1//===-- MCObjectFileInfo.cpp - Object File Information --------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10#include "llvm/MC/MCObjectFileInfo.h"
11#include "llvm/ADT/StringExtras.h"
12#include "llvm/ADT/Triple.h"
13#include "llvm/MC/MCAsmInfo.h"
14#include "llvm/MC/MCContext.h"
15#include "llvm/MC/MCSection.h"
16#include "llvm/MC/MCSectionCOFF.h"
17#include "llvm/MC/MCSectionELF.h"
18#include "llvm/MC/MCSectionMachO.h"
19#include "llvm/Support/COFF.h"
20
21using namespace llvm;
22
23static bool useCompactUnwind(const Triple &T) {
24  // Only on darwin.
25  if (!T.isOSDarwin())
26    return false;
27
28  // aarch64 always has it.
29  if (T.getArch() == Triple::aarch64)
30    return true;
31
32  // armv7k always has it.
33  if (T.isWatchABI())
34    return true;
35
36  // Use it on newer version of OS X.
37  if (T.isMacOSX() && !T.isMacOSXVersionLT(10, 6))
38    return true;
39
40  // And the iOS simulator.
41  if (T.isiOS() &&
42      (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86))
43    return true;
44
45  return false;
46}
47
48void MCObjectFileInfo::initMachOMCObjectFileInfo(const Triple &T) {
49  // MachO
50  SupportsWeakOmittedEHFrame = false;
51
52  EHFrameSection = Ctx->getMachOSection(
53      "__TEXT", "__eh_frame",
54      MachO::S_COALESCED | MachO::S_ATTR_NO_TOC |
55          MachO::S_ATTR_STRIP_STATIC_SYMS | MachO::S_ATTR_LIVE_SUPPORT,
56      SectionKind::getReadOnly());
57
58  if (T.isOSDarwin() && T.getArch() == Triple::aarch64)
59    SupportsCompactUnwindWithoutEHFrame = true;
60
61  if (T.isWatchABI())
62    OmitDwarfIfHaveCompactUnwind = true;
63
64  PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel
65    | dwarf::DW_EH_PE_sdata4;
66  LSDAEncoding = FDECFIEncoding = dwarf::DW_EH_PE_pcrel;
67  TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
68    dwarf::DW_EH_PE_sdata4;
69
70  // .comm doesn't support alignment before Leopard.
71  if (T.isMacOSX() && T.isMacOSXVersionLT(10, 5))
72    CommDirectiveSupportsAlignment = false;
73
74  TextSection // .text
75    = Ctx->getMachOSection("__TEXT", "__text",
76                           MachO::S_ATTR_PURE_INSTRUCTIONS,
77                           SectionKind::getText());
78  DataSection // .data
79      = Ctx->getMachOSection("__DATA", "__data", 0, SectionKind::getData());
80
81  // BSSSection might not be expected initialized on msvc.
82  BSSSection = nullptr;
83
84  TLSDataSection // .tdata
85      = Ctx->getMachOSection("__DATA", "__thread_data",
86                             MachO::S_THREAD_LOCAL_REGULAR,
87                             SectionKind::getData());
88  TLSBSSSection // .tbss
89    = Ctx->getMachOSection("__DATA", "__thread_bss",
90                           MachO::S_THREAD_LOCAL_ZEROFILL,
91                           SectionKind::getThreadBSS());
92
93  // TODO: Verify datarel below.
94  TLSTLVSection // .tlv
95      = Ctx->getMachOSection("__DATA", "__thread_vars",
96                             MachO::S_THREAD_LOCAL_VARIABLES,
97                             SectionKind::getData());
98
99  TLSThreadInitSection = Ctx->getMachOSection(
100      "__DATA", "__thread_init", MachO::S_THREAD_LOCAL_INIT_FUNCTION_POINTERS,
101      SectionKind::getData());
102
103  CStringSection // .cstring
104    = Ctx->getMachOSection("__TEXT", "__cstring",
105                           MachO::S_CSTRING_LITERALS,
106                           SectionKind::getMergeable1ByteCString());
107  UStringSection
108    = Ctx->getMachOSection("__TEXT","__ustring", 0,
109                           SectionKind::getMergeable2ByteCString());
110  FourByteConstantSection // .literal4
111    = Ctx->getMachOSection("__TEXT", "__literal4",
112                           MachO::S_4BYTE_LITERALS,
113                           SectionKind::getMergeableConst4());
114  EightByteConstantSection // .literal8
115    = Ctx->getMachOSection("__TEXT", "__literal8",
116                           MachO::S_8BYTE_LITERALS,
117                           SectionKind::getMergeableConst8());
118
119  SixteenByteConstantSection // .literal16
120      = Ctx->getMachOSection("__TEXT", "__literal16",
121                             MachO::S_16BYTE_LITERALS,
122                             SectionKind::getMergeableConst16());
123
124  ReadOnlySection  // .const
125    = Ctx->getMachOSection("__TEXT", "__const", 0,
126                           SectionKind::getReadOnly());
127
128  // If the target is not powerpc, map the coal sections to the non-coal
129  // sections.
130  //
131  // "__TEXT/__textcoal_nt" => section "__TEXT/__text"
132  // "__TEXT/__const_coal"  => section "__TEXT/__const"
133  // "__DATA/__datacoal_nt" => section "__DATA/__data"
134  Triple::ArchType ArchTy = T.getArch();
135
136  if (ArchTy == Triple::ppc || ArchTy == Triple::ppc64) {
137    TextCoalSection
138      = Ctx->getMachOSection("__TEXT", "__textcoal_nt",
139                             MachO::S_COALESCED |
140                             MachO::S_ATTR_PURE_INSTRUCTIONS,
141                             SectionKind::getText());
142    ConstTextCoalSection
143      = Ctx->getMachOSection("__TEXT", "__const_coal",
144                             MachO::S_COALESCED,
145                             SectionKind::getReadOnly());
146    DataCoalSection = Ctx->getMachOSection(
147        "__DATA", "__datacoal_nt", MachO::S_COALESCED, SectionKind::getData());
148  } else {
149    TextCoalSection = TextSection;
150    ConstTextCoalSection = ReadOnlySection;
151    DataCoalSection = DataSection;
152  }
153
154  ConstDataSection  // .const_data
155    = Ctx->getMachOSection("__DATA", "__const", 0,
156                           SectionKind::getReadOnlyWithRel());
157  DataCommonSection
158    = Ctx->getMachOSection("__DATA","__common",
159                           MachO::S_ZEROFILL,
160                           SectionKind::getBSS());
161  DataBSSSection
162    = Ctx->getMachOSection("__DATA","__bss", MachO::S_ZEROFILL,
163                           SectionKind::getBSS());
164
165
166  LazySymbolPointerSection
167    = Ctx->getMachOSection("__DATA", "__la_symbol_ptr",
168                           MachO::S_LAZY_SYMBOL_POINTERS,
169                           SectionKind::getMetadata());
170  NonLazySymbolPointerSection
171    = Ctx->getMachOSection("__DATA", "__nl_symbol_ptr",
172                           MachO::S_NON_LAZY_SYMBOL_POINTERS,
173                           SectionKind::getMetadata());
174
175  ThreadLocalPointerSection
176    = Ctx->getMachOSection("__DATA", "__thread_ptr",
177                           MachO::S_THREAD_LOCAL_VARIABLE_POINTERS,
178                           SectionKind::getMetadata());
179
180  if (!PositionIndependent) {
181    StaticCtorSection = Ctx->getMachOSection("__TEXT", "__constructor", 0,
182                                             SectionKind::getData());
183    StaticDtorSection = Ctx->getMachOSection("__TEXT", "__destructor", 0,
184                                             SectionKind::getData());
185  } else {
186    StaticCtorSection = Ctx->getMachOSection("__DATA", "__mod_init_func",
187                                             MachO::S_MOD_INIT_FUNC_POINTERS,
188                                             SectionKind::getData());
189    StaticDtorSection = Ctx->getMachOSection("__DATA", "__mod_term_func",
190                                             MachO::S_MOD_TERM_FUNC_POINTERS,
191                                             SectionKind::getData());
192  }
193
194  // Exception Handling.
195  LSDASection = Ctx->getMachOSection("__TEXT", "__gcc_except_tab", 0,
196                                     SectionKind::getReadOnlyWithRel());
197
198  COFFDebugSymbolsSection = nullptr;
199  COFFDebugTypesSection = nullptr;
200
201  if (useCompactUnwind(T)) {
202    CompactUnwindSection =
203        Ctx->getMachOSection("__LD", "__compact_unwind", MachO::S_ATTR_DEBUG,
204                             SectionKind::getReadOnly());
205
206    if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86)
207      CompactUnwindDwarfEHFrameOnly = 0x04000000;  // UNWIND_X86_64_MODE_DWARF
208    else if (T.getArch() == Triple::aarch64)
209      CompactUnwindDwarfEHFrameOnly = 0x03000000;  // UNWIND_ARM64_MODE_DWARF
210    else if (T.getArch() == Triple::arm || T.getArch() == Triple::thumb)
211      CompactUnwindDwarfEHFrameOnly = 0x04000000;  // UNWIND_ARM_MODE_DWARF
212  }
213
214  // Debug Information.
215  DwarfAccelNamesSection =
216      Ctx->getMachOSection("__DWARF", "__apple_names", MachO::S_ATTR_DEBUG,
217                           SectionKind::getMetadata(), "names_begin");
218  DwarfAccelObjCSection =
219      Ctx->getMachOSection("__DWARF", "__apple_objc", MachO::S_ATTR_DEBUG,
220                           SectionKind::getMetadata(), "objc_begin");
221  // 16 character section limit...
222  DwarfAccelNamespaceSection =
223      Ctx->getMachOSection("__DWARF", "__apple_namespac", MachO::S_ATTR_DEBUG,
224                           SectionKind::getMetadata(), "namespac_begin");
225  DwarfAccelTypesSection =
226      Ctx->getMachOSection("__DWARF", "__apple_types", MachO::S_ATTR_DEBUG,
227                           SectionKind::getMetadata(), "types_begin");
228
229  DwarfAbbrevSection =
230      Ctx->getMachOSection("__DWARF", "__debug_abbrev", MachO::S_ATTR_DEBUG,
231                           SectionKind::getMetadata(), "section_abbrev");
232  DwarfInfoSection =
233      Ctx->getMachOSection("__DWARF", "__debug_info", MachO::S_ATTR_DEBUG,
234                           SectionKind::getMetadata(), "section_info");
235  DwarfLineSection =
236      Ctx->getMachOSection("__DWARF", "__debug_line", MachO::S_ATTR_DEBUG,
237                           SectionKind::getMetadata(), "section_line");
238  DwarfFrameSection =
239      Ctx->getMachOSection("__DWARF", "__debug_frame", MachO::S_ATTR_DEBUG,
240                           SectionKind::getMetadata());
241  DwarfPubNamesSection =
242      Ctx->getMachOSection("__DWARF", "__debug_pubnames", MachO::S_ATTR_DEBUG,
243                           SectionKind::getMetadata());
244  DwarfPubTypesSection =
245      Ctx->getMachOSection("__DWARF", "__debug_pubtypes", MachO::S_ATTR_DEBUG,
246                           SectionKind::getMetadata());
247  DwarfGnuPubNamesSection =
248      Ctx->getMachOSection("__DWARF", "__debug_gnu_pubn", MachO::S_ATTR_DEBUG,
249                           SectionKind::getMetadata());
250  DwarfGnuPubTypesSection =
251      Ctx->getMachOSection("__DWARF", "__debug_gnu_pubt", MachO::S_ATTR_DEBUG,
252                           SectionKind::getMetadata());
253  DwarfStrSection =
254      Ctx->getMachOSection("__DWARF", "__debug_str", MachO::S_ATTR_DEBUG,
255                           SectionKind::getMetadata(), "info_string");
256  DwarfLocSection =
257      Ctx->getMachOSection("__DWARF", "__debug_loc", MachO::S_ATTR_DEBUG,
258                           SectionKind::getMetadata(), "section_debug_loc");
259  DwarfARangesSection =
260      Ctx->getMachOSection("__DWARF", "__debug_aranges", MachO::S_ATTR_DEBUG,
261                           SectionKind::getMetadata());
262  DwarfRangesSection =
263      Ctx->getMachOSection("__DWARF", "__debug_ranges", MachO::S_ATTR_DEBUG,
264                           SectionKind::getMetadata(), "debug_range");
265  DwarfMacinfoSection =
266      Ctx->getMachOSection("__DWARF", "__debug_macinfo", MachO::S_ATTR_DEBUG,
267                           SectionKind::getMetadata(), "debug_macinfo");
268  DwarfDebugInlineSection =
269      Ctx->getMachOSection("__DWARF", "__debug_inlined", MachO::S_ATTR_DEBUG,
270                           SectionKind::getMetadata());
271  DwarfCUIndexSection =
272      Ctx->getMachOSection("__DWARF", "__debug_cu_index", MachO::S_ATTR_DEBUG,
273                           SectionKind::getMetadata());
274  DwarfTUIndexSection =
275      Ctx->getMachOSection("__DWARF", "__debug_tu_index", MachO::S_ATTR_DEBUG,
276                           SectionKind::getMetadata());
277  StackMapSection = Ctx->getMachOSection("__LLVM_STACKMAPS", "__llvm_stackmaps",
278                                         0, SectionKind::getMetadata());
279
280  FaultMapSection = Ctx->getMachOSection("__LLVM_FAULTMAPS", "__llvm_faultmaps",
281                                         0, SectionKind::getMetadata());
282
283  TLSExtraDataSection = TLSTLVSection;
284}
285
286void MCObjectFileInfo::initELFMCObjectFileInfo(const Triple &T) {
287  switch (T.getArch()) {
288  case Triple::mips:
289  case Triple::mipsel:
290    FDECFIEncoding = dwarf::DW_EH_PE_sdata4;
291    break;
292  case Triple::mips64:
293  case Triple::mips64el:
294    FDECFIEncoding = dwarf::DW_EH_PE_sdata8;
295    break;
296  case Triple::x86_64:
297    FDECFIEncoding = dwarf::DW_EH_PE_pcrel |
298                     ((CMModel == CodeModel::Large) ? dwarf::DW_EH_PE_sdata8
299                                                    : dwarf::DW_EH_PE_sdata4);
300    break;
301  default:
302    FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
303    break;
304  }
305
306  switch (T.getArch()) {
307  case Triple::arm:
308  case Triple::armeb:
309  case Triple::thumb:
310  case Triple::thumbeb:
311    if (Ctx->getAsmInfo()->getExceptionHandlingType() == ExceptionHandling::ARM)
312      break;
313    // Fallthrough if not using EHABI
314  case Triple::ppc:
315  case Triple::x86:
316    PersonalityEncoding = PositionIndependent
317                              ? dwarf::DW_EH_PE_indirect |
318                                    dwarf::DW_EH_PE_pcrel |
319                                    dwarf::DW_EH_PE_sdata4
320                              : dwarf::DW_EH_PE_absptr;
321    LSDAEncoding = PositionIndependent
322                       ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
323                       : dwarf::DW_EH_PE_absptr;
324    TTypeEncoding = PositionIndependent
325                        ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
326                              dwarf::DW_EH_PE_sdata4
327                        : dwarf::DW_EH_PE_absptr;
328    break;
329  case Triple::x86_64:
330    if (PositionIndependent) {
331      PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
332        ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
333         ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
334      LSDAEncoding = dwarf::DW_EH_PE_pcrel |
335        (CMModel == CodeModel::Small
336         ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
337      TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
338        ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
339         ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
340    } else {
341      PersonalityEncoding =
342        (CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
343        ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
344      LSDAEncoding = (CMModel == CodeModel::Small)
345        ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
346      TTypeEncoding = (CMModel == CodeModel::Small)
347        ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
348    }
349    break;
350  case Triple::hexagon:
351    PersonalityEncoding = dwarf::DW_EH_PE_absptr;
352    LSDAEncoding = dwarf::DW_EH_PE_absptr;
353    FDECFIEncoding = dwarf::DW_EH_PE_absptr;
354    TTypeEncoding = dwarf::DW_EH_PE_absptr;
355    if (PositionIndependent) {
356      PersonalityEncoding |= dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel;
357      LSDAEncoding |= dwarf::DW_EH_PE_pcrel;
358      FDECFIEncoding |= dwarf::DW_EH_PE_pcrel;
359      TTypeEncoding |= dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel;
360    }
361    break;
362  case Triple::aarch64:
363  case Triple::aarch64_be:
364    // The small model guarantees static code/data size < 4GB, but not where it
365    // will be in memory. Most of these could end up >2GB away so even a signed
366    // pc-relative 32-bit address is insufficient, theoretically.
367    if (PositionIndependent) {
368      PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
369        dwarf::DW_EH_PE_sdata8;
370      LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8;
371      TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
372        dwarf::DW_EH_PE_sdata8;
373    } else {
374      PersonalityEncoding = dwarf::DW_EH_PE_absptr;
375      LSDAEncoding = dwarf::DW_EH_PE_absptr;
376      TTypeEncoding = dwarf::DW_EH_PE_absptr;
377    }
378    break;
379  case Triple::lanai:
380    LSDAEncoding = dwarf::DW_EH_PE_absptr;
381    PersonalityEncoding = dwarf::DW_EH_PE_absptr;
382    TTypeEncoding = dwarf::DW_EH_PE_absptr;
383    break;
384  case Triple::mips:
385  case Triple::mipsel:
386  case Triple::mips64:
387  case Triple::mips64el:
388    // MIPS uses indirect pointer to refer personality functions and types, so
389    // that the eh_frame section can be read-only. DW.ref.personality will be
390    // generated for relocation.
391    PersonalityEncoding = dwarf::DW_EH_PE_indirect;
392    // FIXME: The N64 ABI probably ought to use DW_EH_PE_sdata8 but we can't
393    //        identify N64 from just a triple.
394    TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
395                    dwarf::DW_EH_PE_sdata4;
396    // We don't support PC-relative LSDA references in GAS so we use the default
397    // DW_EH_PE_absptr for those.
398    break;
399  case Triple::ppc64:
400  case Triple::ppc64le:
401    PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
402      dwarf::DW_EH_PE_udata8;
403    LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
404    TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
405      dwarf::DW_EH_PE_udata8;
406    break;
407  case Triple::sparcel:
408  case Triple::sparc:
409    if (PositionIndependent) {
410      LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
411      PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
412        dwarf::DW_EH_PE_sdata4;
413      TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
414        dwarf::DW_EH_PE_sdata4;
415    } else {
416      LSDAEncoding = dwarf::DW_EH_PE_absptr;
417      PersonalityEncoding = dwarf::DW_EH_PE_absptr;
418      TTypeEncoding = dwarf::DW_EH_PE_absptr;
419    }
420    break;
421  case Triple::sparcv9:
422    LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
423    if (PositionIndependent) {
424      PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
425        dwarf::DW_EH_PE_sdata4;
426      TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
427        dwarf::DW_EH_PE_sdata4;
428    } else {
429      PersonalityEncoding = dwarf::DW_EH_PE_absptr;
430      TTypeEncoding = dwarf::DW_EH_PE_absptr;
431    }
432    break;
433  case Triple::systemz:
434    // All currently-defined code models guarantee that 4-byte PC-relative
435    // values will be in range.
436    if (PositionIndependent) {
437      PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
438        dwarf::DW_EH_PE_sdata4;
439      LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
440      TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
441        dwarf::DW_EH_PE_sdata4;
442    } else {
443      PersonalityEncoding = dwarf::DW_EH_PE_absptr;
444      LSDAEncoding = dwarf::DW_EH_PE_absptr;
445      TTypeEncoding = dwarf::DW_EH_PE_absptr;
446    }
447    break;
448  default:
449    break;
450  }
451
452  unsigned EHSectionType = T.getArch() == Triple::x86_64
453                               ? ELF::SHT_X86_64_UNWIND
454                               : ELF::SHT_PROGBITS;
455
456  // Solaris requires different flags for .eh_frame to seemingly every other
457  // platform.
458  unsigned EHSectionFlags = ELF::SHF_ALLOC;
459  if (T.isOSSolaris() && T.getArch() != Triple::x86_64)
460    EHSectionFlags |= ELF::SHF_WRITE;
461
462  // ELF
463  BSSSection = Ctx->getELFSection(".bss", ELF::SHT_NOBITS,
464                                  ELF::SHF_WRITE | ELF::SHF_ALLOC);
465
466  TextSection = Ctx->getELFSection(".text", ELF::SHT_PROGBITS,
467                                   ELF::SHF_EXECINSTR | ELF::SHF_ALLOC);
468
469  DataSection = Ctx->getELFSection(".data", ELF::SHT_PROGBITS,
470                                   ELF::SHF_WRITE | ELF::SHF_ALLOC);
471
472  ReadOnlySection =
473      Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
474
475  TLSDataSection =
476      Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS,
477                         ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE);
478
479  TLSBSSSection = Ctx->getELFSection(
480      ".tbss", ELF::SHT_NOBITS, ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE);
481
482  DataRelROSection = Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS,
483                                        ELF::SHF_ALLOC | ELF::SHF_WRITE);
484
485  MergeableConst4Section =
486      Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS,
487                         ELF::SHF_ALLOC | ELF::SHF_MERGE, 4, "");
488
489  MergeableConst8Section =
490      Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS,
491                         ELF::SHF_ALLOC | ELF::SHF_MERGE, 8, "");
492
493  MergeableConst16Section =
494      Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS,
495                         ELF::SHF_ALLOC | ELF::SHF_MERGE, 16, "");
496
497  MergeableConst32Section =
498      Ctx->getELFSection(".rodata.cst32", ELF::SHT_PROGBITS,
499                         ELF::SHF_ALLOC | ELF::SHF_MERGE, 32, "");
500
501  StaticCtorSection = Ctx->getELFSection(".ctors", ELF::SHT_PROGBITS,
502                                         ELF::SHF_ALLOC | ELF::SHF_WRITE);
503
504  StaticDtorSection = Ctx->getELFSection(".dtors", ELF::SHT_PROGBITS,
505                                         ELF::SHF_ALLOC | ELF::SHF_WRITE);
506
507  // Exception Handling Sections.
508
509  // FIXME: We're emitting LSDA info into a readonly section on ELF, even though
510  // it contains relocatable pointers.  In PIC mode, this is probably a big
511  // runtime hit for C++ apps.  Either the contents of the LSDA need to be
512  // adjusted or this should be a data section.
513  LSDASection = Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS,
514                                   ELF::SHF_ALLOC);
515
516  COFFDebugSymbolsSection = nullptr;
517  COFFDebugTypesSection = nullptr;
518
519  // Debug Info Sections.
520  DwarfAbbrevSection = Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0,
521                                          "section_abbrev");
522  DwarfInfoSection =
523      Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0, "section_info");
524  DwarfLineSection = Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0);
525  DwarfFrameSection = Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0);
526  DwarfPubNamesSection =
527      Ctx->getELFSection(".debug_pubnames", ELF::SHT_PROGBITS, 0);
528  DwarfPubTypesSection =
529      Ctx->getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0);
530  DwarfGnuPubNamesSection =
531      Ctx->getELFSection(".debug_gnu_pubnames", ELF::SHT_PROGBITS, 0);
532  DwarfGnuPubTypesSection =
533      Ctx->getELFSection(".debug_gnu_pubtypes", ELF::SHT_PROGBITS, 0);
534  DwarfStrSection =
535      Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS,
536                         ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
537  DwarfLocSection = Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0);
538  DwarfARangesSection =
539      Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0);
540  DwarfRangesSection =
541      Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0, "debug_range");
542  DwarfMacinfoSection = Ctx->getELFSection(".debug_macinfo", ELF::SHT_PROGBITS,
543                                           0, "debug_macinfo");
544
545  // DWARF5 Experimental Debug Info
546
547  // Accelerator Tables
548  DwarfAccelNamesSection =
549      Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0, "names_begin");
550  DwarfAccelObjCSection =
551      Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0, "objc_begin");
552  DwarfAccelNamespaceSection = Ctx->getELFSection(
553      ".apple_namespaces", ELF::SHT_PROGBITS, 0, "namespac_begin");
554  DwarfAccelTypesSection =
555      Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0, "types_begin");
556
557  // Fission Sections
558  DwarfInfoDWOSection =
559      Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0);
560  DwarfTypesDWOSection =
561      Ctx->getELFSection(".debug_types.dwo", ELF::SHT_PROGBITS, 0);
562  DwarfAbbrevDWOSection =
563      Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0);
564  DwarfStrDWOSection =
565      Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS,
566                         ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
567  DwarfLineDWOSection =
568      Ctx->getELFSection(".debug_line.dwo", ELF::SHT_PROGBITS, 0);
569  DwarfLocDWOSection =
570      Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0, "skel_loc");
571  DwarfStrOffDWOSection =
572      Ctx->getELFSection(".debug_str_offsets.dwo", ELF::SHT_PROGBITS, 0);
573  DwarfAddrSection =
574      Ctx->getELFSection(".debug_addr", ELF::SHT_PROGBITS, 0, "addr_sec");
575
576  // DWP Sections
577  DwarfCUIndexSection =
578      Ctx->getELFSection(".debug_cu_index", ELF::SHT_PROGBITS, 0);
579  DwarfTUIndexSection =
580      Ctx->getELFSection(".debug_tu_index", ELF::SHT_PROGBITS, 0);
581
582  StackMapSection =
583      Ctx->getELFSection(".llvm_stackmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
584
585  FaultMapSection =
586      Ctx->getELFSection(".llvm_faultmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
587
588  EHFrameSection =
589      Ctx->getELFSection(".eh_frame", EHSectionType, EHSectionFlags);
590}
591
592void MCObjectFileInfo::initCOFFMCObjectFileInfo(const Triple &T) {
593  EHFrameSection = Ctx->getCOFFSection(
594      ".eh_frame", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
595                       COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
596      SectionKind::getData());
597
598  // Set the `IMAGE_SCN_MEM_16BIT` flag when compiling for thumb mode.  This is
599  // used to indicate to the linker that the text segment contains thumb instructions
600  // and to set the ISA selection bit for calls accordingly.
601  const bool IsThumb = T.getArch() == Triple::thumb;
602
603  CommDirectiveSupportsAlignment = true;
604
605  // COFF
606  BSSSection = Ctx->getCOFFSection(
607      ".bss", COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
608                  COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
609      SectionKind::getBSS());
610  TextSection = Ctx->getCOFFSection(
611      ".text",
612      (IsThumb ? COFF::IMAGE_SCN_MEM_16BIT : (COFF::SectionCharacteristics)0) |
613          COFF::IMAGE_SCN_CNT_CODE | COFF::IMAGE_SCN_MEM_EXECUTE |
614          COFF::IMAGE_SCN_MEM_READ,
615      SectionKind::getText());
616  DataSection = Ctx->getCOFFSection(
617      ".data", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ |
618                   COFF::IMAGE_SCN_MEM_WRITE,
619      SectionKind::getData());
620  ReadOnlySection = Ctx->getCOFFSection(
621      ".rdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
622      SectionKind::getReadOnly());
623
624  if (T.isKnownWindowsMSVCEnvironment() || T.isWindowsItaniumEnvironment()) {
625    StaticCtorSection =
626        Ctx->getCOFFSection(".CRT$XCU", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
627                                            COFF::IMAGE_SCN_MEM_READ,
628                            SectionKind::getReadOnly());
629    StaticDtorSection =
630        Ctx->getCOFFSection(".CRT$XTX", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
631                                            COFF::IMAGE_SCN_MEM_READ,
632                            SectionKind::getReadOnly());
633  } else {
634    StaticCtorSection = Ctx->getCOFFSection(
635        ".ctors", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
636                      COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
637        SectionKind::getData());
638    StaticDtorSection = Ctx->getCOFFSection(
639        ".dtors", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
640                      COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
641        SectionKind::getData());
642  }
643
644  // FIXME: We're emitting LSDA info into a readonly section on COFF, even
645  // though it contains relocatable pointers.  In PIC mode, this is probably a
646  // big runtime hit for C++ apps.  Either the contents of the LSDA need to be
647  // adjusted or this should be a data section.
648  if (T.getArch() == Triple::x86_64) {
649    // On Windows 64 with SEH, the LSDA is emitted into the .xdata section
650    LSDASection = nullptr;
651  } else {
652    LSDASection = Ctx->getCOFFSection(".gcc_except_table",
653                                      COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
654                                          COFF::IMAGE_SCN_MEM_READ,
655                                      SectionKind::getReadOnly());
656  }
657
658  // Debug info.
659  COFFDebugSymbolsSection =
660      Ctx->getCOFFSection(".debug$S", (COFF::IMAGE_SCN_MEM_DISCARDABLE |
661                                       COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
662                                       COFF::IMAGE_SCN_MEM_READ),
663                          SectionKind::getMetadata());
664  COFFDebugTypesSection =
665      Ctx->getCOFFSection(".debug$T", (COFF::IMAGE_SCN_MEM_DISCARDABLE |
666                                       COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
667                                       COFF::IMAGE_SCN_MEM_READ),
668                          SectionKind::getMetadata());
669
670  DwarfAbbrevSection = Ctx->getCOFFSection(
671      ".debug_abbrev",
672      COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
673          COFF::IMAGE_SCN_MEM_READ,
674      SectionKind::getMetadata(), "section_abbrev");
675  DwarfInfoSection = Ctx->getCOFFSection(
676      ".debug_info",
677      COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
678          COFF::IMAGE_SCN_MEM_READ,
679      SectionKind::getMetadata(), "section_info");
680  DwarfLineSection = Ctx->getCOFFSection(
681      ".debug_line",
682      COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
683          COFF::IMAGE_SCN_MEM_READ,
684      SectionKind::getMetadata(), "section_line");
685
686  DwarfFrameSection = Ctx->getCOFFSection(
687      ".debug_frame",
688      COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
689          COFF::IMAGE_SCN_MEM_READ,
690      SectionKind::getMetadata());
691  DwarfPubNamesSection = Ctx->getCOFFSection(
692      ".debug_pubnames",
693      COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
694          COFF::IMAGE_SCN_MEM_READ,
695      SectionKind::getMetadata());
696  DwarfPubTypesSection = Ctx->getCOFFSection(
697      ".debug_pubtypes",
698      COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
699          COFF::IMAGE_SCN_MEM_READ,
700      SectionKind::getMetadata());
701  DwarfGnuPubNamesSection = Ctx->getCOFFSection(
702      ".debug_gnu_pubnames",
703      COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
704          COFF::IMAGE_SCN_MEM_READ,
705      SectionKind::getMetadata());
706  DwarfGnuPubTypesSection = Ctx->getCOFFSection(
707      ".debug_gnu_pubtypes",
708      COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
709          COFF::IMAGE_SCN_MEM_READ,
710      SectionKind::getMetadata());
711  DwarfStrSection = Ctx->getCOFFSection(
712      ".debug_str",
713      COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
714          COFF::IMAGE_SCN_MEM_READ,
715      SectionKind::getMetadata(), "info_string");
716  DwarfLocSection = Ctx->getCOFFSection(
717      ".debug_loc",
718      COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
719          COFF::IMAGE_SCN_MEM_READ,
720      SectionKind::getMetadata(), "section_debug_loc");
721  DwarfARangesSection = Ctx->getCOFFSection(
722      ".debug_aranges",
723      COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
724          COFF::IMAGE_SCN_MEM_READ,
725      SectionKind::getMetadata());
726  DwarfRangesSection = Ctx->getCOFFSection(
727      ".debug_ranges",
728      COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
729          COFF::IMAGE_SCN_MEM_READ,
730      SectionKind::getMetadata(), "debug_range");
731  DwarfMacinfoSection = Ctx->getCOFFSection(
732      ".debug_macinfo",
733      COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
734          COFF::IMAGE_SCN_MEM_READ,
735      SectionKind::getMetadata(), "debug_macinfo");
736  DwarfInfoDWOSection = Ctx->getCOFFSection(
737      ".debug_info.dwo",
738      COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
739          COFF::IMAGE_SCN_MEM_READ,
740      SectionKind::getMetadata(), "section_info_dwo");
741  DwarfTypesDWOSection = Ctx->getCOFFSection(
742      ".debug_types.dwo",
743      COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
744          COFF::IMAGE_SCN_MEM_READ,
745      SectionKind::getMetadata(), "section_types_dwo");
746  DwarfAbbrevDWOSection = Ctx->getCOFFSection(
747      ".debug_abbrev.dwo",
748      COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
749          COFF::IMAGE_SCN_MEM_READ,
750      SectionKind::getMetadata(), "section_abbrev_dwo");
751  DwarfStrDWOSection = Ctx->getCOFFSection(
752      ".debug_str.dwo",
753      COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
754          COFF::IMAGE_SCN_MEM_READ,
755      SectionKind::getMetadata(), "skel_string");
756  DwarfLineDWOSection = Ctx->getCOFFSection(
757      ".debug_line.dwo",
758      COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
759          COFF::IMAGE_SCN_MEM_READ,
760      SectionKind::getMetadata());
761  DwarfLocDWOSection = Ctx->getCOFFSection(
762      ".debug_loc.dwo",
763      COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
764          COFF::IMAGE_SCN_MEM_READ,
765      SectionKind::getMetadata(), "skel_loc");
766  DwarfStrOffDWOSection = Ctx->getCOFFSection(
767      ".debug_str_offsets.dwo",
768      COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
769          COFF::IMAGE_SCN_MEM_READ,
770      SectionKind::getMetadata());
771  DwarfAddrSection = Ctx->getCOFFSection(
772      ".debug_addr",
773      COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
774          COFF::IMAGE_SCN_MEM_READ,
775      SectionKind::getMetadata(), "addr_sec");
776  DwarfCUIndexSection = Ctx->getCOFFSection(
777      ".debug_cu_index",
778      COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
779          COFF::IMAGE_SCN_MEM_READ,
780      SectionKind::getMetadata());
781  DwarfTUIndexSection = Ctx->getCOFFSection(
782      ".debug_tu_index",
783      COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
784          COFF::IMAGE_SCN_MEM_READ,
785      SectionKind::getMetadata());
786  DwarfAccelNamesSection = Ctx->getCOFFSection(
787      ".apple_names",
788      COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
789          COFF::IMAGE_SCN_MEM_READ,
790      SectionKind::getMetadata(), "names_begin");
791  DwarfAccelNamespaceSection = Ctx->getCOFFSection(
792      ".apple_namespaces",
793      COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
794          COFF::IMAGE_SCN_MEM_READ,
795      SectionKind::getMetadata(), "namespac_begin");
796  DwarfAccelTypesSection = Ctx->getCOFFSection(
797      ".apple_types",
798      COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
799          COFF::IMAGE_SCN_MEM_READ,
800      SectionKind::getMetadata(), "types_begin");
801  DwarfAccelObjCSection = Ctx->getCOFFSection(
802      ".apple_objc",
803      COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
804          COFF::IMAGE_SCN_MEM_READ,
805      SectionKind::getMetadata(), "objc_begin");
806
807  DrectveSection = Ctx->getCOFFSection(
808      ".drectve", COFF::IMAGE_SCN_LNK_INFO | COFF::IMAGE_SCN_LNK_REMOVE,
809      SectionKind::getMetadata());
810
811  PDataSection = Ctx->getCOFFSection(
812      ".pdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
813      SectionKind::getData());
814
815  XDataSection = Ctx->getCOFFSection(
816      ".xdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
817      SectionKind::getData());
818
819  SXDataSection = Ctx->getCOFFSection(".sxdata", COFF::IMAGE_SCN_LNK_INFO,
820                                      SectionKind::getMetadata());
821
822  TLSDataSection = Ctx->getCOFFSection(
823      ".tls$", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ |
824                   COFF::IMAGE_SCN_MEM_WRITE,
825      SectionKind::getData());
826
827  StackMapSection = Ctx->getCOFFSection(".llvm_stackmaps",
828                                        COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
829                                            COFF::IMAGE_SCN_MEM_READ,
830                                        SectionKind::getReadOnly());
831}
832
833void MCObjectFileInfo::InitMCObjectFileInfo(const Triple &TheTriple, bool PIC,
834                                            CodeModel::Model cm,
835                                            MCContext &ctx) {
836  PositionIndependent = PIC;
837  CMModel = cm;
838  Ctx = &ctx;
839
840  // Common.
841  CommDirectiveSupportsAlignment = true;
842  SupportsWeakOmittedEHFrame = true;
843  SupportsCompactUnwindWithoutEHFrame = false;
844  OmitDwarfIfHaveCompactUnwind = false;
845
846  PersonalityEncoding = LSDAEncoding = FDECFIEncoding = TTypeEncoding =
847      dwarf::DW_EH_PE_absptr;
848
849  CompactUnwindDwarfEHFrameOnly = 0;
850
851  EHFrameSection = nullptr;             // Created on demand.
852  CompactUnwindSection = nullptr;       // Used only by selected targets.
853  DwarfAccelNamesSection = nullptr;     // Used only by selected targets.
854  DwarfAccelObjCSection = nullptr;      // Used only by selected targets.
855  DwarfAccelNamespaceSection = nullptr; // Used only by selected targets.
856  DwarfAccelTypesSection = nullptr;     // Used only by selected targets.
857
858  TT = TheTriple;
859
860  switch (TT.getObjectFormat()) {
861  case Triple::MachO:
862    Env = IsMachO;
863    initMachOMCObjectFileInfo(TT);
864    break;
865  case Triple::COFF:
866    if (!TT.isOSWindows())
867      report_fatal_error(
868          "Cannot initialize MC for non-Windows COFF object files.");
869
870    Env = IsCOFF;
871    initCOFFMCObjectFileInfo(TT);
872    break;
873  case Triple::ELF:
874    Env = IsELF;
875    initELFMCObjectFileInfo(TT);
876    break;
877  case Triple::UnknownObjectFormat:
878    report_fatal_error("Cannot initialize MC for unknown object file format.");
879    break;
880  }
881}
882
883MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const {
884  return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP,
885                            0, utostr(Hash));
886}
887