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(), "names_begin");
 188   DwarfAccelObjCSection =
 189       Ctx->getMachOSection("__DWARF", "__apple_objc", MachO::S_ATTR_DEBUG,
 190                            SectionKind::getMetadata(), "objc_begin");
 191   // 16 character section limit...
 192   DwarfAccelNamespaceSection =
 193       Ctx->getMachOSection("__DWARF", "__apple_namespac", MachO::S_ATTR_DEBUG,
 194                            SectionKind::getMetadata(), "namespac_begin");
 195   DwarfAccelTypesSection =
 196       Ctx->getMachOSection("__DWARF", "__apple_types", MachO::S_ATTR_DEBUG,
 197                            SectionKind::getMetadata(), "types_begin");
 198
 199   DwarfAbbrevSection =
 200       Ctx->getMachOSection("__DWARF", "__debug_abbrev", MachO::S_ATTR_DEBUG,
 201                            SectionKind::getMetadata(), "section_abbrev");
 202   DwarfInfoSection =
 203       Ctx->getMachOSection("__DWARF", "__debug_info", MachO::S_ATTR_DEBUG,
 204                            SectionKind::getMetadata(), "section_info");
 205   DwarfLineSection =
 206       Ctx->getMachOSection("__DWARF", "__debug_line", MachO::S_ATTR_DEBUG,
 207                            SectionKind::getMetadata(), "section_line");
 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(), "info_string");
 226   DwarfLocSection =
 227       Ctx->getMachOSection("__DWARF", "__debug_loc", MachO::S_ATTR_DEBUG,
 228                            SectionKind::getMetadata(), "section_debug_loc");
 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(), "debug_range");
 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::sparcel:
 341   case Triple::sparc:
 342     if (RelocM == Reloc::PIC_) {
 343       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 344       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 345         dwarf::DW_EH_PE_sdata4;
 346       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 347         dwarf::DW_EH_PE_sdata4;
 348     } else {
 349       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 350       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 351       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 352     }
 353     break;
 354   case Triple::sparcv9:
 355     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 356     if (RelocM == Reloc::PIC_) {
 357       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 358         dwarf::DW_EH_PE_sdata4;
 359       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 360         dwarf::DW_EH_PE_sdata4;
 361     } else {
 362       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 363       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 364     }
 365     break;
 366   case Triple::systemz:
 367     // All currently-defined code models guarantee that 4-byte PC-relative
 368     // values will be in range.
 369     if (RelocM == Reloc::PIC_) {
 370       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 371         dwarf::DW_EH_PE_sdata4;
 372       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 373       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 374         dwarf::DW_EH_PE_sdata4;
 375     } else {
 376       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 377       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 378       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 379     }
 380     break;
 381   default:
 382     break;
 383   }
 384
 385   // Solaris requires different flags for .eh_frame to seemingly every other
 386   // platform.
 387   EHSectionType = ELF::SHT_PROGBITS;
 388   EHSectionFlags = ELF::SHF_ALLOC;
 389   if (T.isOSSolaris()) {
 390     if (T.getArch() == Triple::x86_64)
 391       EHSectionType = ELF::SHT_X86_64_UNWIND;
 392     else
 393       EHSectionFlags |= ELF::SHF_WRITE;
 394   }
 395
 396
 397   // ELF
 398   BSSSection = Ctx->getELFSection(".bss", ELF::SHT_NOBITS,
 399                                   ELF::SHF_WRITE | ELF::SHF_ALLOC);
 400
 401   TextSection = Ctx->getELFSection(".text", ELF::SHT_PROGBITS,
 402                                    ELF::SHF_EXECINSTR | ELF::SHF_ALLOC);
 403
 404   DataSection = Ctx->getELFSection(".data", ELF::SHT_PROGBITS,
 405                                    ELF::SHF_WRITE | ELF::SHF_ALLOC);
 406
 407   ReadOnlySection =
 408       Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
 409
 410   TLSDataSection =
 411       Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS,
 412                          ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE);
 413
 414   TLSBSSSection = Ctx->getELFSection(
 415       ".tbss", ELF::SHT_NOBITS, ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE);
 416
 417   DataRelSection = Ctx->getELFSection(".data.rel", ELF::SHT_PROGBITS,
 418                                       ELF::SHF_ALLOC | ELF::SHF_WRITE);
 419
 420   DataRelLocalSection = Ctx->getELFSection(".data.rel.local", ELF::SHT_PROGBITS,
 421                                            ELF::SHF_ALLOC | ELF::SHF_WRITE);
 422
 423   DataRelROSection = Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS,
 424                                         ELF::SHF_ALLOC | ELF::SHF_WRITE);
 425
 426   DataRelROLocalSection = Ctx->getELFSection(
 427       ".data.rel.ro.local", ELF::SHT_PROGBITS, ELF::SHF_ALLOC | ELF::SHF_WRITE);
 428
 429   MergeableConst4Section =
 430       Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS,
 431                          ELF::SHF_ALLOC | ELF::SHF_MERGE, 4, "");
 432
 433   MergeableConst8Section =
 434       Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS,
 435                          ELF::SHF_ALLOC | ELF::SHF_MERGE, 8, "");
 436
 437   MergeableConst16Section =
 438       Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS,
 439                          ELF::SHF_ALLOC | ELF::SHF_MERGE, 16, "");
 440
 441   StaticCtorSection = Ctx->getELFSection(".ctors", ELF::SHT_PROGBITS,
 442                                          ELF::SHF_ALLOC | ELF::SHF_WRITE);
 443
 444   StaticDtorSection = Ctx->getELFSection(".dtors", ELF::SHT_PROGBITS,
 445                                          ELF::SHF_ALLOC | ELF::SHF_WRITE);
 446
 447   // Exception Handling Sections.
 448
 449   // FIXME: We're emitting LSDA info into a readonly section on ELF, even though
 450   // it contains relocatable pointers.  In PIC mode, this is probably a big
 451   // runtime hit for C++ apps.  Either the contents of the LSDA need to be
 452   // adjusted or this should be a data section.
 453   LSDASection = Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS,
 454                                    ELF::SHF_ALLOC);
 455
 456   COFFDebugSymbolsSection = nullptr;
 457
 458   // Debug Info Sections.
 459   DwarfAbbrevSection = Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0,
 460                                           "section_abbrev");
 461   DwarfInfoSection =
 462       Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0, "section_info");
 463   DwarfLineSection = Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0);
 464   DwarfFrameSection = Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0);
 465   DwarfPubNamesSection =
 466       Ctx->getELFSection(".debug_pubnames", ELF::SHT_PROGBITS, 0);
 467   DwarfPubTypesSection =
 468       Ctx->getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0);
 469   DwarfGnuPubNamesSection =
 470       Ctx->getELFSection(".debug_gnu_pubnames", ELF::SHT_PROGBITS, 0);
 471   DwarfGnuPubTypesSection =
 472       Ctx->getELFSection(".debug_gnu_pubtypes", ELF::SHT_PROGBITS, 0);
 473   DwarfStrSection =
 474       Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS,
 475                          ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
 476   DwarfLocSection = Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0);
 477   DwarfARangesSection =
 478       Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0);
 479   DwarfRangesSection =
 480       Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0, "debug_range");
 481
 482   // DWARF5 Experimental Debug Info
 483
 484   // Accelerator Tables
 485   DwarfAccelNamesSection =
 486       Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0, "names_begin");
 487   DwarfAccelObjCSection =
 488       Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0, "objc_begin");
 489   DwarfAccelNamespaceSection = Ctx->getELFSection(
 490       ".apple_namespaces", ELF::SHT_PROGBITS, 0, "namespac_begin");
 491   DwarfAccelTypesSection =
 492       Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0, "types_begin");
 493
 494   // Fission Sections
 495   DwarfInfoDWOSection =
 496       Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0);
 497   DwarfTypesDWOSection =
 498       Ctx->getELFSection(".debug_types.dwo", ELF::SHT_PROGBITS, 0);
 499   DwarfAbbrevDWOSection =
 500       Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0);
 501   DwarfStrDWOSection =
 502       Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS,
 503                          ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
 504   DwarfLineDWOSection =
 505       Ctx->getELFSection(".debug_line.dwo", ELF::SHT_PROGBITS, 0);
 506   DwarfLocDWOSection =
 507       Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0, "skel_loc");
 508   DwarfStrOffDWOSection =
 509       Ctx->getELFSection(".debug_str_offsets.dwo", ELF::SHT_PROGBITS, 0);
 510   DwarfAddrSection =
 511       Ctx->getELFSection(".debug_addr", ELF::SHT_PROGBITS, 0, "addr_sec");
 512
 513   StackMapSection =
 514       Ctx->getELFSection(".llvm_stackmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
 515 }
 516
 517 void MCObjectFileInfo::InitCOFFMCObjectFileInfo(Triple T) {
 518   bool IsWoA = T.getArch() == Triple::arm || T.getArch() == Triple::thumb;
 519
 520   CommDirectiveSupportsAlignment = true;
 521
 522   // COFF
 523   BSSSection = Ctx->getCOFFSection(
 524       ".bss", COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
 525                   COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
 526       SectionKind::getBSS());
 527   TextSection = Ctx->getCOFFSection(
 528       ".text",
 529       (IsWoA ? COFF::IMAGE_SCN_MEM_16BIT : (COFF::SectionCharacteristics)0) |
 530           COFF::IMAGE_SCN_CNT_CODE | COFF::IMAGE_SCN_MEM_EXECUTE |
 531           COFF::IMAGE_SCN_MEM_READ,
 532       SectionKind::getText());
 533   DataSection = Ctx->getCOFFSection(
 534       ".data", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ |
 535                    COFF::IMAGE_SCN_MEM_WRITE,
 536       SectionKind::getDataRel());
 537   ReadOnlySection = Ctx->getCOFFSection(
 538       ".rdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
 539       SectionKind::getReadOnly());
 540
 541   if (T.isKnownWindowsMSVCEnvironment() || T.isWindowsItaniumEnvironment()) {
 542     StaticCtorSection =
 543         Ctx->getCOFFSection(".CRT$XCU", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 544                                             COFF::IMAGE_SCN_MEM_READ,
 545                             SectionKind::getReadOnly());
 546     StaticDtorSection =
 547         Ctx->getCOFFSection(".CRT$XTX", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 548                                             COFF::IMAGE_SCN_MEM_READ,
 549                             SectionKind::getReadOnly());
 550   } else {
 551     StaticCtorSection = Ctx->getCOFFSection(
 552         ".ctors", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 553                       COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
 554         SectionKind::getDataRel());
 555     StaticDtorSection = Ctx->getCOFFSection(
 556         ".dtors", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 557                       COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
 558         SectionKind::getDataRel());
 559   }
 560
 561   // FIXME: We're emitting LSDA info into a readonly section on COFF, even
 562   // though it contains relocatable pointers.  In PIC mode, this is probably a
 563   // big runtime hit for C++ apps.  Either the contents of the LSDA need to be
 564   // adjusted or this should be a data section.
 565   assert(T.isOSWindows() && "Windows is the only supported COFF target");
 566   if (T.getArch() == Triple::x86_64) {
 567     // On Windows 64 with SEH, the LSDA is emitted into the .xdata section
 568     LSDASection = 0;
 569   } else {
 570     LSDASection = Ctx->getCOFFSection(".gcc_except_table",
 571                                       COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 572                                           COFF::IMAGE_SCN_MEM_READ,
 573                                       SectionKind::getReadOnly());
 574   }
 575
 576   // Debug info.
 577   COFFDebugSymbolsSection =
 578       Ctx->getCOFFSection(".debug$S", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 579                                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 580                                           COFF::IMAGE_SCN_MEM_READ,
 581                           SectionKind::getMetadata());
 582
 583   DwarfAbbrevSection = Ctx->getCOFFSection(
 584       ".debug_abbrev",
 585       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 586           COFF::IMAGE_SCN_MEM_READ,
 587       SectionKind::getMetadata(), "section_abbrev");
 588   DwarfInfoSection = Ctx->getCOFFSection(
 589       ".debug_info",
 590       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 591           COFF::IMAGE_SCN_MEM_READ,
 592       SectionKind::getMetadata(), "section_info");
 593   DwarfLineSection = Ctx->getCOFFSection(
 594       ".debug_line",
 595       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 596           COFF::IMAGE_SCN_MEM_READ,
 597       SectionKind::getMetadata(), "section_line");
 598
 599   DwarfFrameSection = Ctx->getCOFFSection(
 600       ".debug_frame",
 601       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 602           COFF::IMAGE_SCN_MEM_READ,
 603       SectionKind::getMetadata());
 604   DwarfPubNamesSection = Ctx->getCOFFSection(
 605       ".debug_pubnames",
 606       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 607           COFF::IMAGE_SCN_MEM_READ,
 608       SectionKind::getMetadata());
 609   DwarfPubTypesSection = Ctx->getCOFFSection(
 610       ".debug_pubtypes",
 611       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 612           COFF::IMAGE_SCN_MEM_READ,
 613       SectionKind::getMetadata());
 614   DwarfGnuPubNamesSection = Ctx->getCOFFSection(
 615       ".debug_gnu_pubnames",
 616       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 617           COFF::IMAGE_SCN_MEM_READ,
 618       SectionKind::getMetadata());
 619   DwarfGnuPubTypesSection = Ctx->getCOFFSection(
 620       ".debug_gnu_pubtypes",
 621       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 622           COFF::IMAGE_SCN_MEM_READ,
 623       SectionKind::getMetadata());
 624   DwarfStrSection = Ctx->getCOFFSection(
 625       ".debug_str",
 626       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 627           COFF::IMAGE_SCN_MEM_READ,
 628       SectionKind::getMetadata(), "info_string");
 629   DwarfLocSection = Ctx->getCOFFSection(
 630       ".debug_loc",
 631       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 632           COFF::IMAGE_SCN_MEM_READ,
 633       SectionKind::getMetadata(), "section_debug_loc");
 634   DwarfARangesSection = Ctx->getCOFFSection(
 635       ".debug_aranges",
 636       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 637           COFF::IMAGE_SCN_MEM_READ,
 638       SectionKind::getMetadata());
 639   DwarfRangesSection = Ctx->getCOFFSection(
 640       ".debug_ranges",
 641       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 642           COFF::IMAGE_SCN_MEM_READ,
 643       SectionKind::getMetadata(), "debug_range");
 644   DwarfInfoDWOSection = Ctx->getCOFFSection(
 645       ".debug_info.dwo",
 646       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 647           COFF::IMAGE_SCN_MEM_READ,
 648       SectionKind::getMetadata(), "section_info_dwo");
 649   DwarfTypesDWOSection = Ctx->getCOFFSection(
 650       ".debug_types.dwo",
 651       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 652           COFF::IMAGE_SCN_MEM_READ,
 653       SectionKind::getMetadata(), "section_types_dwo");
 654   DwarfAbbrevDWOSection = Ctx->getCOFFSection(
 655       ".debug_abbrev.dwo",
 656       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 657           COFF::IMAGE_SCN_MEM_READ,
 658       SectionKind::getMetadata(), "section_abbrev_dwo");
 659   DwarfStrDWOSection = Ctx->getCOFFSection(
 660       ".debug_str.dwo",
 661       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 662           COFF::IMAGE_SCN_MEM_READ,
 663       SectionKind::getMetadata(), "skel_string");
 664   DwarfLineDWOSection = Ctx->getCOFFSection(
 665       ".debug_line.dwo",
 666       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 667           COFF::IMAGE_SCN_MEM_READ,
 668       SectionKind::getMetadata());
 669   DwarfLocDWOSection = Ctx->getCOFFSection(
 670       ".debug_loc.dwo",
 671       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 672           COFF::IMAGE_SCN_MEM_READ,
 673       SectionKind::getMetadata(), "skel_loc");
 674   DwarfStrOffDWOSection = Ctx->getCOFFSection(
 675       ".debug_str_offsets.dwo",
 676       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 677           COFF::IMAGE_SCN_MEM_READ,
 678       SectionKind::getMetadata());
 679   DwarfAddrSection = Ctx->getCOFFSection(
 680       ".debug_addr",
 681       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 682           COFF::IMAGE_SCN_MEM_READ,
 683       SectionKind::getMetadata(), "addr_sec");
 684   DwarfAccelNamesSection = Ctx->getCOFFSection(
 685       ".apple_names",
 686       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 687           COFF::IMAGE_SCN_MEM_READ,
 688       SectionKind::getMetadata(), "names_begin");
 689   DwarfAccelNamespaceSection = Ctx->getCOFFSection(
 690       ".apple_namespaces",
 691       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 692           COFF::IMAGE_SCN_MEM_READ,
 693       SectionKind::getMetadata(), "namespac_begin");
 694   DwarfAccelTypesSection = Ctx->getCOFFSection(
 695       ".apple_types",
 696       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 697           COFF::IMAGE_SCN_MEM_READ,
 698       SectionKind::getMetadata(), "types_begin");
 699   DwarfAccelObjCSection = Ctx->getCOFFSection(
 700       ".apple_objc",
 701       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 702           COFF::IMAGE_SCN_MEM_READ,
 703       SectionKind::getMetadata(), "objc_begin");
 704
 705   DrectveSection = Ctx->getCOFFSection(
 706       ".drectve", COFF::IMAGE_SCN_LNK_INFO | COFF::IMAGE_SCN_LNK_REMOVE,
 707       SectionKind::getMetadata());
 708
 709   PDataSection = Ctx->getCOFFSection(
 710       ".pdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
 711       SectionKind::getDataRel());
 712
 713   XDataSection = Ctx->getCOFFSection(
 714       ".xdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
 715       SectionKind::getDataRel());
 716
 717   TLSDataSection = Ctx->getCOFFSection(
 718       ".tls$", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ |
 719                    COFF::IMAGE_SCN_MEM_WRITE,
 720       SectionKind::getDataRel());
 721 }
 722
 723 void MCObjectFileInfo::InitMCObjectFileInfo(StringRef T, Reloc::Model relocm,
 724                                             CodeModel::Model cm,
 725                                             MCContext &ctx) {
 726   RelocM = relocm;
 727   CMModel = cm;
 728   Ctx = &ctx;
 729
 730   // Common.
 731   CommDirectiveSupportsAlignment = true;
 732   SupportsWeakOmittedEHFrame = true;
 733   SupportsCompactUnwindWithoutEHFrame = false;
 734
 735   PersonalityEncoding = LSDAEncoding = FDECFIEncoding = TTypeEncoding =
 736       dwarf::DW_EH_PE_absptr;
 737
 738   CompactUnwindDwarfEHFrameOnly = 0;
 739
 740   EHFrameSection = nullptr;             // Created on demand.
 741   CompactUnwindSection = nullptr;       // Used only by selected targets.
 742   DwarfAccelNamesSection = nullptr;     // Used only by selected targets.
 743   DwarfAccelObjCSection = nullptr;      // Used only by selected targets.
 744   DwarfAccelNamespaceSection = nullptr; // Used only by selected targets.
 745   DwarfAccelTypesSection = nullptr;     // Used only by selected targets.
 746
 747   TT = Triple(T);
 748
 749   Triple::ArchType Arch = TT.getArch();
 750   // FIXME: Checking for Arch here to filter out bogus triples such as
 751   // cellspu-apple-darwin. Perhaps we should fix in Triple?
 752   if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
 753        Arch == Triple::arm || Arch == Triple::thumb ||
 754        Arch == Triple::aarch64 ||
 755        Arch == Triple::ppc || Arch == Triple::ppc64 ||
 756        Arch == Triple::UnknownArch) &&
 757       TT.isOSBinFormatMachO()) {
 758     Env = IsMachO;
 759     InitMachOMCObjectFileInfo(TT);
 760   } else if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
 761               Arch == Triple::arm || Arch == Triple::thumb) &&
 762              (TT.isOSWindows() && TT.getObjectFormat() == Triple::COFF)) {
 763     Env = IsCOFF;
 764     InitCOFFMCObjectFileInfo(TT);
 765   } else {
 766     Env = IsELF;
 767     InitELFMCObjectFileInfo(TT);
 768   }
 769 }
 770
 771 MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const {
 772   return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP,
 773                             0, utostr(Hash));
 774 }
 775
 776 void MCObjectFileInfo::InitEHFrameSection() {
 777   if (Env == IsMachO)
 778     EHFrameSection =
 779       Ctx->getMachOSection("__TEXT", "__eh_frame",
 780                            MachO::S_COALESCED |
 781                            MachO::S_ATTR_NO_TOC |
 782                            MachO::S_ATTR_STRIP_STATIC_SYMS |
 783                            MachO::S_ATTR_LIVE_SUPPORT,
 784                            SectionKind::getReadOnly());
 785   else if (Env == IsELF)
 786     EHFrameSection =
 787         Ctx->getELFSection(".eh_frame", EHSectionType, EHSectionFlags);
 788   else
 789     EHFrameSection =
 790       Ctx->getCOFFSection(".eh_frame",
 791                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 792                           COFF::IMAGE_SCN_MEM_READ |
 793                           COFF::IMAGE_SCN_MEM_WRITE,
 794                           SectionKind::getDataRel());
 795 }