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   if (T.isOSDarwin() && T.getArch() == Triple::aarch64)
  53     SupportsCompactUnwindWithoutEHFrame = true;
  54
  55   if (T.isWatchOS())
  56     OmitDwarfIfHaveCompactUnwind = true;
  57
  58   PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel
  59     | dwarf::DW_EH_PE_sdata4;
  60   LSDAEncoding = FDECFIEncoding = dwarf::DW_EH_PE_pcrel;
  61   TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
  62     dwarf::DW_EH_PE_sdata4;
  63
  64   // .comm doesn't support alignment before Leopard.
  65   if (T.isMacOSX() && T.isMacOSXVersionLT(10, 5))
  66     CommDirectiveSupportsAlignment = false;
  67
  68   TextSection // .text
  69     = Ctx->getMachOSection("__TEXT", "__text",
  70                            MachO::S_ATTR_PURE_INSTRUCTIONS,
  71                            SectionKind::getText());
  72   DataSection // .data
  73     = Ctx->getMachOSection("__DATA", "__data", 0,
  74                            SectionKind::getDataRel());
  75
  76   // BSSSection might not be expected initialized on msvc.
  77   BSSSection = nullptr;
  78
  79   TLSDataSection // .tdata
  80     = Ctx->getMachOSection("__DATA", "__thread_data",
  81                            MachO::S_THREAD_LOCAL_REGULAR,
  82                            SectionKind::getDataRel());
  83   TLSBSSSection // .tbss
  84     = Ctx->getMachOSection("__DATA", "__thread_bss",
  85                            MachO::S_THREAD_LOCAL_ZEROFILL,
  86                            SectionKind::getThreadBSS());
  87
  88   // TODO: Verify datarel below.
  89   TLSTLVSection // .tlv
  90     = Ctx->getMachOSection("__DATA", "__thread_vars",
  91                            MachO::S_THREAD_LOCAL_VARIABLES,
  92                            SectionKind::getDataRel());
  93
  94   TLSThreadInitSection
  95     = Ctx->getMachOSection("__DATA", "__thread_init",
  96                           MachO::S_THREAD_LOCAL_INIT_FUNCTION_POINTERS,
  97                           SectionKind::getDataRel());
  98
  99   CStringSection // .cstring
 100     = Ctx->getMachOSection("__TEXT", "__cstring",
 101                            MachO::S_CSTRING_LITERALS,
 102                            SectionKind::getMergeable1ByteCString());
 103   UStringSection
 104     = Ctx->getMachOSection("__TEXT","__ustring", 0,
 105                            SectionKind::getMergeable2ByteCString());
 106   FourByteConstantSection // .literal4
 107     = Ctx->getMachOSection("__TEXT", "__literal4",
 108                            MachO::S_4BYTE_LITERALS,
 109                            SectionKind::getMergeableConst4());
 110   EightByteConstantSection // .literal8
 111     = Ctx->getMachOSection("__TEXT", "__literal8",
 112                            MachO::S_8BYTE_LITERALS,
 113                            SectionKind::getMergeableConst8());
 114
 115   SixteenByteConstantSection // .literal16
 116       = Ctx->getMachOSection("__TEXT", "__literal16",
 117                              MachO::S_16BYTE_LITERALS,
 118                              SectionKind::getMergeableConst16());
 119
 120   ReadOnlySection  // .const
 121     = Ctx->getMachOSection("__TEXT", "__const", 0,
 122                            SectionKind::getReadOnly());
 123
 124   // If the target is not powerpc, map the coal sections to the non-coal
 125   // sections.
 126   //
 127   // "__TEXT/__textcoal_nt" => section "__TEXT/__text"
 128   // "__TEXT/__const_coal"  => section "__TEXT/__const"
 129   // "__DATA/__datacoal_nt" => section "__DATA/__data"
 130   Triple::ArchType ArchTy = T.getArch();
 131
 132   if (ArchTy == Triple::ppc || ArchTy == Triple::ppc64) {
 133     TextCoalSection
 134       = Ctx->getMachOSection("__TEXT", "__textcoal_nt",
 135                              MachO::S_COALESCED |
 136                              MachO::S_ATTR_PURE_INSTRUCTIONS,
 137                              SectionKind::getText());
 138     ConstTextCoalSection
 139       = Ctx->getMachOSection("__TEXT", "__const_coal",
 140                              MachO::S_COALESCED,
 141                              SectionKind::getReadOnly());
 142     DataCoalSection
 143       = Ctx->getMachOSection("__DATA","__datacoal_nt",
 144                              MachO::S_COALESCED,
 145                              SectionKind::getDataRel());
 146   } else {
 147     TextCoalSection = TextSection;
 148     ConstTextCoalSection = ReadOnlySection;
 149     DataCoalSection = DataSection;
 150   }
 151
 152   ConstDataSection  // .const_data
 153     = Ctx->getMachOSection("__DATA", "__const", 0,
 154                            SectionKind::getReadOnlyWithRel());
 155   DataCommonSection
 156     = Ctx->getMachOSection("__DATA","__common",
 157                            MachO::S_ZEROFILL,
 158                            SectionKind::getBSS());
 159   DataBSSSection
 160     = Ctx->getMachOSection("__DATA","__bss", MachO::S_ZEROFILL,
 161                            SectionKind::getBSS());
 162
 163
 164   LazySymbolPointerSection
 165     = Ctx->getMachOSection("__DATA", "__la_symbol_ptr",
 166                            MachO::S_LAZY_SYMBOL_POINTERS,
 167                            SectionKind::getMetadata());
 168   NonLazySymbolPointerSection
 169     = Ctx->getMachOSection("__DATA", "__nl_symbol_ptr",
 170                            MachO::S_NON_LAZY_SYMBOL_POINTERS,
 171                            SectionKind::getMetadata());
 172
 173   if (RelocM == Reloc::Static) {
 174     StaticCtorSection
 175       = Ctx->getMachOSection("__TEXT", "__constructor", 0,
 176                              SectionKind::getDataRel());
 177     StaticDtorSection
 178       = Ctx->getMachOSection("__TEXT", "__destructor", 0,
 179                              SectionKind::getDataRel());
 180   } else {
 181     StaticCtorSection
 182       = Ctx->getMachOSection("__DATA", "__mod_init_func",
 183                              MachO::S_MOD_INIT_FUNC_POINTERS,
 184                              SectionKind::getDataRel());
 185     StaticDtorSection
 186       = Ctx->getMachOSection("__DATA", "__mod_term_func",
 187                              MachO::S_MOD_TERM_FUNC_POINTERS,
 188                              SectionKind::getDataRel());
 189   }
 190
 191   // Exception Handling.
 192   LSDASection = Ctx->getMachOSection("__TEXT", "__gcc_except_tab", 0,
 193                                      SectionKind::getReadOnlyWithRel());
 194
 195   COFFDebugSymbolsSection = nullptr;
 196
 197   if (useCompactUnwind(T)) {
 198     CompactUnwindSection =
 199         Ctx->getMachOSection("__LD", "__compact_unwind", MachO::S_ATTR_DEBUG,
 200                              SectionKind::getReadOnly());
 201
 202     if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86)
 203       CompactUnwindDwarfEHFrameOnly = 0x04000000;  // UNWIND_X86_64_MODE_DWARF
 204     else if (T.getArch() == Triple::aarch64)
 205       CompactUnwindDwarfEHFrameOnly = 0x03000000;  // UNWIND_ARM64_MODE_DWARF
 206     else if (T.getArch() == Triple::arm || T.getArch() == Triple::thumb)
 207       CompactUnwindDwarfEHFrameOnly = 0x04000000;  // UNWIND_ARM_MODE_DWARF
 208   }
 209
 210   // Debug Information.
 211   DwarfAccelNamesSection =
 212       Ctx->getMachOSection("__DWARF", "__apple_names", MachO::S_ATTR_DEBUG,
 213                            SectionKind::getMetadata(), "names_begin");
 214   DwarfAccelObjCSection =
 215       Ctx->getMachOSection("__DWARF", "__apple_objc", MachO::S_ATTR_DEBUG,
 216                            SectionKind::getMetadata(), "objc_begin");
 217   // 16 character section limit...
 218   DwarfAccelNamespaceSection =
 219       Ctx->getMachOSection("__DWARF", "__apple_namespac", MachO::S_ATTR_DEBUG,
 220                            SectionKind::getMetadata(), "namespac_begin");
 221   DwarfAccelTypesSection =
 222       Ctx->getMachOSection("__DWARF", "__apple_types", MachO::S_ATTR_DEBUG,
 223                            SectionKind::getMetadata(), "types_begin");
 224
 225   DwarfAbbrevSection =
 226       Ctx->getMachOSection("__DWARF", "__debug_abbrev", MachO::S_ATTR_DEBUG,
 227                            SectionKind::getMetadata(), "section_abbrev");
 228   DwarfInfoSection =
 229       Ctx->getMachOSection("__DWARF", "__debug_info", MachO::S_ATTR_DEBUG,
 230                            SectionKind::getMetadata(), "section_info");
 231   DwarfLineSection =
 232       Ctx->getMachOSection("__DWARF", "__debug_line", MachO::S_ATTR_DEBUG,
 233                            SectionKind::getMetadata(), "section_line");
 234   DwarfFrameSection =
 235       Ctx->getMachOSection("__DWARF", "__debug_frame", MachO::S_ATTR_DEBUG,
 236                            SectionKind::getMetadata());
 237   DwarfPubNamesSection =
 238       Ctx->getMachOSection("__DWARF", "__debug_pubnames", MachO::S_ATTR_DEBUG,
 239                            SectionKind::getMetadata());
 240   DwarfPubTypesSection =
 241       Ctx->getMachOSection("__DWARF", "__debug_pubtypes", MachO::S_ATTR_DEBUG,
 242                            SectionKind::getMetadata());
 243   DwarfGnuPubNamesSection =
 244       Ctx->getMachOSection("__DWARF", "__debug_gnu_pubn", MachO::S_ATTR_DEBUG,
 245                            SectionKind::getMetadata());
 246   DwarfGnuPubTypesSection =
 247       Ctx->getMachOSection("__DWARF", "__debug_gnu_pubt", MachO::S_ATTR_DEBUG,
 248                            SectionKind::getMetadata());
 249   DwarfStrSection =
 250       Ctx->getMachOSection("__DWARF", "__debug_str", MachO::S_ATTR_DEBUG,
 251                            SectionKind::getMetadata(), "info_string");
 252   DwarfLocSection =
 253       Ctx->getMachOSection("__DWARF", "__debug_loc", MachO::S_ATTR_DEBUG,
 254                            SectionKind::getMetadata(), "section_debug_loc");
 255   DwarfARangesSection =
 256       Ctx->getMachOSection("__DWARF", "__debug_aranges", MachO::S_ATTR_DEBUG,
 257                            SectionKind::getMetadata());
 258   DwarfRangesSection =
 259       Ctx->getMachOSection("__DWARF", "__debug_ranges", MachO::S_ATTR_DEBUG,
 260                            SectionKind::getMetadata(), "debug_range");
 261   DwarfDebugInlineSection =
 262       Ctx->getMachOSection("__DWARF", "__debug_inlined", MachO::S_ATTR_DEBUG,
 263                            SectionKind::getMetadata());
 264   StackMapSection = Ctx->getMachOSection("__LLVM_STACKMAPS", "__llvm_stackmaps",
 265                                          0, SectionKind::getMetadata());
 266
 267   FaultMapSection = Ctx->getMachOSection("__LLVM_FAULTMAPS", "__llvm_faultmaps",
 268                                          0, SectionKind::getMetadata());
 269
 270   TLSExtraDataSection = TLSTLVSection;
 271 }
 272
 273 void MCObjectFileInfo::initELFMCObjectFileInfo(Triple T) {
 274   switch (T.getArch()) {
 275   case Triple::mips:
 276   case Triple::mipsel:
 277     FDECFIEncoding = dwarf::DW_EH_PE_sdata4;
 278     break;
 279   case Triple::mips64:
 280   case Triple::mips64el:
 281     FDECFIEncoding = dwarf::DW_EH_PE_sdata8;
 282     break;
 283   case Triple::x86_64:
 284     FDECFIEncoding = dwarf::DW_EH_PE_pcrel |
 285                      ((CMModel == CodeModel::Large) ? dwarf::DW_EH_PE_sdata8
 286                                                     : dwarf::DW_EH_PE_sdata4);
 287     break;
 288   default:
 289     FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 290     break;
 291   }
 292
 293   switch (T.getArch()) {
 294   case Triple::arm:
 295   case Triple::armeb:
 296   case Triple::thumb:
 297   case Triple::thumbeb:
 298     if (Ctx->getAsmInfo()->getExceptionHandlingType() == ExceptionHandling::ARM)
 299       break;
 300     // Fallthrough if not using EHABI
 301   case Triple::ppc:
 302   case Triple::x86:
 303     PersonalityEncoding = (RelocM == Reloc::PIC_)
 304      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 305      : dwarf::DW_EH_PE_absptr;
 306     LSDAEncoding = (RelocM == Reloc::PIC_)
 307       ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 308       : dwarf::DW_EH_PE_absptr;
 309     TTypeEncoding = (RelocM == Reloc::PIC_)
 310      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 311      : dwarf::DW_EH_PE_absptr;
 312     break;
 313   case Triple::x86_64:
 314     if (RelocM == Reloc::PIC_) {
 315       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 316         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 317          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 318       LSDAEncoding = dwarf::DW_EH_PE_pcrel |
 319         (CMModel == CodeModel::Small
 320          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 321       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 322         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 323          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 324     } else {
 325       PersonalityEncoding =
 326         (CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 327         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 328       LSDAEncoding = (CMModel == CodeModel::Small)
 329         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 330       TTypeEncoding = (CMModel == CodeModel::Small)
 331         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 332     }
 333     break;
 334   case Triple::aarch64:
 335   case Triple::aarch64_be:
 336     // The small model guarantees static code/data size < 4GB, but not where it
 337     // will be in memory. Most of these could end up >2GB away so even a signed
 338     // pc-relative 32-bit address is insufficient, theoretically.
 339     if (RelocM == Reloc::PIC_) {
 340       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 341         dwarf::DW_EH_PE_sdata8;
 342       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8;
 343       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 344         dwarf::DW_EH_PE_sdata8;
 345     } else {
 346       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 347       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 348       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 349     }
 350     break;
 351   case Triple::mips:
 352   case Triple::mipsel:
 353   case Triple::mips64:
 354   case Triple::mips64el:
 355     // MIPS uses indirect pointer to refer personality functions and types, so
 356     // that the eh_frame section can be read-only. DW.ref.personality will be
 357     // generated for relocation.
 358     PersonalityEncoding = dwarf::DW_EH_PE_indirect;
 359     // FIXME: The N64 ABI probably ought to use DW_EH_PE_sdata8 but we can't
 360     //        identify N64 from just a triple.
 361     TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 362                     dwarf::DW_EH_PE_sdata4;
 363     // We don't support PC-relative LSDA references in GAS so we use the default
 364     // DW_EH_PE_absptr for those.
 365     break;
 366   case Triple::ppc64:
 367   case Triple::ppc64le:
 368     PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 369       dwarf::DW_EH_PE_udata8;
 370     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
 371     TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 372       dwarf::DW_EH_PE_udata8;
 373     break;
 374   case Triple::sparcel:
 375   case Triple::sparc:
 376     if (RelocM == Reloc::PIC_) {
 377       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 378       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 379         dwarf::DW_EH_PE_sdata4;
 380       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 381         dwarf::DW_EH_PE_sdata4;
 382     } else {
 383       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 384       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 385       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 386     }
 387     break;
 388   case Triple::sparcv9:
 389     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 390     if (RelocM == Reloc::PIC_) {
 391       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 392         dwarf::DW_EH_PE_sdata4;
 393       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 394         dwarf::DW_EH_PE_sdata4;
 395     } else {
 396       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 397       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 398     }
 399     break;
 400   case Triple::systemz:
 401     // All currently-defined code models guarantee that 4-byte PC-relative
 402     // values will be in range.
 403     if (RelocM == Reloc::PIC_) {
 404       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 405         dwarf::DW_EH_PE_sdata4;
 406       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 407       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 408         dwarf::DW_EH_PE_sdata4;
 409     } else {
 410       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 411       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 412       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 413     }
 414     break;
 415   default:
 416     break;
 417   }
 418
 419   EHSectionType = T.getArch() == Triple::x86_64 ? ELF::SHT_X86_64_UNWIND
 420                                                 : ELF::SHT_PROGBITS;
 421
 422   // Solaris requires different flags for .eh_frame to seemingly every other
 423   // platform.
 424   EHSectionFlags = ELF::SHF_ALLOC;
 425   if (T.isOSSolaris() && T.getArch() != Triple::x86_64)
 426     EHSectionFlags |= ELF::SHF_WRITE;
 427
 428   // ELF
 429   BSSSection = Ctx->getELFSection(".bss", ELF::SHT_NOBITS,
 430                                   ELF::SHF_WRITE | ELF::SHF_ALLOC);
 431
 432   TextSection = Ctx->getELFSection(".text", ELF::SHT_PROGBITS,
 433                                    ELF::SHF_EXECINSTR | ELF::SHF_ALLOC);
 434
 435   DataSection = Ctx->getELFSection(".data", ELF::SHT_PROGBITS,
 436                                    ELF::SHF_WRITE | ELF::SHF_ALLOC);
 437
 438   ReadOnlySection =
 439       Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
 440
 441   TLSDataSection =
 442       Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS,
 443                          ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE);
 444
 445   TLSBSSSection = Ctx->getELFSection(
 446       ".tbss", ELF::SHT_NOBITS, ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE);
 447
 448   DataRelSection = Ctx->getELFSection(".data.rel", ELF::SHT_PROGBITS,
 449                                       ELF::SHF_ALLOC | ELF::SHF_WRITE);
 450
 451   DataRelLocalSection = Ctx->getELFSection(".data.rel.local", ELF::SHT_PROGBITS,
 452                                            ELF::SHF_ALLOC | ELF::SHF_WRITE);
 453
 454   DataRelROSection = Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS,
 455                                         ELF::SHF_ALLOC | ELF::SHF_WRITE);
 456
 457   DataRelROLocalSection = Ctx->getELFSection(
 458       ".data.rel.ro.local", ELF::SHT_PROGBITS, ELF::SHF_ALLOC | ELF::SHF_WRITE);
 459
 460   MergeableConst4Section =
 461       Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS,
 462                          ELF::SHF_ALLOC | ELF::SHF_MERGE, 4, "");
 463
 464   MergeableConst8Section =
 465       Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS,
 466                          ELF::SHF_ALLOC | ELF::SHF_MERGE, 8, "");
 467
 468   MergeableConst16Section =
 469       Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS,
 470                          ELF::SHF_ALLOC | ELF::SHF_MERGE, 16, "");
 471
 472   StaticCtorSection = Ctx->getELFSection(".ctors", ELF::SHT_PROGBITS,
 473                                          ELF::SHF_ALLOC | ELF::SHF_WRITE);
 474
 475   StaticDtorSection = Ctx->getELFSection(".dtors", ELF::SHT_PROGBITS,
 476                                          ELF::SHF_ALLOC | ELF::SHF_WRITE);
 477
 478   // Exception Handling Sections.
 479
 480   // FIXME: We're emitting LSDA info into a readonly section on ELF, even though
 481   // it contains relocatable pointers.  In PIC mode, this is probably a big
 482   // runtime hit for C++ apps.  Either the contents of the LSDA need to be
 483   // adjusted or this should be a data section.
 484   LSDASection = Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS,
 485                                    ELF::SHF_ALLOC);
 486
 487   COFFDebugSymbolsSection = nullptr;
 488
 489   // Debug Info Sections.
 490   DwarfAbbrevSection = Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0,
 491                                           "section_abbrev");
 492   DwarfInfoSection =
 493       Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0, "section_info");
 494   DwarfLineSection = Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0);
 495   DwarfFrameSection = Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0);
 496   DwarfPubNamesSection =
 497       Ctx->getELFSection(".debug_pubnames", ELF::SHT_PROGBITS, 0);
 498   DwarfPubTypesSection =
 499       Ctx->getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0);
 500   DwarfGnuPubNamesSection =
 501       Ctx->getELFSection(".debug_gnu_pubnames", ELF::SHT_PROGBITS, 0);
 502   DwarfGnuPubTypesSection =
 503       Ctx->getELFSection(".debug_gnu_pubtypes", ELF::SHT_PROGBITS, 0);
 504   DwarfStrSection =
 505       Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS,
 506                          ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
 507   DwarfLocSection = Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0);
 508   DwarfARangesSection =
 509       Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0);
 510   DwarfRangesSection =
 511       Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0, "debug_range");
 512
 513   // DWARF5 Experimental Debug Info
 514
 515   // Accelerator Tables
 516   DwarfAccelNamesSection =
 517       Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0, "names_begin");
 518   DwarfAccelObjCSection =
 519       Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0, "objc_begin");
 520   DwarfAccelNamespaceSection = Ctx->getELFSection(
 521       ".apple_namespaces", ELF::SHT_PROGBITS, 0, "namespac_begin");
 522   DwarfAccelTypesSection =
 523       Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0, "types_begin");
 524
 525   // Fission Sections
 526   DwarfInfoDWOSection =
 527       Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0);
 528   DwarfTypesDWOSection =
 529       Ctx->getELFSection(".debug_types.dwo", ELF::SHT_PROGBITS, 0);
 530   DwarfAbbrevDWOSection =
 531       Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0);
 532   DwarfStrDWOSection =
 533       Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS,
 534                          ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
 535   DwarfLineDWOSection =
 536       Ctx->getELFSection(".debug_line.dwo", ELF::SHT_PROGBITS, 0);
 537   DwarfLocDWOSection =
 538       Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0, "skel_loc");
 539   DwarfStrOffDWOSection =
 540       Ctx->getELFSection(".debug_str_offsets.dwo", ELF::SHT_PROGBITS, 0);
 541   DwarfAddrSection =
 542       Ctx->getELFSection(".debug_addr", ELF::SHT_PROGBITS, 0, "addr_sec");
 543
 544   StackMapSection =
 545       Ctx->getELFSection(".llvm_stackmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
 546
 547   FaultMapSection =
 548       Ctx->getELFSection(".llvm_faultmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
 549 }
 550
 551 void MCObjectFileInfo::initCOFFMCObjectFileInfo(Triple T) {
 552   bool IsWoA = T.getArch() == Triple::arm || T.getArch() == Triple::thumb;
 553
 554   CommDirectiveSupportsAlignment = true;
 555
 556   // COFF
 557   BSSSection = Ctx->getCOFFSection(
 558       ".bss", COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
 559                   COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
 560       SectionKind::getBSS());
 561   TextSection = Ctx->getCOFFSection(
 562       ".text",
 563       (IsWoA ? COFF::IMAGE_SCN_MEM_16BIT : (COFF::SectionCharacteristics)0) |
 564           COFF::IMAGE_SCN_CNT_CODE | COFF::IMAGE_SCN_MEM_EXECUTE |
 565           COFF::IMAGE_SCN_MEM_READ,
 566       SectionKind::getText());
 567   DataSection = Ctx->getCOFFSection(
 568       ".data", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ |
 569                    COFF::IMAGE_SCN_MEM_WRITE,
 570       SectionKind::getDataRel());
 571   ReadOnlySection = Ctx->getCOFFSection(
 572       ".rdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
 573       SectionKind::getReadOnly());
 574
 575   if (T.isKnownWindowsMSVCEnvironment() || T.isWindowsItaniumEnvironment()) {
 576     StaticCtorSection =
 577         Ctx->getCOFFSection(".CRT$XCU", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 578                                             COFF::IMAGE_SCN_MEM_READ,
 579                             SectionKind::getReadOnly());
 580     StaticDtorSection =
 581         Ctx->getCOFFSection(".CRT$XTX", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 582                                             COFF::IMAGE_SCN_MEM_READ,
 583                             SectionKind::getReadOnly());
 584   } else {
 585     StaticCtorSection = Ctx->getCOFFSection(
 586         ".ctors", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 587                       COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
 588         SectionKind::getDataRel());
 589     StaticDtorSection = Ctx->getCOFFSection(
 590         ".dtors", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 591                       COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
 592         SectionKind::getDataRel());
 593   }
 594
 595   // FIXME: We're emitting LSDA info into a readonly section on COFF, even
 596   // though it contains relocatable pointers.  In PIC mode, this is probably a
 597   // big runtime hit for C++ apps.  Either the contents of the LSDA need to be
 598   // adjusted or this should be a data section.
 599   assert(T.isOSWindows() && "Windows is the only supported COFF target");
 600   if (T.getArch() == Triple::x86_64) {
 601     // On Windows 64 with SEH, the LSDA is emitted into the .xdata section
 602     LSDASection = nullptr;
 603   } else {
 604     LSDASection = Ctx->getCOFFSection(".gcc_except_table",
 605                                       COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 606                                           COFF::IMAGE_SCN_MEM_READ,
 607                                       SectionKind::getReadOnly());
 608   }
 609
 610   // Debug info.
 611   COFFDebugSymbolsSection =
 612       Ctx->getCOFFSection(".debug$S", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 613                                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 614                                           COFF::IMAGE_SCN_MEM_READ,
 615                           SectionKind::getMetadata());
 616
 617   DwarfAbbrevSection = Ctx->getCOFFSection(
 618       ".debug_abbrev",
 619       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 620           COFF::IMAGE_SCN_MEM_READ,
 621       SectionKind::getMetadata(), "section_abbrev");
 622   DwarfInfoSection = Ctx->getCOFFSection(
 623       ".debug_info",
 624       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 625           COFF::IMAGE_SCN_MEM_READ,
 626       SectionKind::getMetadata(), "section_info");
 627   DwarfLineSection = Ctx->getCOFFSection(
 628       ".debug_line",
 629       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 630           COFF::IMAGE_SCN_MEM_READ,
 631       SectionKind::getMetadata(), "section_line");
 632
 633   DwarfFrameSection = Ctx->getCOFFSection(
 634       ".debug_frame",
 635       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 636           COFF::IMAGE_SCN_MEM_READ,
 637       SectionKind::getMetadata());
 638   DwarfPubNamesSection = Ctx->getCOFFSection(
 639       ".debug_pubnames",
 640       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 641           COFF::IMAGE_SCN_MEM_READ,
 642       SectionKind::getMetadata());
 643   DwarfPubTypesSection = Ctx->getCOFFSection(
 644       ".debug_pubtypes",
 645       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 646           COFF::IMAGE_SCN_MEM_READ,
 647       SectionKind::getMetadata());
 648   DwarfGnuPubNamesSection = Ctx->getCOFFSection(
 649       ".debug_gnu_pubnames",
 650       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 651           COFF::IMAGE_SCN_MEM_READ,
 652       SectionKind::getMetadata());
 653   DwarfGnuPubTypesSection = Ctx->getCOFFSection(
 654       ".debug_gnu_pubtypes",
 655       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 656           COFF::IMAGE_SCN_MEM_READ,
 657       SectionKind::getMetadata());
 658   DwarfStrSection = Ctx->getCOFFSection(
 659       ".debug_str",
 660       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 661           COFF::IMAGE_SCN_MEM_READ,
 662       SectionKind::getMetadata(), "info_string");
 663   DwarfLocSection = Ctx->getCOFFSection(
 664       ".debug_loc",
 665       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 666           COFF::IMAGE_SCN_MEM_READ,
 667       SectionKind::getMetadata(), "section_debug_loc");
 668   DwarfARangesSection = Ctx->getCOFFSection(
 669       ".debug_aranges",
 670       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 671           COFF::IMAGE_SCN_MEM_READ,
 672       SectionKind::getMetadata());
 673   DwarfRangesSection = Ctx->getCOFFSection(
 674       ".debug_ranges",
 675       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 676           COFF::IMAGE_SCN_MEM_READ,
 677       SectionKind::getMetadata(), "debug_range");
 678   DwarfInfoDWOSection = Ctx->getCOFFSection(
 679       ".debug_info.dwo",
 680       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 681           COFF::IMAGE_SCN_MEM_READ,
 682       SectionKind::getMetadata(), "section_info_dwo");
 683   DwarfTypesDWOSection = Ctx->getCOFFSection(
 684       ".debug_types.dwo",
 685       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 686           COFF::IMAGE_SCN_MEM_READ,
 687       SectionKind::getMetadata(), "section_types_dwo");
 688   DwarfAbbrevDWOSection = Ctx->getCOFFSection(
 689       ".debug_abbrev.dwo",
 690       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 691           COFF::IMAGE_SCN_MEM_READ,
 692       SectionKind::getMetadata(), "section_abbrev_dwo");
 693   DwarfStrDWOSection = Ctx->getCOFFSection(
 694       ".debug_str.dwo",
 695       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 696           COFF::IMAGE_SCN_MEM_READ,
 697       SectionKind::getMetadata(), "skel_string");
 698   DwarfLineDWOSection = Ctx->getCOFFSection(
 699       ".debug_line.dwo",
 700       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 701           COFF::IMAGE_SCN_MEM_READ,
 702       SectionKind::getMetadata());
 703   DwarfLocDWOSection = Ctx->getCOFFSection(
 704       ".debug_loc.dwo",
 705       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 706           COFF::IMAGE_SCN_MEM_READ,
 707       SectionKind::getMetadata(), "skel_loc");
 708   DwarfStrOffDWOSection = Ctx->getCOFFSection(
 709       ".debug_str_offsets.dwo",
 710       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 711           COFF::IMAGE_SCN_MEM_READ,
 712       SectionKind::getMetadata());
 713   DwarfAddrSection = Ctx->getCOFFSection(
 714       ".debug_addr",
 715       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 716           COFF::IMAGE_SCN_MEM_READ,
 717       SectionKind::getMetadata(), "addr_sec");
 718   DwarfAccelNamesSection = Ctx->getCOFFSection(
 719       ".apple_names",
 720       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 721           COFF::IMAGE_SCN_MEM_READ,
 722       SectionKind::getMetadata(), "names_begin");
 723   DwarfAccelNamespaceSection = Ctx->getCOFFSection(
 724       ".apple_namespaces",
 725       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 726           COFF::IMAGE_SCN_MEM_READ,
 727       SectionKind::getMetadata(), "namespac_begin");
 728   DwarfAccelTypesSection = Ctx->getCOFFSection(
 729       ".apple_types",
 730       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 731           COFF::IMAGE_SCN_MEM_READ,
 732       SectionKind::getMetadata(), "types_begin");
 733   DwarfAccelObjCSection = Ctx->getCOFFSection(
 734       ".apple_objc",
 735       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 736           COFF::IMAGE_SCN_MEM_READ,
 737       SectionKind::getMetadata(), "objc_begin");
 738
 739   DrectveSection = Ctx->getCOFFSection(
 740       ".drectve", COFF::IMAGE_SCN_LNK_INFO | COFF::IMAGE_SCN_LNK_REMOVE,
 741       SectionKind::getMetadata());
 742
 743   PDataSection = Ctx->getCOFFSection(
 744       ".pdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
 745       SectionKind::getDataRel());
 746
 747   XDataSection = Ctx->getCOFFSection(
 748       ".xdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
 749       SectionKind::getDataRel());
 750
 751   SXDataSection = Ctx->getCOFFSection(".sxdata", COFF::IMAGE_SCN_LNK_INFO,
 752                                       SectionKind::getMetadata());
 753
 754   TLSDataSection = Ctx->getCOFFSection(
 755       ".tls$", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ |
 756                    COFF::IMAGE_SCN_MEM_WRITE,
 757       SectionKind::getDataRel());
 758
 759   StackMapSection = Ctx->getCOFFSection(".llvm_stackmaps",
 760                                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 761                                             COFF::IMAGE_SCN_MEM_READ,
 762                                         SectionKind::getReadOnly());
 763 }
 764
 765 void MCObjectFileInfo::InitMCObjectFileInfo(const Triple &TheTriple,
 766                                             Reloc::Model relocm,
 767                                             CodeModel::Model cm,
 768                                             MCContext &ctx) {
 769   RelocM = relocm;
 770   CMModel = cm;
 771   Ctx = &ctx;
 772
 773   // Common.
 774   CommDirectiveSupportsAlignment = true;
 775   SupportsWeakOmittedEHFrame = true;
 776   SupportsCompactUnwindWithoutEHFrame = false;
 777   OmitDwarfIfHaveCompactUnwind = false;
 778
 779   PersonalityEncoding = LSDAEncoding = FDECFIEncoding = TTypeEncoding =
 780       dwarf::DW_EH_PE_absptr;
 781
 782   CompactUnwindDwarfEHFrameOnly = 0;
 783
 784   EHFrameSection = nullptr;             // Created on demand.
 785   CompactUnwindSection = nullptr;       // Used only by selected targets.
 786   DwarfAccelNamesSection = nullptr;     // Used only by selected targets.
 787   DwarfAccelObjCSection = nullptr;      // Used only by selected targets.
 788   DwarfAccelNamespaceSection = nullptr; // Used only by selected targets.
 789   DwarfAccelTypesSection = nullptr;     // Used only by selected targets.
 790
 791   TT = TheTriple;
 792
 793   Triple::ArchType Arch = TT.getArch();
 794   // FIXME: Checking for Arch here to filter out bogus triples such as
 795   // cellspu-apple-darwin. Perhaps we should fix in Triple?
 796   if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
 797        Arch == Triple::arm || Arch == Triple::thumb ||
 798        Arch == Triple::aarch64 ||
 799        Arch == Triple::ppc || Arch == Triple::ppc64 ||
 800        Arch == Triple::UnknownArch) &&
 801       TT.isOSBinFormatMachO()) {
 802     Env = IsMachO;
 803     initMachOMCObjectFileInfo(TT);
 804   } else if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
 805               Arch == Triple::arm || Arch == Triple::thumb) &&
 806              (TT.isOSWindows() && TT.getObjectFormat() == Triple::COFF)) {
 807     Env = IsCOFF;
 808     initCOFFMCObjectFileInfo(TT);
 809   } else {
 810     Env = IsELF;
 811     initELFMCObjectFileInfo(TT);
 812   }
 813 }
 814
 815 void MCObjectFileInfo::InitMCObjectFileInfo(StringRef TT, Reloc::Model RM,
 816                                             CodeModel::Model CM,
 817                                             MCContext &ctx) {
 818   InitMCObjectFileInfo(Triple(TT), RM, CM, ctx);
 819 }
 820
 821 MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const {
 822   return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP,
 823                             0, utostr(Hash));
 824 }
 825
 826 void MCObjectFileInfo::InitEHFrameSection() {
 827   if (Env == IsMachO)
 828     EHFrameSection =
 829       Ctx->getMachOSection("__TEXT", "__eh_frame",
 830                            MachO::S_COALESCED |
 831                            MachO::S_ATTR_NO_TOC |
 832                            MachO::S_ATTR_STRIP_STATIC_SYMS |
 833                            MachO::S_ATTR_LIVE_SUPPORT,
 834                            SectionKind::getReadOnly());
 835   else if (Env == IsELF)
 836     EHFrameSection =
 837         Ctx->getELFSection(".eh_frame", EHSectionType, EHSectionFlags);
 838   else
 839     EHFrameSection =
 840       Ctx->getCOFFSection(".eh_frame",
 841                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 842                           COFF::IMAGE_SCN_MEM_READ |
 843                           COFF::IMAGE_SCN_MEM_WRITE,
 844                           SectionKind::getDataRel());
 845 }