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 static bool useCompactUnwind(const Triple &T) {
  22   // Only on darwin.
  23   if (!T.isOSDarwin())
  24     return false;
  25
  26   // aarch64 always has it.
  27   if (T.getArch() == Triple::aarch64)
  28     return true;
  29
  30   // Use it on newer version of OS X.
  31   if (T.isMacOSX() && !T.isMacOSXVersionLT(10, 6))
  32     return true;
  33
  34   // And the iOS simulator.
  35   if (T.isiOS() &&
  36       (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86))
  37     return true;
  38
  39   return false;
  40 }
  41
  42 void MCObjectFileInfo::InitMachOMCObjectFileInfo(Triple T) {
  43   // MachO
  44   SupportsWeakOmittedEHFrame = false;
  45
  46   if (T.isOSDarwin() && T.getArch() == Triple::aarch64)
  47     SupportsCompactUnwindWithoutEHFrame = true;
  48
  49   PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel
  50     | dwarf::DW_EH_PE_sdata4;
  51   LSDAEncoding = FDECFIEncoding = dwarf::DW_EH_PE_pcrel;
  52   TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
  53     dwarf::DW_EH_PE_sdata4;
  54
  55   // .comm doesn't support alignment before Leopard.
  56   if (T.isMacOSX() && T.isMacOSXVersionLT(10, 5))
  57     CommDirectiveSupportsAlignment = false;
  58
  59   TextSection // .text
  60     = Ctx->getMachOSection("__TEXT", "__text",
  61                            MachO::S_ATTR_PURE_INSTRUCTIONS,
  62                            SectionKind::getText());
  63   DataSection // .data
  64     = Ctx->getMachOSection("__DATA", "__data", 0,
  65                            SectionKind::getDataRel());
  66
  67   // BSSSection might not be expected initialized on msvc.
  68   BSSSection = nullptr;
  69
  70   TLSDataSection // .tdata
  71     = Ctx->getMachOSection("__DATA", "__thread_data",
  72                            MachO::S_THREAD_LOCAL_REGULAR,
  73                            SectionKind::getDataRel());
  74   TLSBSSSection // .tbss
  75     = Ctx->getMachOSection("__DATA", "__thread_bss",
  76                            MachO::S_THREAD_LOCAL_ZEROFILL,
  77                            SectionKind::getThreadBSS());
  78
  79   // TODO: Verify datarel below.
  80   TLSTLVSection // .tlv
  81     = Ctx->getMachOSection("__DATA", "__thread_vars",
  82                            MachO::S_THREAD_LOCAL_VARIABLES,
  83                            SectionKind::getDataRel());
  84
  85   TLSThreadInitSection
  86     = Ctx->getMachOSection("__DATA", "__thread_init",
  87                           MachO::S_THREAD_LOCAL_INIT_FUNCTION_POINTERS,
  88                           SectionKind::getDataRel());
  89
  90   CStringSection // .cstring
  91     = Ctx->getMachOSection("__TEXT", "__cstring",
  92                            MachO::S_CSTRING_LITERALS,
  93                            SectionKind::getMergeable1ByteCString());
  94   UStringSection
  95     = Ctx->getMachOSection("__TEXT","__ustring", 0,
  96                            SectionKind::getMergeable2ByteCString());
  97   FourByteConstantSection // .literal4
  98     = Ctx->getMachOSection("__TEXT", "__literal4",
  99                            MachO::S_4BYTE_LITERALS,
 100                            SectionKind::getMergeableConst4());
 101   EightByteConstantSection // .literal8
 102     = Ctx->getMachOSection("__TEXT", "__literal8",
 103                            MachO::S_8BYTE_LITERALS,
 104                            SectionKind::getMergeableConst8());
 105
 106   SixteenByteConstantSection // .literal16
 107       = Ctx->getMachOSection("__TEXT", "__literal16",
 108                              MachO::S_16BYTE_LITERALS,
 109                              SectionKind::getMergeableConst16());
 110
 111   ReadOnlySection  // .const
 112     = Ctx->getMachOSection("__TEXT", "__const", 0,
 113                            SectionKind::getReadOnly());
 114
 115   TextCoalSection
 116     = Ctx->getMachOSection("__TEXT", "__textcoal_nt",
 117                            MachO::S_COALESCED |
 118                            MachO::S_ATTR_PURE_INSTRUCTIONS,
 119                            SectionKind::getText());
 120   ConstTextCoalSection
 121     = Ctx->getMachOSection("__TEXT", "__const_coal",
 122                            MachO::S_COALESCED,
 123                            SectionKind::getReadOnly());
 124   ConstDataSection  // .const_data
 125     = Ctx->getMachOSection("__DATA", "__const", 0,
 126                            SectionKind::getReadOnlyWithRel());
 127   DataCoalSection
 128     = Ctx->getMachOSection("__DATA","__datacoal_nt",
 129                            MachO::S_COALESCED,
 130                            SectionKind::getDataRel());
 131   DataCommonSection
 132     = Ctx->getMachOSection("__DATA","__common",
 133                            MachO::S_ZEROFILL,
 134                            SectionKind::getBSS());
 135   DataBSSSection
 136     = Ctx->getMachOSection("__DATA","__bss", MachO::S_ZEROFILL,
 137                            SectionKind::getBSS());
 138
 139
 140   LazySymbolPointerSection
 141     = Ctx->getMachOSection("__DATA", "__la_symbol_ptr",
 142                            MachO::S_LAZY_SYMBOL_POINTERS,
 143                            SectionKind::getMetadata());
 144   NonLazySymbolPointerSection
 145     = Ctx->getMachOSection("__DATA", "__nl_symbol_ptr",
 146                            MachO::S_NON_LAZY_SYMBOL_POINTERS,
 147                            SectionKind::getMetadata());
 148
 149   if (RelocM == Reloc::Static) {
 150     StaticCtorSection
 151       = Ctx->getMachOSection("__TEXT", "__constructor", 0,
 152                              SectionKind::getDataRel());
 153     StaticDtorSection
 154       = Ctx->getMachOSection("__TEXT", "__destructor", 0,
 155                              SectionKind::getDataRel());
 156   } else {
 157     StaticCtorSection
 158       = Ctx->getMachOSection("__DATA", "__mod_init_func",
 159                              MachO::S_MOD_INIT_FUNC_POINTERS,
 160                              SectionKind::getDataRel());
 161     StaticDtorSection
 162       = Ctx->getMachOSection("__DATA", "__mod_term_func",
 163                              MachO::S_MOD_TERM_FUNC_POINTERS,
 164                              SectionKind::getDataRel());
 165   }
 166
 167   // Exception Handling.
 168   LSDASection = Ctx->getMachOSection("__TEXT", "__gcc_except_tab", 0,
 169                                      SectionKind::getReadOnlyWithRel());
 170
 171   COFFDebugSymbolsSection = nullptr;
 172
 173   if (useCompactUnwind(T)) {
 174     CompactUnwindSection =
 175         Ctx->getMachOSection("__LD", "__compact_unwind", MachO::S_ATTR_DEBUG,
 176                              SectionKind::getReadOnly());
 177
 178     if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86)
 179       CompactUnwindDwarfEHFrameOnly = 0x04000000;
 180     else if (T.getArch() == Triple::aarch64)
 181       CompactUnwindDwarfEHFrameOnly = 0x03000000;
 182   }
 183
 184   // Debug Information.
 185   DwarfAccelNamesSection =
 186       Ctx->getMachOSection("__DWARF", "__apple_names", MachO::S_ATTR_DEBUG,
 187                            SectionKind::getMetadata());
 188   DwarfAccelObjCSection =
 189       Ctx->getMachOSection("__DWARF", "__apple_objc", MachO::S_ATTR_DEBUG,
 190                            SectionKind::getMetadata());
 191   // 16 character section limit...
 192   DwarfAccelNamespaceSection =
 193       Ctx->getMachOSection("__DWARF", "__apple_namespac", MachO::S_ATTR_DEBUG,
 194                            SectionKind::getMetadata());
 195   DwarfAccelTypesSection =
 196       Ctx->getMachOSection("__DWARF", "__apple_types", MachO::S_ATTR_DEBUG,
 197                            SectionKind::getMetadata());
 198
 199   DwarfAbbrevSection =
 200       Ctx->getMachOSection("__DWARF", "__debug_abbrev", MachO::S_ATTR_DEBUG,
 201                            SectionKind::getMetadata());
 202   DwarfInfoSection =
 203       Ctx->getMachOSection("__DWARF", "__debug_info", MachO::S_ATTR_DEBUG,
 204                            SectionKind::getMetadata());
 205   DwarfLineSection =
 206       Ctx->getMachOSection("__DWARF", "__debug_line", MachO::S_ATTR_DEBUG,
 207                            SectionKind::getMetadata());
 208   DwarfFrameSection =
 209       Ctx->getMachOSection("__DWARF", "__debug_frame", MachO::S_ATTR_DEBUG,
 210                            SectionKind::getMetadata());
 211   DwarfPubNamesSection =
 212       Ctx->getMachOSection("__DWARF", "__debug_pubnames", MachO::S_ATTR_DEBUG,
 213                            SectionKind::getMetadata());
 214   DwarfPubTypesSection =
 215       Ctx->getMachOSection("__DWARF", "__debug_pubtypes", MachO::S_ATTR_DEBUG,
 216                            SectionKind::getMetadata());
 217   DwarfGnuPubNamesSection =
 218       Ctx->getMachOSection("__DWARF", "__debug_gnu_pubn", MachO::S_ATTR_DEBUG,
 219                            SectionKind::getMetadata());
 220   DwarfGnuPubTypesSection =
 221       Ctx->getMachOSection("__DWARF", "__debug_gnu_pubt", MachO::S_ATTR_DEBUG,
 222                            SectionKind::getMetadata());
 223   DwarfStrSection =
 224       Ctx->getMachOSection("__DWARF", "__debug_str", MachO::S_ATTR_DEBUG,
 225                            SectionKind::getMetadata());
 226   DwarfLocSection =
 227       Ctx->getMachOSection("__DWARF", "__debug_loc", MachO::S_ATTR_DEBUG,
 228                            SectionKind::getMetadata());
 229   DwarfARangesSection =
 230       Ctx->getMachOSection("__DWARF", "__debug_aranges", MachO::S_ATTR_DEBUG,
 231                            SectionKind::getMetadata());
 232   DwarfRangesSection =
 233       Ctx->getMachOSection("__DWARF", "__debug_ranges", MachO::S_ATTR_DEBUG,
 234                            SectionKind::getMetadata());
 235   DwarfDebugInlineSection =
 236       Ctx->getMachOSection("__DWARF", "__debug_inlined", MachO::S_ATTR_DEBUG,
 237                            SectionKind::getMetadata());
 238   StackMapSection = Ctx->getMachOSection("__LLVM_STACKMAPS", "__llvm_stackmaps",
 239                                          0, SectionKind::getMetadata());
 240
 241   TLSExtraDataSection = TLSTLVSection;
 242 }
 243
 244 void MCObjectFileInfo::InitELFMCObjectFileInfo(Triple T) {
 245   switch (T.getArch()) {
 246   case Triple::mips:
 247   case Triple::mipsel:
 248     FDECFIEncoding = dwarf::DW_EH_PE_sdata4;
 249     break;
 250   case Triple::mips64:
 251   case Triple::mips64el:
 252     FDECFIEncoding = dwarf::DW_EH_PE_sdata8;
 253     break;
 254   case Triple::x86_64:
 255     FDECFIEncoding = dwarf::DW_EH_PE_pcrel |
 256                      ((CMModel == CodeModel::Large) ? dwarf::DW_EH_PE_sdata8
 257                                                     : dwarf::DW_EH_PE_sdata4);
 258
 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::ppc:
 274   case Triple::x86:
 275     PersonalityEncoding = (RelocM == Reloc::PIC_)
 276      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 277      : dwarf::DW_EH_PE_absptr;
 278     LSDAEncoding = (RelocM == Reloc::PIC_)
 279       ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 280       : dwarf::DW_EH_PE_absptr;
 281     TTypeEncoding = (RelocM == Reloc::PIC_)
 282      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 283      : dwarf::DW_EH_PE_absptr;
 284     break;
 285   case Triple::x86_64:
 286     if (RelocM == Reloc::PIC_) {
 287       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 288         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 289          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 290       LSDAEncoding = dwarf::DW_EH_PE_pcrel |
 291         (CMModel == CodeModel::Small
 292          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 293       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 294         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 295          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 296     } else {
 297       PersonalityEncoding =
 298         (CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 299         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 300       LSDAEncoding = (CMModel == CodeModel::Small)
 301         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 302       TTypeEncoding = (CMModel == CodeModel::Small)
 303         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 304     }
 305     break;
 306   case Triple::aarch64:
 307   case Triple::aarch64_be:
 308     // The small model guarantees static code/data size < 4GB, but not where it
 309     // will be in memory. Most of these could end up >2GB away so even a signed
 310     // pc-relative 32-bit address is insufficient, theoretically.
 311     if (RelocM == Reloc::PIC_) {
 312       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 313         dwarf::DW_EH_PE_sdata8;
 314       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8;
 315       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 316         dwarf::DW_EH_PE_sdata8;
 317     } else {
 318       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 319       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 320       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 321     }
 322     break;
 323   case Triple::mips:
 324   case Triple::mipsel:
 325   case Triple::mips64:
 326   case Triple::mips64el:
 327     // MIPS uses indirect pointer to refer personality functions, so that the
 328     // eh_frame section can be read-only.  DW.ref.personality will be generated
 329     // for relocation.
 330     PersonalityEncoding = dwarf::DW_EH_PE_indirect;
 331     break;
 332   case Triple::ppc64:
 333   case Triple::ppc64le:
 334     PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 335       dwarf::DW_EH_PE_udata8;
 336     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
 337     TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 338       dwarf::DW_EH_PE_udata8;
 339     break;
 340   case Triple::sparc:
 341     if (RelocM == Reloc::PIC_) {
 342       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 343       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 344         dwarf::DW_EH_PE_sdata4;
 345       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 346         dwarf::DW_EH_PE_sdata4;
 347     } else {
 348       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 349       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 350       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 351     }
 352     break;
 353   case Triple::sparcv9:
 354     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 355     if (RelocM == Reloc::PIC_) {
 356       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 357         dwarf::DW_EH_PE_sdata4;
 358       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 359         dwarf::DW_EH_PE_sdata4;
 360     } else {
 361       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 362       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 363     }
 364     break;
 365   case Triple::systemz:
 366     // All currently-defined code models guarantee that 4-byte PC-relative
 367     // values will be in range.
 368     if (RelocM == Reloc::PIC_) {
 369       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 370         dwarf::DW_EH_PE_sdata4;
 371       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 372       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 373         dwarf::DW_EH_PE_sdata4;
 374     } else {
 375       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 376       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 377       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 378     }
 379     break;
 380   default:
 381     break;
 382   }
 383
 384   // Solaris requires different flags for .eh_frame to seemingly every other
 385   // platform.
 386   EHSectionType = ELF::SHT_PROGBITS;
 387   EHSectionFlags = ELF::SHF_ALLOC;
 388   if (T.isOSSolaris()) {
 389     if (T.getArch() == Triple::x86_64)
 390       EHSectionType = ELF::SHT_X86_64_UNWIND;
 391     else
 392       EHSectionFlags |= ELF::SHF_WRITE;
 393   }
 394
 395
 396   // ELF
 397   BSSSection = Ctx->getELFSection(".bss", ELF::SHT_NOBITS,
 398                                   ELF::SHF_WRITE | ELF::SHF_ALLOC);
 399
 400   TextSection = Ctx->getELFSection(".text", ELF::SHT_PROGBITS,
 401                                    ELF::SHF_EXECINSTR | ELF::SHF_ALLOC);
 402
 403   DataSection = Ctx->getELFSection(".data", ELF::SHT_PROGBITS,
 404                                    ELF::SHF_WRITE | ELF::SHF_ALLOC);
 405
 406   ReadOnlySection =
 407       Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
 408
 409   TLSDataSection =
 410       Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS,
 411                          ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE);
 412
 413   TLSBSSSection = Ctx->getELFSection(
 414       ".tbss", ELF::SHT_NOBITS, ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE);
 415
 416   DataRelSection = Ctx->getELFSection(".data.rel", ELF::SHT_PROGBITS,
 417                                       ELF::SHF_ALLOC | ELF::SHF_WRITE);
 418
 419   DataRelLocalSection = Ctx->getELFSection(".data.rel.local", ELF::SHT_PROGBITS,
 420                                            ELF::SHF_ALLOC | ELF::SHF_WRITE);
 421
 422   DataRelROSection = Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS,
 423                                         ELF::SHF_ALLOC | ELF::SHF_WRITE);
 424
 425   DataRelROLocalSection = Ctx->getELFSection(
 426       ".data.rel.ro.local", ELF::SHT_PROGBITS, ELF::SHF_ALLOC | ELF::SHF_WRITE);
 427
 428   MergeableConst4Section =
 429       Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS,
 430                          ELF::SHF_ALLOC | ELF::SHF_MERGE, 4, "");
 431
 432   MergeableConst8Section =
 433       Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS,
 434                          ELF::SHF_ALLOC | ELF::SHF_MERGE, 8, "");
 435
 436   MergeableConst16Section =
 437       Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS,
 438                          ELF::SHF_ALLOC | ELF::SHF_MERGE, 16, "");
 439
 440   StaticCtorSection = Ctx->getELFSection(".ctors", ELF::SHT_PROGBITS,
 441                                          ELF::SHF_ALLOC | ELF::SHF_WRITE);
 442
 443   StaticDtorSection = Ctx->getELFSection(".dtors", ELF::SHT_PROGBITS,
 444                                          ELF::SHF_ALLOC | ELF::SHF_WRITE);
 445
 446   // Exception Handling Sections.
 447
 448   // FIXME: We're emitting LSDA info into a readonly section on ELF, even though
 449   // it contains relocatable pointers.  In PIC mode, this is probably a big
 450   // runtime hit for C++ apps.  Either the contents of the LSDA need to be
 451   // adjusted or this should be a data section.
 452   LSDASection = Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS,
 453                                    ELF::SHF_ALLOC);
 454
 455   COFFDebugSymbolsSection = nullptr;
 456
 457   // Debug Info Sections.
 458   DwarfAbbrevSection =
 459       Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0);
 460   DwarfInfoSection = Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0);
 461   DwarfLineSection = Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0);
 462   DwarfFrameSection = Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0);
 463   DwarfPubNamesSection =
 464       Ctx->getELFSection(".debug_pubnames", ELF::SHT_PROGBITS, 0);
 465   DwarfPubTypesSection =
 466       Ctx->getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0);
 467   DwarfGnuPubNamesSection =
 468       Ctx->getELFSection(".debug_gnu_pubnames", ELF::SHT_PROGBITS, 0);
 469   DwarfGnuPubTypesSection =
 470       Ctx->getELFSection(".debug_gnu_pubtypes", ELF::SHT_PROGBITS, 0);
 471   DwarfStrSection =
 472       Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS,
 473                          ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
 474   DwarfLocSection = Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0);
 475   DwarfARangesSection =
 476       Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0);
 477   DwarfRangesSection =
 478       Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0);
 479
 480   // DWARF5 Experimental Debug Info
 481
 482   // Accelerator Tables
 483   DwarfAccelNamesSection =
 484       Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0);
 485   DwarfAccelObjCSection =
 486       Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0);
 487   DwarfAccelNamespaceSection =
 488       Ctx->getELFSection(".apple_namespaces", ELF::SHT_PROGBITS, 0);
 489   DwarfAccelTypesSection =
 490       Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0);
 491
 492   // Fission Sections
 493   DwarfInfoDWOSection =
 494       Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0);
 495   DwarfTypesDWOSection =
 496       Ctx->getELFSection(".debug_types.dwo", ELF::SHT_PROGBITS, 0);
 497   DwarfAbbrevDWOSection =
 498       Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0);
 499   DwarfStrDWOSection =
 500       Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS,
 501                          ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
 502   DwarfLineDWOSection =
 503       Ctx->getELFSection(".debug_line.dwo", ELF::SHT_PROGBITS, 0);
 504   DwarfLocDWOSection =
 505       Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0);
 506   DwarfStrOffDWOSection =
 507       Ctx->getELFSection(".debug_str_offsets.dwo", ELF::SHT_PROGBITS, 0);
 508   DwarfAddrSection = Ctx->getELFSection(".debug_addr", ELF::SHT_PROGBITS, 0);
 509
 510   StackMapSection =
 511       Ctx->getELFSection(".llvm_stackmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
 512 }
 513
 514 void MCObjectFileInfo::InitCOFFMCObjectFileInfo(Triple T) {
 515   bool IsWoA = T.getArch() == Triple::arm || T.getArch() == Triple::thumb;
 516
 517   CommDirectiveSupportsAlignment = true;
 518
 519   // COFF
 520   BSSSection = Ctx->getCOFFSection(
 521       ".bss", COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
 522                   COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
 523       SectionKind::getBSS());
 524   TextSection = Ctx->getCOFFSection(
 525       ".text",
 526       (IsWoA ? COFF::IMAGE_SCN_MEM_16BIT : (COFF::SectionCharacteristics)0) |
 527           COFF::IMAGE_SCN_CNT_CODE | COFF::IMAGE_SCN_MEM_EXECUTE |
 528           COFF::IMAGE_SCN_MEM_READ,
 529       SectionKind::getText());
 530   DataSection = Ctx->getCOFFSection(
 531       ".data", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ |
 532                    COFF::IMAGE_SCN_MEM_WRITE,
 533       SectionKind::getDataRel());
 534   ReadOnlySection = Ctx->getCOFFSection(
 535       ".rdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
 536       SectionKind::getReadOnly());
 537
 538   if (T.isKnownWindowsMSVCEnvironment() || T.isWindowsItaniumEnvironment()) {
 539     StaticCtorSection =
 540         Ctx->getCOFFSection(".CRT$XCU", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 541                                             COFF::IMAGE_SCN_MEM_READ,
 542                             SectionKind::getReadOnly());
 543     StaticDtorSection =
 544         Ctx->getCOFFSection(".CRT$XTX", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 545                                             COFF::IMAGE_SCN_MEM_READ,
 546                             SectionKind::getReadOnly());
 547   } else {
 548     StaticCtorSection = Ctx->getCOFFSection(
 549         ".ctors", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 550                       COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
 551         SectionKind::getDataRel());
 552     StaticDtorSection = Ctx->getCOFFSection(
 553         ".dtors", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 554                       COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
 555         SectionKind::getDataRel());
 556   }
 557
 558   // FIXME: We're emitting LSDA info into a readonly section on COFF, even
 559   // though it contains relocatable pointers.  In PIC mode, this is probably a
 560   // big runtime hit for C++ apps.  Either the contents of the LSDA need to be
 561   // adjusted or this should be a data section.
 562   assert(T.isOSWindows() && "Windows is the only supported COFF target");
 563   if (T.getArch() == Triple::x86_64) {
 564     // On Windows 64 with SEH, the LSDA is emitted into the .xdata section
 565     LSDASection = 0;
 566   } else {
 567     LSDASection = Ctx->getCOFFSection(".gcc_except_table",
 568                                       COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 569                                           COFF::IMAGE_SCN_MEM_READ,
 570                                       SectionKind::getReadOnly());
 571   }
 572
 573   // Debug info.
 574   COFFDebugSymbolsSection =
 575       Ctx->getCOFFSection(".debug$S", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 576                                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 577                                           COFF::IMAGE_SCN_MEM_READ,
 578                           SectionKind::getMetadata());
 579
 580   DwarfAbbrevSection = Ctx->getCOFFSection(
 581       ".debug_abbrev",
 582       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 583           COFF::IMAGE_SCN_MEM_READ,
 584       SectionKind::getMetadata());
 585   DwarfInfoSection = Ctx->getCOFFSection(
 586       ".debug_info",
 587       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 588           COFF::IMAGE_SCN_MEM_READ,
 589       SectionKind::getMetadata());
 590   DwarfLineSection = Ctx->getCOFFSection(
 591       ".debug_line",
 592       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 593           COFF::IMAGE_SCN_MEM_READ,
 594       SectionKind::getMetadata());
 595   DwarfFrameSection = Ctx->getCOFFSection(
 596       ".debug_frame",
 597       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 598           COFF::IMAGE_SCN_MEM_READ,
 599       SectionKind::getMetadata());
 600   DwarfPubNamesSection = Ctx->getCOFFSection(
 601       ".debug_pubnames",
 602       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 603           COFF::IMAGE_SCN_MEM_READ,
 604       SectionKind::getMetadata());
 605   DwarfPubTypesSection = Ctx->getCOFFSection(
 606       ".debug_pubtypes",
 607       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 608           COFF::IMAGE_SCN_MEM_READ,
 609       SectionKind::getMetadata());
 610   DwarfGnuPubNamesSection = Ctx->getCOFFSection(
 611       ".debug_gnu_pubnames",
 612       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 613           COFF::IMAGE_SCN_MEM_READ,
 614       SectionKind::getMetadata());
 615   DwarfGnuPubTypesSection = Ctx->getCOFFSection(
 616       ".debug_gnu_pubtypes",
 617       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 618           COFF::IMAGE_SCN_MEM_READ,
 619       SectionKind::getMetadata());
 620   DwarfStrSection = Ctx->getCOFFSection(
 621       ".debug_str",
 622       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 623           COFF::IMAGE_SCN_MEM_READ,
 624       SectionKind::getMetadata());
 625   DwarfLocSection = Ctx->getCOFFSection(
 626       ".debug_loc",
 627       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 628           COFF::IMAGE_SCN_MEM_READ,
 629       SectionKind::getMetadata());
 630   DwarfARangesSection = Ctx->getCOFFSection(
 631       ".debug_aranges",
 632       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 633           COFF::IMAGE_SCN_MEM_READ,
 634       SectionKind::getMetadata());
 635   DwarfRangesSection = Ctx->getCOFFSection(
 636       ".debug_ranges",
 637       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 638           COFF::IMAGE_SCN_MEM_READ,
 639       SectionKind::getMetadata());
 640   DwarfInfoDWOSection = Ctx->getCOFFSection(
 641       ".debug_info.dwo",
 642       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 643           COFF::IMAGE_SCN_MEM_READ,
 644       SectionKind::getMetadata());
 645   DwarfTypesDWOSection = Ctx->getCOFFSection(
 646       ".debug_types.dwo",
 647       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 648           COFF::IMAGE_SCN_MEM_READ,
 649       SectionKind::getMetadata());
 650   DwarfAbbrevDWOSection = Ctx->getCOFFSection(
 651       ".debug_abbrev.dwo",
 652       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 653           COFF::IMAGE_SCN_MEM_READ,
 654       SectionKind::getMetadata());
 655   DwarfStrDWOSection = Ctx->getCOFFSection(
 656       ".debug_str.dwo",
 657       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 658           COFF::IMAGE_SCN_MEM_READ,
 659       SectionKind::getMetadata());
 660   DwarfLineDWOSection = Ctx->getCOFFSection(
 661       ".debug_line.dwo",
 662       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 663           COFF::IMAGE_SCN_MEM_READ,
 664       SectionKind::getMetadata());
 665   DwarfLocDWOSection = Ctx->getCOFFSection(
 666       ".debug_loc.dwo",
 667       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 668           COFF::IMAGE_SCN_MEM_READ,
 669       SectionKind::getMetadata());
 670   DwarfStrOffDWOSection = Ctx->getCOFFSection(
 671       ".debug_str_offsets.dwo",
 672       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 673           COFF::IMAGE_SCN_MEM_READ,
 674       SectionKind::getMetadata());
 675   DwarfAddrSection = Ctx->getCOFFSection(
 676       ".debug_addr",
 677       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 678           COFF::IMAGE_SCN_MEM_READ,
 679       SectionKind::getMetadata());
 680   DwarfAccelNamesSection = Ctx->getCOFFSection(
 681       ".apple_names",
 682       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 683           COFF::IMAGE_SCN_MEM_READ,
 684       SectionKind::getMetadata());
 685   DwarfAccelNamespaceSection = Ctx->getCOFFSection(
 686       ".apple_namespaces",
 687       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 688           COFF::IMAGE_SCN_MEM_READ,
 689       SectionKind::getMetadata());
 690   DwarfAccelTypesSection = Ctx->getCOFFSection(
 691       ".apple_types",
 692       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 693           COFF::IMAGE_SCN_MEM_READ,
 694       SectionKind::getMetadata());
 695   DwarfAccelObjCSection = Ctx->getCOFFSection(
 696       ".apple_objc",
 697       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 698           COFF::IMAGE_SCN_MEM_READ,
 699       SectionKind::getMetadata());
 700
 701   DrectveSection = Ctx->getCOFFSection(
 702       ".drectve", COFF::IMAGE_SCN_LNK_INFO | COFF::IMAGE_SCN_LNK_REMOVE,
 703       SectionKind::getMetadata());
 704
 705   PDataSection = Ctx->getCOFFSection(
 706       ".pdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
 707       SectionKind::getDataRel());
 708
 709   XDataSection = Ctx->getCOFFSection(
 710       ".xdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
 711       SectionKind::getDataRel());
 712
 713   TLSDataSection = Ctx->getCOFFSection(
 714       ".tls$", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ |
 715                    COFF::IMAGE_SCN_MEM_WRITE,
 716       SectionKind::getDataRel());
 717 }
 718
 719 void MCObjectFileInfo::InitMCObjectFileInfo(StringRef T, Reloc::Model relocm,
 720                                             CodeModel::Model cm,
 721                                             MCContext &ctx) {
 722   RelocM = relocm;
 723   CMModel = cm;
 724   Ctx = &ctx;
 725
 726   // Common.
 727   CommDirectiveSupportsAlignment = true;
 728   SupportsWeakOmittedEHFrame = true;
 729   SupportsCompactUnwindWithoutEHFrame = false;
 730
 731   PersonalityEncoding = LSDAEncoding = FDECFIEncoding = TTypeEncoding =
 732       dwarf::DW_EH_PE_absptr;
 733
 734   CompactUnwindDwarfEHFrameOnly = 0;
 735
 736   EHFrameSection = nullptr;             // Created on demand.
 737   CompactUnwindSection = nullptr;       // Used only by selected targets.
 738   DwarfAccelNamesSection = nullptr;     // Used only by selected targets.
 739   DwarfAccelObjCSection = nullptr;      // Used only by selected targets.
 740   DwarfAccelNamespaceSection = nullptr; // Used only by selected targets.
 741   DwarfAccelTypesSection = nullptr;     // Used only by selected targets.
 742
 743   TT = Triple(T);
 744
 745   Triple::ArchType Arch = TT.getArch();
 746   // FIXME: Checking for Arch here to filter out bogus triples such as
 747   // cellspu-apple-darwin. Perhaps we should fix in Triple?
 748   if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
 749        Arch == Triple::arm || Arch == Triple::thumb ||
 750        Arch == Triple::aarch64 ||
 751        Arch == Triple::ppc || Arch == Triple::ppc64 ||
 752        Arch == Triple::UnknownArch) &&
 753       (TT.isOSDarwin() || TT.isOSBinFormatMachO())) {
 754     Env = IsMachO;
 755     InitMachOMCObjectFileInfo(TT);
 756   } else if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
 757               Arch == Triple::arm || Arch == Triple::thumb) &&
 758              (TT.isOSWindows() && TT.getObjectFormat() == Triple::COFF)) {
 759     Env = IsCOFF;
 760     InitCOFFMCObjectFileInfo(TT);
 761   } else {
 762     Env = IsELF;
 763     InitELFMCObjectFileInfo(TT);
 764   }
 765 }
 766
 767 const MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const {
 768   return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP,
 769                             0, utostr(Hash));
 770 }
 771
 772 void MCObjectFileInfo::InitEHFrameSection() {
 773   if (Env == IsMachO)
 774     EHFrameSection =
 775       Ctx->getMachOSection("__TEXT", "__eh_frame",
 776                            MachO::S_COALESCED |
 777                            MachO::S_ATTR_NO_TOC |
 778                            MachO::S_ATTR_STRIP_STATIC_SYMS |
 779                            MachO::S_ATTR_LIVE_SUPPORT,
 780                            SectionKind::getReadOnly());
 781   else if (Env == IsELF)
 782     EHFrameSection =
 783         Ctx->getELFSection(".eh_frame", EHSectionType, EHSectionFlags);
 784   else
 785     EHFrameSection =
 786       Ctx->getCOFFSection(".eh_frame",
 787                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 788                           COFF::IMAGE_SCN_MEM_READ |
 789                           COFF::IMAGE_SCN_MEM_WRITE,
 790                           SectionKind::getDataRel());
 791 }