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