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::ppc64:
 325   case Triple::ppc64le:
 326     PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 327       dwarf::DW_EH_PE_udata8;
 328     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
 329     TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 330       dwarf::DW_EH_PE_udata8;
 331     break;
 332   case Triple::sparc:
 333     if (RelocM == Reloc::PIC_) {
 334       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 335       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 336         dwarf::DW_EH_PE_sdata4;
 337       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 338         dwarf::DW_EH_PE_sdata4;
 339     } else {
 340       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 341       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 342       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 343     }
 344     break;
 345   case Triple::sparcv9:
 346     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 347     if (RelocM == Reloc::PIC_) {
 348       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 349         dwarf::DW_EH_PE_sdata4;
 350       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 351         dwarf::DW_EH_PE_sdata4;
 352     } else {
 353       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 354       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 355     }
 356     break;
 357   case Triple::systemz:
 358     // All currently-defined code models guarantee that 4-byte PC-relative
 359     // values will be in range.
 360     if (RelocM == Reloc::PIC_) {
 361       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 362         dwarf::DW_EH_PE_sdata4;
 363       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 364       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 365         dwarf::DW_EH_PE_sdata4;
 366     } else {
 367       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 368       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 369       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 370     }
 371     break;
 372   default:
 373     break;
 374   }
 375
 376   // Solaris requires different flags for .eh_frame to seemingly every other
 377   // platform.
 378   EHSectionType = ELF::SHT_PROGBITS;
 379   EHSectionFlags = ELF::SHF_ALLOC;
 380   if (T.getOS() == Triple::Solaris) {
 381     if (T.getArch() == Triple::x86_64)
 382       EHSectionType = ELF::SHT_X86_64_UNWIND;
 383     else
 384       EHSectionFlags |= ELF::SHF_WRITE;
 385   }
 386
 387
 388   // ELF
 389   BSSSection =
 390     Ctx->getELFSection(".bss", ELF::SHT_NOBITS,
 391                        ELF::SHF_WRITE | ELF::SHF_ALLOC,
 392                        SectionKind::getBSS());
 393
 394   TextSection =
 395     Ctx->getELFSection(".text", ELF::SHT_PROGBITS,
 396                        ELF::SHF_EXECINSTR |
 397                        ELF::SHF_ALLOC,
 398                        SectionKind::getText());
 399
 400   DataSection =
 401     Ctx->getELFSection(".data", ELF::SHT_PROGBITS,
 402                        ELF::SHF_WRITE |ELF::SHF_ALLOC,
 403                        SectionKind::getDataRel());
 404
 405   ReadOnlySection =
 406     Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS,
 407                        ELF::SHF_ALLOC,
 408                        SectionKind::getReadOnly());
 409
 410   TLSDataSection =
 411     Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS,
 412                        ELF::SHF_ALLOC | ELF::SHF_TLS |
 413                        ELF::SHF_WRITE,
 414                        SectionKind::getThreadData());
 415
 416   TLSBSSSection =
 417     Ctx->getELFSection(".tbss", ELF::SHT_NOBITS,
 418                        ELF::SHF_ALLOC | ELF::SHF_TLS |
 419                        ELF::SHF_WRITE,
 420                        SectionKind::getThreadBSS());
 421
 422   DataRelSection =
 423     Ctx->getELFSection(".data.rel", ELF::SHT_PROGBITS,
 424                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 425                        SectionKind::getDataRel());
 426
 427   DataRelLocalSection =
 428     Ctx->getELFSection(".data.rel.local", ELF::SHT_PROGBITS,
 429                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 430                        SectionKind::getDataRelLocal());
 431
 432   DataRelROSection =
 433     Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS,
 434                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 435                        SectionKind::getReadOnlyWithRel());
 436
 437   DataRelROLocalSection =
 438     Ctx->getELFSection(".data.rel.ro.local", ELF::SHT_PROGBITS,
 439                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 440                        SectionKind::getReadOnlyWithRelLocal());
 441
 442   MergeableConst4Section =
 443     Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS,
 444                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
 445                        SectionKind::getMergeableConst4());
 446
 447   MergeableConst8Section =
 448     Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS,
 449                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
 450                        SectionKind::getMergeableConst8());
 451
 452   MergeableConst16Section =
 453     Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS,
 454                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
 455                        SectionKind::getMergeableConst16());
 456
 457   StaticCtorSection =
 458     Ctx->getELFSection(".ctors", ELF::SHT_PROGBITS,
 459                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 460                        SectionKind::getDataRel());
 461
 462   StaticDtorSection =
 463     Ctx->getELFSection(".dtors", ELF::SHT_PROGBITS,
 464                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 465                        SectionKind::getDataRel());
 466
 467   // Exception Handling Sections.
 468
 469   // FIXME: We're emitting LSDA info into a readonly section on ELF, even though
 470   // it contains relocatable pointers.  In PIC mode, this is probably a big
 471   // runtime hit for C++ apps.  Either the contents of the LSDA need to be
 472   // adjusted or this should be a data section.
 473   LSDASection =
 474     Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS,
 475                        ELF::SHF_ALLOC,
 476                        SectionKind::getReadOnly());
 477
 478   COFFDebugSymbolsSection = nullptr;
 479
 480   // Debug Info Sections.
 481   DwarfAbbrevSection =
 482     Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0,
 483                        SectionKind::getMetadata());
 484   DwarfInfoSection =
 485     Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0,
 486                        SectionKind::getMetadata());
 487   DwarfLineSection =
 488     Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0,
 489                        SectionKind::getMetadata());
 490   DwarfFrameSection =
 491     Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0,
 492                        SectionKind::getMetadata());
 493   DwarfPubNamesSection =
 494     Ctx->getELFSection(".debug_pubnames", ELF::SHT_PROGBITS, 0,
 495                        SectionKind::getMetadata());
 496   DwarfPubTypesSection =
 497     Ctx->getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0,
 498                        SectionKind::getMetadata());
 499   DwarfGnuPubNamesSection =
 500     Ctx->getELFSection(".debug_gnu_pubnames", ELF::SHT_PROGBITS, 0,
 501                        SectionKind::getMetadata());
 502   DwarfGnuPubTypesSection =
 503     Ctx->getELFSection(".debug_gnu_pubtypes", ELF::SHT_PROGBITS, 0,
 504                        SectionKind::getMetadata());
 505   DwarfStrSection =
 506     Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS,
 507                        ELF::SHF_MERGE | ELF::SHF_STRINGS,
 508                        SectionKind::getMergeable1ByteCString());
 509   DwarfLocSection =
 510     Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0,
 511                        SectionKind::getMetadata());
 512   DwarfARangesSection =
 513     Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0,
 514                        SectionKind::getMetadata());
 515   DwarfRangesSection =
 516     Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0,
 517                        SectionKind::getMetadata());
 518   DwarfMacroInfoSection =
 519     Ctx->getELFSection(".debug_macinfo", ELF::SHT_PROGBITS, 0,
 520                        SectionKind::getMetadata());
 521
 522   // DWARF5 Experimental Debug Info
 523
 524   // Accelerator Tables
 525   DwarfAccelNamesSection =
 526     Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0,
 527                        SectionKind::getMetadata());
 528   DwarfAccelObjCSection =
 529     Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0,
 530                        SectionKind::getMetadata());
 531   DwarfAccelNamespaceSection =
 532     Ctx->getELFSection(".apple_namespaces", ELF::SHT_PROGBITS, 0,
 533                        SectionKind::getMetadata());
 534   DwarfAccelTypesSection =
 535     Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0,
 536                        SectionKind::getMetadata());
 537
 538   // Fission Sections
 539   DwarfInfoDWOSection =
 540     Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0,
 541                        SectionKind::getMetadata());
 542   DwarfAbbrevDWOSection =
 543     Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0,
 544                        SectionKind::getMetadata());
 545   DwarfStrDWOSection =
 546     Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS,
 547                        ELF::SHF_MERGE | ELF::SHF_STRINGS,
 548                        SectionKind::getMergeable1ByteCString());
 549   DwarfLineDWOSection =
 550     Ctx->getELFSection(".debug_line.dwo", ELF::SHT_PROGBITS, 0,
 551                        SectionKind::getMetadata());
 552   DwarfLocDWOSection =
 553     Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0,
 554                        SectionKind::getMetadata());
 555   DwarfStrOffDWOSection =
 556     Ctx->getELFSection(".debug_str_offsets.dwo", ELF::SHT_PROGBITS, 0,
 557                        SectionKind::getMetadata());
 558   DwarfAddrSection =
 559     Ctx->getELFSection(".debug_addr", ELF::SHT_PROGBITS, 0,
 560                        SectionKind::getMetadata());
 561 }
 562
 563
 564 void MCObjectFileInfo::InitCOFFMCObjectFileInfo(Triple T) {
 565   // The object file format cannot represent common symbols with explicit
 566   // alignments.
 567   CommDirectiveSupportsAlignment = false;
 568
 569   // COFF
 570   BSSSection =
 571     Ctx->getCOFFSection(".bss",
 572                         COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
 573                         COFF::IMAGE_SCN_MEM_READ |
 574                         COFF::IMAGE_SCN_MEM_WRITE,
 575                         SectionKind::getBSS());
 576   TextSection =
 577     Ctx->getCOFFSection(".text",
 578                         COFF::IMAGE_SCN_CNT_CODE |
 579                         COFF::IMAGE_SCN_MEM_EXECUTE |
 580                         COFF::IMAGE_SCN_MEM_READ,
 581                         SectionKind::getText());
 582   DataSection =
 583     Ctx->getCOFFSection(".data",
 584                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 585                         COFF::IMAGE_SCN_MEM_READ |
 586                         COFF::IMAGE_SCN_MEM_WRITE,
 587                         SectionKind::getDataRel());
 588   ReadOnlySection =
 589     Ctx->getCOFFSection(".rdata",
 590                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 591                         COFF::IMAGE_SCN_MEM_READ,
 592                         SectionKind::getReadOnly());
 593   if (T.isKnownWindowsMSVCEnvironment()) {
 594     StaticCtorSection =
 595       Ctx->getCOFFSection(".CRT$XCU",
 596                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 597                           COFF::IMAGE_SCN_MEM_READ,
 598                           SectionKind::getReadOnly());
 599   } else {
 600     StaticCtorSection =
 601       Ctx->getCOFFSection(".ctors",
 602                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 603                           COFF::IMAGE_SCN_MEM_READ |
 604                           COFF::IMAGE_SCN_MEM_WRITE,
 605                           SectionKind::getDataRel());
 606   }
 607
 608
 609   if (T.isKnownWindowsMSVCEnvironment()) {
 610     StaticDtorSection =
 611       Ctx->getCOFFSection(".CRT$XTX",
 612                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 613                           COFF::IMAGE_SCN_MEM_READ,
 614                           SectionKind::getReadOnly());
 615   } else {
 616     StaticDtorSection =
 617       Ctx->getCOFFSection(".dtors",
 618                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 619                           COFF::IMAGE_SCN_MEM_READ |
 620                           COFF::IMAGE_SCN_MEM_WRITE,
 621                           SectionKind::getDataRel());
 622   }
 623
 624   // FIXME: We're emitting LSDA info into a readonly section on COFF, even
 625   // though it contains relocatable pointers.  In PIC mode, this is probably a
 626   // big runtime hit for C++ apps.  Either the contents of the LSDA need to be
 627   // adjusted or this should be a data section.
 628   LSDASection =
 629     Ctx->getCOFFSection(".gcc_except_table",
 630                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 631                         COFF::IMAGE_SCN_MEM_READ,
 632                         SectionKind::getReadOnly());
 633
 634   // Debug info.
 635   COFFDebugSymbolsSection =
 636     Ctx->getCOFFSection(".debug$S",
 637                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 638                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 639                         COFF::IMAGE_SCN_MEM_READ,
 640                         SectionKind::getMetadata());
 641
 642   DwarfAbbrevSection =
 643     Ctx->getCOFFSection(".debug_abbrev",
 644                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 645                         COFF::IMAGE_SCN_MEM_READ,
 646                         SectionKind::getMetadata());
 647   DwarfInfoSection =
 648     Ctx->getCOFFSection(".debug_info",
 649                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 650                         COFF::IMAGE_SCN_MEM_READ,
 651                         SectionKind::getMetadata());
 652   DwarfLineSection =
 653     Ctx->getCOFFSection(".debug_line",
 654                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 655                         COFF::IMAGE_SCN_MEM_READ,
 656                         SectionKind::getMetadata());
 657   DwarfFrameSection =
 658     Ctx->getCOFFSection(".debug_frame",
 659                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 660                         COFF::IMAGE_SCN_MEM_READ,
 661                         SectionKind::getMetadata());
 662   DwarfPubNamesSection =
 663     Ctx->getCOFFSection(".debug_pubnames",
 664                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 665                         COFF::IMAGE_SCN_MEM_READ,
 666                         SectionKind::getMetadata());
 667   DwarfPubTypesSection =
 668     Ctx->getCOFFSection(".debug_pubtypes",
 669                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 670                         COFF::IMAGE_SCN_MEM_READ,
 671                         SectionKind::getMetadata());
 672   DwarfGnuPubNamesSection =
 673     Ctx->getCOFFSection(".debug_gnu_pubnames",
 674                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 675                         COFF::IMAGE_SCN_MEM_READ,
 676                         SectionKind::getMetadata());
 677   DwarfGnuPubTypesSection =
 678     Ctx->getCOFFSection(".debug_gnu_pubtypes",
 679                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 680                         COFF::IMAGE_SCN_MEM_READ,
 681                         SectionKind::getMetadata());
 682   DwarfStrSection =
 683     Ctx->getCOFFSection(".debug_str",
 684                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 685                         COFF::IMAGE_SCN_MEM_READ,
 686                         SectionKind::getMetadata());
 687   DwarfLocSection =
 688     Ctx->getCOFFSection(".debug_loc",
 689                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 690                         COFF::IMAGE_SCN_MEM_READ,
 691                         SectionKind::getMetadata());
 692   DwarfARangesSection =
 693     Ctx->getCOFFSection(".debug_aranges",
 694                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 695                         COFF::IMAGE_SCN_MEM_READ,
 696                         SectionKind::getMetadata());
 697   DwarfRangesSection =
 698     Ctx->getCOFFSection(".debug_ranges",
 699                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 700                         COFF::IMAGE_SCN_MEM_READ,
 701                         SectionKind::getMetadata());
 702   DwarfMacroInfoSection =
 703     Ctx->getCOFFSection(".debug_macinfo",
 704                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 705                         COFF::IMAGE_SCN_MEM_READ,
 706                         SectionKind::getMetadata());
 707   DwarfInfoDWOSection =
 708       Ctx->getCOFFSection(".debug_info.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 709                                                 COFF::IMAGE_SCN_MEM_READ,
 710                           SectionKind::getMetadata());
 711   DwarfAbbrevDWOSection =
 712       Ctx->getCOFFSection(".debug_abbrev.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 713                                                   COFF::IMAGE_SCN_MEM_READ,
 714                           SectionKind::getMetadata());
 715   DwarfStrDWOSection =
 716       Ctx->getCOFFSection(".debug_str.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 717                                                COFF::IMAGE_SCN_MEM_READ,
 718                           SectionKind::getMetadata());
 719   DwarfLineDWOSection =
 720       Ctx->getCOFFSection(".debug_line.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 721                                                 COFF::IMAGE_SCN_MEM_READ,
 722                           SectionKind::getMetadata());
 723   DwarfLocDWOSection =
 724       Ctx->getCOFFSection(".debug_loc.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 725                                                COFF::IMAGE_SCN_MEM_READ,
 726                           SectionKind::getMetadata());
 727   DwarfStrOffDWOSection =
 728       Ctx->getCOFFSection(".debug_str_offsets.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 729                                                   COFF::IMAGE_SCN_MEM_READ,
 730                           SectionKind::getMetadata());
 731   DwarfAddrSection = Ctx->getCOFFSection(
 732       ".debug_addr", COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_MEM_READ,
 733       SectionKind::getMetadata());
 734
 735   DrectveSection =
 736     Ctx->getCOFFSection(".drectve",
 737                         COFF::IMAGE_SCN_LNK_INFO | COFF::IMAGE_SCN_LNK_REMOVE,
 738                         SectionKind::getMetadata());
 739
 740   PDataSection =
 741     Ctx->getCOFFSection(".pdata",
 742                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 743                         COFF::IMAGE_SCN_MEM_READ,
 744                         SectionKind::getDataRel());
 745
 746   XDataSection =
 747     Ctx->getCOFFSection(".xdata",
 748                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 749                         COFF::IMAGE_SCN_MEM_READ,
 750                         SectionKind::getDataRel());
 751   TLSDataSection =
 752     Ctx->getCOFFSection(".tls$",
 753                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 754                         COFF::IMAGE_SCN_MEM_READ |
 755                         COFF::IMAGE_SCN_MEM_WRITE,
 756                         SectionKind::getDataRel());
 757 }
 758
 759 void MCObjectFileInfo::InitMCObjectFileInfo(StringRef TT, Reloc::Model relocm,
 760                                             CodeModel::Model cm,
 761                                             MCContext &ctx) {
 762   RelocM = relocm;
 763   CMModel = cm;
 764   Ctx = &ctx;
 765
 766   // Common.
 767   CommDirectiveSupportsAlignment = true;
 768   SupportsWeakOmittedEHFrame = true;
 769   IsFunctionEHFrameSymbolPrivate = true;
 770   SupportsCompactUnwindWithoutEHFrame = false;
 771
 772   PersonalityEncoding = LSDAEncoding = FDECFIEncoding = TTypeEncoding =
 773       dwarf::DW_EH_PE_absptr;
 774
 775   CompactUnwindDwarfEHFrameOnly = 0;
 776
 777   EHFrameSection = nullptr;             // Created on demand.
 778   CompactUnwindSection = nullptr;       // Used only by selected targets.
 779   DwarfAccelNamesSection = nullptr;     // Used only by selected targets.
 780   DwarfAccelObjCSection = nullptr;      // Used only by selected targets.
 781   DwarfAccelNamespaceSection = nullptr; // Used only by selected targets.
 782   DwarfAccelTypesSection = nullptr;     // Used only by selected targets.
 783
 784   Triple T(TT);
 785   Triple::ArchType Arch = T.getArch();
 786   // FIXME: Checking for Arch here to filter out bogus triples such as
 787   // cellspu-apple-darwin. Perhaps we should fix in Triple?
 788   if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
 789        Arch == Triple::arm || Arch == Triple::thumb ||
 790        Arch == Triple::arm64 || Arch == Triple::aarch64 ||
 791        Arch == Triple::ppc || Arch == Triple::ppc64 ||
 792        Arch == Triple::UnknownArch) &&
 793       (T.isOSDarwin() || T.isOSBinFormatMachO())) {
 794     Env = IsMachO;
 795     InitMachOMCObjectFileInfo(T);
 796   } else if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
 797               Arch == Triple::arm || Arch == Triple::thumb) &&
 798              (T.isOSWindows() && T.getObjectFormat() == Triple::COFF)) {
 799     Env = IsCOFF;
 800     InitCOFFMCObjectFileInfo(T);
 801   } else {
 802     Env = IsELF;
 803     InitELFMCObjectFileInfo(T);
 804   }
 805 }
 806
 807 const MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const {
 808   return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP,
 809                             SectionKind::getMetadata(), 0, utostr(Hash));
 810 }
 811
 812 const MCSection *
 813 MCObjectFileInfo::getDwarfTypesDWOSection(uint64_t Hash) const {
 814   return Ctx->getELFSection(".debug_types.dwo", ELF::SHT_PROGBITS,
 815                             ELF::SHF_GROUP, SectionKind::getMetadata(), 0,
 816                             utostr(Hash));
 817 }
 818
 819 void MCObjectFileInfo::InitEHFrameSection() {
 820   if (Env == IsMachO)
 821     EHFrameSection =
 822       Ctx->getMachOSection("__TEXT", "__eh_frame",
 823                            MachO::S_COALESCED |
 824                            MachO::S_ATTR_NO_TOC |
 825                            MachO::S_ATTR_STRIP_STATIC_SYMS |
 826                            MachO::S_ATTR_LIVE_SUPPORT,
 827                            SectionKind::getReadOnly());
 828   else if (Env == IsELF)
 829     EHFrameSection =
 830       Ctx->getELFSection(".eh_frame", EHSectionType,
 831                          EHSectionFlags,
 832                          SectionKind::getDataRel());
 833   else
 834     EHFrameSection =
 835       Ctx->getCOFFSection(".eh_frame",
 836                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 837                           COFF::IMAGE_SCN_MEM_READ |
 838                           COFF::IMAGE_SCN_MEM_WRITE,
 839                           SectionKind::getDataRel());
 840 }