc.dwo", 720 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 721 COFF::IMAGE_SCN_MEM_READ, 722 SectionKind::getMetadata(), "skel_loc"); 723 DwarfStrOffDWOSection = Ctx->getCOFFSection( 724 ".debug_str_offsets.dwo", 725 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 726 COFF::IMAGE_SCN_MEM_READ, 727 SectionKind::getMetadata()); 728 DwarfAddrSection = Ctx->getCOFFSection( 729 ".debug_addr", 730 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 731 COFF::IMAGE_SCN_MEM_READ, 732 SectionKind::getMetadata(), "addr_sec"); 733 DwarfAccelNamesSection = Ctx->getCOFFSection( 734 ".apple_names", 735 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 736 COFF::IMAGE_SCN_MEM_READ, 737 SectionKind::getMetadata(), "names_begin"); 738 DwarfAccelNamespaceSection = Ctx->getCOFFSection( 739 ".apple_namespaces", 740 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 741 COFF::IMAGE_SCN_MEM_READ, 742 SectionKind::getMetadata(), "namespac_begin"); 743 DwarfAccelTypesSection = Ctx->getCOFFSection( 744 ".apple_types", 745 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 746 COFF::IMAGE_SCN_MEM_READ, 747 SectionKind::getMetadata(), "types_begin"); 748 DwarfAccelObjCSection = Ctx->getCOFFSection( 749 ".apple_objc", 750 COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 751 COFF::IMAGE_SCN_MEM_READ, 752 SectionKind::getMetadata(), "objc_begin"); 753 754 DrectveSection = Ctx->getCOFFSection( 755 ".drectve", COFF::IMAGE_SCN_LNK_INFO | COFF::IMAGE_SCN_LNK_REMOVE, 756 SectionKind::getMetadata()); 757 758 PDataSection = Ctx->getCOFFSection( 759 ".pdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 760 SectionKind::getDataRel()); 761 762 XDataSection = Ctx->getCOFFSection( 763 ".xdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ, 764 SectionKind::getDataRel()); 765 766 SXDataSection = Ctx->getCOFFSection(".sxdata", COFF::IMAGE_SCN_LNK_INFO, 767 SectionKind::getMetadata()); 768 769 TLSDataSection = Ctx->getCOFFSection( 770 ".tls$", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ | 771 COFF::IMAGE_SCN_MEM_WRITE, 772 SectionKind::getDataRel()); 773 774 StackMapSection = Ctx->getCOFFSection(".llvm_stackmaps", 775 COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | 776 COFF::IMAGE_SCN_MEM_READ, 777 SectionKind::getReadOnly()); 778 } 779 780 void MCObjectFileInfo::InitMCObjectFileInfo(const Triple &TheTriple, 781 Reloc::Model relocm, 782 CodeModel::Model cm, 783 MCContext &ctx) { 784 RelocM = relocm; 785 CMModel = cm; 786 Ctx = &ctx; 787 788 // Common. 789 CommDirectiveSupportsAlignment = true; 790 SupportsWeakOmittedEHFrame = true; 791 SupportsCompactUnwindWithoutEHFrame = false; 792 OmitDwarfIfHaveCompactUnwind = false; 793 794 PersonalityEncoding = LSDAEncoding = FDECFIEncoding = TTypeEncoding = 795 dwarf::DW_EH_PE_absptr; 796 797 CompactUnwindDwarfEHFrameOnly = 0; 798 799 EHFrameSection = nullptr; // Created on demand. 800 CompactUnwindSection = nullptr; // Used only by selected targets. 801 DwarfAccelNamesSection = nullptr; // Used only by selected targets. 802 DwarfAccelObjCSection = nullptr; // Used only by selected targets. 803 DwarfAccelNamespaceSection = nullptr; // Used only by selected targets. 804 DwarfAccelTypesSection = nullptr; // Used only by selected targets. 805 806 TT = TheTriple; 807 808 Triple::ArchType Arch = TT.getArch(); 809 // FIXME: Checking for Arch here to filter out bogus triples such as 810 // cellspu-apple-darwin. Perhaps we should fix in Triple? 811 if ((Arch == Triple::x86 || Arch == Triple::x86_64 || 812 Arch == Triple::arm || Arch == Triple::thumb || 813 Arch == Triple::aarch64 || 814 Arch == Triple::ppc || Arch == Triple::ppc64 || 815 Arch == Triple::UnknownArch) && 816 TT.isOSBinFormatMachO()) { 817 Env = IsMachO; 818 initMachOMCObjectFileInfo(TT); 819 } else if ((Arch == Triple::x86 || Arch == Triple::x86_64 || 820 Arch == Triple::arm || Arch == Triple::thumb) && 821 (TT.isOSWindows() && TT.getObjectFormat() == Triple::COFF)) { 822 Env = IsCOFF; 823 initCOFFMCObjectFileInfo(TT); 824 } else { 825 Env = IsELF; 826 initELFMCObjectFileInfo(TT); 827 } 828 } 829 830 void MCObjectFileInfo::InitMCObjectFileInfo(StringRef TT, Reloc::Model RM, 831 CodeModel::Model CM, 832 MCContext &ctx) { 833 InitMCObjectFileInfo(Triple(TT), RM, CM, ctx); 834 } 835 836 MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const { 837 return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP, 838 0, utostr(Hash)); 839 } 840