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/MCContext.h"
  14 #include "llvm/MC/MCSection.h"
  15 #include "llvm/MC/MCSectionCOFF.h"
  16 #include "llvm/MC/MCSectionELF.h"
  17 #include "llvm/MC/MCSectionMachO.h"
  18 using namespace llvm;
  19
  20 void MCObjectFileInfo::InitMachOMCObjectFileInfo(Triple T) {
  21   // MachO
  22   IsFunctionEHFrameSymbolPrivate = false;
  23   SupportsWeakOmittedEHFrame = false;
  24
  25   if (T.isOSDarwin() && T.getArch() == Triple::arm64)
  26     SupportsCompactUnwindWithoutEHFrame = true;
  27
  28   PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel
  29     | dwarf::DW_EH_PE_sdata4;
  30   LSDAEncoding = FDEEncoding = FDECFIEncoding = dwarf::DW_EH_PE_pcrel;
  31   TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
  32     dwarf::DW_EH_PE_sdata4;
  33
  34   // .comm doesn't support alignment before Leopard.
  35   if (T.isMacOSX() && T.isMacOSXVersionLT(10, 5))
  36     CommDirectiveSupportsAlignment = false;
  37
  38   TextSection // .text
  39     = Ctx->getMachOSection("__TEXT", "__text",
  40                            MachO::S_ATTR_PURE_INSTRUCTIONS,
  41                            SectionKind::getText());
  42   DataSection // .data
  43     = Ctx->getMachOSection("__DATA", "__data", 0,
  44                            SectionKind::getDataRel());
  45
  46   // BSSSection might not be expected initialized on msvc.
  47   BSSSection = nullptr;
  48
  49   TLSDataSection // .tdata
  50     = Ctx->getMachOSection("__DATA", "__thread_data",
  51                            MachO::S_THREAD_LOCAL_REGULAR,
  52                            SectionKind::getDataRel());
  53   TLSBSSSection // .tbss
  54     = Ctx->getMachOSection("__DATA", "__thread_bss",
  55                            MachO::S_THREAD_LOCAL_ZEROFILL,
  56                            SectionKind::getThreadBSS());
  57
  58   // TODO: Verify datarel below.
  59   TLSTLVSection // .tlv
  60     = Ctx->getMachOSection("__DATA", "__thread_vars",
  61                            MachO::S_THREAD_LOCAL_VARIABLES,
  62                            SectionKind::getDataRel());
  63
  64   TLSThreadInitSection
  65     = Ctx->getMachOSection("__DATA", "__thread_init",
  66                           MachO::S_THREAD_LOCAL_INIT_FUNCTION_POINTERS,
  67                           SectionKind::getDataRel());
  68
  69   CStringSection // .cstring
  70     = Ctx->getMachOSection("__TEXT", "__cstring",
  71                            MachO::S_CSTRING_LITERALS,
  72                            SectionKind::getMergeable1ByteCString());
  73   UStringSection
  74     = Ctx->getMachOSection("__TEXT","__ustring", 0,
  75                            SectionKind::getMergeable2ByteCString());
  76   FourByteConstantSection // .literal4
  77     = Ctx->getMachOSection("__TEXT", "__literal4",
  78                            MachO::S_4BYTE_LITERALS,
  79                            SectionKind::getMergeableConst4());
  80   EightByteConstantSection // .literal8
  81     = Ctx->getMachOSection("__TEXT", "__literal8",
  82                            MachO::S_8BYTE_LITERALS,
  83                            SectionKind::getMergeableConst8());
  84
  85   SixteenByteConstantSection // .literal16
  86       = Ctx->getMachOSection("__TEXT", "__literal16",
  87                              MachO::S_16BYTE_LITERALS,
  88                              SectionKind::getMergeableConst16());
  89
  90   ReadOnlySection  // .const
  91     = Ctx->getMachOSection("__TEXT", "__const", 0,
  92                            SectionKind::getReadOnly());
  93
  94   TextCoalSection
  95     = Ctx->getMachOSection("__TEXT", "__textcoal_nt",
  96                            MachO::S_COALESCED |
  97                            MachO::S_ATTR_PURE_INSTRUCTIONS,
  98                            SectionKind::getText());
  99   ConstTextCoalSection
 100     = Ctx->getMachOSection("__TEXT", "__const_coal",
 101                            MachO::S_COALESCED,
 102                            SectionKind::getReadOnly());
 103   ConstDataSection  // .const_data
 104     = Ctx->getMachOSection("__DATA", "__const", 0,
 105                            SectionKind::getReadOnlyWithRel());
 106   DataCoalSection
 107     = Ctx->getMachOSection("__DATA","__datacoal_nt",
 108                            MachO::S_COALESCED,
 109                            SectionKind::getDataRel());
 110   DataCommonSection
 111     = Ctx->getMachOSection("__DATA","__common",
 112                            MachO::S_ZEROFILL,
 113                            SectionKind::getBSS());
 114   DataBSSSection
 115     = Ctx->getMachOSection("__DATA","__bss", MachO::S_ZEROFILL,
 116                            SectionKind::getBSS());
 117
 118
 119   LazySymbolPointerSection
 120     = Ctx->getMachOSection("__DATA", "__la_symbol_ptr",
 121                            MachO::S_LAZY_SYMBOL_POINTERS,
 122                            SectionKind::getMetadata());
 123   NonLazySymbolPointerSection
 124     = Ctx->getMachOSection("__DATA", "__nl_symbol_ptr",
 125                            MachO::S_NON_LAZY_SYMBOL_POINTERS,
 126                            SectionKind::getMetadata());
 127
 128   if (RelocM == Reloc::Static) {
 129     StaticCtorSection
 130       = Ctx->getMachOSection("__TEXT", "__constructor", 0,
 131                              SectionKind::getDataRel());
 132     StaticDtorSection
 133       = Ctx->getMachOSection("__TEXT", "__destructor", 0,
 134                              SectionKind::getDataRel());
 135   } else {
 136     StaticCtorSection
 137       = Ctx->getMachOSection("__DATA", "__mod_init_func",
 138                              MachO::S_MOD_INIT_FUNC_POINTERS,
 139                              SectionKind::getDataRel());
 140     StaticDtorSection
 141       = Ctx->getMachOSection("__DATA", "__mod_term_func",
 142                              MachO::S_MOD_TERM_FUNC_POINTERS,
 143                              SectionKind::getDataRel());
 144   }
 145
 146   // Exception Handling.
 147   LSDASection = Ctx->getMachOSection("__TEXT", "__gcc_except_tab", 0,
 148                                      SectionKind::getReadOnlyWithRel());
 149
 150   COFFDebugSymbolsSection = nullptr;
 151
 152   if ((T.isMacOSX() && !T.isMacOSXVersionLT(10, 6)) ||
 153       (T.isOSDarwin() && T.getArch() == Triple::arm64)) {
 154     CompactUnwindSection =
 155       Ctx->getMachOSection("__LD", "__compact_unwind",
 156                            MachO::S_ATTR_DEBUG,
 157                            SectionKind::getReadOnly());
 158
 159     if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86)
 160       CompactUnwindDwarfEHFrameOnly = 0x04000000;
 161     else if (T.getArch() == Triple::arm64)
 162       CompactUnwindDwarfEHFrameOnly = 0x03000000;
 163   }
 164
 165   // Debug Information.
 166   DwarfAccelNamesSection =
 167     Ctx->getMachOSection("__DWARF", "__apple_names",
 168                          MachO::S_ATTR_DEBUG,
 169                          SectionKind::getMetadata());
 170   DwarfAccelObjCSection =
 171     Ctx->getMachOSection("__DWARF", "__apple_objc",
 172                          MachO::S_ATTR_DEBUG,
 173                          SectionKind::getMetadata());
 174   // 16 character section limit...
 175   DwarfAccelNamespaceSection =
 176     Ctx->getMachOSection("__DWARF", "__apple_namespac",
 177                          MachO::S_ATTR_DEBUG,
 178                          SectionKind::getMetadata());
 179   DwarfAccelTypesSection =
 180     Ctx->getMachOSection("__DWARF", "__apple_types",
 181                          MachO::S_ATTR_DEBUG,
 182                          SectionKind::getMetadata());
 183
 184   DwarfAbbrevSection =
 185     Ctx->getMachOSection("__DWARF", "__debug_abbrev",
 186                          MachO::S_ATTR_DEBUG,
 187                          SectionKind::getMetadata());
 188   DwarfInfoSection =
 189     Ctx->getMachOSection("__DWARF", "__debug_info",
 190                          MachO::S_ATTR_DEBUG,
 191                          SectionKind::getMetadata());
 192   DwarfLineSection =
 193     Ctx->getMachOSection("__DWARF", "__debug_line",
 194                          MachO::S_ATTR_DEBUG,
 195                          SectionKind::getMetadata());
 196   DwarfFrameSection =
 197     Ctx->getMachOSection("__DWARF", "__debug_frame",
 198                          MachO::S_ATTR_DEBUG,
 199                          SectionKind::getMetadata());
 200   DwarfPubNamesSection =
 201     Ctx->getMachOSection("__DWARF", "__debug_pubnames",
 202                          MachO::S_ATTR_DEBUG,
 203                          SectionKind::getMetadata());
 204   DwarfPubTypesSection =
 205     Ctx->getMachOSection("__DWARF", "__debug_pubtypes",
 206                          MachO::S_ATTR_DEBUG,
 207                          SectionKind::getMetadata());
 208   DwarfGnuPubNamesSection =
 209     Ctx->getMachOSection("__DWARF", "__debug_gnu_pubn",
 210                          MachO::S_ATTR_DEBUG,
 211                          SectionKind::getMetadata());
 212   DwarfGnuPubTypesSection =
 213     Ctx->getMachOSection("__DWARF", "__debug_gnu_pubt",
 214                          MachO::S_ATTR_DEBUG,
 215                          SectionKind::getMetadata());
 216   DwarfStrSection =
 217     Ctx->getMachOSection("__DWARF", "__debug_str",
 218                          MachO::S_ATTR_DEBUG,
 219                          SectionKind::getMetadata());
 220   DwarfLocSection =
 221     Ctx->getMachOSection("__DWARF", "__debug_loc",
 222                          MachO::S_ATTR_DEBUG,
 223                          SectionKind::getMetadata());
 224   DwarfARangesSection =
 225     Ctx->getMachOSection("__DWARF", "__debug_aranges",
 226                          MachO::S_ATTR_DEBUG,
 227                          SectionKind::getMetadata());
 228   DwarfRangesSection =
 229     Ctx->getMachOSection("__DWARF", "__debug_ranges",
 230                          MachO::S_ATTR_DEBUG,
 231                          SectionKind::getMetadata());
 232   DwarfMacroInfoSection =
 233     Ctx->getMachOSection("__DWARF", "__debug_macinfo",
 234                          MachO::S_ATTR_DEBUG,
 235                          SectionKind::getMetadata());
 236   DwarfDebugInlineSection =
 237     Ctx->getMachOSection("__DWARF", "__debug_inlined",
 238                          MachO::S_ATTR_DEBUG,
 239                          SectionKind::getMetadata());
 240   StackMapSection =
 241     Ctx->getMachOSection("__LLVM_STACKMAPS", "__llvm_stackmaps", 0,
 242                          SectionKind::getMetadata());
 243
 244   TLSExtraDataSection = TLSTLVSection;
 245 }
 246
 247 void MCObjectFileInfo::InitELFMCObjectFileInfo(Triple T) {
 248   if (T.getArch() == Triple::mips ||
 249       T.getArch() == Triple::mipsel)
 250     FDECFIEncoding = dwarf::DW_EH_PE_sdata4;
 251   else if (T.getArch() == Triple::mips64 ||
 252            T.getArch() == Triple::mips64el)
 253     FDECFIEncoding = dwarf::DW_EH_PE_sdata8;
 254   else
 255     FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 256
 257   if (T.getArch() == Triple::x86) {
 258     PersonalityEncoding = (RelocM == Reloc::PIC_)
 259      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 260      : dwarf::DW_EH_PE_absptr;
 261     LSDAEncoding = (RelocM == Reloc::PIC_)
 262       ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 263       : dwarf::DW_EH_PE_absptr;
 264     FDEEncoding = (RelocM == Reloc::PIC_)
 265       ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 266       : dwarf::DW_EH_PE_absptr;
 267     TTypeEncoding = (RelocM == Reloc::PIC_)
 268      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
 269      : dwarf::DW_EH_PE_absptr;
 270   } else if (T.getArch() == Triple::x86_64) {
 271     if (RelocM == Reloc::PIC_) {
 272       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 273         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 274          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 275       LSDAEncoding = dwarf::DW_EH_PE_pcrel |
 276         (CMModel == CodeModel::Small
 277          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 278       FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 279       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 280         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 281          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
 282     } else {
 283       PersonalityEncoding =
 284         (CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
 285         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 286       LSDAEncoding = (CMModel == CodeModel::Small)
 287         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 288       FDEEncoding = dwarf::DW_EH_PE_udata4;
 289       TTypeEncoding = (CMModel == CodeModel::Small)
 290         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
 291     }
 292   } else if (T.getArch() == Triple::aarch64 ||
 293              T.getArch() == Triple::aarch64_be ||
 294              T.getArch() == Triple::arm64 ||
 295              T.getArch() == Triple::arm64_be) {
 296     // The small model guarantees static code/data size < 4GB, but not where it
 297     // will be in memory. Most of these could end up >2GB away so even a signed
 298     // pc-relative 32-bit address is insufficient, theoretically.
 299     if (RelocM == Reloc::PIC_) {
 300       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 301         dwarf::DW_EH_PE_sdata8;
 302       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8;
 303       FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 304       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 305         dwarf::DW_EH_PE_sdata8;
 306     } else {
 307       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 308       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 309       FDEEncoding = dwarf::DW_EH_PE_udata4;
 310       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 311     }
 312   } else if (T.getArch() == Triple::ppc64 || T.getArch() == Triple::ppc64le) {
 313     PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 314       dwarf::DW_EH_PE_udata8;
 315     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
 316     FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
 317     TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 318       dwarf::DW_EH_PE_udata8;
 319   } else if (T.getArch() == Triple::sparc) {
 320     if (RelocM == Reloc::PIC_) {
 321       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 322       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 323         dwarf::DW_EH_PE_sdata4;
 324       FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 325       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 326         dwarf::DW_EH_PE_sdata4;
 327     } else {
 328       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 329       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 330       FDEEncoding = dwarf::DW_EH_PE_udata4;
 331       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 332     }
 333   } else if (T.getArch() == Triple::sparcv9) {
 334     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 335     if (RelocM == Reloc::PIC_) {
 336       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 337         dwarf::DW_EH_PE_sdata4;
 338       FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 339       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 340         dwarf::DW_EH_PE_sdata4;
 341     } else {
 342       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 343       FDEEncoding = dwarf::DW_EH_PE_udata4;
 344       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 345     }
 346   } else if (T.getArch() == Triple::systemz) {
 347     // All currently-defined code models guarantee that 4-byte PC-relative
 348     // values will be in range.
 349     if (RelocM == Reloc::PIC_) {
 350       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 351         dwarf::DW_EH_PE_sdata4;
 352       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 353       FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
 354       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
 355         dwarf::DW_EH_PE_sdata4;
 356     } else {
 357       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
 358       LSDAEncoding = dwarf::DW_EH_PE_absptr;
 359       FDEEncoding = dwarf::DW_EH_PE_absptr;
 360       TTypeEncoding = dwarf::DW_EH_PE_absptr;
 361     }
 362   }
 363
 364   // Solaris requires different flags for .eh_frame to seemingly every other
 365   // platform.
 366   EHSectionType = ELF::SHT_PROGBITS;
 367   EHSectionFlags = ELF::SHF_ALLOC;
 368   if (T.getOS() == Triple::Solaris) {
 369     if (T.getArch() == Triple::x86_64)
 370       EHSectionType = ELF::SHT_X86_64_UNWIND;
 371     else
 372       EHSectionFlags |= ELF::SHF_WRITE;
 373   }
 374
 375
 376   // ELF
 377   BSSSection =
 378     Ctx->getELFSection(".bss", ELF::SHT_NOBITS,
 379                        ELF::SHF_WRITE | ELF::SHF_ALLOC,
 380                        SectionKind::getBSS());
 381
 382   TextSection =
 383     Ctx->getELFSection(".text", ELF::SHT_PROGBITS,
 384                        ELF::SHF_EXECINSTR |
 385                        ELF::SHF_ALLOC,
 386                        SectionKind::getText());
 387
 388   DataSection =
 389     Ctx->getELFSection(".data", ELF::SHT_PROGBITS,
 390                        ELF::SHF_WRITE |ELF::SHF_ALLOC,
 391                        SectionKind::getDataRel());
 392
 393   ReadOnlySection =
 394     Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS,
 395                        ELF::SHF_ALLOC,
 396                        SectionKind::getReadOnly());
 397
 398   TLSDataSection =
 399     Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS,
 400                        ELF::SHF_ALLOC | ELF::SHF_TLS |
 401                        ELF::SHF_WRITE,
 402                        SectionKind::getThreadData());
 403
 404   TLSBSSSection =
 405     Ctx->getELFSection(".tbss", ELF::SHT_NOBITS,
 406                        ELF::SHF_ALLOC | ELF::SHF_TLS |
 407                        ELF::SHF_WRITE,
 408                        SectionKind::getThreadBSS());
 409
 410   DataRelSection =
 411     Ctx->getELFSection(".data.rel", ELF::SHT_PROGBITS,
 412                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 413                        SectionKind::getDataRel());
 414
 415   DataRelLocalSection =
 416     Ctx->getELFSection(".data.rel.local", ELF::SHT_PROGBITS,
 417                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 418                        SectionKind::getDataRelLocal());
 419
 420   DataRelROSection =
 421     Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS,
 422                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 423                        SectionKind::getReadOnlyWithRel());
 424
 425   DataRelROLocalSection =
 426     Ctx->getELFSection(".data.rel.ro.local", ELF::SHT_PROGBITS,
 427                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 428                        SectionKind::getReadOnlyWithRelLocal());
 429
 430   MergeableConst4Section =
 431     Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS,
 432                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
 433                        SectionKind::getMergeableConst4());
 434
 435   MergeableConst8Section =
 436     Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS,
 437                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
 438                        SectionKind::getMergeableConst8());
 439
 440   MergeableConst16Section =
 441     Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS,
 442                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
 443                        SectionKind::getMergeableConst16());
 444
 445   StaticCtorSection =
 446     Ctx->getELFSection(".ctors", ELF::SHT_PROGBITS,
 447                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 448                        SectionKind::getDataRel());
 449
 450   StaticDtorSection =
 451     Ctx->getELFSection(".dtors", ELF::SHT_PROGBITS,
 452                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
 453                        SectionKind::getDataRel());
 454
 455   // Exception Handling Sections.
 456
 457   // FIXME: We're emitting LSDA info into a readonly section on ELF, even though
 458   // it contains relocatable pointers.  In PIC mode, this is probably a big
 459   // runtime hit for C++ apps.  Either the contents of the LSDA need to be
 460   // adjusted or this should be a data section.
 461   LSDASection =
 462     Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS,
 463                        ELF::SHF_ALLOC,
 464                        SectionKind::getReadOnly());
 465
 466   COFFDebugSymbolsSection = nullptr;
 467
 468   // Debug Info Sections.
 469   DwarfAbbrevSection =
 470     Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0,
 471                        SectionKind::getMetadata());
 472   DwarfInfoSection =
 473     Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0,
 474                        SectionKind::getMetadata());
 475   DwarfLineSection =
 476     Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0,
 477                        SectionKind::getMetadata());
 478   DwarfFrameSection =
 479     Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0,
 480                        SectionKind::getMetadata());
 481   DwarfPubNamesSection =
 482     Ctx->getELFSection(".debug_pubnames", ELF::SHT_PROGBITS, 0,
 483                        SectionKind::getMetadata());
 484   DwarfPubTypesSection =
 485     Ctx->getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0,
 486                        SectionKind::getMetadata());
 487   DwarfGnuPubNamesSection =
 488     Ctx->getELFSection(".debug_gnu_pubnames", ELF::SHT_PROGBITS, 0,
 489                        SectionKind::getMetadata());
 490   DwarfGnuPubTypesSection =
 491     Ctx->getELFSection(".debug_gnu_pubtypes", ELF::SHT_PROGBITS, 0,
 492                        SectionKind::getMetadata());
 493   DwarfStrSection =
 494     Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS,
 495                        ELF::SHF_MERGE | ELF::SHF_STRINGS,
 496                        SectionKind::getMergeable1ByteCString());
 497   DwarfLocSection =
 498     Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0,
 499                        SectionKind::getMetadata());
 500   DwarfARangesSection =
 501     Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0,
 502                        SectionKind::getMetadata());
 503   DwarfRangesSection =
 504     Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0,
 505                        SectionKind::getMetadata());
 506   DwarfMacroInfoSection =
 507     Ctx->getELFSection(".debug_macinfo", ELF::SHT_PROGBITS, 0,
 508                        SectionKind::getMetadata());
 509
 510   // DWARF5 Experimental Debug Info
 511
 512   // Accelerator Tables
 513   DwarfAccelNamesSection =
 514     Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0,
 515                        SectionKind::getMetadata());
 516   DwarfAccelObjCSection =
 517     Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0,
 518                        SectionKind::getMetadata());
 519   DwarfAccelNamespaceSection =
 520     Ctx->getELFSection(".apple_namespaces", ELF::SHT_PROGBITS, 0,
 521                        SectionKind::getMetadata());
 522   DwarfAccelTypesSection =
 523     Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0,
 524                        SectionKind::getMetadata());
 525
 526   // Fission Sections
 527   DwarfInfoDWOSection =
 528     Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0,
 529                        SectionKind::getMetadata());
 530   DwarfAbbrevDWOSection =
 531     Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0,
 532                        SectionKind::getMetadata());
 533   DwarfStrDWOSection =
 534     Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS,
 535                        ELF::SHF_MERGE | ELF::SHF_STRINGS,
 536                        SectionKind::getMergeable1ByteCString());
 537   DwarfLineDWOSection =
 538     Ctx->getELFSection(".debug_line.dwo", ELF::SHT_PROGBITS, 0,
 539                        SectionKind::getMetadata());
 540   DwarfLocDWOSection =
 541     Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0,
 542                        SectionKind::getMetadata());
 543   DwarfStrOffDWOSection =
 544     Ctx->getELFSection(".debug_str_offsets.dwo", ELF::SHT_PROGBITS, 0,
 545                        SectionKind::getMetadata());
 546   DwarfAddrSection =
 547     Ctx->getELFSection(".debug_addr", ELF::SHT_PROGBITS, 0,
 548                        SectionKind::getMetadata());
 549 }
 550
 551
 552 void MCObjectFileInfo::InitCOFFMCObjectFileInfo(Triple T) {
 553   // The object file format cannot represent common symbols with explicit
 554   // alignments.
 555   CommDirectiveSupportsAlignment = false;
 556
 557   // COFF
 558   BSSSection =
 559     Ctx->getCOFFSection(".bss",
 560                         COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
 561                         COFF::IMAGE_SCN_MEM_READ |
 562                         COFF::IMAGE_SCN_MEM_WRITE,
 563                         SectionKind::getBSS());
 564   TextSection =
 565     Ctx->getCOFFSection(".text",
 566                         COFF::IMAGE_SCN_CNT_CODE |
 567                         COFF::IMAGE_SCN_MEM_EXECUTE |
 568                         COFF::IMAGE_SCN_MEM_READ,
 569                         SectionKind::getText());
 570   DataSection =
 571     Ctx->getCOFFSection(".data",
 572                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 573                         COFF::IMAGE_SCN_MEM_READ |
 574                         COFF::IMAGE_SCN_MEM_WRITE,
 575                         SectionKind::getDataRel());
 576   ReadOnlySection =
 577     Ctx->getCOFFSection(".rdata",
 578                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 579                         COFF::IMAGE_SCN_MEM_READ,
 580                         SectionKind::getReadOnly());
 581   if (T.isKnownWindowsMSVCEnvironment()) {
 582     StaticCtorSection =
 583       Ctx->getCOFFSection(".CRT$XCU",
 584                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 585                           COFF::IMAGE_SCN_MEM_READ,
 586                           SectionKind::getReadOnly());
 587   } else {
 588     StaticCtorSection =
 589       Ctx->getCOFFSection(".ctors",
 590                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 591                           COFF::IMAGE_SCN_MEM_READ |
 592                           COFF::IMAGE_SCN_MEM_WRITE,
 593                           SectionKind::getDataRel());
 594   }
 595
 596
 597   if (T.isKnownWindowsMSVCEnvironment()) {
 598     StaticDtorSection =
 599       Ctx->getCOFFSection(".CRT$XTX",
 600                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 601                           COFF::IMAGE_SCN_MEM_READ,
 602                           SectionKind::getReadOnly());
 603   } else {
 604     StaticDtorSection =
 605       Ctx->getCOFFSection(".dtors",
 606                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 607                           COFF::IMAGE_SCN_MEM_READ |
 608                           COFF::IMAGE_SCN_MEM_WRITE,
 609                           SectionKind::getDataRel());
 610   }
 611
 612   // FIXME: We're emitting LSDA info into a readonly section on COFF, even
 613   // though it contains relocatable pointers.  In PIC mode, this is probably a
 614   // big runtime hit for C++ apps.  Either the contents of the LSDA need to be
 615   // adjusted or this should be a data section.
 616   LSDASection =
 617     Ctx->getCOFFSection(".gcc_except_table",
 618                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 619                         COFF::IMAGE_SCN_MEM_READ,
 620                         SectionKind::getReadOnly());
 621
 622   // Debug info.
 623   COFFDebugSymbolsSection =
 624     Ctx->getCOFFSection(".debug$S",
 625                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 626                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 627                         COFF::IMAGE_SCN_MEM_READ,
 628                         SectionKind::getMetadata());
 629
 630   DwarfAbbrevSection =
 631     Ctx->getCOFFSection(".debug_abbrev",
 632                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 633                         COFF::IMAGE_SCN_MEM_READ,
 634                         SectionKind::getMetadata());
 635   DwarfInfoSection =
 636     Ctx->getCOFFSection(".debug_info",
 637                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 638                         COFF::IMAGE_SCN_MEM_READ,
 639                         SectionKind::getMetadata());
 640   DwarfLineSection =
 641     Ctx->getCOFFSection(".debug_line",
 642                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 643                         COFF::IMAGE_SCN_MEM_READ,
 644                         SectionKind::getMetadata());
 645   DwarfFrameSection =
 646     Ctx->getCOFFSection(".debug_frame",
 647                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 648                         COFF::IMAGE_SCN_MEM_READ,
 649                         SectionKind::getMetadata());
 650   DwarfPubNamesSection =
 651     Ctx->getCOFFSection(".debug_pubnames",
 652                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 653                         COFF::IMAGE_SCN_MEM_READ,
 654                         SectionKind::getMetadata());
 655   DwarfPubTypesSection =
 656     Ctx->getCOFFSection(".debug_pubtypes",
 657                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 658                         COFF::IMAGE_SCN_MEM_READ,
 659                         SectionKind::getMetadata());
 660   DwarfGnuPubNamesSection =
 661     Ctx->getCOFFSection(".debug_gnu_pubnames",
 662                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 663                         COFF::IMAGE_SCN_MEM_READ,
 664                         SectionKind::getMetadata());
 665   DwarfGnuPubTypesSection =
 666     Ctx->getCOFFSection(".debug_gnu_pubtypes",
 667                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 668                         COFF::IMAGE_SCN_MEM_READ,
 669                         SectionKind::getMetadata());
 670   DwarfStrSection =
 671     Ctx->getCOFFSection(".debug_str",
 672                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 673                         COFF::IMAGE_SCN_MEM_READ,
 674                         SectionKind::getMetadata());
 675   DwarfLocSection =
 676     Ctx->getCOFFSection(".debug_loc",
 677                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 678                         COFF::IMAGE_SCN_MEM_READ,
 679                         SectionKind::getMetadata());
 680   DwarfARangesSection =
 681     Ctx->getCOFFSection(".debug_aranges",
 682                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 683                         COFF::IMAGE_SCN_MEM_READ,
 684                         SectionKind::getMetadata());
 685   DwarfRangesSection =
 686     Ctx->getCOFFSection(".debug_ranges",
 687                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 688                         COFF::IMAGE_SCN_MEM_READ,
 689                         SectionKind::getMetadata());
 690   DwarfMacroInfoSection =
 691     Ctx->getCOFFSection(".debug_macinfo",
 692                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
 693                         COFF::IMAGE_SCN_MEM_READ,
 694                         SectionKind::getMetadata());
 695   DwarfInfoDWOSection =
 696       Ctx->getCOFFSection(".debug_info.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 697                                                 COFF::IMAGE_SCN_MEM_READ,
 698                           SectionKind::getMetadata());
 699   DwarfAbbrevDWOSection =
 700       Ctx->getCOFFSection(".debug_abbrev.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 701                                                   COFF::IMAGE_SCN_MEM_READ,
 702                           SectionKind::getMetadata());
 703   DwarfStrDWOSection =
 704       Ctx->getCOFFSection(".debug_str.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 705                                                COFF::IMAGE_SCN_MEM_READ,
 706                           SectionKind::getMetadata());
 707   DwarfLineDWOSection =
 708       Ctx->getCOFFSection(".debug_line.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 709                                                 COFF::IMAGE_SCN_MEM_READ,
 710                           SectionKind::getMetadata());
 711   DwarfLocDWOSection =
 712       Ctx->getCOFFSection(".debug_loc.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 713                                                COFF::IMAGE_SCN_MEM_READ,
 714                           SectionKind::getMetadata());
 715   DwarfStrOffDWOSection =
 716       Ctx->getCOFFSection(".debug_str_offsets.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
 717                                                   COFF::IMAGE_SCN_MEM_READ,
 718                           SectionKind::getMetadata());
 719   DwarfAddrSection = Ctx->getCOFFSection(
 720       ".debug_addr", COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_MEM_READ,
 721       SectionKind::getMetadata());
 722
 723   DrectveSection =
 724     Ctx->getCOFFSection(".drectve",
 725                         COFF::IMAGE_SCN_LNK_INFO,
 726                         SectionKind::getMetadata());
 727
 728   PDataSection =
 729     Ctx->getCOFFSection(".pdata",
 730                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 731                         COFF::IMAGE_SCN_MEM_READ,
 732                         SectionKind::getDataRel());
 733
 734   XDataSection =
 735     Ctx->getCOFFSection(".xdata",
 736                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 737                         COFF::IMAGE_SCN_MEM_READ,
 738                         SectionKind::getDataRel());
 739   TLSDataSection =
 740     Ctx->getCOFFSection(".tls$",
 741                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 742                         COFF::IMAGE_SCN_MEM_READ |
 743                         COFF::IMAGE_SCN_MEM_WRITE,
 744                         SectionKind::getDataRel());
 745 }
 746
 747 void MCObjectFileInfo::InitMCObjectFileInfo(StringRef TT, Reloc::Model relocm,
 748                                             CodeModel::Model cm,
 749                                             MCContext &ctx) {
 750   RelocM = relocm;
 751   CMModel = cm;
 752   Ctx = &ctx;
 753
 754   // Common.
 755   CommDirectiveSupportsAlignment = true;
 756   SupportsWeakOmittedEHFrame = true;
 757   IsFunctionEHFrameSymbolPrivate = true;
 758   SupportsCompactUnwindWithoutEHFrame = false;
 759
 760   PersonalityEncoding = LSDAEncoding = FDEEncoding = FDECFIEncoding =
 761     TTypeEncoding = dwarf::DW_EH_PE_absptr;
 762
 763   CompactUnwindDwarfEHFrameOnly = 0;
 764
 765   EHFrameSection = nullptr;             // Created on demand.
 766   CompactUnwindSection = nullptr;       // Used only by selected targets.
 767   DwarfAccelNamesSection = nullptr;     // Used only by selected targets.
 768   DwarfAccelObjCSection = nullptr;      // Used only by selected targets.
 769   DwarfAccelNamespaceSection = nullptr; // Used only by selected targets.
 770   DwarfAccelTypesSection = nullptr;     // Used only by selected targets.
 771
 772   Triple T(TT);
 773   Triple::ArchType Arch = T.getArch();
 774   // FIXME: Checking for Arch here to filter out bogus triples such as
 775   // cellspu-apple-darwin. Perhaps we should fix in Triple?
 776   if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
 777        Arch == Triple::arm || Arch == Triple::thumb ||
 778        Arch == Triple::arm64 ||
 779        Arch == Triple::ppc || Arch == Triple::ppc64 ||
 780        Arch == Triple::UnknownArch) &&
 781       (T.isOSDarwin() || T.isOSBinFormatMachO())) {
 782     Env = IsMachO;
 783     InitMachOMCObjectFileInfo(T);
 784   } else if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
 785               Arch == Triple::arm || Arch == Triple::thumb) &&
 786              (T.isOSWindows() && T.getObjectFormat() == Triple::COFF)) {
 787     Env = IsCOFF;
 788     InitCOFFMCObjectFileInfo(T);
 789   } else {
 790     Env = IsELF;
 791     InitELFMCObjectFileInfo(T);
 792   }
 793 }
 794
 795 const MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const {
 796   return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP,
 797                             SectionKind::getMetadata(), 0, utostr(Hash));
 798 }
 799
 800 const MCSection *
 801 MCObjectFileInfo::getDwarfTypesDWOSection(uint64_t Hash) const {
 802   return Ctx->getELFSection(".debug_types.dwo", ELF::SHT_PROGBITS,
 803                             ELF::SHF_GROUP, SectionKind::getMetadata(), 0,
 804                             utostr(Hash));
 805 }
 806
 807 void MCObjectFileInfo::InitEHFrameSection() {
 808   if (Env == IsMachO)
 809     EHFrameSection =
 810       Ctx->getMachOSection("__TEXT", "__eh_frame",
 811                            MachO::S_COALESCED |
 812                            MachO::S_ATTR_NO_TOC |
 813                            MachO::S_ATTR_STRIP_STATIC_SYMS |
 814                            MachO::S_ATTR_LIVE_SUPPORT,
 815                            SectionKind::getReadOnly());
 816   else if (Env == IsELF)
 817     EHFrameSection =
 818       Ctx->getELFSection(".eh_frame", EHSectionType,
 819                          EHSectionFlags,
 820                          SectionKind::getDataRel());
 821   else
 822     EHFrameSection =
 823       Ctx->getCOFFSection(".eh_frame",
 824                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
 825                           COFF::IMAGE_SCN_MEM_READ |
 826                           COFF::IMAGE_SCN_MEM_WRITE,
 827                           SectionKind::getDataRel());
 828 }