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   // armv7k always has it.
  33   if (T.isWatchOS())
  34     return true;
  35
  36   // Use it on newer version of OS X.
  37   if (T.isMacOSX() && !T.isMacOSXVersionLT(10, 6))
  38     return true;
  39
  40   // And the iOS simulator.
  41   if (T.isiOS() &&
  42       (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86))
  43     return true;
  44
  45   return false;
  46 }
  47
  48 void MCObjectFileInfo::initMachOMCObjectFileInfo(Triple T) {
  49   // MachO
  50   SupportsWeakOmittedEHFrame = false;
  51
  52   EHFrameSection = Ctx->getMachOSection(
  53       "__TEXT", "__eh_frame",
  54       MachO::S_COALESCED | MachO::S_ATTR_NO_TOC |
  55           MachO::S_ATTR_STRIP_STATIC_SYMS | MachO::S_ATTR_LIVE_SUPPORT,
  56       SectionKind::getReadOnly());
  57
  58   if (T.isOSDarwin() && T.getArch() == Triple::aarch64)
  59     SupportsCompactUnwindWithoutEHFrame = true;
  60
  61   if (T.isWatchOS())
  62     OmitDwarfIfHaveCompactUnwind = true;
  63
  64   PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel
  65     | dwarf::DW_EH_PE_sdata4;
  66   LSDAEncoding = FDECFIEncoding = dwarf::DW_EH_PE_pcrel;
  67   TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
  68     dwarf::DW_EH_PE_sdata4;
  69
  70   // .comm doesn't support alignment before Leopard.
  71   if (T.isMacOSX() && T.isMacOSXVersionLT(10, 5))
  72     CommDirectiveSupportsAlignment = false;
  73
  74   TextSection // .text
  75     = Ctx->getMachOSection("__TEXT", "__text",
  76                            MachO::S_ATTR_PURE_INSTRUCTIONS,
  77                            SectionKind::getText());
  78   DataSection // .data
  79       = Ctx->getMachOSection("__DATA", "__data", 0, SectionKind::getData());
  80
  81   // BSSSection might not be expected initialized on msvc.
  82   BSSSection = nullptr;
  83
  84   TLSDataSection // .tdata
  85       = Ctx->getMachOSection("__DATA", "__thread_data",
  86                              MachO::S_THREAD_LOCAL_REGULAR,
  87                              SectionKind::getData());
  88   TLSBSSSection // .tbss
  89     = Ctx->getMachOSection("__DATA", "__thread_bss",
  90                            MachO::S_THREAD_LOCAL_ZEROFILL,
  91                            SectionKind::getThreadBSS());
  92
  93   // TODO: Verify datarel below.
  94   TLSTLVSection // .tlv
  95       = Ctx->getMachOSection("__DATA", "__thread_vars",
  96                              MachO::S_THREAD_LOCAL_VARIABLES,
  97                              SectionKind::getData());
  98
  99   TLSThreadInitSection = Ctx->getMachOSection(
 100       "__DATA", "__thread_init", MachO::S_THREAD_LOCAL_INIT_FUNCTION_POINTERS,
 101       SectionKind::getData());
 102
 103   CStringSection // .cstring
 104     = Ctx->getMachOSection("__TEXT", "__cstring",
 105                            MachO::S_CSTRING_LITERALS,
 106                            SectionKind::getMergeable1ByteCString());
 107   UStringSection
 108     = Ctx->getMachOSection("__TEXT","__ustring", 0,
 109                            SectionKind::getMergeable2ByteCString());
 110   FourByteConstantSection // .literal4
 111     = Ctx->getMachOSection("__TEXT", "__literal4",
 112                            MachO::S_4BYTE_LITERALS,
 113                            SectionKind::getMergeableConst4());
 114   EightByteConstantSection // .literal8
 115     = Ctx->getMachOSection("__TEXT", "__literal8",
 116                            MachO::S_8BYTE_LITERALS,
 117                            SectionKind::getMergeableConst8());
 118
 119   SixteenByteConstantSection // .literal16
 120       = Ctx->getMachOSection("__TEXT", "__literal16",
 121                              MachO::S_16BYTE_LITERALS,
 122                              SectionKind::getMergeableConst16());
 123
 124   ReadOnlySection  // .const
 125     = Ctx->getMachOSection("__TEXT", "__const", 0,
 126                            SectionKind::getReadOnly());
 127
 128   // If the target is not powerpc, map the coal sections to the non-coal
 129   // sections.
 130   //
 131   // "__TEXT/__textcoal_nt" => section "__TEXT/__text"
 132   // "__TEXT/__const_coal"  => section "__TEXT/__const"
 133   // "__DATA/__datacoal_nt" => section "__DATA/__data"
 134   Triple::ArchType ArchTy = T.getArch();
 135
 136   if (ArchTy == Triple::ppc || ArchTy == Triple::ppc64) {
 137     TextCoalSection
 138       = Ctx->getMachOSection("__TEXT", "__textcoal_nt",
 139                              MachO::S_COALESCED |
 140                              MachO::S_ATTR_PURE_INSTRUCTIONS,
 141                              SectionKind::getText());
 142     ConstTextCoalSection
 143       = Ctx->getMachOSection("__TEXT", "__const_coal",
 144                              MachO::S_COALESCED,
 145                              SectionKind::getReadOnly());
 146     DataCoalSection = Ctx->getMachOSection(
 147         "__DATA", "__datacoal_nt", MachO::S_COALESCED, SectionKind::getData());
 148   } else {
 149     TextCoalSection = TextSection;
 150     ConstTextCoalSection = ReadOnlySection;
 151     DataCoalSection = DataSection;
 152   }
 153
 154   ConstDataSection  // .const_data
 155     = Ctx->getMachOSection("__DATA", "__const", 0,
 156                            SectionKind::getReadOnlyWithRel());
 157   DataCommonSection
 158     = Ctx->getMachOSection("__DATA","__common",
 159                            MachO::S_ZEROFILL,
 160                            SectionKind::getBSS());
 161   DataBSSSection
 162     = Ctx->getMachOSection("__DATA","__bss", MachO::S_ZEROFILL,
 163                            SectionKind::getBSS());
 164
 165
 166   LazySymbolPointerSection
 167     = Ctx->getMachOSection("__DATA", "__la_symbol_ptr",
 168                            MachO::S_LAZY_SYMBOL_POINTERS,
 169                            SectionKind::getMetadata());
 170   NonLazySymbolPointerSection
 171     = Ctx->getMachOSection("__DATA", "__nl_symbol_ptr",
 172                            MachO::S_NON_LAZY_SYMBOL_POINTERS,
 173                            SectionKind::getMetadata());
 174
 175   if (RelocM == Reloc::Static) {
 176     StaticCtorSection = Ctx->getMachOSection("__TEXT", "__constructor", 0,
 177                                              SectionKind::getData());
 178     StaticDtorSection = Ctx->getMachOSection("__TEXT", "__destructor", 0,
 179                                              SectionKind::getData());
 180   } else {
 181     StaticCtorSection = Ctx->getMachOSection("__DATA", "__mod_init_func",
 182                                              MachO::S_MOD_INIT_FUNC_POINTERS,
 183                                              SectionKind::getData());
 184     StaticDtorSection = Ctx->getMachOSection("__DATA", "__mod_term_func",
 185                                              MachO::S_MOD_TERM_FUNC_POINTERS,
 186                                              SectionKind::getData());
 187   }
 188
 189   // Exception Handling.
 190   LSDASection = Ctx->getMachOSection("__TEXT", "__gcc_except_tab", 0,
 191                                      SectionKind::getReadOnlyWithRel());
 192
 193   COFFDebugSymbolsSection = nullptr;
 194
 195   if (useCompactUnwind(T)) {
 196     CompactUnwindSection =
 197         Ctx->getMachOSection("__LD", "__compact_unwind", MachO::S_ATTR_DEBUG,
 198                              SectionKind::getReadOnly());
 199
 200     if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86)
 201       CompactUnwindDwarfEHFrameOnly = 0x04000000;  // UNWIND_X86_64_MODE_DWARF
 202     else if (T.getArch() == Triple::aarch64)
 203       CompactUnwindDwarfEHFrameOnly = 0x03000000;  // UNWIND_ARM64_MODE_DWARF
 204     else if (T.getArch() == Triple::arm || T.getArch() == Triple::thumb)
 205       CompactUnwindDwarfEHFrameOnly = 0x04000000;  // UNWIND_ARM_MODE_DWARF
 206   }
 207
 208   // Debug Information.
 209   DwarfAccelNamesSection =
 210       Ctx->getMachOSection("__DWARF", "__apple_names", MachO::S_ATTR_DEBUG,
 211                            SectionKind::getMetadata(), "names_begin");
 212   DwarfAccelObjCSection =
 213       Ctx->getMachOSection("__DWARF", "__apple_objc", MachO::S_ATTR_DEBUG,
 214                            SectionKind::getMetadata(), "objc_begin");
 215   // 16 character section limit...
 216   DwarfAccelNamespaceSection =
 217       Ctx->getMachOSection("__DWARF", "__apple_namespac", MachO::S_ATTR_DEBUG,
 218                            SectionKind::getMetadata(), "namespac_begin");
 219   DwarfAccelTypesSection =
 220       Ctx->getMachOSection("__DWARF", "__apple_types", MachO::S_ATTR_DEBUG,
 221                            SectionKind::getMetadata(), "types_begin");
 222
 223   DwarfAbbrevSection =
 224       Ctx->getMachOSection("__DWARF", "__debug_abbrev", MachO::S_ATTR_DEBUG,
 225                            SectionKind::getMetadata(), "section_abbrev");
 226   DwarfInfoSection =
 227       Ctx->getMachOSection("__DWARF", "__debug_info", MachO::S_ATTR_DEBUG,
 228                            SectionKind::getMetadata(), "section_info");
 229   DwarfLineSection =
 230       Ctx->getMachOSection("__DWARF", "__debug_line", MachO::S_ATTR_DEBUG,
 231                            SectionKind::getMetadata(), "section_line");
 232   DwarfFrameSection =
 233       Ctx->getMachOSection("__DWARF", "__debug_frame", MachO::S_ATTR_DEBUG,
 234                            SectionKind::getMetadata());
 235   DwarfPubNamesSection =
 236       Ctx->getMachOSection("__DWARF", "__debug_pubnames", MachO::S_ATTR_DEBUG,
 237                            SectionKind::getMetadata());
 238   DwarfPubTypesSection =
 239       Ctx->getMachOSection("__DWARF", "__debug_pubtypes", MachO::S_ATTR_DEBUG,
 240                            SectionKind::getMetadata());
 241   DwarfGnuPubNamesSection =
 242       Ctx->getMachOSection("__DWARF", "__debug_gnu_pubn", MachO::S_ATTR_DEBUG,
 243                            SectionKind::getMetadata());
 244   DwarfGnuPubTypesSection =
 245       Ctx->getMachOSection("__DWARF", "__debug_gnu_pubt", MachO::S_ATTR_DEBUG,
 246                            SectionKind::getMetadata());
 247   DwarfStrSection =
 248       Ctx->getMachOSection("__DWARF", "__debug_str", MachO::S_ATTR_DEBUG,
 249                            SectionKind::getMetadata(), "info_string");
 250   DwarfLocSection =
 251       Ctx->getMachOSection("__DWARF", "__debug_loc", MachO::S_ATTR_DEBUG,
 252                            SectionKind::getMetadata(), "section_debug_loc");
 253   DwarfARangesSection =
 254       Ctx->getMachOSection("__DWARF", "__debug_aranges", MachO::S_ATTR_DEBUG,
 255                            SectionKind::getMetadata());
 256   DwarfRangesSection =
 257       Ctx->getMachOSection("__DWARF", "__debug_ranges", MachO::S_ATTR_DEBUG,
 258                            SectionKind::getMetadata(), "debug_range");
 259   DwarfDebugInlineSection =
 260       Ctx->getMachOSection("__DWARF", "__debug_inlined", MachO::S_ATTR_DEBUG,
 261                            SectionKind::getMetadata());
 262   StackMapSection = Ctx->getMachOSection("__LLVM_STACKMAPS", "__llvm_stackmaps",
 263                                          0, SectionKind::getMetadata());
 264
 265   FaultMapSection = Ctx->getMachOSection("__LLVM_FAULTMAPS", "__llvm_faultmaps",
 266                                          0, SectionKind::getMetadata());
 267
 268   TLSExtraDataSection = TLSTLVSection;
 269 }
 270
 271 void MCObjectFileInfo::initELFMCObjectFileInfo(Triple T) {
 272   switch (T.getArch()) {
 273   case Triple::mips:
 274   case Triple::mipsel:
 275     FDECFIEncoding = dwarf::DW_EH_PE_sdata4;
 276     break;
 277   case Triple::mips64:
 278   case Triple::mips64el:
 279     FDECFIEncoding = dwarf::DW_EH_PE_sdata8;
 280     break;
 281   case Triple::x86_64:
 282     FDECFIEncoding = dwarf::DW_EH_PE_pcrel |
 283                      ((CMModel == CodeModel::Large) ? dwarf::DW_EH_PE_sdata8
 284                                                     : dwarf::DW_EH_PE_sdata4);
 285     break;
 286   default:
 287     FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 288     break;
 289   }
 290
 291   switch (T.getArch()) {
 292   case Triple::arm:
 293   case Triple::armeb:
 294   case Triple::thumb:
 295   case Triple::thumbeb:
 296     if (Ctx->getAsmInfo()->getExceptionHandlingType() == ExceptionHandling::ARM)
 297       break;
 298     // Fallthrough if not using EHABI
 299   case Triple::ppc:
 300   case Triple::x86:
 301     PersonalityEncoding = (RelocM == Reloc::PIC_)
 302      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 303      : dwarf::DW_EH_PE_absptr;
 304     LSDAEncoding = (RelocM == Reloc::PIC_)
 305       ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 306       : dwarf::DW_EH_PE_absptr;
 307     TTypeEncoding = (RelocM == Reloc::PIC_)
 308      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 309      : dwarf::DW_EH_PE_absptr;
 310     break;
 311   case Triple::x86_64:
 312     if (RelocM == Reloc::PIC_) {
 313       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 314         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 315          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 316       LSDAEncoding = dwarf::DW_EH_PE_pcrel |
 317         (CMModel == CodeModel::Small
 318          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 319       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 320         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 321          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 322     } else {
 323       PersonalityEncoding =
 324         (CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 325         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 326       LSDAEncoding = (CMModel == CodeModel::Small)
 327         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 328       TTypeEncoding = (CMModel == CodeModel::Small)
 329         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 330     }
 331     break;
 332   case Triple::aarch64:
 333   case Triple::aarch64_be:
 334     // The small model guarantees static code/data size < 4GB, but not where it
 335     // will be in memory. Most of these could end up >2GB away so even a signed
 336     // pc-relative 32-bit address is insufficient, theoretically.
 337     if (RelocM == Reloc::PIC_) {
 338       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 339         dwarf::DW_EH_PE_sdata8;
 340       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8;
 341       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 342         dwarf::DW_EH_PE_sdata8;
 343     } else {
 344       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 345       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 346       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 347     }
 348     break;
 349   case Triple::mips:
 350   case Triple::mipsel:
 351   case Triple::mips64:
 352   case Triple::mips64el:
 353     // MIPS uses indirect pointer to refer personality functions and types, so
 354     // that the eh_frame section can be read-only. DW.ref.personality will be
 355     // generated for relocation.
 356     PersonalityEncoding = dwarf::DW_EH_PE_indirect;
 357     // FIXME: The N64 ABI probably ought to use DW_EH_PE_sdata8 but we can't
 358     //        identify N64 from just a triple.
 359     TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 360                     dwarf::DW_EH_PE_sdata4;
 361     // We don't support PC-relative LSDA references in GAS so we use the default
 362     // DW_EH_PE_absptr for those.
 363     break;
 364   case Triple::ppc64:
 365   case Triple::ppc64le:
 366     PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 367       dwarf::DW_EH_PE_udata8;
 368     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
 369     TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 370       dwarf::DW_EH_PE_udata8;
 371     break;
 372   case Triple::sparcel:
 373   case Triple::sparc:
 374     if (RelocM == Reloc::PIC_) {
 375       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 376       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 377         dwarf::DW_EH_PE_sdata4;
 378       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 379         dwarf::DW_EH_PE_sdata4;
 380     } else {
 381       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 382       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 383       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 384     }
 385     break;
 386   case Triple::sparcv9:
 387     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 388     if (RelocM == Reloc::PIC_) {
 389       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 390         dwarf::DW_EH_PE_sdata4;
 391       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 392         dwarf::DW_EH_PE_sdata4;
 393     } else {
 394       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 395       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 396     }
 397     break;
 398   case Triple::systemz:
 399     // All currently-defined code models guarantee that 4-byte PC-relative
 400     // values will be in range.
 401     if (RelocM == Reloc::PIC_) {
 402       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 403         dwarf::DW_EH_PE_sdata4;
 404       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 405       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 406         dwarf::DW_EH_PE_sdata4;
 407     } else {
 408       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 409       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 410       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 411     }
 412     break;
 413   default:
 414     break;
 415   }
 416
 417   unsigned EHSectionType = T.getArch() == Triple::x86_64
 418                                ? ELF::SHT_X86_64_UNWIND
 419                                : ELF::SHT_PROGBITS;
 420
 421   // Solaris requires different flags for .eh_frame to seemingly every other
 422   // platform.
 423   unsigned EHSectionFlags = ELF::SHF_ALLOC;
 424   if (T.isOSSolaris() && T.getArch() != Triple::x86_64)
 425     EHSectionFlags |= ELF::SHF_WRITE;
 426
 427   // ELF
 428   BSSSection = Ctx->getELFSection(".bss", ELF::SHT_NOBITS,
 429                                   ELF::SHF_WRITE | ELF::SHF_ALLOC);
 430
 431   TextSection = Ctx->getELFSection(".text", ELF::SHT_PROGBITS,
 432                                    ELF::SHF_EXECINSTR | ELF::SHF_ALLOC);
 433
 434   DataSection = Ctx->getELFSection(".data", ELF::SHT_PROGBITS,
 435                                    ELF::SHF_WRITE | ELF::SHF_ALLOC);
 436
 437   ReadOnlySection =
 438       Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
 439
 440   TLSDataSection =
 441       Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS,
 442                          ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE);
 443
 444   TLSBSSSection = Ctx->getELFSection(
 445       ".tbss", ELF::SHT_NOBITS, ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE);
 446
 447   DataRelROSection = Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS,
 448                                         ELF::SHF_ALLOC | ELF::SHF_WRITE);
 449
 450   MergeableConst4Section =
 451       Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS,
 452                          ELF::SHF_ALLOC | ELF::SHF_MERGE, 4, "");
 453
 454   MergeableConst8Section =
 455       Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS,
 456                          ELF::SHF_ALLOC | ELF::SHF_MERGE, 8, "");
 457
 458   MergeableConst16Section =
 459       Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS,
 460                          ELF::SHF_ALLOC | ELF::SHF_MERGE, 16, "");
 461
 462   StaticCtorSection = Ctx->getELFSection(".ctors", ELF::SHT_PROGBITS,
 463                                          ELF::SHF_ALLOC | ELF::SHF_WRITE);
 464
 465   StaticDtorSection = Ctx->getELFSection(".dtors", ELF::SHT_PROGBITS,
 466                                          ELF::SHF_ALLOC | ELF::SHF_WRITE);
 467
 468   // Exception Handling Sections.
 469
 470   // FIXME: We're emitting LSDA info into a readonly section on ELF, even though
 471   // it contains relocatable pointers.  In PIC mode, this is probably a big
 472   // runtime hit for C++ apps.  Either the contents of the LSDA need to be
 473   // adjusted or this should be a data section.
 474   LSDASection = Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS,
 475                                    ELF::SHF_ALLOC);
 476
 477   COFFDebugSymbolsSection = nullptr;
 478
 479   // Debug Info Sections.
 480   DwarfAbbrevSection = Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0,
 481                                           "section_abbrev");
 482   DwarfInfoSection =
 483       Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0, "section_info");
 484   DwarfLineSection = Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0);
 485   DwarfFrameSection = Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0);
 486   DwarfPubNamesSection =
 487       Ctx->getELFSection(".debug_pubnames", ELF::SHT_PROGBITS, 0);
 488   DwarfPubTypesSection =
 489       Ctx->getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0);
 490   DwarfGnuPubNamesSection =
 491       Ctx->getELFSection(".debug_gnu_pubnames", ELF::SHT_PROGBITS, 0);
 492   DwarfGnuPubTypesSection =
 493       Ctx->getELFSection(".debug_gnu_pubtypes", ELF::SHT_PROGBITS, 0);
 494   DwarfStrSection =
 495       Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS,
 496                          ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
 497   DwarfLocSection = Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0);
 498   DwarfARangesSection =
 499       Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0);
 500   DwarfRangesSection =
 501       Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0, "debug_range");
 502
 503   // DWARF5 Experimental Debug Info
 504
 505   // Accelerator Tables
 506   DwarfAccelNamesSection =
 507       Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0, "names_begin");
 508   DwarfAccelObjCSection =
 509       Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0, "objc_begin");
 510   DwarfAccelNamespaceSection = Ctx->getELFSection(
 511       ".apple_namespaces", ELF::SHT_PROGBITS, 0, "namespac_begin");
 512   DwarfAccelTypesSection =
 513       Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0, "types_begin");
 514
 515   // Fission Sections
 516   DwarfInfoDWOSection =
 517       Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0);
 518   DwarfTypesDWOSection =
 519       Ctx->getELFSection(".debug_types.dwo", ELF::SHT_PROGBITS, 0);
 520   DwarfAbbrevDWOSection =
 521       Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0);
 522   DwarfStrDWOSection =
 523       Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS,
 524                          ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
 525   DwarfLineDWOSection =
 526       Ctx->getELFSection(".debug_line.dwo", ELF::SHT_PROGBITS, 0);
 527   DwarfLocDWOSection =
 528       Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0, "skel_loc");
 529   DwarfStrOffDWOSection =
 530       Ctx->getELFSection(".debug_str_offsets.dwo", ELF::SHT_PROGBITS, 0);
 531   DwarfAddrSection =
 532       Ctx->getELFSection(".debug_addr", ELF::SHT_PROGBITS, 0, "addr_sec");
 533
 534   StackMapSection =
 535       Ctx->getELFSection(".llvm_stackmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
 536
 537   FaultMapSection =
 538       Ctx->getELFSection(".llvm_faultmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
 539
 540   EHFrameSection =
 541       Ctx->getELFSection(".eh_frame", EHSectionType, EHSectionFlags);
 542 }
 543
 544 void MCObjectFileInfo::initCOFFMCObjectFileInfo(Triple T) {
 545   EHFrameSection = Ctx->getCOFFSection(
 546       ".eh_frame", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 547                        COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
 548       SectionKind::getData());
 549
 550   bool IsWoA = T.getArch() == Triple::arm || T.getArch() == Triple::thumb;
 551
 552   CommDirectiveSupportsAlignment = true;
 553
 554   // COFF
 555   BSSSection = Ctx->getCOFFSection(
 556       ".bss", COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
 557                   COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
 558       SectionKind::getBSS());
 559   TextSection = Ctx->getCOFFSection(
 560       ".text",
 561       (IsWoA ? COFF::IMAGE_SCN_MEM_16BIT : (COFF::SectionCharacteristics)0) |
 562           COFF::IMAGE_SCN_CNT_CODE | COFF::IMAGE_SCN_MEM_EXECUTE |
 563           COFF::IMAGE_SCN_MEM_READ,
 564       SectionKind::getText());
 565   DataSection = Ctx->getCOFFSection(
 566       ".data", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ |
 567                    COFF::IMAGE_SCN_MEM_WRITE,
 568       SectionKind::getData());
 569   ReadOnlySection = Ctx->getCOFFSection(
 570       ".rdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
 571       SectionKind::getReadOnly());
 572
 573   if (T.isKnownWindowsMSVCEnvironment() || T.isWindowsItaniumEnvironment()) {
 574     StaticCtorSection =
 575         Ctx->getCOFFSection(".CRT$XCU", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 576                                             COFF::IMAGE_SCN_MEM_READ,
 577                             SectionKind::getReadOnly());
 578     StaticDtorSection =
 579         Ctx->getCOFFSection(".CRT$XTX", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 580                                             COFF::IMAGE_SCN_MEM_READ,
 581                             SectionKind::getReadOnly());
 582   } else {
 583     StaticCtorSection = Ctx->getCOFFSection(
 584         ".ctors", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 585                       COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
 586         SectionKind::getData());
 587     StaticDtorSection = Ctx->getCOFFSection(
 588         ".dtors", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 589                       COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
 590         SectionKind::getData());
 591   }
 592
 593   // FIXME: We're emitting LSDA info into a readonly section on COFF, even
 594   // though it contains relocatable pointers.  In PIC mode, this is probably a
 595   // big runtime hit for C++ apps.  Either the contents of the LSDA need to be
 596   // adjusted or this should be a data section.
 597   assert(T.isOSWindows() && "Windows is the only supported COFF target");
 598   if (T.getArch() == Triple::x86_64) {
 599     // On Windows 64 with SEH, the LSDA is emitted into the .xdata section
 600     LSDASection = nullptr;
 601   } else {
 602     LSDASection = Ctx->getCOFFSection(".gcc_except_table",
 603                                       COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 604                                           COFF::IMAGE_SCN_MEM_READ,
 605                                       SectionKind::getReadOnly());
 606   }
 607
 608   // Debug info.
 609   COFFDebugSymbolsSection =
 610       Ctx->getCOFFSection(".debug$S", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 611                                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 612                                           COFF::IMAGE_SCN_MEM_READ,
 613                           SectionKind::getMetadata());
 614
 615   DwarfAbbrevSection = Ctx->getCOFFSection(
 616       ".debug_abbrev",
 617       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 618           COFF::IMAGE_SCN_MEM_READ,
 619       SectionKind::getMetadata(), "section_abbrev");
 620   DwarfInfoSection = Ctx->getCOFFSection(
 621       ".debug_info",
 622       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 623           COFF::IMAGE_SCN_MEM_READ,
 624       SectionKind::getMetadata(), "section_info");
 625   DwarfLineSection = Ctx->getCOFFSection(
 626       ".debug_line",
 627       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 628           COFF::IMAGE_SCN_MEM_READ,
 629       SectionKind::getMetadata(), "section_line");
 630
 631   DwarfFrameSection = Ctx->getCOFFSection(
 632       ".debug_frame",
 633       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 634           COFF::IMAGE_SCN_MEM_READ,
 635       SectionKind::getMetadata());
 636   DwarfPubNamesSection = Ctx->getCOFFSection(
 637       ".debug_pubnames",
 638       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 639           COFF::IMAGE_SCN_MEM_READ,
 640       SectionKind::getMetadata());
 641   DwarfPubTypesSection = Ctx->getCOFFSection(
 642       ".debug_pubtypes",
 643       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 644           COFF::IMAGE_SCN_MEM_READ,
 645       SectionKind::getMetadata());
 646   DwarfGnuPubNamesSection = Ctx->getCOFFSection(
 647       ".debug_gnu_pubnames",
 648       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 649           COFF::IMAGE_SCN_MEM_READ,
 650       SectionKind::getMetadata());
 651   DwarfGnuPubTypesSection = Ctx->getCOFFSection(
 652       ".debug_gnu_pubtypes",
 653       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 654           COFF::IMAGE_SCN_MEM_READ,
 655       SectionKind::getMetadata());
 656   DwarfStrSection = Ctx->getCOFFSection(
 657       ".debug_str",
 658       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 659           COFF::IMAGE_SCN_MEM_READ,
 660       SectionKind::getMetadata(), "info_string");
 661   DwarfLocSection = Ctx->getCOFFSection(
 662       ".debug_loc",
 663       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 664           COFF::IMAGE_SCN_MEM_READ,
 665       SectionKind::getMetadata(), "section_debug_loc");
 666   DwarfARangesSection = Ctx->getCOFFSection(
 667       ".debug_aranges",
 668       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 669           COFF::IMAGE_SCN_MEM_READ,
 670       SectionKind::getMetadata());
 671   DwarfRangesSection = Ctx->getCOFFSection(
 672       ".debug_ranges",
 673       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 674           COFF::IMAGE_SCN_MEM_READ,
 675       SectionKind::getMetadata(), "debug_range");
 676   DwarfInfoDWOSection = Ctx->getCOFFSection(
 677       ".debug_info.dwo",
 678       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 679           COFF::IMAGE_SCN_MEM_READ,
 680       SectionKind::getMetadata(), "section_info_dwo");
 681   DwarfTypesDWOSection = Ctx->getCOFFSection(
 682       ".debug_types.dwo",
 683       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 684           COFF::IMAGE_SCN_MEM_READ,
 685       SectionKind::getMetadata(), "section_types_dwo");
 686   DwarfAbbrevDWOSection = Ctx->getCOFFSection(
 687       ".debug_abbrev.dwo",
 688       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 689           COFF::IMAGE_SCN_MEM_READ,
 690       SectionKind::getMetadata(), "section_abbrev_dwo");
 691   DwarfStrDWOSection = Ctx->getCOFFSection(
 692       ".debug_str.dwo",
 693       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 694           COFF::IMAGE_SCN_MEM_READ,
 695       SectionKind::getMetadata(), "skel_string");
 696   DwarfLineDWOSection = Ctx->getCOFFSection(
 697       ".debug_line.dwo",
 698       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 699           COFF::IMAGE_SCN_MEM_READ,
 700       SectionKind::getMetadata());
 701   DwarfLocDWOSection = Ctx->getCOFFSection(
 702       ".debug_loc.dwo",
 703       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 704           COFF::IMAGE_SCN_MEM_READ,
 705       SectionKind::getMetadata(), "skel_loc");
 706   DwarfStrOffDWOSection = Ctx->getCOFFSection(
 707       ".debug_str_offsets.dwo",
 708       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 709           COFF::IMAGE_SCN_MEM_READ,
 710       SectionKind::getMetadata());
 711   DwarfAddrSection = Ctx->getCOFFSection(
 712       ".debug_addr",
 713       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 714           COFF::IMAGE_SCN_MEM_READ,
 715       SectionKind::getMetadata(), "addr_sec");
 716   DwarfAccelNamesSection = Ctx->getCOFFSection(
 717       ".apple_names",
 718       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 719           COFF::IMAGE_SCN_MEM_READ,
 720       SectionKind::getMetadata(), "names_begin");
 721   DwarfAccelNamespaceSection = Ctx->getCOFFSection(
 722       ".apple_namespaces",
 723       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 724           COFF::IMAGE_SCN_MEM_READ,
 725       SectionKind::getMetadata(), "namespac_begin");
 726   DwarfAccelTypesSection = Ctx->getCOFFSection(
 727       ".apple_types",
 728       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 729           COFF::IMAGE_SCN_MEM_READ,
 730       SectionKind::getMetadata(), "types_begin");
 731   DwarfAccelObjCSection = Ctx->getCOFFSection(
 732       ".apple_objc",
 733       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 734           COFF::IMAGE_SCN_MEM_READ,
 735       SectionKind::getMetadata(), "objc_begin");
 736
 737   DrectveSection = Ctx->getCOFFSection(
 738       ".drectve", COFF::IMAGE_SCN_LNK_INFO | COFF::IMAGE_SCN_LNK_REMOVE,
 739       SectionKind::getMetadata());
 740
 741   PDataSection = Ctx->getCOFFSection(
 742       ".pdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
 743       SectionKind::getData());
 744
 745   XDataSection = Ctx->getCOFFSection(
 746       ".xdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
 747       SectionKind::getData());
 748
 749   SXDataSection = Ctx->getCOFFSection(".sxdata", COFF::IMAGE_SCN_LNK_INFO,
 750                                       SectionKind::getMetadata());
 751
 752   TLSDataSection = Ctx->getCOFFSection(
 753       ".tls$", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ |
 754                    COFF::IMAGE_SCN_MEM_WRITE,
 755       SectionKind::getData());
 756
 757   StackMapSection = Ctx->getCOFFSection(".llvm_stackmaps",
 758                                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 759                                             COFF::IMAGE_SCN_MEM_READ,
 760                                         SectionKind::getReadOnly());
 761 }
 762
 763 void MCObjectFileInfo::InitMCObjectFileInfo(const Triple &TheTriple,
 764                                             Reloc::Model relocm,
 765                                             CodeModel::Model cm,
 766                                             MCContext &ctx) {
 767   RelocM = relocm;
 768   CMModel = cm;
 769   Ctx = &ctx;
 770
 771   // Common.
 772   CommDirectiveSupportsAlignment = true;
 773   SupportsWeakOmittedEHFrame = true;
 774   SupportsCompactUnwindWithoutEHFrame = false;
 775   OmitDwarfIfHaveCompactUnwind = false;
 776
 777   PersonalityEncoding = LSDAEncoding = FDECFIEncoding = TTypeEncoding =
 778       dwarf::DW_EH_PE_absptr;
 779
 780   CompactUnwindDwarfEHFrameOnly = 0;
 781
 782   EHFrameSection = nullptr;             // Created on demand.
 783   CompactUnwindSection = nullptr;       // Used only by selected targets.
 784   DwarfAccelNamesSection = nullptr;     // Used only by selected targets.
 785   DwarfAccelObjCSection = nullptr;      // Used only by selected targets.
 786   DwarfAccelNamespaceSection = nullptr; // Used only by selected targets.
 787   DwarfAccelTypesSection = nullptr;     // Used only by selected targets.
 788
 789   TT = TheTriple;
 790
 791   Triple::ArchType Arch = TT.getArch();
 792   // FIXME: Checking for Arch here to filter out bogus triples such as
 793   // cellspu-apple-darwin. Perhaps we should fix in Triple?
 794   if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
 795        Arch == Triple::arm || Arch == Triple::thumb ||
 796        Arch == Triple::aarch64 ||
 797        Arch == Triple::ppc || Arch == Triple::ppc64 ||
 798        Arch == Triple::UnknownArch) &&
 799       TT.isOSBinFormatMachO()) {
 800     Env = IsMachO;
 801     initMachOMCObjectFileInfo(TT);
 802   } else if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
 803               Arch == Triple::arm || Arch == Triple::thumb) &&
 804              (TT.isOSWindows() && TT.getObjectFormat() == Triple::COFF)) {
 805     Env = IsCOFF;
 806     initCOFFMCObjectFileInfo(TT);
 807   } else {
 808     Env = IsELF;
 809     initELFMCObjectFileInfo(TT);
 810   }
 811 }
 812
 813 void MCObjectFileInfo::InitMCObjectFileInfo(StringRef TT, Reloc::Model RM,
 814                                             CodeModel::Model CM,
 815                                             MCContext &ctx) {
 816   InitMCObjectFileInfo(Triple(TT), RM, CM, ctx);
 817 }
 818
 819 MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const {
 820   return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP,
 821                             0, utostr(Hash));
 822 }