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 #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   // Use it on newer version of OS X.
  33   if (T.isMacOSX() && !T.isMacOSXVersionLT(10, 6))
  34     return true;
  35
  36   // And the iOS simulator.
  37   if (T.isiOS() &&
  38       (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86))
  39     return true;
  40
  41   return false;
  42 }
  43
  44 void MCObjectFileInfo::initMachOMCObjectFileInfo(Triple T) {
  45   // MachO
  46   SupportsWeakOmittedEHFrame = false;
  47
  48   if (T.isOSDarwin() && T.getArch() == Triple::aarch64)
  49     SupportsCompactUnwindWithoutEHFrame = true;
  50
  51   PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel
  52     | dwarf::DW_EH_PE_sdata4;
  53   LSDAEncoding = FDECFIEncoding = dwarf::DW_EH_PE_pcrel;
  54   TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
  55     dwarf::DW_EH_PE_sdata4;
  56
  57   // .comm doesn't support alignment before Leopard.
  58   if (T.isMacOSX() && T.isMacOSXVersionLT(10, 5))
  59     CommDirectiveSupportsAlignment = false;
  60
  61   TextSection // .text
  62     = Ctx->getMachOSection("__TEXT", "__text",
  63                            MachO::S_ATTR_PURE_INSTRUCTIONS,
  64                            SectionKind::getText());
  65   DataSection // .data
  66     = Ctx->getMachOSection("__DATA", "__data", 0,
  67                            SectionKind::getDataRel());
  68
  69   // BSSSection might not be expected initialized on msvc.
  70   BSSSection = nullptr;
  71
  72   TLSDataSection // .tdata
  73     = Ctx->getMachOSection("__DATA", "__thread_data",
  74                            MachO::S_THREAD_LOCAL_REGULAR,
  75                            SectionKind::getDataRel());
  76   TLSBSSSection // .tbss
  77     = Ctx->getMachOSection("__DATA", "__thread_bss",
  78                            MachO::S_THREAD_LOCAL_ZEROFILL,
  79                            SectionKind::getThreadBSS());
  80
  81   // TODO: Verify datarel below.
  82   TLSTLVSection // .tlv
  83     = Ctx->getMachOSection("__DATA", "__thread_vars",
  84                            MachO::S_THREAD_LOCAL_VARIABLES,
  85                            SectionKind::getDataRel());
  86
  87   TLSThreadInitSection
  88     = Ctx->getMachOSection("__DATA", "__thread_init",
  89                           MachO::S_THREAD_LOCAL_INIT_FUNCTION_POINTERS,
  90                           SectionKind::getDataRel());
  91
  92   CStringSection // .cstring
  93     = Ctx->getMachOSection("__TEXT", "__cstring",
  94                            MachO::S_CSTRING_LITERALS,
  95                            SectionKind::getMergeable1ByteCString());
  96   UStringSection
  97     = Ctx->getMachOSection("__TEXT","__ustring", 0,
  98                            SectionKind::getMergeable2ByteCString());
  99   FourByteConstantSection // .literal4
 100     = Ctx->getMachOSection("__TEXT", "__literal4",
 101                            MachO::S_4BYTE_LITERALS,
 102                            SectionKind::getMergeableConst4());
 103   EightByteConstantSection // .literal8
 104     = Ctx->getMachOSection("__TEXT", "__literal8",
 105                            MachO::S_8BYTE_LITERALS,
 106                            SectionKind::getMergeableConst8());
 107
 108   SixteenByteConstantSection // .literal16
 109       = Ctx->getMachOSection("__TEXT", "__literal16",
 110                              MachO::S_16BYTE_LITERALS,
 111                              SectionKind::getMergeableConst16());
 112
 113   ReadOnlySection  // .const
 114     = Ctx->getMachOSection("__TEXT", "__const", 0,
 115                            SectionKind::getReadOnly());
 116
 117   // If the target is not powerpc, map the coal sections to the non-coal
 118   // sections.
 119   //
 120   // "__TEXT/__textcoal_nt" => section "__TEXT/__text"
 121   // "__TEXT/__const_coal"  => section "__TEXT/__const"
 122   // "__DATA/__datacoal_nt" => section "__DATA/__data"
 123   Triple::ArchType ArchTy = T.getArch();
 124
 125   if (ArchTy == Triple::ppc || ArchTy == Triple::ppc64) {
 126     TextCoalSection
 127       = Ctx->getMachOSection("__TEXT", "__textcoal_nt",
 128                              MachO::S_COALESCED |
 129                              MachO::S_ATTR_PURE_INSTRUCTIONS,
 130                              SectionKind::getText());
 131     ConstTextCoalSection
 132       = Ctx->getMachOSection("__TEXT", "__const_coal",
 133                              MachO::S_COALESCED,
 134                              SectionKind::getReadOnly());
 135     DataCoalSection
 136       = Ctx->getMachOSection("__DATA","__datacoal_nt",
 137                              MachO::S_COALESCED,
 138                              SectionKind::getDataRel());
 139   } else {
 140     TextCoalSection = TextSection;
 141     ConstTextCoalSection = ReadOnlySection;
 142     DataCoalSection = DataSection;
 143   }
 144
 145   ConstDataSection  // .const_data
 146     = Ctx->getMachOSection("__DATA", "__const", 0,
 147                            SectionKind::getReadOnlyWithRel());
 148   DataCommonSection
 149     = Ctx->getMachOSection("__DATA","__common",
 150                            MachO::S_ZEROFILL,
 151                            SectionKind::getBSS());
 152   DataBSSSection
 153     = Ctx->getMachOSection("__DATA","__bss", MachO::S_ZEROFILL,
 154                            SectionKind::getBSS());
 155
 156
 157   LazySymbolPointerSection
 158     = Ctx->getMachOSection("__DATA", "__la_symbol_ptr",
 159                            MachO::S_LAZY_SYMBOL_POINTERS,
 160                            SectionKind::getMetadata());
 161   NonLazySymbolPointerSection
 162     = Ctx->getMachOSection("__DATA", "__nl_symbol_ptr",
 163                            MachO::S_NON_LAZY_SYMBOL_POINTERS,
 164                            SectionKind::getMetadata());
 165
 166   if (RelocM == Reloc::Static) {
 167     StaticCtorSection
 168       = Ctx->getMachOSection("__TEXT", "__constructor", 0,
 169                              SectionKind::getDataRel());
 170     StaticDtorSection
 171       = Ctx->getMachOSection("__TEXT", "__destructor", 0,
 172                              SectionKind::getDataRel());
 173   } else {
 174     StaticCtorSection
 175       = Ctx->getMachOSection("__DATA", "__mod_init_func",
 176                              MachO::S_MOD_INIT_FUNC_POINTERS,
 177                              SectionKind::getDataRel());
 178     StaticDtorSection
 179       = Ctx->getMachOSection("__DATA", "__mod_term_func",
 180                              MachO::S_MOD_TERM_FUNC_POINTERS,
 181                              SectionKind::getDataRel());
 182   }
 183
 184   // Exception Handling.
 185   LSDASection = Ctx->getMachOSection("__TEXT", "__gcc_except_tab", 0,
 186                                      SectionKind::getReadOnlyWithRel());
 187
 188   COFFDebugSymbolsSection = nullptr;
 189
 190   if (useCompactUnwind(T)) {
 191     CompactUnwindSection =
 192         Ctx->getMachOSection("__LD", "__compact_unwind", MachO::S_ATTR_DEBUG,
 193                              SectionKind::getReadOnly());
 194
 195     if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86)
 196       CompactUnwindDwarfEHFrameOnly = 0x04000000;
 197     else if (T.getArch() == Triple::aarch64)
 198       CompactUnwindDwarfEHFrameOnly = 0x03000000;
 199   }
 200
 201   // Debug Information.
 202   DwarfAccelNamesSection =
 203       Ctx->getMachOSection("__DWARF", "__apple_names", MachO::S_ATTR_DEBUG,
 204                            SectionKind::getMetadata(), "names_begin");
 205   DwarfAccelObjCSection =
 206       Ctx->getMachOSection("__DWARF", "__apple_objc", MachO::S_ATTR_DEBUG,
 207                            SectionKind::getMetadata(), "objc_begin");
 208   // 16 character section limit...
 209   DwarfAccelNamespaceSection =
 210       Ctx->getMachOSection("__DWARF", "__apple_namespac", MachO::S_ATTR_DEBUG,
 211                            SectionKind::getMetadata(), "namespac_begin");
 212   DwarfAccelTypesSection =
 213       Ctx->getMachOSection("__DWARF", "__apple_types", MachO::S_ATTR_DEBUG,
 214                            SectionKind::getMetadata(), "types_begin");
 215
 216   DwarfAbbrevSection =
 217       Ctx->getMachOSection("__DWARF", "__debug_abbrev", MachO::S_ATTR_DEBUG,
 218                            SectionKind::getMetadata(), "section_abbrev");
 219   DwarfInfoSection =
 220       Ctx->getMachOSection("__DWARF", "__debug_info", MachO::S_ATTR_DEBUG,
 221                            SectionKind::getMetadata(), "section_info");
 222   DwarfLineSection =
 223       Ctx->getMachOSection("__DWARF", "__debug_line", MachO::S_ATTR_DEBUG,
 224                            SectionKind::getMetadata(), "section_line");
 225   DwarfFrameSection =
 226       Ctx->getMachOSection("__DWARF", "__debug_frame", MachO::S_ATTR_DEBUG,
 227                            SectionKind::getMetadata());
 228   DwarfPubNamesSection =
 229       Ctx->getMachOSection("__DWARF", "__debug_pubnames", MachO::S_ATTR_DEBUG,
 230                            SectionKind::getMetadata());
 231   DwarfPubTypesSection =
 232       Ctx->getMachOSection("__DWARF", "__debug_pubtypes", MachO::S_ATTR_DEBUG,
 233                            SectionKind::getMetadata());
 234   DwarfGnuPubNamesSection =
 235       Ctx->getMachOSection("__DWARF", "__debug_gnu_pubn", MachO::S_ATTR_DEBUG,
 236                            SectionKind::getMetadata());
 237   DwarfGnuPubTypesSection =
 238       Ctx->getMachOSection("__DWARF", "__debug_gnu_pubt", MachO::S_ATTR_DEBUG,
 239                            SectionKind::getMetadata());
 240   DwarfStrSection =
 241       Ctx->getMachOSection("__DWARF", "__debug_str", MachO::S_ATTR_DEBUG,
 242                            SectionKind::getMetadata(), "info_string");
 243   DwarfLocSection =
 244       Ctx->getMachOSection("__DWARF", "__debug_loc", MachO::S_ATTR_DEBUG,
 245                            SectionKind::getMetadata(), "section_debug_loc");
 246   DwarfARangesSection =
 247       Ctx->getMachOSection("__DWARF", "__debug_aranges", MachO::S_ATTR_DEBUG,
 248                            SectionKind::getMetadata());
 249   DwarfRangesSection =
 250       Ctx->getMachOSection("__DWARF", "__debug_ranges", MachO::S_ATTR_DEBUG,
 251                            SectionKind::getMetadata(), "debug_range");
 252   DwarfDebugInlineSection =
 253       Ctx->getMachOSection("__DWARF", "__debug_inlined", MachO::S_ATTR_DEBUG,
 254                            SectionKind::getMetadata());
 255   StackMapSection = Ctx->getMachOSection("__LLVM_STACKMAPS", "__llvm_stackmaps",
 256                                          0, SectionKind::getMetadata());
 257
 258   FaultMapSection = Ctx->getMachOSection("__LLVM_FAULTMAPS", "__llvm_faultmaps",
 259                                          0, SectionKind::getMetadata());
 260
 261   TLSExtraDataSection = TLSTLVSection;
 262 }
 263
 264 void MCObjectFileInfo::initELFMCObjectFileInfo(Triple T) {
 265   switch (T.getArch()) {
 266   case Triple::mips:
 267   case Triple::mipsel:
 268     FDECFIEncoding = dwarf::DW_EH_PE_sdata4;
 269     break;
 270   case Triple::mips64:
 271   case Triple::mips64el:
 272     FDECFIEncoding = dwarf::DW_EH_PE_sdata8;
 273     break;
 274   case Triple::x86_64:
 275     FDECFIEncoding = dwarf::DW_EH_PE_pcrel |
 276                      ((CMModel == CodeModel::Large) ? dwarf::DW_EH_PE_sdata8
 277                                                     : dwarf::DW_EH_PE_sdata4);
 278     break;
 279   default:
 280     FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 281     break;
 282   }
 283
 284   switch (T.getArch()) {
 285   case Triple::arm:
 286   case Triple::armeb:
 287   case Triple::thumb:
 288   case Triple::thumbeb:
 289     if (Ctx->getAsmInfo()->getExceptionHandlingType() == ExceptionHandling::ARM)
 290       break;
 291     // Fallthrough if not using EHABI
 292   case Triple::ppc:
 293   case Triple::x86:
 294     PersonalityEncoding = (RelocM == Reloc::PIC_)
 295      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 296      : dwarf::DW_EH_PE_absptr;
 297     LSDAEncoding = (RelocM == Reloc::PIC_)
 298       ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 299       : dwarf::DW_EH_PE_absptr;
 300     TTypeEncoding = (RelocM == Reloc::PIC_)
 301      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 302      : dwarf::DW_EH_PE_absptr;
 303     break;
 304   case Triple::x86_64:
 305     if (RelocM == Reloc::PIC_) {
 306       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 307         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 308          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 309       LSDAEncoding = dwarf::DW_EH_PE_pcrel |
 310         (CMModel == CodeModel::Small
 311          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 312       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 313         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 314          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 315     } else {
 316       PersonalityEncoding =
 317         (CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 318         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 319       LSDAEncoding = (CMModel == CodeModel::Small)
 320         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 321       TTypeEncoding = (CMModel == CodeModel::Small)
 322         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 323     }
 324     break;
 325   case Triple::aarch64:
 326   case Triple::aarch64_be:
 327     // The small model guarantees static code/data size < 4GB, but not where it
 328     // will be in memory. Most of these could end up >2GB away so even a signed
 329     // pc-relative 32-bit address is insufficient, theoretically.
 330     if (RelocM == Reloc::PIC_) {
 331       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 332         dwarf::DW_EH_PE_sdata8;
 333       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8;
 334       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 335         dwarf::DW_EH_PE_sdata8;
 336     } else {
 337       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 338       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 339       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 340     }
 341     break;
 342   case Triple::mips:
 343   case Triple::mipsel:
 344   case Triple::mips64:
 345   case Triple::mips64el:
 346     // MIPS uses indirect pointer to refer personality functions and types, so
 347     // that the eh_frame section can be read-only. DW.ref.personality will be
 348     // generated for relocation.
 349     PersonalityEncoding = dwarf::DW_EH_PE_indirect;
 350     // FIXME: The N64 ABI probably ought to use DW_EH_PE_sdata8 but we can't
 351     //        identify N64 from just a triple.
 352     TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 353                     dwarf::DW_EH_PE_sdata4;
 354     // We don't support PC-relative LSDA references in GAS so we use the default
 355     // DW_EH_PE_absptr for those.
 356     break;
 357   case Triple::ppc64:
 358   case Triple::ppc64le:
 359     PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 360       dwarf::DW_EH_PE_udata8;
 361     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
 362     TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 363       dwarf::DW_EH_PE_udata8;
 364     break;
 365   case Triple::sparcel:
 366   case Triple::sparc:
 367     if (RelocM == Reloc::PIC_) {
 368       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 369       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 370         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       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 375       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 376       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 377     }
 378     break;
 379   case Triple::sparcv9:
 380     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 381     if (RelocM == Reloc::PIC_) {
 382       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 383         dwarf::DW_EH_PE_sdata4;
 384       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 385         dwarf::DW_EH_PE_sdata4;
 386     } else {
 387       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 388       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 389     }
 390     break;
 391   case Triple::systemz:
 392     // All currently-defined code models guarantee that 4-byte PC-relative
 393     // values will be in range.
 394     if (RelocM == Reloc::PIC_) {
 395       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 396         dwarf::DW_EH_PE_sdata4;
 397       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 398       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 399         dwarf::DW_EH_PE_sdata4;
 400     } else {
 401       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 402       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 403       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 404     }
 405     break;
 406   default:
 407     break;
 408   }
 409
 410   // Solaris requires different flags for .eh_frame to seemingly every other
 411   // platform.
 412   EHSectionType = ELF::SHT_PROGBITS;
 413   EHSectionFlags = ELF::SHF_ALLOC;
 414   if (T.isOSSolaris()) {
 415     if (T.getArch() == Triple::x86_64)
 416       EHSectionType = ELF::SHT_X86_64_UNWIND;
 417     else
 418       EHSectionFlags |= ELF::SHF_WRITE;
 419   }
 420
 421   // ELF
 422   BSSSection = Ctx->getELFSection(".bss", ELF::SHT_NOBITS,
 423                                   ELF::SHF_WRITE | ELF::SHF_ALLOC);
 424
 425   TextSection = Ctx->getELFSection(".text", ELF::SHT_PROGBITS,
 426                                    ELF::SHF_EXECINSTR | ELF::SHF_ALLOC);
 427
 428   DataSection = Ctx->getELFSection(".data", ELF::SHT_PROGBITS,
 429                                    ELF::SHF_WRITE | ELF::SHF_ALLOC);
 430
 431   ReadOnlySection =
 432       Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
 433
 434   TLSDataSection =
 435       Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS,
 436                          ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE);
 437
 438   TLSBSSSection = Ctx->getELFSection(
 439       ".tbss", ELF::SHT_NOBITS, ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE);
 440
 441   DataRelSection = Ctx->getELFSection(".data.rel", ELF::SHT_PROGBITS,
 442                                       ELF::SHF_ALLOC | ELF::SHF_WRITE);
 443
 444   DataRelLocalSection = Ctx->getELFSection(".data.rel.local", ELF::SHT_PROGBITS,
 445                                            ELF::SHF_ALLOC | ELF::SHF_WRITE);
 446
 447   DataRelROSection = Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS,
 448                                         ELF::SHF_ALLOC | ELF::SHF_WRITE);
 449
 450   DataRelROLocalSection = Ctx->getELFSection(
 451       ".data.rel.ro.local", ELF::SHT_PROGBITS, ELF::SHF_ALLOC | ELF::SHF_WRITE);
 452
 453   MergeableConst4Section =
 454       Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS,
 455                          ELF::SHF_ALLOC | ELF::SHF_MERGE, 4, "");
 456
 457   MergeableConst8Section =
 458       Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS,
 459                          ELF::SHF_ALLOC | ELF::SHF_MERGE, 8, "");
 460
 461   MergeableConst16Section =
 462       Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS,
 463                          ELF::SHF_ALLOC | ELF::SHF_MERGE, 16, "");
 464
 465   StaticCtorSection = Ctx->getELFSection(".ctors", ELF::SHT_PROGBITS,
 466                                          ELF::SHF_ALLOC | ELF::SHF_WRITE);
 467
 468   StaticDtorSection = Ctx->getELFSection(".dtors", ELF::SHT_PROGBITS,
 469                                          ELF::SHF_ALLOC | ELF::SHF_WRITE);
 470
 471   // Exception Handling Sections.
 472
 473   // FIXME: We're emitting LSDA info into a readonly section on ELF, even though
 474   // it contains relocatable pointers.  In PIC mode, this is probably a big
 475   // runtime hit for C++ apps.  Either the contents of the LSDA need to be
 476   // adjusted or this should be a data section.
 477   LSDASection = Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS,
 478                                    ELF::SHF_ALLOC);
 479
 480   COFFDebugSymbolsSection = nullptr;
 481
 482   // Debug Info Sections.
 483   DwarfAbbrevSection = Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0,
 484                                           "section_abbrev");
 485   DwarfInfoSection =
 486       Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0, "section_info");
 487   DwarfLineSection = Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0);
 488   DwarfFrameSection = Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0);
 489   DwarfPubNamesSection =
 490       Ctx->getELFSection(".debug_pubnames", ELF::SHT_PROGBITS, 0);
 491   DwarfPubTypesSection =
 492       Ctx->getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0);
 493   DwarfGnuPubNamesSection =
 494       Ctx->getELFSection(".debug_gnu_pubnames", ELF::SHT_PROGBITS, 0);
 495   DwarfGnuPubTypesSection =
 496       Ctx->getELFSection(".debug_gnu_pubtypes", ELF::SHT_PROGBITS, 0);
 497   DwarfStrSection =
 498       Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS,
 499                          ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
 500   DwarfLocSection = Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0);
 501   DwarfARangesSection =
 502       Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0);
 503   DwarfRangesSection =
 504       Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0, "debug_range");
 505
 506   // DWARF5 Experimental Debug Info
 507
 508   // Accelerator Tables
 509   DwarfAccelNamesSection =
 510       Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0, "names_begin");
 511   DwarfAccelObjCSection =
 512       Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0, "objc_begin");
 513   DwarfAccelNamespaceSection = Ctx->getELFSection(
 514       ".apple_namespaces", ELF::SHT_PROGBITS, 0, "namespac_begin");
 515   DwarfAccelTypesSection =
 516       Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0, "types_begin");
 517
 518   // Fission Sections
 519   DwarfInfoDWOSection =
 520       Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0);
 521   DwarfTypesDWOSection =
 522       Ctx->getELFSection(".debug_types.dwo", ELF::SHT_PROGBITS, 0);
 523   DwarfAbbrevDWOSection =
 524       Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0);
 525   DwarfStrDWOSection =
 526       Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS,
 527                          ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
 528   DwarfLineDWOSection =
 529       Ctx->getELFSection(".debug_line.dwo", ELF::SHT_PROGBITS, 0);
 530   DwarfLocDWOSection =
 531       Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0, "skel_loc");
 532   DwarfStrOffDWOSection =
 533       Ctx->getELFSection(".debug_str_offsets.dwo", ELF::SHT_PROGBITS, 0);
 534   DwarfAddrSection =
 535       Ctx->getELFSection(".debug_addr", ELF::SHT_PROGBITS, 0, "addr_sec");
 536
 537   StackMapSection =
 538       Ctx->getELFSection(".llvm_stackmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
 539
 540   FaultMapSection =
 541       Ctx->getELFSection(".llvm_faultmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
 542 }
 543
 544 void MCObjectFileInfo::initCOFFMCObjectFileInfo(Triple T) {
 545   bool IsWoA = T.getArch() == Triple::arm || T.getArch() == Triple::thumb;
 546
 547   CommDirectiveSupportsAlignment = true;
 548
 549   // COFF
 550   BSSSection = Ctx->getCOFFSection(
 551       ".bss", COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
 552                   COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
 553       SectionKind::getBSS());
 554   TextSection = Ctx->getCOFFSection(
 555       ".text",
 556       (IsWoA ? COFF::IMAGE_SCN_MEM_16BIT : (COFF::SectionCharacteristics)0) |
 557           COFF::IMAGE_SCN_CNT_CODE | COFF::IMAGE_SCN_MEM_EXECUTE |
 558           COFF::IMAGE_SCN_MEM_READ,
 559       SectionKind::getText());
 560   DataSection = Ctx->getCOFFSection(
 561       ".data", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ |
 562                    COFF::IMAGE_SCN_MEM_WRITE,
 563       SectionKind::getDataRel());
 564   ReadOnlySection = Ctx->getCOFFSection(
 565       ".rdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
 566       SectionKind::getReadOnly());
 567
 568   if (T.isKnownWindowsMSVCEnvironment() || T.isWindowsItaniumEnvironment()) {
 569     StaticCtorSection =
 570         Ctx->getCOFFSection(".CRT$XCU", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 571                                             COFF::IMAGE_SCN_MEM_READ,
 572                             SectionKind::getReadOnly());
 573     StaticDtorSection =
 574         Ctx->getCOFFSection(".CRT$XTX", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 575                                             COFF::IMAGE_SCN_MEM_READ,
 576                             SectionKind::getReadOnly());
 577   } else {
 578     StaticCtorSection = Ctx->getCOFFSection(
 579         ".ctors", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 580                       COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
 581         SectionKind::getDataRel());
 582     StaticDtorSection = Ctx->getCOFFSection(
 583         ".dtors", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 584                       COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
 585         SectionKind::getDataRel());
 586   }
 587
 588   // FIXME: We're emitting LSDA info into a readonly section on COFF, even
 589   // though it contains relocatable pointers.  In PIC mode, this is probably a
 590   // big runtime hit for C++ apps.  Either the contents of the LSDA need to be
 591   // adjusted or this should be a data section.
 592   assert(T.isOSWindows() && "Windows is the only supported COFF target");
 593   if (T.getArch() == Triple::x86_64) {
 594     // On Windows 64 with SEH, the LSDA is emitted into the .xdata section
 595     LSDASection = nullptr;
 596   } else {
 597     LSDASection = Ctx->getCOFFSection(".gcc_except_table",
 598                                       COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 599                                           COFF::IMAGE_SCN_MEM_READ,
 600                                       SectionKind::getReadOnly());
 601   }
 602
 603   // Debug info.
 604   COFFDebugSymbolsSection =
 605       Ctx->getCOFFSection(".debug$S", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 606                                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 607                                           COFF::IMAGE_SCN_MEM_READ,
 608                           SectionKind::getMetadata());
 609
 610   DwarfAbbrevSection = Ctx->getCOFFSection(
 611       ".debug_abbrev",
 612       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 613           COFF::IMAGE_SCN_MEM_READ,
 614       SectionKind::getMetadata(), "section_abbrev");
 615   DwarfInfoSection = Ctx->getCOFFSection(
 616       ".debug_info",
 617       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 618           COFF::IMAGE_SCN_MEM_READ,
 619       SectionKind::getMetadata(), "section_info");
 620   DwarfLineSection = Ctx->getCOFFSection(
 621       ".debug_line",
 622       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 623           COFF::IMAGE_SCN_MEM_READ,
 624       SectionKind::getMetadata(), "section_line");
 625
 626   DwarfFrameSection = Ctx->getCOFFSection(
 627       ".debug_frame",
 628       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 629           COFF::IMAGE_SCN_MEM_READ,
 630       SectionKind::getMetadata());
 631   DwarfPubNamesSection = Ctx->getCOFFSection(
 632       ".debug_pubnames",
 633       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 634           COFF::IMAGE_SCN_MEM_READ,
 635       SectionKind::getMetadata());
 636   DwarfPubTypesSection = Ctx->getCOFFSection(
 637       ".debug_pubtypes",
 638       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 639           COFF::IMAGE_SCN_MEM_READ,
 640       SectionKind::getMetadata());
 641   DwarfGnuPubNamesSection = Ctx->getCOFFSection(
 642       ".debug_gnu_pubnames",
 643       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 644           COFF::IMAGE_SCN_MEM_READ,
 645       SectionKind::getMetadata());
 646   DwarfGnuPubTypesSection = Ctx->getCOFFSection(
 647       ".debug_gnu_pubtypes",
 648       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 649           COFF::IMAGE_SCN_MEM_READ,
 650       SectionKind::getMetadata());
 651   DwarfStrSection = Ctx->getCOFFSection(
 652       ".debug_str",
 653       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 654           COFF::IMAGE_SCN_MEM_READ,
 655       SectionKind::getMetadata(), "info_string");
 656   DwarfLocSection = Ctx->getCOFFSection(
 657       ".debug_loc",
 658       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 659           COFF::IMAGE_SCN_MEM_READ,
 660       SectionKind::getMetadata(), "section_debug_loc");
 661   DwarfARangesSection = Ctx->getCOFFSection(
 662       ".debug_aranges",
 663       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 664           COFF::IMAGE_SCN_MEM_READ,
 665       SectionKind::getMetadata());
 666   DwarfRangesSection = Ctx->getCOFFSection(
 667       ".debug_ranges",
 668       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 669           COFF::IMAGE_SCN_MEM_READ,
 670       SectionKind::getMetadata(), "debug_range");
 671   DwarfInfoDWOSection = Ctx->getCOFFSection(
 672       ".debug_info.dwo",
 673       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 674           COFF::IMAGE_SCN_MEM_READ,
 675       SectionKind::getMetadata(), "section_info_dwo");
 676   DwarfTypesDWOSection = Ctx->getCOFFSection(
 677       ".debug_types.dwo",
 678       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 679           COFF::IMAGE_SCN_MEM_READ,
 680       SectionKind::getMetadata(), "section_types_dwo");
 681   DwarfAbbrevDWOSection = Ctx->getCOFFSection(
 682       ".debug_abbrev.dwo",
 683       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 684           COFF::IMAGE_SCN_MEM_READ,
 685       SectionKind::getMetadata(), "section_abbrev_dwo");
 686   DwarfStrDWOSection = Ctx->getCOFFSection(
 687       ".debug_str.dwo",
 688       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 689           COFF::IMAGE_SCN_MEM_READ,
 690       SectionKind::getMetadata(), "skel_string");
 691   DwarfLineDWOSection = Ctx->getCOFFSection(
 692       ".debug_line.dwo",
 693       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 694           COFF::IMAGE_SCN_MEM_READ,
 695       SectionKind::getMetadata());
 696   DwarfLocDWOSection = Ctx->getCOFFSection(
 697       ".debug_loc.dwo",
 698       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 699           COFF::IMAGE_SCN_MEM_READ,
 700       SectionKind::getMetadata(), "skel_loc");
 701   DwarfStrOffDWOSection = Ctx->getCOFFSection(
 702       ".debug_str_offsets.dwo",
 703       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 704           COFF::IMAGE_SCN_MEM_READ,
 705       SectionKind::getMetadata());
 706   DwarfAddrSection = Ctx->getCOFFSection(
 707       ".debug_addr",
 708       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 709           COFF::IMAGE_SCN_MEM_READ,
 710       SectionKind::getMetadata(), "addr_sec");
 711   DwarfAccelNamesSection = Ctx->getCOFFSection(
 712       ".apple_names",
 713       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 714           COFF::IMAGE_SCN_MEM_READ,
 715       SectionKind::getMetadata(), "names_begin");
 716   DwarfAccelNamespaceSection = Ctx->getCOFFSection(
 717       ".apple_namespaces",
 718       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 719           COFF::IMAGE_SCN_MEM_READ,
 720       SectionKind::getMetadata(), "namespac_begin");
 721   DwarfAccelTypesSection = Ctx->getCOFFSection(
 722       ".apple_types",
 723       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 724           COFF::IMAGE_SCN_MEM_READ,
 725       SectionKind::getMetadata(), "types_begin");
 726   DwarfAccelObjCSection = Ctx->getCOFFSection(
 727       ".apple_objc",
 728       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 729           COFF::IMAGE_SCN_MEM_READ,
 730       SectionKind::getMetadata(), "objc_begin");
 731
 732   DrectveSection = Ctx->getCOFFSection(
 733       ".drectve", COFF::IMAGE_SCN_LNK_INFO | COFF::IMAGE_SCN_LNK_REMOVE,
 734       SectionKind::getMetadata());
 735
 736   PDataSection = Ctx->getCOFFSection(
 737       ".pdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
 738       SectionKind::getDataRel());
 739
 740   XDataSection = Ctx->getCOFFSection(
 741       ".xdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
 742       SectionKind::getDataRel());
 743
 744   SXDataSection = Ctx->getCOFFSection(".sxdata", COFF::IMAGE_SCN_LNK_INFO,
 745                                       SectionKind::getMetadata());
 746
 747   TLSDataSection = Ctx->getCOFFSection(
 748       ".tls$", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ |
 749                    COFF::IMAGE_SCN_MEM_WRITE,
 750       SectionKind::getDataRel());
 751
 752   StackMapSection = Ctx->getCOFFSection(".llvm_stackmaps",
 753                                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 754                                             COFF::IMAGE_SCN_MEM_READ,
 755                                         SectionKind::getReadOnly());
 756 }
 757
 758 void MCObjectFileInfo::InitMCObjectFileInfo(const Triple &TheTriple,
 759                                             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   SupportsCompactUnwindWithoutEHFrame = false;
 770
 771   PersonalityEncoding = LSDAEncoding = FDECFIEncoding = TTypeEncoding =
 772       dwarf::DW_EH_PE_absptr;
 773
 774   CompactUnwindDwarfEHFrameOnly = 0;
 775
 776   EHFrameSection = nullptr;             // Created on demand.
 777   CompactUnwindSection = nullptr;       // Used only by selected targets.
 778   DwarfAccelNamesSection = nullptr;     // Used only by selected targets.
 779   DwarfAccelObjCSection = nullptr;      // Used only by selected targets.
 780   DwarfAccelNamespaceSection = nullptr; // Used only by selected targets.
 781   DwarfAccelTypesSection = nullptr;     // Used only by selected targets.
 782
 783   TT = TheTriple;
 784
 785   Triple::ArchType Arch = TT.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::aarch64 ||
 791        Arch == Triple::ppc || Arch == Triple::ppc64 ||
 792        Arch == Triple::UnknownArch) &&
 793       TT.isOSBinFormatMachO()) {
 794     Env = IsMachO;
 795     initMachOMCObjectFileInfo(TT);
 796   } else if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
 797               Arch == Triple::arm || Arch == Triple::thumb) &&
 798              (TT.isOSWindows() && TT.getObjectFormat() == Triple::COFF)) {
 799     Env = IsCOFF;
 800     initCOFFMCObjectFileInfo(TT);
 801   } else {
 802     Env = IsELF;
 803     initELFMCObjectFileInfo(TT);
 804   }
 805 }
 806
 807 void MCObjectFileInfo::InitMCObjectFileInfo(StringRef TT, Reloc::Model RM,
 808                                             CodeModel::Model CM,
 809                                             MCContext &ctx) {
 810   InitMCObjectFileInfo(Triple(TT), RM, CM, ctx);
 811 }
 812
 813 MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const {
 814   return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP,
 815                             0, utostr(Hash));
 816 }
 817
 818 void MCObjectFileInfo::InitEHFrameSection() {
 819   if (Env == IsMachO)
 820     EHFrameSection =
 821       Ctx->getMachOSection("__TEXT", "__eh_frame",
 822                            MachO::S_COALESCED |
 823                            MachO::S_ATTR_NO_TOC |
 824                            MachO::S_ATTR_STRIP_STATIC_SYMS |
 825                            MachO::S_ATTR_LIVE_SUPPORT,
 826                            SectionKind::getReadOnly());
 827   else if (Env == IsELF)
 828     EHFrameSection =
 829         Ctx->getELFSection(".eh_frame", EHSectionType, EHSectionFlags);
 830   else
 831     EHFrameSection =
 832       Ctx->getCOFFSection(".eh_frame",
 833                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 834                           COFF::IMAGE_SCN_MEM_READ |
 835                           COFF::IMAGE_SCN_MEM_WRITE,
 836                           SectionKind::getDataRel());
 837 }