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     // The small model guarantees static code/data size < 4GB, but not where it
295     // will be in memory. Most of these could end up >2GB away so even a signed
296     // pc-relative 32-bit address is insufficient, theoretically.
297     if (RelocM == Reloc::PIC_) {
298       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
299         dwarf::DW_EH_PE_sdata8;
300       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8;
301       FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
302       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
303         dwarf::DW_EH_PE_sdata8;
304     } else {
305       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
306       LSDAEncoding = dwarf::DW_EH_PE_absptr;
307       FDEEncoding = dwarf::DW_EH_PE_udata4;
308       TTypeEncoding = dwarf::DW_EH_PE_absptr;
309     }
310   } else if (T.getArch() == Triple::ppc64 || T.getArch() == Triple::ppc64le) {
311     PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
312       dwarf::DW_EH_PE_udata8;
313     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
314     FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
315     TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
316       dwarf::DW_EH_PE_udata8;
317   } else if (T.getArch() == Triple::sparc) {
318     if (RelocM == Reloc::PIC_) {
319       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
320       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
321         dwarf::DW_EH_PE_sdata4;
322       FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
323       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
324         dwarf::DW_EH_PE_sdata4;
325     } else {
326       LSDAEncoding = dwarf::DW_EH_PE_absptr;
327       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
328       FDEEncoding = dwarf::DW_EH_PE_udata4;
329       TTypeEncoding = dwarf::DW_EH_PE_absptr;
330     }
331   } else if (T.getArch() == Triple::sparcv9) {
332     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
333     if (RelocM == Reloc::PIC_) {
334       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
335         dwarf::DW_EH_PE_sdata4;
336       FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
337       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
338         dwarf::DW_EH_PE_sdata4;
339     } else {
340       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
341       FDEEncoding = dwarf::DW_EH_PE_udata4;
342       TTypeEncoding = dwarf::DW_EH_PE_absptr;
343     }
344   } else if (T.getArch() == Triple::systemz) {
345     // All currently-defined code models guarantee that 4-byte PC-relative
346     // values will be in range.
347     if (RelocM == Reloc::PIC_) {
348       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
349         dwarf::DW_EH_PE_sdata4;
350       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
351       FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
352       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
353         dwarf::DW_EH_PE_sdata4;
354     } else {
355       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
356       LSDAEncoding = dwarf::DW_EH_PE_absptr;
357       FDEEncoding = dwarf::DW_EH_PE_absptr;
358       TTypeEncoding = dwarf::DW_EH_PE_absptr;
359     }
360   }
361 
362   // Solaris requires different flags for .eh_frame to seemingly every other
363   // platform.
364   EHSectionType = ELF::SHT_PROGBITS;
365   EHSectionFlags = ELF::SHF_ALLOC;
366   if (T.getOS() == Triple::Solaris) {
367     if (T.getArch() == Triple::x86_64)
368       EHSectionType = ELF::SHT_X86_64_UNWIND;
369     else
370       EHSectionFlags |= ELF::SHF_WRITE;
371   }
372 
373 
374   // ELF
375   BSSSection =
376     Ctx->getELFSection(".bss", ELF::SHT_NOBITS,
377                        ELF::SHF_WRITE | ELF::SHF_ALLOC,
378                        SectionKind::getBSS());
379 
380   TextSection =
381     Ctx->getELFSection(".text", ELF::SHT_PROGBITS,
382                        ELF::SHF_EXECINSTR |
383                        ELF::SHF_ALLOC,
384                        SectionKind::getText());
385 
386   DataSection =
387     Ctx->getELFSection(".data", ELF::SHT_PROGBITS,
388                        ELF::SHF_WRITE |ELF::SHF_ALLOC,
389                        SectionKind::getDataRel());
390 
391   ReadOnlySection =
392     Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS,
393                        ELF::SHF_ALLOC,
394                        SectionKind::getReadOnly());
395 
396   TLSDataSection =
397     Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS,
398                        ELF::SHF_ALLOC | ELF::SHF_TLS |
399                        ELF::SHF_WRITE,
400                        SectionKind::getThreadData());
401 
402   TLSBSSSection =
403     Ctx->getELFSection(".tbss", ELF::SHT_NOBITS,
404                        ELF::SHF_ALLOC | ELF::SHF_TLS |
405                        ELF::SHF_WRITE,
406                        SectionKind::getThreadBSS());
407 
408   DataRelSection =
409     Ctx->getELFSection(".data.rel", ELF::SHT_PROGBITS,
410                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
411                        SectionKind::getDataRel());
412 
413   DataRelLocalSection =
414     Ctx->getELFSection(".data.rel.local", ELF::SHT_PROGBITS,
415                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
416                        SectionKind::getDataRelLocal());
417 
418   DataRelROSection =
419     Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS,
420                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
421                        SectionKind::getReadOnlyWithRel());
422 
423   DataRelROLocalSection =
424     Ctx->getELFSection(".data.rel.ro.local", ELF::SHT_PROGBITS,
425                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
426                        SectionKind::getReadOnlyWithRelLocal());
427 
428   MergeableConst4Section =
429     Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS,
430                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
431                        SectionKind::getMergeableConst4());
432 
433   MergeableConst8Section =
434     Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS,
435                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
436                        SectionKind::getMergeableConst8());
437 
438   MergeableConst16Section =
439     Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS,
440                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
441                        SectionKind::getMergeableConst16());
442 
443   StaticCtorSection =
444     Ctx->getELFSection(".ctors", ELF::SHT_PROGBITS,
445                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
446                        SectionKind::getDataRel());
447 
448   StaticDtorSection =
449     Ctx->getELFSection(".dtors", ELF::SHT_PROGBITS,
450                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
451                        SectionKind::getDataRel());
452 
453   // Exception Handling Sections.
454 
455   // FIXME: We're emitting LSDA info into a readonly section on ELF, even though
456   // it contains relocatable pointers.  In PIC mode, this is probably a big
457   // runtime hit for C++ apps.  Either the contents of the LSDA need to be
458   // adjusted or this should be a data section.
459   LSDASection =
460     Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS,
461                        ELF::SHF_ALLOC,
462                        SectionKind::getReadOnly());
463 
464   COFFDebugSymbolsSection = nullptr;
465 
466   // Debug Info Sections.
467   DwarfAbbrevSection =
468     Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0,
469                        SectionKind::getMetadata());
470   DwarfInfoSection =
471     Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0,
472                        SectionKind::getMetadata());
473   DwarfLineSection =
474     Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0,
475                        SectionKind::getMetadata());
476   DwarfFrameSection =
477     Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0,
478                        SectionKind::getMetadata());
479   DwarfPubNamesSection =
480     Ctx->getELFSection(".debug_pubnames", ELF::SHT_PROGBITS, 0,
481                        SectionKind::getMetadata());
482   DwarfPubTypesSection =
483     Ctx->getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0,
484                        SectionKind::getMetadata());
485   DwarfGnuPubNamesSection =
486     Ctx->getELFSection(".debug_gnu_pubnames", ELF::SHT_PROGBITS, 0,
487                        SectionKind::getMetadata());
488   DwarfGnuPubTypesSection =
489     Ctx->getELFSection(".debug_gnu_pubtypes", ELF::SHT_PROGBITS, 0,
490                        SectionKind::getMetadata());
491   DwarfStrSection =
492     Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS,
493                        ELF::SHF_MERGE | ELF::SHF_STRINGS,
494                        SectionKind::getMergeable1ByteCString());
495   DwarfLocSection =
496     Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0,
497                        SectionKind::getMetadata());
498   DwarfARangesSection =
499     Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0,
500                        SectionKind::getMetadata());
501   DwarfRangesSection =
502     Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0,
503                        SectionKind::getMetadata());
504   DwarfMacroInfoSection =
505     Ctx->getELFSection(".debug_macinfo", ELF::SHT_PROGBITS, 0,
506                        SectionKind::getMetadata());
507 
508   // DWARF5 Experimental Debug Info
509 
510   // Accelerator Tables
511   DwarfAccelNamesSection =
512     Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0,
513                        SectionKind::getMetadata());
514   DwarfAccelObjCSection =
515     Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0,
516                        SectionKind::getMetadata());
517   DwarfAccelNamespaceSection =
518     Ctx->getELFSection(".apple_namespaces", ELF::SHT_PROGBITS, 0,
519                        SectionKind::getMetadata());
520   DwarfAccelTypesSection =
521     Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0,
522                        SectionKind::getMetadata());
523 
524   // Fission Sections
525   DwarfInfoDWOSection =
526     Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0,
527                        SectionKind::getMetadata());
528   DwarfAbbrevDWOSection =
529     Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0,
530                        SectionKind::getMetadata());
531   DwarfStrDWOSection =
532     Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS,
533                        ELF::SHF_MERGE | ELF::SHF_STRINGS,
534                        SectionKind::getMergeable1ByteCString());
535   DwarfLineDWOSection =
536     Ctx->getELFSection(".debug_line.dwo", ELF::SHT_PROGBITS, 0,
537                        SectionKind::getMetadata());
538   DwarfLocDWOSection =
539     Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0,
540                        SectionKind::getMetadata());
541   DwarfStrOffDWOSection =
542     Ctx->getELFSection(".debug_str_offsets.dwo", ELF::SHT_PROGBITS, 0,
543                        SectionKind::getMetadata());
544   DwarfAddrSection =
545     Ctx->getELFSection(".debug_addr", ELF::SHT_PROGBITS, 0,
546                        SectionKind::getMetadata());
547 }
548 
549 
550 void MCObjectFileInfo::InitCOFFMCObjectFileInfo(Triple T) {
551   // The object file format cannot represent common symbols with explicit
552   // alignments.
553   CommDirectiveSupportsAlignment = false;
554 
555   // COFF
556   BSSSection =
557     Ctx->getCOFFSection(".bss",
558                         COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
559                         COFF::IMAGE_SCN_MEM_READ |
560                         COFF::IMAGE_SCN_MEM_WRITE,
561                         SectionKind::getBSS());
562   TextSection =
563     Ctx->getCOFFSection(".text",
564                         COFF::IMAGE_SCN_CNT_CODE |
565                         COFF::IMAGE_SCN_MEM_EXECUTE |
566                         COFF::IMAGE_SCN_MEM_READ,
567                         SectionKind::getText());
568   DataSection =
569     Ctx->getCOFFSection(".data",
570                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
571                         COFF::IMAGE_SCN_MEM_READ |
572                         COFF::IMAGE_SCN_MEM_WRITE,
573                         SectionKind::getDataRel());
574   ReadOnlySection =
575     Ctx->getCOFFSection(".rdata",
576                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
577                         COFF::IMAGE_SCN_MEM_READ,
578                         SectionKind::getReadOnly());
579   if (T.isKnownWindowsMSVCEnvironment()) {
580     StaticCtorSection =
581       Ctx->getCOFFSection(".CRT$XCU",
582                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
583                           COFF::IMAGE_SCN_MEM_READ,
584                           SectionKind::getReadOnly());
585   } else {
586     StaticCtorSection =
587       Ctx->getCOFFSection(".ctors",
588                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
589                           COFF::IMAGE_SCN_MEM_READ |
590                           COFF::IMAGE_SCN_MEM_WRITE,
591                           SectionKind::getDataRel());
592   }
593 
594 
595   if (T.isKnownWindowsMSVCEnvironment()) {
596     StaticDtorSection =
597       Ctx->getCOFFSection(".CRT$XTX",
598                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
599                           COFF::IMAGE_SCN_MEM_READ,
600                           SectionKind::getReadOnly());
601   } else {
602     StaticDtorSection =
603       Ctx->getCOFFSection(".dtors",
604                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
605                           COFF::IMAGE_SCN_MEM_READ |
606                           COFF::IMAGE_SCN_MEM_WRITE,
607                           SectionKind::getDataRel());
608   }
609 
610   // FIXME: We're emitting LSDA info into a readonly section on COFF, even
611   // though it contains relocatable pointers.  In PIC mode, this is probably a
612   // big runtime hit for C++ apps.  Either the contents of the LSDA need to be
613   // adjusted or this should be a data section.
614   LSDASection =
615     Ctx->getCOFFSection(".gcc_except_table",
616                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
617                         COFF::IMAGE_SCN_MEM_READ,
618                         SectionKind::getReadOnly());
619 
620   // Debug info.
621   COFFDebugSymbolsSection =
622     Ctx->getCOFFSection(".debug$S",
623                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
624                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
625                         COFF::IMAGE_SCN_MEM_READ,
626                         SectionKind::getMetadata());
627 
628   DwarfAbbrevSection =
629     Ctx->getCOFFSection(".debug_abbrev",
630                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
631                         COFF::IMAGE_SCN_MEM_READ,
632                         SectionKind::getMetadata());
633   DwarfInfoSection =
634     Ctx->getCOFFSection(".debug_info",
635                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
636                         COFF::IMAGE_SCN_MEM_READ,
637                         SectionKind::getMetadata());
638   DwarfLineSection =
639     Ctx->getCOFFSection(".debug_line",
640                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
641                         COFF::IMAGE_SCN_MEM_READ,
642                         SectionKind::getMetadata());
643   DwarfFrameSection =
644     Ctx->getCOFFSection(".debug_frame",
645                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
646                         COFF::IMAGE_SCN_MEM_READ,
647                         SectionKind::getMetadata());
648   DwarfPubNamesSection =
649     Ctx->getCOFFSection(".debug_pubnames",
650                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
651                         COFF::IMAGE_SCN_MEM_READ,
652                         SectionKind::getMetadata());
653   DwarfPubTypesSection =
654     Ctx->getCOFFSection(".debug_pubtypes",
655                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
656                         COFF::IMAGE_SCN_MEM_READ,
657                         SectionKind::getMetadata());
658   DwarfGnuPubNamesSection =
659     Ctx->getCOFFSection(".debug_gnu_pubnames",
660                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
661                         COFF::IMAGE_SCN_MEM_READ,
662                         SectionKind::getMetadata());
663   DwarfGnuPubTypesSection =
664     Ctx->getCOFFSection(".debug_gnu_pubtypes",
665                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
666                         COFF::IMAGE_SCN_MEM_READ,
667                         SectionKind::getMetadata());
668   DwarfStrSection =
669     Ctx->getCOFFSection(".debug_str",
670                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
671                         COFF::IMAGE_SCN_MEM_READ,
672                         SectionKind::getMetadata());
673   DwarfLocSection =
674     Ctx->getCOFFSection(".debug_loc",
675                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
676                         COFF::IMAGE_SCN_MEM_READ,
677                         SectionKind::getMetadata());
678   DwarfARangesSection =
679     Ctx->getCOFFSection(".debug_aranges",
680                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
681                         COFF::IMAGE_SCN_MEM_READ,
682                         SectionKind::getMetadata());
683   DwarfRangesSection =
684     Ctx->getCOFFSection(".debug_ranges",
685                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
686                         COFF::IMAGE_SCN_MEM_READ,
687                         SectionKind::getMetadata());
688   DwarfMacroInfoSection =
689     Ctx->getCOFFSection(".debug_macinfo",
690                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
691                         COFF::IMAGE_SCN_MEM_READ,
692                         SectionKind::getMetadata());
693   DwarfInfoDWOSection =
694       Ctx->getCOFFSection(".debug_info.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
695                                                 COFF::IMAGE_SCN_MEM_READ,
696                           SectionKind::getMetadata());
697   DwarfAbbrevDWOSection =
698       Ctx->getCOFFSection(".debug_abbrev.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
699                                                   COFF::IMAGE_SCN_MEM_READ,
700                           SectionKind::getMetadata());
701   DwarfStrDWOSection =
702       Ctx->getCOFFSection(".debug_str.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
703                                                COFF::IMAGE_SCN_MEM_READ,
704                           SectionKind::getMetadata());
705   DwarfLineDWOSection =
706       Ctx->getCOFFSection(".debug_line.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
707                                                 COFF::IMAGE_SCN_MEM_READ,
708                           SectionKind::getMetadata());
709   DwarfLocDWOSection =
710       Ctx->getCOFFSection(".debug_loc.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
711                                                COFF::IMAGE_SCN_MEM_READ,
712                           SectionKind::getMetadata());
713   DwarfStrOffDWOSection =
714       Ctx->getCOFFSection(".debug_str_offsets.dwo", COFF::IMAGE_SCN_MEM_DISCARDABLE |
715                                                   COFF::IMAGE_SCN_MEM_READ,
716                           SectionKind::getMetadata());
717   DwarfAddrSection = Ctx->getCOFFSection(
718       ".debug_addr", COFF::IMAGE_SCN_MEM_DISCARDABLE | COFF::IMAGE_SCN_MEM_READ,
719       SectionKind::getMetadata());
720 
721   DrectveSection =
722     Ctx->getCOFFSection(".drectve",
723                         COFF::IMAGE_SCN_LNK_INFO,
724                         SectionKind::getMetadata());
725 
726   PDataSection =
727     Ctx->getCOFFSection(".pdata",
728                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
729                         COFF::IMAGE_SCN_MEM_READ,
730                         SectionKind::getDataRel());
731 
732   XDataSection =
733     Ctx->getCOFFSection(".xdata",
734                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
735                         COFF::IMAGE_SCN_MEM_READ,
736                         SectionKind::getDataRel());
737   TLSDataSection =
738     Ctx->getCOFFSection(".tls$",
739                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
740                         COFF::IMAGE_SCN_MEM_READ |
741                         COFF::IMAGE_SCN_MEM_WRITE,
742                         SectionKind::getDataRel());
743 }
744 
745 void MCObjectFileInfo::InitMCObjectFileInfo(StringRef TT, Reloc::Model relocm,
746                                             CodeModel::Model cm,
747                                             MCContext &ctx) {
748   RelocM = relocm;
749   CMModel = cm;
750   Ctx = &ctx;
751 
752   // Common.
753   CommDirectiveSupportsAlignment = true;
754   SupportsWeakOmittedEHFrame = true;
755   IsFunctionEHFrameSymbolPrivate = true;
756   SupportsCompactUnwindWithoutEHFrame = false;
757 
758   PersonalityEncoding = LSDAEncoding = FDEEncoding = FDECFIEncoding =
759     TTypeEncoding = dwarf::DW_EH_PE_absptr;
760 
761   CompactUnwindDwarfEHFrameOnly = 0;
762 
763   EHFrameSection = nullptr;             // Created on demand.
764   CompactUnwindSection = nullptr;       // Used only by selected targets.
765   DwarfAccelNamesSection = nullptr;     // Used only by selected targets.
766   DwarfAccelObjCSection = nullptr;      // Used only by selected targets.
767   DwarfAccelNamespaceSection = nullptr; // Used only by selected targets.
768   DwarfAccelTypesSection = nullptr;     // Used only by selected targets.
769 
770   Triple T(TT);
771   Triple::ArchType Arch = T.getArch();
772   // FIXME: Checking for Arch here to filter out bogus triples such as
773   // cellspu-apple-darwin. Perhaps we should fix in Triple?
774   if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
775        Arch == Triple::arm || Arch == Triple::thumb ||
776        Arch == Triple::arm64 ||
777        Arch == Triple::ppc || Arch == Triple::ppc64 ||
778        Arch == Triple::UnknownArch) &&
779       (T.isOSDarwin() || T.isOSBinFormatMachO())) {
780     Env = IsMachO;
781     InitMachOMCObjectFileInfo(T);
782   } else if ((Arch == Triple::x86 || Arch == Triple::x86_64) &&
783              T.getObjectFormat() != Triple::ELF && T.isOSWindows()) {
784     Env = IsCOFF;
785     InitCOFFMCObjectFileInfo(T);
786   } else {
787     Env = IsELF;
788     InitELFMCObjectFileInfo(T);
789   }
790 }
791 
792 const MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const {
793   return Ctx->getELFSection(".debug_types", ELF::SHT_PROGBITS, ELF::SHF_GROUP,
794                             SectionKind::getMetadata(), 0, utostr(Hash));
795 }
796 
797 const MCSection *
798 MCObjectFileInfo::getDwarfTypesDWOSection(uint64_t Hash) const {
799   return Ctx->getELFSection(".debug_types.dwo", ELF::SHT_PROGBITS,
800                             ELF::SHF_GROUP, SectionKind::getMetadata(), 0,
801                             utostr(Hash));
802 }
803 
804 void MCObjectFileInfo::InitEHFrameSection() {
805   if (Env == IsMachO)
806     EHFrameSection =
807       Ctx->getMachOSection("__TEXT", "__eh_frame",
808                            MachO::S_COALESCED |
809                            MachO::S_ATTR_NO_TOC |
810                            MachO::S_ATTR_STRIP_STATIC_SYMS |
811                            MachO::S_ATTR_LIVE_SUPPORT,
812                            SectionKind::getReadOnly());
813   else if (Env == IsELF)
814     EHFrameSection =
815       Ctx->getELFSection(".eh_frame", EHSectionType,
816                          EHSectionFlags,
817                          SectionKind::getDataRel());
818   else
819     EHFrameSection =
820       Ctx->getCOFFSection(".eh_frame",
821                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
822                           COFF::IMAGE_SCN_MEM_READ |
823                           COFF::IMAGE_SCN_MEM_WRITE,
824                           SectionKind::getDataRel());
825 }
826