lib/MC/MCObjectFileInfo.cpp

   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 using namespace llvm;
  20
  21 void MCObjectFileInfo::InitMachOMCObjectFileInfo(Triple T) {
  22   // MachO
  23   IsFunctionEHFrameSymbolPrivate = false;
  24   SupportsWeakOmittedEHFrame = false;
  25
  26   if (T.isOSDarwin() &&
  27       (T.getArch() == Triple::arm64 || T.getArch() == Triple::aarch64))
  28     SupportsCompactUnwindWithoutEHFrame = true;
  29
  30   PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel
  31     | dwarf::DW_EH_PE_sdata4;
  32   LSDAEncoding = FDECFIEncoding = dwarf::DW_EH_PE_pcrel;
  33   TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
  34     dwarf::DW_EH_PE_sdata4;
  35
  36   // .comm doesn't support alignment before Leopard.
  37   if (T.isMacOSX() && T.isMacOSXVersionLT(10, 5))
  38     CommDirectiveSupportsAlignment = false;
  39
  40   TextSection // .text
  41     = Ctx->getMachOSection("__TEXT", "__text",
  42                            MachO::S_ATTR_PURE_INSTRUCTIONS,
  43                            SectionKind::getText());
  44   DataSection // .data
  45     = Ctx->getMachOSection("__DATA", "__data", 0,
  46                            SectionKind::getDataRel());
  47
  48   // BSSSection might not be expected initialized on msvc.
  49   BSSSection = nullptr;
  50
  51   TLSDataSection // .tdata
  52     = Ctx->getMachOSection("__DATA", "__thread_data",
  53                            MachO::S_THREAD_LOCAL_REGULAR,
  54                            SectionKind::getDataRel());
  55   TLSBSSSection // .tbss
  56     = Ctx->getMachOSection("__DATA", "__thread_bss",
  57                            MachO::S_THREAD_LOCAL_ZEROFILL,
  58                            SectionKind::getThreadBSS());
  59
  60   // TODO: Verify datarel below.
  61   TLSTLVSection // .tlv
  62     = Ctx->getMachOSection("__DATA", "__thread_vars",
  63                            MachO::S_THREAD_LOCAL_VARIABLES,
  64                            SectionKind::getDataRel());
  65
  66   TLSThreadInitSection
  67     = Ctx->getMachOSection("__DATA", "__thread_init",
  68                           MachO::S_THREAD_LOCAL_INIT_FUNCTION_POINTERS,
  69                           SectionKind::getDataRel());
  70
  71   CStringSection // .cstring
  72     = Ctx->getMachOSection("__TEXT", "__cstring",
  73                            MachO::S_CSTRING_LITERALS,
  74                            SectionKind::getMergeable1ByteCString());
  75   UStringSection
  76     = Ctx->getMachOSection("__TEXT","__ustring", 0,
  77                            SectionKind::getMergeable2ByteCString());
  78   FourByteConstantSection // .literal4
  79     = Ctx->getMachOSection("__TEXT", "__literal4",
  80                            MachO::S_4BYTE_LITERALS,
  81                            SectionKind::getMergeableConst4());
  82   EightByteConstantSection // .literal8
  83     = Ctx->getMachOSection("__TEXT", "__literal8",
  84                            MachO::S_8BYTE_LITERALS,
  85                            SectionKind::getMergeableConst8());
  86
  87   SixteenByteConstantSection // .literal16
  88       = Ctx->getMachOSection("__TEXT", "__literal16",
  89                              MachO::S_16BYTE_LITERALS,
  90                              SectionKind::getMergeableConst16());
  91
  92   ReadOnlySection  // .const
  93     = Ctx->getMachOSection("__TEXT", "__const", 0,
  94                            SectionKind::getReadOnly());
  95
  96   TextCoalSection
  97     = Ctx->getMachOSection("__TEXT", "__textcoal_nt",
  98                            MachO::S_COALESCED |
  99                            MachO::S_ATTR_PURE_INSTRUCTIONS,
 100                            SectionKind::getText());
 101   ConstTextCoalSection
 102     = Ctx->getMachOSection("__TEXT", "__const_coal",
 103                            MachO::S_COALESCED,
 104                            SectionKind::getReadOnly());
 105   ConstDataSection  // .const_data
 106     = Ctx->getMachOSection("__DATA", "__const", 0,
 107                            SectionKind::getReadOnlyWithRel());
 108   DataCoalSection
 109     = Ctx->getMachOSection("__DATA","__datacoal_nt",
 110                            MachO::S_COALESCED,
 111                            SectionKind::getDataRel());
 112   DataCommonSection
 113     = Ctx->getMachOSection("__DATA","__common",
 114                            MachO::S_ZEROFILL,
 115                            SectionKind::getBSS());
 116   DataBSSSection
 117     = Ctx->getMachOSection("__DATA","__bss", MachO::S_ZEROFILL,
 118                            SectionKind::getBSS());
 119
 120
 121   LazySymbolPointerSection
 122     = Ctx->getMachOSection("__DATA", "__la_symbol_ptr",
 123                            MachO::S_LAZY_SYMBOL_POINTERS,
 124                            SectionKind::getMetadata());
 125   NonLazySymbolPointerSection
 126     = Ctx->getMachOSection("__DATA", "__nl_symbol_ptr",
 127                            MachO::S_NON_LAZY_SYMBOL_POINTERS,
 128                            SectionKind::getMetadata());
 129
 130   if (RelocM == Reloc::Static) {
 131     StaticCtorSection
 132       = Ctx->getMachOSection("__TEXT", "__constructor", 0,
 133                              SectionKind::getDataRel());
 134     StaticDtorSection
 135       = Ctx->getMachOSection("__TEXT", "__destructor", 0,
 136                              SectionKind::getDataRel());
 137   } else {
 138     StaticCtorSection
 139       = Ctx->getMachOSection("__DATA", "__mod_init_func",
 140                              MachO::S_MOD_INIT_FUNC_POINTERS,
 141                              SectionKind::getDataRel());
 142     StaticDtorSection
 143       = Ctx->getMachOSection("__DATA", "__mod_term_func",
 144                              MachO::S_MOD_TERM_FUNC_POINTERS,
 145                              SectionKind::getDataRel());
 146   }
 147
 148   // Exception Handling.
 149   LSDASection = Ctx->getMachOSection("__TEXT", "__gcc_except_tab", 0,
 150                                      SectionKind::getReadOnlyWithRel());
 151
 152   COFFDebugSymbolsSection = nullptr;
 153
 154   if ((T.isMacOSX() && !T.isMacOSXVersionLT(10, 6)) ||
 155       (T.isOSDarwin() &&
 156        (T.getArch() == Triple::arm64 || T.getArch() == Triple::aarch64))) {
 157     CompactUnwindSection =
 158       Ctx->getMachOSection("__LD", "__compact_unwind",
 159                            MachO::S_ATTR_DEBUG,
 160                            SectionKind::getReadOnly());
 161
 162     if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86)
 163       CompactUnwindDwarfEHFrameOnly = 0x04000000;
 164     else if (T.getArch() == Triple::arm64 || T.getArch() == Triple::aarch64)
 165       CompactUnwindDwarfEHFrameOnly = 0x03000000;
 166   }
 167
 168   // Debug Information.
 169   DwarfAccelNamesSection =
 170     Ctx->getMachOSection("__DWARF", "__apple_names",
 171                          MachO::S_ATTR_DEBUG,
 172                          SectionKind::getMetadata());
 173   DwarfAccelObjCSection =
 174     Ctx->getMachOSection("__DWARF", "__apple_objc",
 175                          MachO::S_ATTR_DEBUG,
 176                          SectionKind::getMetadata());
 177   // 16 character section limit...
 178   DwarfAccelNamespaceSection =
 179     Ctx->getMachOSection("__DWARF", "__apple_namespac",
 180                          MachO::S_ATTR_DEBUG,
 181                          SectionKind::getMetadata());
 182   DwarfAccelTypesSection =
 183     Ctx->getMachOSection("__DWARF", "__apple_types",
 184                          MachO::S_ATTR_DEBUG,
 185                          SectionKind::getMetadata());
 186
 187   DwarfAbbrevSection =
 188     Ctx->getMachOSection("__DWARF", "__debug_abbrev",
 189                          MachO::S_ATTR_DEBUG,
 190                          SectionKind::getMetadata());
 191   DwarfInfoSection =
 192     Ctx->getMachOSection("__DWARF", "__debug_info",
 193                          MachO::S_ATTR_DEBUG,
 194                          SectionKind::getMetadata());
 195   DwarfLineSection =
 196     Ctx->getMachOSection("__DWARF", "__debug_line",
 197                          MachO::S_ATTR_DEBUG,
 198                          SectionKind::getMetadata());
 199   DwarfFrameSection =
 200     Ctx->getMachOSection("__DWARF", "__debug_frame",
 201                          MachO::S_ATTR_DEBUG,
 202                          SectionKind::getMetadata());
 203   DwarfPubNamesSection =
 204     Ctx->getMachOSection("__DWARF", "__debug_pubnames",
 205                          MachO::S_ATTR_DEBUG,
 206                          SectionKind::getMetadata());
 207   DwarfPubTypesSection =
 208     Ctx->getMachOSection("__DWARF", "__debug_pubtypes",
 209                          MachO::S_ATTR_DEBUG,
 210                          SectionKind::getMetadata());
 211   DwarfGnuPubNamesSection =
 212     Ctx->getMachOSection("__DWARF", "__debug_gnu_pubn",
 213                          MachO::S_ATTR_DEBUG,
 214                          SectionKind::getMetadata());
 215   DwarfGnuPubTypesSection =
 216     Ctx->getMachOSection("__DWARF", "__debug_gnu_pubt",
 217                          MachO::S_ATTR_DEBUG,
 218                          SectionKind::getMetadata());
 219   DwarfStrSection =
 220     Ctx->getMachOSection("__DWARF", "__debug_str",
 221                          MachO::S_ATTR_DEBUG,
 222                          SectionKind::getMetadata());
 223   DwarfLocSection =
 224     Ctx->getMachOSection("__DWARF", "__debug_loc",
 225                          MachO::S_ATTR_DEBUG,
 226                          SectionKind::getMetadata());
 227   DwarfARangesSection =
 228     Ctx->getMachOSection("__DWARF", "__debug_aranges",
 229                          MachO::S_ATTR_DEBUG,
 230                          SectionKind::getMetadata());
 231   DwarfRangesSection =
 232     Ctx->getMachOSection("__DWARF", "__debug_ranges",
 233                          MachO::S_ATTR_DEBUG,
 234                          SectionKind::getMetadata());
 235   DwarfMacroInfoSection =
 236     Ctx->getMachOSection("__DWARF", "__debug_macinfo",
 237                          MachO::S_ATTR_DEBUG,
 238                          SectionKind::getMetadata());
 239   DwarfDebugInlineSection =
 240     Ctx->getMachOSection("__DWARF", "__debug_inlined",
 241                          MachO::S_ATTR_DEBUG,
 242                          SectionKind::getMetadata());
 243   StackMapSection =
 244     Ctx->getMachOSection("__LLVM_STACKMAPS", "__llvm_stackmaps", 0,
 245                          SectionKind::getMetadata());
 246
 247   TLSExtraDataSection = TLSTLVSection;
 248 }
 249
 250 void MCObjectFileInfo::InitELFMCObjectFileInfo(Triple T) {
 251   switch (T.getArch()) {
 252   case Triple::mips:
 253   case Triple::mipsel:
 254     FDECFIEncoding = dwarf::DW_EH_PE_sdata4;
 255     break;
 256   case Triple::mips64:
 257   case Triple::mips64el:
 258     FDECFIEncoding = dwarf::DW_EH_PE_sdata8;
 259     break;
 260   default:
 261     FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 262     break;
 263   }
 264
 265   switch (T.getArch()) {
 266   case Triple::arm:
 267   case Triple::armeb:
 268   case Triple::thumb:
 269   case Triple::thumbeb:
 270     if (Ctx->getAsmInfo()->getExceptionHandlingType() == ExceptionHandling::ARM)
 271       break;
 272     // Fallthrough if not using EHABI
 273   case Triple::x86:
 274     PersonalityEncoding = (RelocM == Reloc::PIC_)
 275      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 276      : dwarf::DW_EH_PE_absptr;
 277     LSDAEncoding = (RelocM == Reloc::PIC_)
 278       ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 279       : dwarf::DW_EH_PE_absptr;
 280     TTypeEncoding = (RelocM == Reloc::PIC_)
 281      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 282      : dwarf::DW_EH_PE_absptr;
 283     break;
 284   case Triple::x86_64:
 285     if (RelocM == Reloc::PIC_) {
 286       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 287         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 288          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 289       LSDAEncoding = dwarf::DW_EH_PE_pcrel |
 290         (CMModel == CodeModel::Small
 291          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 292       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 293         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 294          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 295     } else {
 296       PersonalityEncoding =
 297         (CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 298         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 299       LSDAEncoding = (CMModel == CodeModel::Small)
 300         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 301       TTypeEncoding = (CMModel == CodeModel::Small)
 302         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 303     }
 304     break;
 305   case Triple::aarch64:
 306   case Triple::aarch64_be:
 307   case Triple::arm64:
 308   case Triple::arm64_be:
 309     // The small model guarantees static code/data size < 4GB, but not where it
 310     // will be in memory. Most of these could end up >2GB away so even a signed
 311     // pc-relative 32-bit address is insufficient, theoretically.
 312     if (RelocM == Reloc::PIC_) {
 313       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 314         dwarf::DW_EH_PE_sdata8;
 315       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8;
 316       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 317         dwarf::DW_EH_PE_sdata8;
 318     } else {
 319       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 320       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 321       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 322     }
 323     break;
 324   case Triple::mips:
 325   case Triple::mipsel:
 326     // MIPS uses indirect pointer to refer personality functions, so that the
 327     // eh_frame section can be read-only.  DW.ref.personality will be generated
 328     // for relocation.
 329     PersonalityEncoding = dwarf::DW_EH_PE_indirect;
 330     break;
 331   case Triple::ppc64:
 332   case Triple::ppc64le:
 333     PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 334       dwarf::DW_EH_PE_udata8;
 335     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
 336     TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 337       dwarf::DW_EH_PE_udata8;
 338     break;
 339   case Triple::sparc:
 340     if (RelocM == Reloc::PIC_) {
 341       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 342       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 343         dwarf::DW_EH_PE_sdata4;
 344       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 345         dwarf::DW_EH_PE_sdata4;
 346     } else {
 347       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 348       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 349       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 350     }
 351     break;
 352   case Triple::sparcv9:
 353     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 354     if (RelocM == Reloc::PIC_) {
 355       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 356         dwarf::DW_EH_PE_sdata4;
 357       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 358         dwarf::DW_EH_PE_sdata4;
 359     } else {
 360       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 361       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 362     }
 363     break;
 364   case Triple::systemz:
 365     // All currently-defined code models guarantee that 4-byte PC-relative
 366     // values will be in range.
 367     if (RelocM == Reloc::PIC_) {
 368       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 369         dwarf::DW_EH_PE_sdata4;
 370       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 371       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 372         dwarf::DW_EH_PE_sdata4;
 373     } else {
 374       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 375       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 376       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 377     }
 378     break;
 379   default:
 380     break;
 381   }
 382
 383   // Solaris requires different flags for .eh_frame to seemingly every other
 384   // platform.
 385   EHSectionType = ELF::SHT_PROGBITS;
 386   EHSectionFlags = ELF::SHF_ALLOC;
 387   if (T.getOS() == Triple::Solaris) {
 388     if (T.getArch() == Triple::x86_64)
 389       EHSectionType = ELF::SHT_X86_64_UNWIND;
 390     else
 391       EHSectionFlags |= ELF::SHF_WRITE;
 392   }
 393
 394
 395   // ELF
 396   BSSSection =
 397     Ctx->getELFSection(".bss", ELF::SHT_NOBITS,
 398                        ELF::SHF_WRITE | ELF::SHF_ALLOC,
 399                        SectionKind::getBSS());
 400
 401   TextSection =
 402     Ctx->getELFSection(".text", ELF::SHT_PROGBITS,
 403                        ELF::SHF_EXECINSTR |
 404                        ELF::SHF_ALLOC,
 405                        SectionKind::getText());
 406
 407   DataSection =
 408     Ctx->getELFSection(".data", ELF::SHT_PROGBITS,
 409                        ELF::SHF_WRITE |ELF::SHF_ALLOC,
 410                        SectionKind::getDataRel());
 411
 412   ReadOnlySection =
 413     Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS,
 414                        ELF::SHF_ALLOC,
 415                        SectionKind::getReadOnly());
 416
 417   TLSDataSection =
 418     Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS,
 419                        ELF::SHF_ALLOC | ELF::SHF_TLS |
 420                        ELF::SHF_WRITE,
 421                        SectionKind::getThreadData());
 422
 423   TLSBSSSection =
 424     Ctx->getELFSection(".tbss", ELF::SHT_NOBITS,
 425                        ELF::SHF_ALLOC | ELF::SHF_TLS |
 426                        ELF::SHF_WRITE,
 427                        SectionKind::getThreadBSS());
 428
 429   DataRelSection =
 430     Ctx->getELFSection(".data.rel", ELF::SHT_PROGBITS,
 431                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 432                        SectionKind::getDataRel());
 433
 434   DataRelLocalSection =
 435     Ctx->getELFSection(".data.rel.local", ELF::SHT_PROGBITS,
 436                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 437                        SectionKind::getDataRelLocal());
 438
 439   DataRelROSection =
 440     Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS,
 441                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 442                        SectionKind::getReadOnlyWithRel());
 443
 444   DataRelROLocalSection =
 445     Ctx->getELFSection(".data.rel.ro.local", ELF::SHT_PROGBITS,
 446                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 447                        SectionKind::getReadOnlyWithRelLocal());
 448
 449   MergeableConst4Section =
 450     Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS,
 451                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
 452                        SectionKind::getMergeableConst4());
 453
 454   MergeableConst8Section =
 455     Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS,
 456                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
 457                        SectionKind::getMergeableConst8());
 458
 459   MergeableConst16Section =
 460     Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS,
 461                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
 462                        SectionKind::getMergeableConst16());
 463
 464   StaticCtorSection =
 465     Ctx->getELFSection(".ctors", ELF::SHT_PROGBITS,
 466                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 467                        SectionKind::getDataRel());
 468
 469   StaticDtorSection =
 470     Ctx->getELFSection(".dtors", ELF::SHT_PROGBITS,
 471                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 472                        SectionKind::getDataRel());
 473
 474   // Exception Handling Sections.
 475
 476   // FIXME: We're emitting LSDA info into a readonly section on ELF, even though
 477   // it contains relocatable pointers.  In PIC mode, this is probably a big
 478   // runtime hit for C++ apps.  Either the contents of the LSDA need to be
 479   // adjusted or this should be a data section.
 480   LSDASection =
 481     Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS,
 482                        ELF::SHF_ALLOC,
 483                        SectionKind::getReadOnly());
 484
 485   COFFDebugSymbolsSection = nullptr;
 486
 487   // Debug Info Sections.
 488   DwarfAbbrevSection =
 489     Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0,
 490                        SectionKind::getMetadata());
 491   DwarfInfoSection =
 492     Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0,
 493                        SectionKind::getMetadata());
 494   DwarfLineSection =
 495     Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0,
 496                        SectionKind::getMetadata());
 497   DwarfFrameSection =
 498     Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0,
 499                        SectionKind::getMetadata());
 500   DwarfPubNamesSection =
 501     Ctx->getELFSection(".debug_pubnames", ELF::SHT_PROGBITS, 0,
 502                        SectionKind::getMetadata());
 503   DwarfPubTypesSection =
 504     Ctx->getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0,
 505                        SectionKind::getMetadata());
 506   DwarfGnuPubNamesSection =
 507     Ctx->getELFSection(".debug_gnu_pubnames", ELF::SHT_PROGBITS, 0,
 508                        SectionKind::getMetadata());
 509   DwarfGnuPubTypesSection =
 510     Ctx->getELFSection(".debug_gnu_pubtypes", ELF::SHT_PROGBITS, 0,
 511                        SectionKind::getMetadata());
 512   DwarfStrSection =
 513     Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS,
 514                        ELF::SHF_MERGE | ELF::SHF_STRINGS,
 515                        SectionKind::getMergeable1ByteCString());
 516   DwarfLocSection =
 517     Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0,
 518                        SectionKind::getMetadata());
 519   DwarfARangesSection =
 520     Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0,
 521                        SectionKind::getMetadata());
 522   DwarfRangesSection =
 523     Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0,
 524                        SectionKind::getMetadata());
 525   DwarfMacroInfoSection =
 526     Ctx->getELFSection(".debug_macinfo", ELF::SHT_PROGBITS, 0,
 527                        SectionKind::getMetadata());
 528
 529   // DWARF5 Experimental Debug Info
 530
 531   // Accelerator Tables
 532   DwarfAccelNamesSection =
 533     Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0,
 534                        SectionKind::getMetadata());
 535   DwarfAccelObjCSection =
 536     Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0,
 537                        SectionKind::getMetadata());
 538   DwarfAccelNamespaceSection =
 539     Ctx->getELFSection(".apple_namespaces", ELF::SHT_PROGBITS, 0,
 540                        SectionKind::getMetadata());
 541   DwarfAccelTypesSection =
 542     Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0,
 543                        SectionKind::getMetadata());
 544
 545   // Fission Sections
 546   DwarfInfoDWOSection =
 547     Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0,
 548                        SectionKind::getMetadata());
 549   DwarfAbbrevDWOSection =
 550     Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0,
 551                        SectionKind::getMetadata());
 552   DwarfStrDWOSection =
 553     Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS,
 554                        ELF::SHF_MERGE | ELF::SHF_STRINGS,
 555                        SectionKind::getMergeable1ByteCString());
 556   DwarfLineDWOSection =
 557     Ctx->getELFSection(".debug_line.dwo", ELF::SHT_PROGBITS, 0,
 558                        SectionKind::getMetadata());
 559   DwarfLocDWOSection =
 560     Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0,
 561                        SectionKind::getMetadata());
 562   DwarfStrOffDWOSection =
 563     Ctx->getELFSection(".debug_str_offsets.dwo", ELF::SHT_PROGBITS, 0,
 564                        SectionKind::getMetadata());
 565   DwarfAddrSection =
 566     Ctx->getELFSection(".debug_addr", ELF::SHT_PROGBITS, 0,
 567                        SectionKind::getMetadata());
 568 }
 569
 570
 571 void MCObjectFileInfo::InitCOFFMCObjectFileInfo(Triple T) {
 572   // The object file format cannot represent common symbols with explicit
 573   // alignments.
 574   CommDirectiveSupportsAlignment = false;
 575
 576   // COFF
 577   BSSSection =
 578     Ctx->getCOFFSection(".bss",
 579                         COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
 580                         COFF::IMAGE_SCN_MEM_READ |
 581                         COFF::IMAGE_SCN_MEM_WRITE,
 582                         SectionKind::getBSS());
 583   TextSection =
 584     Ctx->getCOFFSection(".text",
 585                         COFF::IMAGE_SCN_CNT_CODE |
 586                         COFF::IMAGE_SCN_MEM_EXECUTE |
 587                         COFF::IMAGE_SCN_MEM_READ,
 588                         SectionKind::getText());
 589   DataSection =
 590     Ctx->getCOFFSection(".data",
 591                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 592                         COFF::IMAGE_SCN_MEM_READ |
 593                         COFF::IMAGE_SCN_MEM_WRITE,
 594                         SectionKind::getDataRel());
 595   ReadOnlySection =
 596     Ctx->getCOFFSection(".rdata",
 597                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 598                         COFF::IMAGE_SCN_MEM_READ,
 599                         SectionKind::getReadOnly());
 600
 601   if (T.isKnownWindowsMSVCEnvironment()) {
 602     StaticCtorSection =
 603       Ctx->getCOFFSection(".CRT$XCU",
 604                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 605                           COFF::IMAGE_SCN_MEM_READ,
 606                           SectionKind::getReadOnly());
 607     StaticDtorSection =
 608       Ctx->getCOFFSection(".CRT$XTX",
 609                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 610                           COFF::IMAGE_SCN_MEM_READ,
 611                           SectionKind::getReadOnly());
 612   } else {
 613     StaticCtorSection =
 614       Ctx->getCOFFSection(".ctors",
 615                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 616                           COFF::IMAGE_SCN_MEM_READ |
 617                           COFF::IMAGE_SCN_MEM_WRITE,
 618                           SectionKind::getDataRel());
 619     StaticDtorSection =
 620       Ctx->getCOFFSection(".dtors",
 621                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 622                           COFF::IMAGE_SCN_MEM_READ |
 623                           COFF::IMAGE_SCN_MEM_WRITE,
 624                           SectionKind::getDataRel());
 625   }
 626
 627   // FIXME: We're emitting LSDA info into a readonly section on COFF, even
 628   // though it contains relocatable pointers.  In PIC mode, this is probably a
 629   // big runtime hit for C++ apps.  Either the contents of the LSDA need to be
 630   // adjusted or this should be a data section.
 631   LSDASection =
 632     Ctx->getCOFFSection(".gcc_except_table",
 633                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 634                         COFF::IMAGE_SCN_MEM_READ,
 635                         SectionKind::getReadOnly());
 636
 637   // Debug info.
 638   COFFDebugSymbolsSection =
 639     Ctx->getCOFFSection(".debug$S",
 640                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 641                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 642                         COFF::IMAGE_SCN_MEM_READ,
 643                         SectionKind::getMetadata());
 644
 645   DwarfAbbrevSection =
 646     Ctx->getCOFFSection(".debug_abbrev",
 647                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 648                         COFF::IMAGE_SCN_MEM_READ,
 649                         SectionKind::getMetadata());
 650   DwarfInfoSection =
 651     Ctx->getCOFFSection(".debug_info",
 652                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 653                         COFF::IMAGE_SCN_MEM_READ,
 654                         SectionKind::getMetadata());
 655   DwarfLineSection =
 656     Ctx->getCOFFSection(".debug_line",
 657                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 658                         COFF::IMAGE_SCN_MEM_READ,
 659                         SectionKind::getMetadata());
 660   DwarfFrameSection =
 661     Ctx->getCOFFSection(".debug_frame",
 662                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 663                         COFF::IMAGE_SCN_MEM_READ,
 664                         SectionKind::getMetadata());
 665   DwarfPubNamesSection =
 666     Ctx->getCOFFSection(".debug_pubnames",
 667                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 668                         COFF::IMAGE_SCN_MEM_READ,
 669                         SectionKind::getMetadata());
 670   DwarfPubTypesSection =
 671     Ctx->getCOFFSection(".debug_pubtypes",
 672                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 673                         COFF::IMAGE_SCN_MEM_READ,
 674                         SectionKind::getMetadata());
 675   DwarfGnuPubNamesSection =
 676     Ctx->getCOFFSection(".debug_gnu_pubnames",
 677                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 678                         COFF::IMAGE_SCN_MEM_READ,
 679                         SectionKind::getMetadata());
 680   DwarfGnuPubTypesSection =
 681     Ctx->getCOFFSection(".debug_gnu_pubtypes",
 682                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 683                         COFF::IMAGE_SCN_MEM_READ,
 684                         SectionKind::getMetadata());
 685   DwarfStrSection =
 686     Ctx->getCOFFSection(".debug_str",
 687                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 688                         COFF::IMAGE_SCN_MEM_READ,
 689                         SectionKind::getMetadata());
 690   DwarfLocSection =
 691     Ctx->getCOFFSection(".debug_loc",
 692                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 693                         COFF::IMAGE_SCN_MEM_READ,
 694                         SectionKind::getMetadata());
 695   DwarfARangesSection =
 696     Ctx->getCOFFSection(".debug_aranges",
 697                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 698                         COFF::IMAGE_SCN_MEM_READ,
 699                         SectionKind::getMetadata());
 700   DwarfRangesSection =
 701     Ctx->getCOFFSection(".debug_ranges",
 702                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 703                         COFF::IMAGE_SCN_MEM_READ,
 704                         SectionKind::getMetadata());
 705   DwarfMacroInfoSection =
 706     Ctx->getCOFFSection(".debug_macinfo",
 707                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 708                         COFF::IMAGE_SCN_MEM_READ,
 709                         SectionKind::getMetadata());
 710   DwarfInfoDWOSection =
 711       Ctx->getCOFFSection(".debug_info.dwo",
 712                           COFF::IMAGE_SCN_MEM_DISCARDABLE |
 713                           COFF::IMAGE_SCN_MEM_READ,
 714                           SectionKind::getMetadata());
 715   DwarfAbbrevDWOSection =
 716       Ctx->getCOFFSection(".debug_abbrev.dwo",
 717                           COFF::IMAGE_SCN_MEM_DISCARDABLE |
 718                           COFF::IMAGE_SCN_MEM_READ,
 719                           SectionKind::getMetadata());
 720   DwarfStrDWOSection =
 721       Ctx->getCOFFSection(".debug_str.dwo",
 722                           COFF::IMAGE_SCN_MEM_DISCARDABLE |
 723                           COFF::IMAGE_SCN_MEM_READ,
 724                           SectionKind::getMetadata());
 725   DwarfLineDWOSection =
 726       Ctx->getCOFFSection(".debug_line.dwo",
 727                           COFF::IMAGE_SCN_MEM_DISCARDABLE |
 728                           COFF::IMAGE_SCN_MEM_READ,
 729                           SectionKind::getMetadata());
 730   DwarfLocDWOSection =
 731       Ctx->getCOFFSection(".debug_loc.dwo",
 732                           COFF::IMAGE_SCN_MEM_DISCARDABLE |
 733                           COFF::IMAGE_SCN_MEM_READ,
 734                           SectionKind::getMetadata());
 735   DwarfStrOffDWOSection =
 736       Ctx->getCOFFSection(".debug_str_offsets.dwo",
 737                           COFF::IMAGE_SCN_MEM_DISCARDABLE |
 738                           COFF::IMAGE_SCN_MEM_READ,
 739                           SectionKind::getMetadata());
 740
 741   DwarfAddrSection =
 742     Ctx->getCOFFSection(".debug_addr",
 743                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 744                         COFF::IMAGE_SCN_MEM_READ,
 745                         SectionKind::getMetadata());
 746
 747   DrectveSection =
 748     Ctx->getCOFFSection(".drectve",
 749                         COFF::IMAGE_SCN_LNK_INFO |
 750                         COFF::IMAGE_SCN_LNK_REMOVE,
 751                         SectionKind::getMetadata());
 752
 753   PDataSection =
 754     Ctx->getCOFFSection(".pdata",
 755                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 756                         COFF::IMAGE_SCN_MEM_READ,
 757                         SectionKind::getDataRel());
 758
 759   XDataSection =
 760     Ctx->getCOFFSection(".xdata",
 761                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 762                         COFF::IMAGE_SCN_MEM_READ,
 763                         SectionKind::getDataRel());
 764
 765   TLSDataSection =
 766     Ctx->getCOFFSection(".tls$",
 767                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 768                         COFF::IMAGE_SCN_MEM_READ |
 769                         COFF::IMAGE_SCN_MEM_WRITE,
 770                         SectionKind::getDataRel());
 771 }
 772
 773 void MCObjectFileInfo::InitMCObjectFileInfo(StringRef TT, Reloc::Model relocm,
 774                                             CodeModel::Model cm,
 775                                             MCContext &ctx) {
 776   RelocM = relocm;
 777   CMModel = cm;
 778   Ctx = &ctx;
 779
 780   // Common.
 781   CommDirectiveSupportsAlignment = true;
 782   SupportsWeakOmittedEHFrame = true;
 783   IsFunctionEHFrameSymbolPrivate = true;
 784   SupportsCompactUnwindWithoutEHFrame = false;
 785
 786   PersonalityEncoding = LSDAEncoding = FDECFIEncoding = TTypeEncoding =
 787       dwarf::DW_EH_PE_absptr;
 788
 789   CompactUnwindDwarfEHFrameOnly = 0;
 790
 791   EHFrameSection = nullptr;             // Created on demand.
 792   CompactUnwindSection = nullptr;       // Used only by selected targets.
 793   DwarfAccelNamesSection = nullptr;     // Used only by selected targets.
 794   DwarfAccelObjCSection = nullptr;      // Used only by selected targets.
 795   DwarfAccelNamespaceSection = nullptr; // Used only by selected targets.
 796   DwarfAccelTypesSection = nullptr;     // Used only by selected targets.
 797
 798   Triple T(TT);
 799   Triple::ArchType Arch = T.getArch();
 800   // FIXME: Checking for Arch here to filter out bogus triples such as
 801   // cellspu-apple-darwin. Perhaps we should fix in Triple?
 802   if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
 803        Arch == Triple::arm || Arch == Triple::thumb ||
 804        Arch == Triple::arm64 || Arch == Triple::aarch64 ||
 805        Arch == Triple::ppc || Arch == Triple::ppc64 ||
 806        Arch == Triple::UnknownArch) &&
 807       (T.isOSDarwin() || T.isOSBinFormatMachO())) {
 808     Env = IsMachO;
 809     InitMachOMCObjectFileInfo(T);
 810   } else if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
 811               Arch == Triple::arm || Arch == Triple::thumb) &&
 812              (T.isOSWindows() && T.getObjectFormat() == Triple::COFF)) {
 813     Env = IsCOFF;
 814     InitCOFFMCObjectFileInfo(T);
 815   } else {
 816     Env = IsELF;
 817     InitELFMCObjectFileInfo(T);
 818   }
 819 }
 820
 821 const MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const {
 822   return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP,
 823                             SectionKind::getMetadata(), 0, utostr(Hash));
 824 }
 825
 826 const MCSection *
 827 MCObjectFileInfo::getDwarfTypesDWOSection(uint64_t Hash) const {
 828   return Ctx->getELFSection(".debug_types.dwo", ELF::SHT_PROGBITS,
 829                             ELF::SHF_GROUP, SectionKind::getMetadata(), 0,
 830                             utostr(Hash));
 831 }
 832
 833 void MCObjectFileInfo::InitEHFrameSection() {
 834   if (Env == IsMachO)
 835     EHFrameSection =
 836       Ctx->getMachOSection("__TEXT", "__eh_frame",
 837                            MachO::S_COALESCED |
 838                            MachO::S_ATTR_NO_TOC |
 839                            MachO::S_ATTR_STRIP_STATIC_SYMS |
 840                            MachO::S_ATTR_LIVE_SUPPORT,
 841                            SectionKind::getReadOnly());
 842   else if (Env == IsELF)
 843     EHFrameSection =
 844       Ctx->getELFSection(".eh_frame", EHSectionType,
 845                          EHSectionFlags,
 846                          SectionKind::getDataRel());
 847   else
 848     EHFrameSection =
 849       Ctx->getCOFFSection(".eh_frame",
 850                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 851                           COFF::IMAGE_SCN_MEM_READ |
 852                           COFF::IMAGE_SCN_MEM_WRITE,
 853                           SectionKind::getDataRel());
 854 }