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",
 187                          MachO::S_ATTR_DEBUG,
 188                          SectionKind::getMetadata());
 189   DwarfAccelObjCSection =
 190     Ctx->getMachOSection("__DWARF", "__apple_objc",
 191                          MachO::S_ATTR_DEBUG,
 192                          SectionKind::getMetadata());
 193   // 16 character section limit...
 194   DwarfAccelNamespaceSection =
 195     Ctx->getMachOSection("__DWARF", "__apple_namespac",
 196                          MachO::S_ATTR_DEBUG,
 197                          SectionKind::getMetadata());
 198   DwarfAccelTypesSection =
 199     Ctx->getMachOSection("__DWARF", "__apple_types",
 200                          MachO::S_ATTR_DEBUG,
 201                          SectionKind::getMetadata());
 202
 203   DwarfAbbrevSection =
 204     Ctx->getMachOSection("__DWARF", "__debug_abbrev",
 205                          MachO::S_ATTR_DEBUG,
 206                          SectionKind::getMetadata());
 207   DwarfInfoSection =
 208     Ctx->getMachOSection("__DWARF", "__debug_info",
 209                          MachO::S_ATTR_DEBUG,
 210                          SectionKind::getMetadata());
 211   DwarfLineSection =
 212     Ctx->getMachOSection("__DWARF", "__debug_line",
 213                          MachO::S_ATTR_DEBUG,
 214                          SectionKind::getMetadata());
 215   DwarfFrameSection =
 216     Ctx->getMachOSection("__DWARF", "__debug_frame",
 217                          MachO::S_ATTR_DEBUG,
 218                          SectionKind::getMetadata());
 219   DwarfPubNamesSection =
 220     Ctx->getMachOSection("__DWARF", "__debug_pubnames",
 221                          MachO::S_ATTR_DEBUG,
 222                          SectionKind::getMetadata());
 223   DwarfPubTypesSection =
 224     Ctx->getMachOSection("__DWARF", "__debug_pubtypes",
 225                          MachO::S_ATTR_DEBUG,
 226                          SectionKind::getMetadata());
 227   DwarfGnuPubNamesSection =
 228     Ctx->getMachOSection("__DWARF", "__debug_gnu_pubn",
 229                          MachO::S_ATTR_DEBUG,
 230                          SectionKind::getMetadata());
 231   DwarfGnuPubTypesSection =
 232     Ctx->getMachOSection("__DWARF", "__debug_gnu_pubt",
 233                          MachO::S_ATTR_DEBUG,
 234                          SectionKind::getMetadata());
 235   DwarfStrSection =
 236     Ctx->getMachOSection("__DWARF", "__debug_str",
 237                          MachO::S_ATTR_DEBUG,
 238                          SectionKind::getMetadata());
 239   DwarfLocSection =
 240     Ctx->getMachOSection("__DWARF", "__debug_loc",
 241                          MachO::S_ATTR_DEBUG,
 242                          SectionKind::getMetadata());
 243   DwarfARangesSection =
 244     Ctx->getMachOSection("__DWARF", "__debug_aranges",
 245                          MachO::S_ATTR_DEBUG,
 246                          SectionKind::getMetadata());
 247   DwarfRangesSection =
 248     Ctx->getMachOSection("__DWARF", "__debug_ranges",
 249                          MachO::S_ATTR_DEBUG,
 250                          SectionKind::getMetadata());
 251   DwarfMacroInfoSection =
 252     Ctx->getMachOSection("__DWARF", "__debug_macinfo",
 253                          MachO::S_ATTR_DEBUG,
 254                          SectionKind::getMetadata());
 255   DwarfDebugInlineSection =
 256     Ctx->getMachOSection("__DWARF", "__debug_inlined",
 257                          MachO::S_ATTR_DEBUG,
 258                          SectionKind::getMetadata());
 259   StackMapSection =
 260     Ctx->getMachOSection("__LLVM_STACKMAPS", "__llvm_stackmaps", 0,
 261                          SectionKind::getMetadata());
 262
 263   TLSExtraDataSection = TLSTLVSection;
 264 }
 265
 266 void MCObjectFileInfo::InitELFMCObjectFileInfo(Triple T) {
 267   switch (T.getArch()) {
 268   case Triple::mips:
 269   case Triple::mipsel:
 270     FDECFIEncoding = dwarf::DW_EH_PE_sdata4;
 271     break;
 272   case Triple::mips64:
 273   case Triple::mips64el:
 274     FDECFIEncoding = dwarf::DW_EH_PE_sdata8;
 275     break;
 276   case Triple::x86_64:
 277     if (RelocM == Reloc::PIC_) {
 278       FDECFIEncoding = dwarf::DW_EH_PE_pcrel |
 279         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 280          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 281     } else {
 282       FDECFIEncoding =
 283         (CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 284         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 285     }
 286     break;
 287   default:
 288     FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 289     break;
 290   }
 291
 292   switch (T.getArch()) {
 293   case Triple::arm:
 294   case Triple::armeb:
 295   case Triple::thumb:
 296   case Triple::thumbeb:
 297     if (Ctx->getAsmInfo()->getExceptionHandlingType() == ExceptionHandling::ARM)
 298       break;
 299     // Fallthrough if not using EHABI
 300   case Triple::ppc:
 301   case Triple::x86:
 302     PersonalityEncoding = (RelocM == Reloc::PIC_)
 303      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 304      : dwarf::DW_EH_PE_absptr;
 305     LSDAEncoding = (RelocM == Reloc::PIC_)
 306       ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 307       : dwarf::DW_EH_PE_absptr;
 308     TTypeEncoding = (RelocM == Reloc::PIC_)
 309      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 310      : dwarf::DW_EH_PE_absptr;
 311     break;
 312   case Triple::x86_64:
 313     if (RelocM == Reloc::PIC_) {
 314       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 315         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 316          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 317       LSDAEncoding = dwarf::DW_EH_PE_pcrel |
 318         (CMModel == CodeModel::Small
 319          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 320       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 321         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 322          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 323     } else {
 324       PersonalityEncoding =
 325         (CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 326         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 327       LSDAEncoding = (CMModel == CodeModel::Small)
 328         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 329       TTypeEncoding = (CMModel == CodeModel::Small)
 330         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 331     }
 332     break;
 333   case Triple::aarch64:
 334   case Triple::aarch64_be:
 335     // The small model guarantees static code/data size < 4GB, but not where it
 336     // will be in memory. Most of these could end up >2GB away so even a signed
 337     // pc-relative 32-bit address is insufficient, theoretically.
 338     if (RelocM == Reloc::PIC_) {
 339       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 340         dwarf::DW_EH_PE_sdata8;
 341       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8;
 342       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 343         dwarf::DW_EH_PE_sdata8;
 344     } else {
 345       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 346       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 347       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 348     }
 349     break;
 350   case Triple::mips:
 351   case Triple::mipsel:
 352   case Triple::mips64:
 353   case Triple::mips64el:
 354     // MIPS uses indirect pointer to refer personality functions, so that the
 355     // eh_frame section can be read-only.  DW.ref.personality will be generated
 356     // for relocation.
 357     PersonalityEncoding = dwarf::DW_EH_PE_indirect;
 358     break;
 359   case Triple::ppc64:
 360   case Triple::ppc64le:
 361     PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 362       dwarf::DW_EH_PE_udata8;
 363     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
 364     TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 365       dwarf::DW_EH_PE_udata8;
 366     break;
 367   case Triple::sparc:
 368     if (RelocM == Reloc::PIC_) {
 369       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 370       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 371         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       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 376       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 377       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 378     }
 379     break;
 380   case Triple::sparcv9:
 381     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 382     if (RelocM == Reloc::PIC_) {
 383       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 384         dwarf::DW_EH_PE_sdata4;
 385       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 386         dwarf::DW_EH_PE_sdata4;
 387     } else {
 388       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 389       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 390     }
 391     break;
 392   case Triple::systemz:
 393     // All currently-defined code models guarantee that 4-byte PC-relative
 394     // values will be in range.
 395     if (RelocM == Reloc::PIC_) {
 396       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 397         dwarf::DW_EH_PE_sdata4;
 398       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 399       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 400         dwarf::DW_EH_PE_sdata4;
 401     } else {
 402       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 403       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 404       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 405     }
 406     break;
 407   default:
 408     break;
 409   }
 410
 411   // Solaris requires different flags for .eh_frame to seemingly every other
 412   // platform.
 413   EHSectionType = ELF::SHT_PROGBITS;
 414   EHSectionFlags = ELF::SHF_ALLOC;
 415   if (T.getOS() == Triple::Solaris) {
 416     if (T.getArch() == Triple::x86_64)
 417       EHSectionType = ELF::SHT_X86_64_UNWIND;
 418     else
 419       EHSectionFlags |= ELF::SHF_WRITE;
 420   }
 421
 422
 423   // ELF
 424   BSSSection =
 425     Ctx->getELFSection(".bss", ELF::SHT_NOBITS,
 426                        ELF::SHF_WRITE | ELF::SHF_ALLOC,
 427                        SectionKind::getBSS());
 428
 429   TextSection =
 430     Ctx->getELFSection(".text", ELF::SHT_PROGBITS,
 431                        ELF::SHF_EXECINSTR |
 432                        ELF::SHF_ALLOC,
 433                        SectionKind::getText());
 434
 435   DataSection =
 436     Ctx->getELFSection(".data", ELF::SHT_PROGBITS,
 437                        ELF::SHF_WRITE |ELF::SHF_ALLOC,
 438                        SectionKind::getDataRel());
 439
 440   ReadOnlySection =
 441     Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS,
 442                        ELF::SHF_ALLOC,
 443                        SectionKind::getReadOnly());
 444
 445   TLSDataSection =
 446     Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS,
 447                        ELF::SHF_ALLOC | ELF::SHF_TLS |
 448                        ELF::SHF_WRITE,
 449                        SectionKind::getThreadData());
 450
 451   TLSBSSSection =
 452     Ctx->getELFSection(".tbss", ELF::SHT_NOBITS,
 453                        ELF::SHF_ALLOC | ELF::SHF_TLS |
 454                        ELF::SHF_WRITE,
 455                        SectionKind::getThreadBSS());
 456
 457   DataRelSection =
 458     Ctx->getELFSection(".data.rel", ELF::SHT_PROGBITS,
 459                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 460                        SectionKind::getDataRel());
 461
 462   DataRelLocalSection =
 463     Ctx->getELFSection(".data.rel.local", ELF::SHT_PROGBITS,
 464                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 465                        SectionKind::getDataRelLocal());
 466
 467   DataRelROSection =
 468     Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS,
 469                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 470                        SectionKind::getReadOnlyWithRel());
 471
 472   DataRelROLocalSection =
 473     Ctx->getELFSection(".data.rel.ro.local", ELF::SHT_PROGBITS,
 474                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 475                        SectionKind::getReadOnlyWithRelLocal());
 476
 477   MergeableConst4Section =
 478     Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS,
 479                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
 480                        SectionKind::getMergeableConst4());
 481
 482   MergeableConst8Section =
 483     Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS,
 484                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
 485                        SectionKind::getMergeableConst8());
 486
 487   MergeableConst16Section =
 488     Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS,
 489                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
 490                        SectionKind::getMergeableConst16());
 491
 492   StaticCtorSection =
 493     Ctx->getELFSection(".ctors", ELF::SHT_PROGBITS,
 494                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 495                        SectionKind::getDataRel());
 496
 497   StaticDtorSection =
 498     Ctx->getELFSection(".dtors", ELF::SHT_PROGBITS,
 499                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 500                        SectionKind::getDataRel());
 501
 502   // Exception Handling Sections.
 503
 504   // FIXME: We're emitting LSDA info into a readonly section on ELF, even though
 505   // it contains relocatable pointers.  In PIC mode, this is probably a big
 506   // runtime hit for C++ apps.  Either the contents of the LSDA need to be
 507   // adjusted or this should be a data section.
 508   LSDASection =
 509     Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS,
 510                        ELF::SHF_ALLOC,
 511                        SectionKind::getReadOnly());
 512
 513   COFFDebugSymbolsSection = nullptr;
 514
 515   // Debug Info Sections.
 516   DwarfAbbrevSection =
 517     Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0,
 518                        SectionKind::getMetadata());
 519   DwarfInfoSection =
 520     Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0,
 521                        SectionKind::getMetadata());
 522   DwarfLineSection =
 523     Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0,
 524                        SectionKind::getMetadata());
 525   DwarfFrameSection =
 526     Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0,
 527                        SectionKind::getMetadata());
 528   DwarfPubNamesSection =
 529     Ctx->getELFSection(".debug_pubnames", ELF::SHT_PROGBITS, 0,
 530                        SectionKind::getMetadata());
 531   DwarfPubTypesSection =
 532     Ctx->getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0,
 533                        SectionKind::getMetadata());
 534   DwarfGnuPubNamesSection =
 535     Ctx->getELFSection(".debug_gnu_pubnames", ELF::SHT_PROGBITS, 0,
 536                        SectionKind::getMetadata());
 537   DwarfGnuPubTypesSection =
 538     Ctx->getELFSection(".debug_gnu_pubtypes", ELF::SHT_PROGBITS, 0,
 539                        SectionKind::getMetadata());
 540   DwarfStrSection =
 541     Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS,
 542                        ELF::SHF_MERGE | ELF::SHF_STRINGS,
 543                        SectionKind::getMergeable1ByteCString());
 544   DwarfLocSection =
 545     Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0,
 546                        SectionKind::getMetadata());
 547   DwarfARangesSection =
 548     Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0,
 549                        SectionKind::getMetadata());
 550   DwarfRangesSection =
 551     Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0,
 552                        SectionKind::getMetadata());
 553   DwarfMacroInfoSection =
 554     Ctx->getELFSection(".debug_macinfo", ELF::SHT_PROGBITS, 0,
 555                        SectionKind::getMetadata());
 556
 557   // DWARF5 Experimental Debug Info
 558
 559   // Accelerator Tables
 560   DwarfAccelNamesSection =
 561     Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0,
 562                        SectionKind::getMetadata());
 563   DwarfAccelObjCSection =
 564     Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0,
 565                        SectionKind::getMetadata());
 566   DwarfAccelNamespaceSection =
 567     Ctx->getELFSection(".apple_namespaces", ELF::SHT_PROGBITS, 0,
 568                        SectionKind::getMetadata());
 569   DwarfAccelTypesSection =
 570     Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0,
 571                        SectionKind::getMetadata());
 572
 573   // Fission Sections
 574   DwarfInfoDWOSection =
 575     Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0,
 576                        SectionKind::getMetadata());
 577   DwarfTypesDWOSection =
 578     Ctx->getELFSection(".debug_types.dwo", ELF::SHT_PROGBITS, 0,
 579                        SectionKind::getMetadata());
 580   DwarfAbbrevDWOSection =
 581     Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0,
 582                        SectionKind::getMetadata());
 583   DwarfStrDWOSection =
 584     Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS,
 585                        ELF::SHF_MERGE | ELF::SHF_STRINGS,
 586                        SectionKind::getMergeable1ByteCString());
 587   DwarfLineDWOSection =
 588     Ctx->getELFSection(".debug_line.dwo", ELF::SHT_PROGBITS, 0,
 589                        SectionKind::getMetadata());
 590   DwarfLocDWOSection =
 591     Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0,
 592                        SectionKind::getMetadata());
 593   DwarfStrOffDWOSection =
 594     Ctx->getELFSection(".debug_str_offsets.dwo", ELF::SHT_PROGBITS, 0,
 595                        SectionKind::getMetadata());
 596   DwarfAddrSection =
 597     Ctx->getELFSection(".debug_addr", ELF::SHT_PROGBITS, 0,
 598                        SectionKind::getMetadata());
 599
 600   StackMapSection =
 601     Ctx->getELFSection(".llvm_stackmaps", ELF::SHT_PROGBITS,
 602                        ELF::SHF_ALLOC,
 603                        SectionKind::getMetadata());
 604
 605 }
 606
 607
 608 void MCObjectFileInfo::InitCOFFMCObjectFileInfo(Triple T) {
 609   bool IsWoA = T.getArch() == Triple::arm || T.getArch() == Triple::thumb;
 610
 611   CommDirectiveSupportsAlignment = true;
 612
 613   // COFF
 614   BSSSection =
 615     Ctx->getCOFFSection(".bss",
 616                         COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
 617                         COFF::IMAGE_SCN_MEM_READ |
 618                         COFF::IMAGE_SCN_MEM_WRITE,
 619                         SectionKind::getBSS());
 620   TextSection =
 621     Ctx->getCOFFSection(".text",
 622                         (IsWoA ? COFF::IMAGE_SCN_MEM_16BIT
 623                                : (COFF::SectionCharacteristics)0) |
 624                         COFF::IMAGE_SCN_CNT_CODE |
 625                         COFF::IMAGE_SCN_MEM_EXECUTE |
 626                         COFF::IMAGE_SCN_MEM_READ,
 627                         SectionKind::getText());
 628   DataSection =
 629     Ctx->getCOFFSection(".data",
 630                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 631                         COFF::IMAGE_SCN_MEM_READ |
 632                         COFF::IMAGE_SCN_MEM_WRITE,
 633                         SectionKind::getDataRel());
 634   ReadOnlySection =
 635     Ctx->getCOFFSection(".rdata",
 636                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 637                         COFF::IMAGE_SCN_MEM_READ,
 638                         SectionKind::getReadOnly());
 639
 640   if (T.isKnownWindowsMSVCEnvironment() || T.isWindowsItaniumEnvironment()) {
 641     StaticCtorSection =
 642       Ctx->getCOFFSection(".CRT$XCU",
 643                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 644                           COFF::IMAGE_SCN_MEM_READ,
 645                           SectionKind::getReadOnly());
 646     StaticDtorSection =
 647       Ctx->getCOFFSection(".CRT$XTX",
 648                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 649                           COFF::IMAGE_SCN_MEM_READ,
 650                           SectionKind::getReadOnly());
 651   } else {
 652     StaticCtorSection =
 653       Ctx->getCOFFSection(".ctors",
 654                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 655                           COFF::IMAGE_SCN_MEM_READ |
 656                           COFF::IMAGE_SCN_MEM_WRITE,
 657                           SectionKind::getDataRel());
 658     StaticDtorSection =
 659       Ctx->getCOFFSection(".dtors",
 660                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 661                           COFF::IMAGE_SCN_MEM_READ |
 662                           COFF::IMAGE_SCN_MEM_WRITE,
 663                           SectionKind::getDataRel());
 664   }
 665
 666   // FIXME: We're emitting LSDA info into a readonly section on COFF, even
 667   // though it contains relocatable pointers.  In PIC mode, this is probably a
 668   // big runtime hit for C++ apps.  Either the contents of the LSDA need to be
 669   // adjusted or this should be a data section.
 670   assert(T.isOSWindows() && "Windows is the only supported COFF target");
 671   if (T.getArch() == Triple::x86_64) {
 672     // On Windows 64 with SEH, the LSDA is emitted into the .xdata section
 673     LSDASection = 0;
 674   } else {
 675     LSDASection = Ctx->getCOFFSection(".gcc_except_table",
 676                                       COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 677                                           COFF::IMAGE_SCN_MEM_READ,
 678                                       SectionKind::getReadOnly());
 679   }
 680
 681   // Debug info.
 682   COFFDebugSymbolsSection =
 683     Ctx->getCOFFSection(".debug$S",
 684                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 685                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 686                         COFF::IMAGE_SCN_MEM_READ,
 687                         SectionKind::getMetadata());
 688
 689   DwarfAbbrevSection =
 690     Ctx->getCOFFSection(".debug_abbrev",
 691                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 692                         COFF::IMAGE_SCN_MEM_READ,
 693                         SectionKind::getMetadata());
 694   DwarfInfoSection =
 695     Ctx->getCOFFSection(".debug_info",
 696                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 697                         COFF::IMAGE_SCN_MEM_READ,
 698                         SectionKind::getMetadata());
 699   DwarfLineSection =
 700     Ctx->getCOFFSection(".debug_line",
 701                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 702                         COFF::IMAGE_SCN_MEM_READ,
 703                         SectionKind::getMetadata());
 704   DwarfFrameSection =
 705     Ctx->getCOFFSection(".debug_frame",
 706                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 707                         COFF::IMAGE_SCN_MEM_READ,
 708                         SectionKind::getMetadata());
 709   DwarfPubNamesSection =
 710     Ctx->getCOFFSection(".debug_pubnames",
 711                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 712                         COFF::IMAGE_SCN_MEM_READ,
 713                         SectionKind::getMetadata());
 714   DwarfPubTypesSection =
 715     Ctx->getCOFFSection(".debug_pubtypes",
 716                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 717                         COFF::IMAGE_SCN_MEM_READ,
 718                         SectionKind::getMetadata());
 719   DwarfGnuPubNamesSection =
 720     Ctx->getCOFFSection(".debug_gnu_pubnames",
 721                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 722                         COFF::IMAGE_SCN_MEM_READ,
 723                         SectionKind::getMetadata());
 724   DwarfGnuPubTypesSection =
 725     Ctx->getCOFFSection(".debug_gnu_pubtypes",
 726                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 727                         COFF::IMAGE_SCN_MEM_READ,
 728                         SectionKind::getMetadata());
 729   DwarfStrSection =
 730     Ctx->getCOFFSection(".debug_str",
 731                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 732                         COFF::IMAGE_SCN_MEM_READ,
 733                         SectionKind::getMetadata());
 734   DwarfLocSection =
 735     Ctx->getCOFFSection(".debug_loc",
 736                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 737                         COFF::IMAGE_SCN_MEM_READ,
 738                         SectionKind::getMetadata());
 739   DwarfARangesSection =
 740     Ctx->getCOFFSection(".debug_aranges",
 741                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 742                         COFF::IMAGE_SCN_MEM_READ,
 743                         SectionKind::getMetadata());
 744   DwarfRangesSection =
 745     Ctx->getCOFFSection(".debug_ranges",
 746                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 747                         COFF::IMAGE_SCN_MEM_READ,
 748                         SectionKind::getMetadata());
 749   DwarfMacroInfoSection =
 750     Ctx->getCOFFSection(".debug_macinfo",
 751                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 752                         COFF::IMAGE_SCN_MEM_READ,
 753                         SectionKind::getMetadata());
 754   DwarfInfoDWOSection =
 755       Ctx->getCOFFSection(".debug_info.dwo",
 756                           COFF::IMAGE_SCN_MEM_DISCARDABLE |
 757                           COFF::IMAGE_SCN_MEM_READ,
 758                           SectionKind::getMetadata());
 759   DwarfTypesDWOSection =
 760       Ctx->getCOFFSection(".debug_types.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 761                                                   COFF::IMAGE_SCN_MEM_READ,
 762                           SectionKind::getMetadata());
 763   DwarfAbbrevDWOSection =
 764       Ctx->getCOFFSection(".debug_abbrev.dwo",
 765                           COFF::IMAGE_SCN_MEM_DISCARDABLE |
 766                           COFF::IMAGE_SCN_MEM_READ,
 767                           SectionKind::getMetadata());
 768   DwarfStrDWOSection =
 769       Ctx->getCOFFSection(".debug_str.dwo",
 770                           COFF::IMAGE_SCN_MEM_DISCARDABLE |
 771                           COFF::IMAGE_SCN_MEM_READ,
 772                           SectionKind::getMetadata());
 773   DwarfLineDWOSection =
 774       Ctx->getCOFFSection(".debug_line.dwo",
 775                           COFF::IMAGE_SCN_MEM_DISCARDABLE |
 776                           COFF::IMAGE_SCN_MEM_READ,
 777                           SectionKind::getMetadata());
 778   DwarfLocDWOSection =
 779       Ctx->getCOFFSection(".debug_loc.dwo",
 780                           COFF::IMAGE_SCN_MEM_DISCARDABLE |
 781                           COFF::IMAGE_SCN_MEM_READ,
 782                           SectionKind::getMetadata());
 783   DwarfStrOffDWOSection =
 784       Ctx->getCOFFSection(".debug_str_offsets.dwo",
 785                           COFF::IMAGE_SCN_MEM_DISCARDABLE |
 786                           COFF::IMAGE_SCN_MEM_READ,
 787                           SectionKind::getMetadata());
 788
 789   DwarfAddrSection =
 790     Ctx->getCOFFSection(".debug_addr",
 791                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 792                         COFF::IMAGE_SCN_MEM_READ,
 793                         SectionKind::getMetadata());
 794
 795   DwarfAccelNamesSection =
 796       Ctx->getCOFFSection(".apple_names",
 797                           COFF::IMAGE_SCN_MEM_DISCARDABLE |
 798                           COFF::IMAGE_SCN_MEM_READ,
 799                           SectionKind::getMetadata());
 800   DwarfAccelNamespaceSection =
 801       Ctx->getCOFFSection(".apple_namespaces",
 802                           COFF::IMAGE_SCN_MEM_DISCARDABLE |
 803                           COFF::IMAGE_SCN_MEM_READ,
 804                           SectionKind::getMetadata());
 805   DwarfAccelTypesSection =
 806       Ctx->getCOFFSection(".apple_types",
 807                           COFF::IMAGE_SCN_MEM_DISCARDABLE |
 808                           COFF::IMAGE_SCN_MEM_READ,
 809                           SectionKind::getMetadata());
 810   DwarfAccelObjCSection =
 811       Ctx->getCOFFSection(".apple_objc",
 812                           COFF::IMAGE_SCN_MEM_DISCARDABLE |
 813                           COFF::IMAGE_SCN_MEM_READ,
 814                           SectionKind::getMetadata());
 815
 816   DrectveSection =
 817     Ctx->getCOFFSection(".drectve",
 818                         COFF::IMAGE_SCN_LNK_INFO |
 819                         COFF::IMAGE_SCN_LNK_REMOVE,
 820                         SectionKind::getMetadata());
 821
 822   PDataSection =
 823     Ctx->getCOFFSection(".pdata",
 824                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 825                         COFF::IMAGE_SCN_MEM_READ,
 826                         SectionKind::getDataRel());
 827
 828   XDataSection =
 829     Ctx->getCOFFSection(".xdata",
 830                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 831                         COFF::IMAGE_SCN_MEM_READ,
 832                         SectionKind::getDataRel());
 833
 834   TLSDataSection =
 835     Ctx->getCOFFSection(".tls$",
 836                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 837                         COFF::IMAGE_SCN_MEM_READ |
 838                         COFF::IMAGE_SCN_MEM_WRITE,
 839                         SectionKind::getDataRel());
 840 }
 841
 842 void MCObjectFileInfo::InitMCObjectFileInfo(StringRef T, Reloc::Model relocm,
 843                                             CodeModel::Model cm,
 844                                             MCContext &ctx) {
 845   RelocM = relocm;
 846   CMModel = cm;
 847   Ctx = &ctx;
 848
 849   // Common.
 850   CommDirectiveSupportsAlignment = true;
 851   SupportsWeakOmittedEHFrame = true;
 852   SupportsCompactUnwindWithoutEHFrame = false;
 853
 854   PersonalityEncoding = LSDAEncoding = FDECFIEncoding = TTypeEncoding =
 855       dwarf::DW_EH_PE_absptr;
 856
 857   CompactUnwindDwarfEHFrameOnly = 0;
 858
 859   EHFrameSection = nullptr;             // Created on demand.
 860   CompactUnwindSection = nullptr;       // Used only by selected targets.
 861   DwarfAccelNamesSection = nullptr;     // Used only by selected targets.
 862   DwarfAccelObjCSection = nullptr;      // Used only by selected targets.
 863   DwarfAccelNamespaceSection = nullptr; // Used only by selected targets.
 864   DwarfAccelTypesSection = nullptr;     // Used only by selected targets.
 865
 866   TT = Triple(T);
 867
 868   Triple::ArchType Arch = TT.getArch();
 869   // FIXME: Checking for Arch here to filter out bogus triples such as
 870   // cellspu-apple-darwin. Perhaps we should fix in Triple?
 871   if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
 872        Arch == Triple::arm || Arch == Triple::thumb ||
 873        Arch == Triple::aarch64 ||
 874        Arch == Triple::ppc || Arch == Triple::ppc64 ||
 875        Arch == Triple::UnknownArch) &&
 876       (TT.isOSDarwin() || TT.isOSBinFormatMachO())) {
 877     Env = IsMachO;
 878     InitMachOMCObjectFileInfo(TT);
 879   } else if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
 880               Arch == Triple::arm || Arch == Triple::thumb) &&
 881              (TT.isOSWindows() && TT.getObjectFormat() == Triple::COFF)) {
 882     Env = IsCOFF;
 883     InitCOFFMCObjectFileInfo(TT);
 884   } else {
 885     Env = IsELF;
 886     InitELFMCObjectFileInfo(TT);
 887   }
 888 }
 889
 890 const MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const {
 891   return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP,
 892                             SectionKind::getMetadata(), 0, utostr(Hash));
 893 }
 894
 895 void MCObjectFileInfo::InitEHFrameSection() {
 896   if (Env == IsMachO)
 897     EHFrameSection =
 898       Ctx->getMachOSection("__TEXT", "__eh_frame",
 899                            MachO::S_COALESCED |
 900                            MachO::S_ATTR_NO_TOC |
 901                            MachO::S_ATTR_STRIP_STATIC_SYMS |
 902                            MachO::S_ATTR_LIVE_SUPPORT,
 903                            SectionKind::getReadOnly());
 904   else if (Env == IsELF)
 905     EHFrameSection =
 906       Ctx->getELFSection(".eh_frame", EHSectionType,
 907                          EHSectionFlags,
 908                          SectionKind::getDataRel());
 909   else
 910     EHFrameSection =
 911       Ctx->getCOFFSection(".eh_frame",
 912                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 913                           COFF::IMAGE_SCN_MEM_READ |
 914                           COFF::IMAGE_SCN_MEM_WRITE,
 915                           SectionKind::getDataRel());
 916 }