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 
21 using namespace llvm;
22 
23 static 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 
48 void MCObjectFileInfo::initMachOMCObjectFileInfo(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   if (RelocM == Reloc::Static) {
176     StaticCtorSection = Ctx->getMachOSection("__TEXT", "__constructor", 0,
177                                              SectionKind::getData());
178     StaticDtorSection = Ctx->getMachOSection("__TEXT", "__destructor", 0,
179                                              SectionKind::getData());
180   } else {
181     StaticCtorSection = Ctx->getMachOSection("__DATA", "__mod_init_func",
182                                              MachO::S_MOD_INIT_FUNC_POINTERS,
183                                              SectionKind::getData());
184     StaticDtorSection = Ctx->getMachOSection("__DATA", "__mod_term_func",
185                                              MachO::S_MOD_TERM_FUNC_POINTERS,
186                                              SectionKind::getData());
187   }
188 
189   // Exception Handling.
190   LSDASection = Ctx->getMachOSection("__TEXT", "__gcc_except_tab", 0,
191                                      SectionKind::getReadOnlyWithRel());
192 
193   COFFDebugSymbolsSection = nullptr;
194   COFFDebugTypesSection = nullptr;
195 
196   if (useCompactUnwind(T)) {
197     CompactUnwindSection =
198         Ctx->getMachOSection("__LD", "__compact_unwind", MachO::S_ATTR_DEBUG,
199                              SectionKind::getReadOnly());
200 
201     if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86)
202       CompactUnwindDwarfEHFrameOnly = 0x04000000;  // UNWIND_X86_64_MODE_DWARF
203     else if (T.getArch() == Triple::aarch64)
204       CompactUnwindDwarfEHFrameOnly = 0x03000000;  // UNWIND_ARM64_MODE_DWARF
205     else if (T.getArch() == Triple::arm || T.getArch() == Triple::thumb)
206       CompactUnwindDwarfEHFrameOnly = 0x04000000;  // UNWIND_ARM_MODE_DWARF
207   }
208 
209   // Debug Information.
210   DwarfAccelNamesSection =
211       Ctx->getMachOSection("__DWARF", "__apple_names", MachO::S_ATTR_DEBUG,
212                            SectionKind::getMetadata(), "names_begin");
213   DwarfAccelObjCSection =
214       Ctx->getMachOSection("__DWARF", "__apple_objc", MachO::S_ATTR_DEBUG,
215                            SectionKind::getMetadata(), "objc_begin");
216   // 16 character section limit...
217   DwarfAccelNamespaceSection =
218       Ctx->getMachOSection("__DWARF", "__apple_namespac", MachO::S_ATTR_DEBUG,
219                            SectionKind::getMetadata(), "namespac_begin");
220   DwarfAccelTypesSection =
221       Ctx->getMachOSection("__DWARF", "__apple_types", MachO::S_ATTR_DEBUG,
222                            SectionKind::getMetadata(), "types_begin");
223 
224   DwarfAbbrevSection =
225       Ctx->getMachOSection("__DWARF", "__debug_abbrev", MachO::S_ATTR_DEBUG,
226                            SectionKind::getMetadata(), "section_abbrev");
227   DwarfInfoSection =
228       Ctx->getMachOSection("__DWARF", "__debug_info", MachO::S_ATTR_DEBUG,
229                            SectionKind::getMetadata(), "section_info");
230   DwarfLineSection =
231       Ctx->getMachOSection("__DWARF", "__debug_line", MachO::S_ATTR_DEBUG,
232                            SectionKind::getMetadata(), "section_line");
233   DwarfFrameSection =
234       Ctx->getMachOSection("__DWARF", "__debug_frame", MachO::S_ATTR_DEBUG,
235                            SectionKind::getMetadata());
236   DwarfPubNamesSection =
237       Ctx->getMachOSection("__DWARF", "__debug_pubnames", MachO::S_ATTR_DEBUG,
238                            SectionKind::getMetadata());
239   DwarfPubTypesSection =
240       Ctx->getMachOSection("__DWARF", "__debug_pubtypes", MachO::S_ATTR_DEBUG,
241                            SectionKind::getMetadata());
242   DwarfGnuPubNamesSection =
243       Ctx->getMachOSection("__DWARF", "__debug_gnu_pubn", MachO::S_ATTR_DEBUG,
244                            SectionKind::getMetadata());
245   DwarfGnuPubTypesSection =
246       Ctx->getMachOSection("__DWARF", "__debug_gnu_pubt", MachO::S_ATTR_DEBUG,
247                            SectionKind::getMetadata());
248   DwarfStrSection =
249       Ctx->getMachOSection("__DWARF", "__debug_str", MachO::S_ATTR_DEBUG,
250                            SectionKind::getMetadata(), "info_string");
251   DwarfLocSection =
252       Ctx->getMachOSection("__DWARF", "__debug_loc", MachO::S_ATTR_DEBUG,
253                            SectionKind::getMetadata(), "section_debug_loc");
254   DwarfARangesSection =
255       Ctx->getMachOSection("__DWARF", "__debug_aranges", MachO::S_ATTR_DEBUG,
256                            SectionKind::getMetadata());
257   DwarfRangesSection =
258       Ctx->getMachOSection("__DWARF", "__debug_ranges", MachO::S_ATTR_DEBUG,
259                            SectionKind::getMetadata(), "debug_range");
260   DwarfMacinfoSection =
261       Ctx->getMachOSection("__DWARF", "__debug_macinfo", MachO::S_ATTR_DEBUG,
262                            SectionKind::getMetadata(), "debug_macinfo");
263   DwarfDebugInlineSection =
264       Ctx->getMachOSection("__DWARF", "__debug_inlined", MachO::S_ATTR_DEBUG,
265                            SectionKind::getMetadata());
266   DwarfCUIndexSection =
267       Ctx->getMachOSection("__DWARF", "__debug_cu_index", MachO::S_ATTR_DEBUG,
268                            SectionKind::getMetadata());
269   DwarfTUIndexSection =
270       Ctx->getMachOSection("__DWARF", "__debug_tu_index", MachO::S_ATTR_DEBUG,
271                            SectionKind::getMetadata());
272   StackMapSection = Ctx->getMachOSection("__LLVM_STACKMAPS", "__llvm_stackmaps",
273                                          0, SectionKind::getMetadata());
274 
275   FaultMapSection = Ctx->getMachOSection("__LLVM_FAULTMAPS", "__llvm_faultmaps",
276                                          0, SectionKind::getMetadata());
277 
278   TLSExtraDataSection = TLSTLVSection;
279 }
280 
281 void MCObjectFileInfo::initELFMCObjectFileInfo(Triple T) {
282   switch (T.getArch()) {
283   case Triple::mips:
284   case Triple::mipsel:
285     FDECFIEncoding = dwarf::DW_EH_PE_sdata4;
286     break;
287   case Triple::mips64:
288   case Triple::mips64el:
289     FDECFIEncoding = dwarf::DW_EH_PE_sdata8;
290     break;
291   case Triple::x86_64:
292     FDECFIEncoding = dwarf::DW_EH_PE_pcrel |
293                      ((CMModel == CodeModel::Large) ? dwarf::DW_EH_PE_sdata8
294                                                     : dwarf::DW_EH_PE_sdata4);
295     break;
296   default:
297     FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
298     break;
299   }
300 
301   switch (T.getArch()) {
302   case Triple::arm:
303   case Triple::armeb:
304   case Triple::thumb:
305   case Triple::thumbeb:
306     if (Ctx->getAsmInfo()->getExceptionHandlingType() == ExceptionHandling::ARM)
307       break;
308     // Fallthrough if not using EHABI
309   case Triple::ppc:
310   case Triple::x86:
311     PersonalityEncoding = (RelocM == Reloc::PIC_)
312      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
313      : dwarf::DW_EH_PE_absptr;
314     LSDAEncoding = (RelocM == Reloc::PIC_)
315       ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
316       : dwarf::DW_EH_PE_absptr;
317     TTypeEncoding = (RelocM == Reloc::PIC_)
318      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
319      : dwarf::DW_EH_PE_absptr;
320     break;
321   case Triple::x86_64:
322     if (RelocM == Reloc::PIC_) {
323       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
324         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
325          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
326       LSDAEncoding = dwarf::DW_EH_PE_pcrel |
327         (CMModel == CodeModel::Small
328          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
329       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
330         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
331          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
332     } else {
333       PersonalityEncoding =
334         (CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
335         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
336       LSDAEncoding = (CMModel == CodeModel::Small)
337         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
338       TTypeEncoding = (CMModel == CodeModel::Small)
339         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
340     }
341     break;
342   case Triple::aarch64:
343   case Triple::aarch64_be:
344     // The small model guarantees static code/data size < 4GB, but not where it
345     // will be in memory. Most of these could end up >2GB away so even a signed
346     // pc-relative 32-bit address is insufficient, theoretically.
347     if (RelocM == Reloc::PIC_) {
348       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
349         dwarf::DW_EH_PE_sdata8;
350       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8;
351       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
352         dwarf::DW_EH_PE_sdata8;
353     } else {
354       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
355       LSDAEncoding = dwarf::DW_EH_PE_absptr;
356       TTypeEncoding = dwarf::DW_EH_PE_absptr;
357     }
358     break;
359   case Triple::mips:
360   case Triple::mipsel:
361   case Triple::mips64:
362   case Triple::mips64el:
363     // MIPS uses indirect pointer to refer personality functions and types, so
364     // that the eh_frame section can be read-only. DW.ref.personality will be
365     // generated for relocation.
366     PersonalityEncoding = dwarf::DW_EH_PE_indirect;
367     // FIXME: The N64 ABI probably ought to use DW_EH_PE_sdata8 but we can't
368     //        identify N64 from just a triple.
369     TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
370                     dwarf::DW_EH_PE_sdata4;
371     // We don't support PC-relative LSDA references in GAS so we use the default
372     // DW_EH_PE_absptr for those.
373     break;
374   case Triple::ppc64:
375   case Triple::ppc64le:
376     PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
377       dwarf::DW_EH_PE_udata8;
378     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
379     TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
380       dwarf::DW_EH_PE_udata8;
381     break;
382   case Triple::sparcel:
383   case Triple::sparc:
384     if (RelocM == Reloc::PIC_) {
385       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
386       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
387         dwarf::DW_EH_PE_sdata4;
388       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
389         dwarf::DW_EH_PE_sdata4;
390     } else {
391       LSDAEncoding = dwarf::DW_EH_PE_absptr;
392       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
393       TTypeEncoding = dwarf::DW_EH_PE_absptr;
394     }
395     break;
396   case Triple::sparcv9:
397     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
398     if (RelocM == Reloc::PIC_) {
399       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
400         dwarf::DW_EH_PE_sdata4;
401       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
402         dwarf::DW_EH_PE_sdata4;
403     } else {
404       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
405       TTypeEncoding = dwarf::DW_EH_PE_absptr;
406     }
407     break;
408   case Triple::systemz:
409     // All currently-defined code models guarantee that 4-byte PC-relative
410     // values will be in range.
411     if (RelocM == Reloc::PIC_) {
412       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
413         dwarf::DW_EH_PE_sdata4;
414       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
415       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
416         dwarf::DW_EH_PE_sdata4;
417     } else {
418       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
419       LSDAEncoding = dwarf::DW_EH_PE_absptr;
420       TTypeEncoding = dwarf::DW_EH_PE_absptr;
421     }
422     break;
423   default:
424     break;
425   }
426 
427   unsigned EHSectionType = T.getArch() == Triple::x86_64
428                                ? ELF::SHT_X86_64_UNWIND
429                                : ELF::SHT_PROGBITS;
430 
431   // Solaris requires different flags for .eh_frame to seemingly every other
432   // platform.
433   unsigned EHSectionFlags = ELF::SHF_ALLOC;
434   if (T.isOSSolaris() && T.getArch() != Triple::x86_64)
435     EHSectionFlags |= ELF::SHF_WRITE;
436 
437   // ELF
438   BSSSection = Ctx->getELFSection(".bss", ELF::SHT_NOBITS,
439                                   ELF::SHF_WRITE | ELF::SHF_ALLOC);
440 
441   TextSection = Ctx->getELFSection(".text", ELF::SHT_PROGBITS,
442                                    ELF::SHF_EXECINSTR | ELF::SHF_ALLOC);
443 
444   DataSection = Ctx->getELFSection(".data", ELF::SHT_PROGBITS,
445                                    ELF::SHF_WRITE | ELF::SHF_ALLOC);
446 
447   ReadOnlySection =
448       Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
449 
450   TLSDataSection =
451       Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS,
452                          ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE);
453 
454   TLSBSSSection = Ctx->getELFSection(
455       ".tbss", ELF::SHT_NOBITS, ELF::SHF_ALLOC | ELF::SHF_TLS | ELF::SHF_WRITE);
456 
457   DataRelROSection = Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS,
458                                         ELF::SHF_ALLOC | ELF::SHF_WRITE);
459 
460   MergeableConst4Section =
461       Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS,
462                          ELF::SHF_ALLOC | ELF::SHF_MERGE, 4, "");
463 
464   MergeableConst8Section =
465       Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS,
466                          ELF::SHF_ALLOC | ELF::SHF_MERGE, 8, "");
467 
468   MergeableConst16Section =
469       Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS,
470                          ELF::SHF_ALLOC | ELF::SHF_MERGE, 16, "");
471 
472   MergeableConst32Section =
473       Ctx->getELFSection(".rodata.cst32", ELF::SHT_PROGBITS,
474                          ELF::SHF_ALLOC | ELF::SHF_MERGE, 32, "");
475 
476   StaticCtorSection = Ctx->getELFSection(".ctors", ELF::SHT_PROGBITS,
477                                          ELF::SHF_ALLOC | ELF::SHF_WRITE);
478 
479   StaticDtorSection = Ctx->getELFSection(".dtors", ELF::SHT_PROGBITS,
480                                          ELF::SHF_ALLOC | ELF::SHF_WRITE);
481 
482   // Exception Handling Sections.
483 
484   // FIXME: We're emitting LSDA info into a readonly section on ELF, even though
485   // it contains relocatable pointers.  In PIC mode, this is probably a big
486   // runtime hit for C++ apps.  Either the contents of the LSDA need to be
487   // adjusted or this should be a data section.
488   LSDASection = Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS,
489                                    ELF::SHF_ALLOC);
490 
491   COFFDebugSymbolsSection = nullptr;
492   COFFDebugTypesSection = nullptr;
493 
494   // Debug Info Sections.
495   DwarfAbbrevSection = Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0,
496                                           "section_abbrev");
497   DwarfInfoSection =
498       Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0, "section_info");
499   DwarfLineSection = Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0);
500   DwarfFrameSection = Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0);
501   DwarfPubNamesSection =
502       Ctx->getELFSection(".debug_pubnames", ELF::SHT_PROGBITS, 0);
503   DwarfPubTypesSection =
504       Ctx->getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0);
505   DwarfGnuPubNamesSection =
506       Ctx->getELFSection(".debug_gnu_pubnames", ELF::SHT_PROGBITS, 0);
507   DwarfGnuPubTypesSection =
508       Ctx->getELFSection(".debug_gnu_pubtypes", ELF::SHT_PROGBITS, 0);
509   DwarfStrSection =
510       Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS,
511                          ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
512   DwarfLocSection = Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0);
513   DwarfARangesSection =
514       Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0);
515   DwarfRangesSection =
516       Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0, "debug_range");
517   DwarfMacinfoSection = Ctx->getELFSection(".debug_macinfo", ELF::SHT_PROGBITS,
518                                            0, "debug_macinfo");
519 
520   // DWARF5 Experimental Debug Info
521 
522   // Accelerator Tables
523   DwarfAccelNamesSection =
524       Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0, "names_begin");
525   DwarfAccelObjCSection =
526       Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0, "objc_begin");
527   DwarfAccelNamespaceSection = Ctx->getELFSection(
528       ".apple_namespaces", ELF::SHT_PROGBITS, 0, "namespac_begin");
529   DwarfAccelTypesSection =
530       Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0, "types_begin");
531 
532   // Fission Sections
533   DwarfInfoDWOSection =
534       Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0);
535   DwarfTypesDWOSection =
536       Ctx->getELFSection(".debug_types.dwo", ELF::SHT_PROGBITS, 0);
537   DwarfAbbrevDWOSection =
538       Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0);
539   DwarfStrDWOSection =
540       Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS,
541                          ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
542   DwarfLineDWOSection =
543       Ctx->getELFSection(".debug_line.dwo", ELF::SHT_PROGBITS, 0);
544   DwarfLocDWOSection =
545       Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0, "skel_loc");
546   DwarfStrOffDWOSection =
547       Ctx->getELFSection(".debug_str_offsets.dwo", ELF::SHT_PROGBITS, 0);
548   DwarfAddrSection =
549       Ctx->getELFSection(".debug_addr", ELF::SHT_PROGBITS, 0, "addr_sec");
550 
551   // DWP Sections
552   DwarfCUIndexSection =
553       Ctx->getELFSection(".debug_cu_index", ELF::SHT_PROGBITS, 0);
554   DwarfTUIndexSection =
555       Ctx->getELFSection(".debug_tu_index", ELF::SHT_PROGBITS, 0);
556 
557   StackMapSection =
558       Ctx->getELFSection(".llvm_stackmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
559 
560   FaultMapSection =
561       Ctx->getELFSection(".llvm_faultmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
562 
563   EHFrameSection =
564       Ctx->getELFSection(".eh_frame", EHSectionType, EHSectionFlags);
565 }
566 
567 void MCObjectFileInfo::initCOFFMCObjectFileInfo(Triple T) {
568   EHFrameSection = Ctx->getCOFFSection(
569       ".eh_frame", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
570                        COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
571       SectionKind::getData());
572 
573   bool IsWoA = T.getArch() == Triple::arm || T.getArch() == Triple::thumb;
574 
575   CommDirectiveSupportsAlignment = true;
576 
577   // COFF
578   BSSSection = Ctx->getCOFFSection(
579       ".bss", COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
580                   COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
581       SectionKind::getBSS());
582   TextSection = Ctx->getCOFFSection(
583       ".text",
584       (IsWoA ? COFF::IMAGE_SCN_MEM_16BIT : (COFF::SectionCharacteristics)0) |
585           COFF::IMAGE_SCN_CNT_CODE | COFF::IMAGE_SCN_MEM_EXECUTE |
586           COFF::IMAGE_SCN_MEM_READ,
587       SectionKind::getText());
588   DataSection = Ctx->getCOFFSection(
589       ".data", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ |
590                    COFF::IMAGE_SCN_MEM_WRITE,
591       SectionKind::getData());
592   ReadOnlySection = Ctx->getCOFFSection(
593       ".rdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
594       SectionKind::getReadOnly());
595 
596   if (T.isKnownWindowsMSVCEnvironment() || T.isWindowsItaniumEnvironment()) {
597     StaticCtorSection =
598         Ctx->getCOFFSection(".CRT$XCU", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
599                                             COFF::IMAGE_SCN_MEM_READ,
600                             SectionKind::getReadOnly());
601     StaticDtorSection =
602         Ctx->getCOFFSection(".CRT$XTX", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
603                                             COFF::IMAGE_SCN_MEM_READ,
604                             SectionKind::getReadOnly());
605   } else {
606     StaticCtorSection = Ctx->getCOFFSection(
607         ".ctors", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
608                       COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
609         SectionKind::getData());
610     StaticDtorSection = Ctx->getCOFFSection(
611         ".dtors", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
612                       COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE,
613         SectionKind::getData());
614   }
615 
616   // FIXME: We're emitting LSDA info into a readonly section on COFF, even
617   // though it contains relocatable pointers.  In PIC mode, this is probably a
618   // big runtime hit for C++ apps.  Either the contents of the LSDA need to be
619   // adjusted or this should be a data section.
620   if (T.getArch() == Triple::x86_64) {
621     // On Windows 64 with SEH, the LSDA is emitted into the .xdata section
622     LSDASection = nullptr;
623   } else {
624     LSDASection = Ctx->getCOFFSection(".gcc_except_table",
625                                       COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
626                                           COFF::IMAGE_SCN_MEM_READ,
627                                       SectionKind::getReadOnly());
628   }
629 
630   // Debug info.
631   COFFDebugSymbolsSection =
632       Ctx->getCOFFSection(".debug$S", (COFF::IMAGE_SCN_MEM_DISCARDABLE |
633                                        COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
634                                        COFF::IMAGE_SCN_MEM_READ),
635                           SectionKind::getMetadata());
636   COFFDebugTypesSection =
637       Ctx->getCOFFSection(".debug$T", (COFF::IMAGE_SCN_MEM_DISCARDABLE |
638                                        COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
639                                        COFF::IMAGE_SCN_MEM_READ),
640                           SectionKind::getMetadata());
641 
642   DwarfAbbrevSection = Ctx->getCOFFSection(
643       ".debug_abbrev",
644       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
645           COFF::IMAGE_SCN_MEM_READ,
646       SectionKind::getMetadata(), "section_abbrev");
647   DwarfInfoSection = Ctx->getCOFFSection(
648       ".debug_info",
649       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
650           COFF::IMAGE_SCN_MEM_READ,
651       SectionKind::getMetadata(), "section_info");
652   DwarfLineSection = Ctx->getCOFFSection(
653       ".debug_line",
654       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
655           COFF::IMAGE_SCN_MEM_READ,
656       SectionKind::getMetadata(), "section_line");
657 
658   DwarfFrameSection = Ctx->getCOFFSection(
659       ".debug_frame",
660       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
661           COFF::IMAGE_SCN_MEM_READ,
662       SectionKind::getMetadata());
663   DwarfPubNamesSection = Ctx->getCOFFSection(
664       ".debug_pubnames",
665       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
666           COFF::IMAGE_SCN_MEM_READ,
667       SectionKind::getMetadata());
668   DwarfPubTypesSection = Ctx->getCOFFSection(
669       ".debug_pubtypes",
670       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
671           COFF::IMAGE_SCN_MEM_READ,
672       SectionKind::getMetadata());
673   DwarfGnuPubNamesSection = Ctx->getCOFFSection(
674       ".debug_gnu_pubnames",
675       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
676           COFF::IMAGE_SCN_MEM_READ,
677       SectionKind::getMetadata());
678   DwarfGnuPubTypesSection = Ctx->getCOFFSection(
679       ".debug_gnu_pubtypes",
680       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
681           COFF::IMAGE_SCN_MEM_READ,
682       SectionKind::getMetadata());
683   DwarfStrSection = Ctx->getCOFFSection(
684       ".debug_str",
685       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
686           COFF::IMAGE_SCN_MEM_READ,
687       SectionKind::getMetadata(), "info_string");
688   DwarfLocSection = Ctx->getCOFFSection(
689       ".debug_loc",
690       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
691           COFF::IMAGE_SCN_MEM_READ,
692       SectionKind::getMetadata(), "section_debug_loc");
693   DwarfARangesSection = Ctx->getCOFFSection(
694       ".debug_aranges",
695       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
696           COFF::IMAGE_SCN_MEM_READ,
697       SectionKind::getMetadata());
698   DwarfRangesSection = Ctx->getCOFFSection(
699       ".debug_ranges",
700       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
701           COFF::IMAGE_SCN_MEM_READ,
702       SectionKind::getMetadata(), "debug_range");
703   DwarfMacinfoSection = Ctx->getCOFFSection(
704       ".debug_macinfo",
705       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
706           COFF::IMAGE_SCN_MEM_READ,
707       SectionKind::getMetadata(), "debug_macinfo");
708   DwarfInfoDWOSection = Ctx->getCOFFSection(
709       ".debug_info.dwo",
710       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
711           COFF::IMAGE_SCN_MEM_READ,
712       SectionKind::getMetadata(), "section_info_dwo");
713   DwarfTypesDWOSection = Ctx->getCOFFSection(
714       ".debug_types.dwo",
715       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
716           COFF::IMAGE_SCN_MEM_READ,
717       SectionKind::getMetadata(), "section_types_dwo");
718   DwarfAbbrevDWOSection = Ctx->getCOFFSection(
719       ".debug_abbrev.dwo",
720       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
721           COFF::IMAGE_SCN_MEM_READ,
722       SectionKind::getMetadata(), "section_abbrev_dwo");
723   DwarfStrDWOSection = Ctx->getCOFFSection(
724       ".debug_str.dwo",
725       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
726           COFF::IMAGE_SCN_MEM_READ,
727       SectionKind::getMetadata(), "skel_string");
728   DwarfLineDWOSection = Ctx->getCOFFSection(
729       ".debug_line.dwo",
730       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
731           COFF::IMAGE_SCN_MEM_READ,
732       SectionKind::getMetadata());
733   DwarfLocDWOSection = Ctx->getCOFFSection(
734       ".debug_loc.dwo",
735       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
736           COFF::IMAGE_SCN_MEM_READ,
737       SectionKind::getMetadata(), "skel_loc");
738   DwarfStrOffDWOSection = Ctx->getCOFFSection(
739       ".debug_str_offsets.dwo",
740       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
741           COFF::IMAGE_SCN_MEM_READ,
742       SectionKind::getMetadata());
743   DwarfAddrSection = Ctx->getCOFFSection(
744       ".debug_addr",
745       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
746           COFF::IMAGE_SCN_MEM_READ,
747       SectionKind::getMetadata(), "addr_sec");
748   DwarfCUIndexSection = Ctx->getCOFFSection(
749       ".debug_cu_index",
750       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
751           COFF::IMAGE_SCN_MEM_READ,
752       SectionKind::getMetadata());
753   DwarfTUIndexSection = Ctx->getCOFFSection(
754       ".debug_tu_index",
755       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
756           COFF::IMAGE_SCN_MEM_READ,
757       SectionKind::getMetadata());
758   DwarfAccelNamesSection = Ctx->getCOFFSection(
759       ".apple_names",
760       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
761           COFF::IMAGE_SCN_MEM_READ,
762       SectionKind::getMetadata(), "names_begin");
763   DwarfAccelNamespaceSection = Ctx->getCOFFSection(
764       ".apple_namespaces",
765       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
766           COFF::IMAGE_SCN_MEM_READ,
767       SectionKind::getMetadata(), "namespac_begin");
768   DwarfAccelTypesSection = Ctx->getCOFFSection(
769       ".apple_types",
770       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
771           COFF::IMAGE_SCN_MEM_READ,
772       SectionKind::getMetadata(), "types_begin");
773   DwarfAccelObjCSection = Ctx->getCOFFSection(
774       ".apple_objc",
775       COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
776           COFF::IMAGE_SCN_MEM_READ,
777       SectionKind::getMetadata(), "objc_begin");
778 
779   DrectveSection = Ctx->getCOFFSection(
780       ".drectve", COFF::IMAGE_SCN_LNK_INFO | COFF::IMAGE_SCN_LNK_REMOVE,
781       SectionKind::getMetadata());
782 
783   PDataSection = Ctx->getCOFFSection(
784       ".pdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
785       SectionKind::getData());
786 
787   XDataSection = Ctx->getCOFFSection(
788       ".xdata", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ,
789       SectionKind::getData());
790 
791   SXDataSection = Ctx->getCOFFSection(".sxdata", COFF::IMAGE_SCN_LNK_INFO,
792                                       SectionKind::getMetadata());
793 
794   TLSDataSection = Ctx->getCOFFSection(
795       ".tls$", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ |
796                    COFF::IMAGE_SCN_MEM_WRITE,
797       SectionKind::getData());
798 
799   StackMapSection = Ctx->getCOFFSection(".llvm_stackmaps",
800                                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
801                                             COFF::IMAGE_SCN_MEM_READ,
802                                         SectionKind::getReadOnly());
803 }
804 
805 void MCObjectFileInfo::InitMCObjectFileInfo(const Triple &TheTriple,
806                                             Reloc::Model relocm,
807                                             CodeModel::Model cm,
808                                             MCContext &ctx) {
809   RelocM = relocm;
810   CMModel = cm;
811   Ctx = &ctx;
812 
813   // Common.
814   CommDirectiveSupportsAlignment = true;
815   SupportsWeakOmittedEHFrame = true;
816   SupportsCompactUnwindWithoutEHFrame = false;
817   OmitDwarfIfHaveCompactUnwind = false;
818 
819   PersonalityEncoding = LSDAEncoding = FDECFIEncoding = TTypeEncoding =
820       dwarf::DW_EH_PE_absptr;
821 
822   CompactUnwindDwarfEHFrameOnly = 0;
823 
824   EHFrameSection = nullptr;             // Created on demand.
825   CompactUnwindSection = nullptr;       // Used only by selected targets.
826   DwarfAccelNamesSection = nullptr;     // Used only by selected targets.
827   DwarfAccelObjCSection = nullptr;      // Used only by selected targets.
828   DwarfAccelNamespaceSection = nullptr; // Used only by selected targets.
829   DwarfAccelTypesSection = nullptr;     // Used only by selected targets.
830 
831   TT = TheTriple;
832 
833   switch (TT.getObjectFormat()) {
834   case Triple::MachO:
835     Env = IsMachO;
836     initMachOMCObjectFileInfo(TT);
837     break;
838   case Triple::COFF:
839     if (!TT.isOSWindows())
840       report_fatal_error(
841           "Cannot initialize MC for non-Windows COFF object files.");
842 
843     Env = IsCOFF;
844     initCOFFMCObjectFileInfo(TT);
845     break;
846   case Triple::ELF:
847     Env = IsELF;
848     initELFMCObjectFileInfo(TT);
849     break;
850   case Triple::UnknownObjectFormat:
851     report_fatal_error("Cannot initialize MC for unknown object file format.");
852     break;
853   }
854 }
855 
856 void MCObjectFileInfo::InitMCObjectFileInfo(StringRef TT, Reloc::Model RM,
857                                             CodeModel::Model CM,
858                                             MCContext &ctx) {
859   InitMCObjectFileInfo(Triple(TT), RM, CM, ctx);
860 }
861 
862 MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const {
863   return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP,
864                             0, utostr(Hash));
865 }
866