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/Triple.h"
12 #include "llvm/MC/MCContext.h"
13 #include "llvm/MC/MCSection.h"
14 #include "llvm/MC/MCSectionCOFF.h"
15 #include "llvm/MC/MCSectionELF.h"
16 #include "llvm/MC/MCSectionMachO.h"
17 using namespace llvm;
18 
19 void MCObjectFileInfo::InitMachOMCObjectFileInfo(Triple T) {
20   // MachO
21   IsFunctionEHFrameSymbolPrivate = false;
22   SupportsWeakOmittedEHFrame = false;
23 
24   PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel
25     | dwarf::DW_EH_PE_sdata4;
26   LSDAEncoding = FDEEncoding = FDECFIEncoding = dwarf::DW_EH_PE_pcrel;
27   TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
28     dwarf::DW_EH_PE_sdata4;
29 
30   // .comm doesn't support alignment before Leopard.
31   if (T.isMacOSX() && T.isMacOSXVersionLT(10, 5))
32     CommDirectiveSupportsAlignment = false;
33 
34   TextSection // .text
35     = Ctx->getMachOSection("__TEXT", "__text",
36                            MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
37                            SectionKind::getText());
38   DataSection // .data
39     = Ctx->getMachOSection("__DATA", "__data", 0,
40                            SectionKind::getDataRel());
41 
42   TLSDataSection // .tdata
43     = Ctx->getMachOSection("__DATA", "__thread_data",
44                            MCSectionMachO::S_THREAD_LOCAL_REGULAR,
45                            SectionKind::getDataRel());
46   TLSBSSSection // .tbss
47     = Ctx->getMachOSection("__DATA", "__thread_bss",
48                            MCSectionMachO::S_THREAD_LOCAL_ZEROFILL,
49                            SectionKind::getThreadBSS());
50 
51   // TODO: Verify datarel below.
52   TLSTLVSection // .tlv
53     = Ctx->getMachOSection("__DATA", "__thread_vars",
54                            MCSectionMachO::S_THREAD_LOCAL_VARIABLES,
55                            SectionKind::getDataRel());
56 
57   TLSThreadInitSection
58     = Ctx->getMachOSection("__DATA", "__thread_init",
59                           MCSectionMachO::S_THREAD_LOCAL_INIT_FUNCTION_POINTERS,
60                           SectionKind::getDataRel());
61 
62   CStringSection // .cstring
63     = Ctx->getMachOSection("__TEXT", "__cstring",
64                            MCSectionMachO::S_CSTRING_LITERALS,
65                            SectionKind::getMergeable1ByteCString());
66   UStringSection
67     = Ctx->getMachOSection("__TEXT","__ustring", 0,
68                            SectionKind::getMergeable2ByteCString());
69   FourByteConstantSection // .literal4
70     = Ctx->getMachOSection("__TEXT", "__literal4",
71                            MCSectionMachO::S_4BYTE_LITERALS,
72                            SectionKind::getMergeableConst4());
73   EightByteConstantSection // .literal8
74     = Ctx->getMachOSection("__TEXT", "__literal8",
75                            MCSectionMachO::S_8BYTE_LITERALS,
76                            SectionKind::getMergeableConst8());
77 
78   // ld_classic doesn't support .literal16 in 32-bit mode, and ld64 falls back
79   // to using it in -static mode.
80   SixteenByteConstantSection = 0;
81   if (RelocM != Reloc::Static &&
82       T.getArch() != Triple::x86_64 && T.getArch() != Triple::ppc64)
83     SixteenByteConstantSection =   // .literal16
84       Ctx->getMachOSection("__TEXT", "__literal16",
85                            MCSectionMachO::S_16BYTE_LITERALS,
86                            SectionKind::getMergeableConst16());
87 
88   ReadOnlySection  // .const
89     = Ctx->getMachOSection("__TEXT", "__const", 0,
90                            SectionKind::getReadOnly());
91 
92   TextCoalSection
93     = Ctx->getMachOSection("__TEXT", "__textcoal_nt",
94                            MCSectionMachO::S_COALESCED |
95                            MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
96                            SectionKind::getText());
97   ConstTextCoalSection
98     = Ctx->getMachOSection("__TEXT", "__const_coal",
99                            MCSectionMachO::S_COALESCED,
100                            SectionKind::getReadOnly());
101   ConstDataSection  // .const_data
102     = Ctx->getMachOSection("__DATA", "__const", 0,
103                            SectionKind::getReadOnlyWithRel());
104   DataCoalSection
105     = Ctx->getMachOSection("__DATA","__datacoal_nt",
106                            MCSectionMachO::S_COALESCED,
107                            SectionKind::getDataRel());
108   DataCommonSection
109     = Ctx->getMachOSection("__DATA","__common",
110                            MCSectionMachO::S_ZEROFILL,
111                            SectionKind::getBSS());
112   DataBSSSection
113     = Ctx->getMachOSection("__DATA","__bss", MCSectionMachO::S_ZEROFILL,
114                            SectionKind::getBSS());
115 
116 
117   LazySymbolPointerSection
118     = Ctx->getMachOSection("__DATA", "__la_symbol_ptr",
119                            MCSectionMachO::S_LAZY_SYMBOL_POINTERS,
120                            SectionKind::getMetadata());
121   NonLazySymbolPointerSection
122     = Ctx->getMachOSection("__DATA", "__nl_symbol_ptr",
123                            MCSectionMachO::S_NON_LAZY_SYMBOL_POINTERS,
124                            SectionKind::getMetadata());
125 
126   if (RelocM == Reloc::Static) {
127     StaticCtorSection
128       = Ctx->getMachOSection("__TEXT", "__constructor", 0,
129                              SectionKind::getDataRel());
130     StaticDtorSection
131       = Ctx->getMachOSection("__TEXT", "__destructor", 0,
132                              SectionKind::getDataRel());
133   } else {
134     StaticCtorSection
135       = Ctx->getMachOSection("__DATA", "__mod_init_func",
136                              MCSectionMachO::S_MOD_INIT_FUNC_POINTERS,
137                              SectionKind::getDataRel());
138     StaticDtorSection
139       = Ctx->getMachOSection("__DATA", "__mod_term_func",
140                              MCSectionMachO::S_MOD_TERM_FUNC_POINTERS,
141                              SectionKind::getDataRel());
142   }
143 
144   // Exception Handling.
145   LSDASection = Ctx->getMachOSection("__TEXT", "__gcc_except_tab", 0,
146                                      SectionKind::getReadOnlyWithRel());
147 
148   if (T.isMacOSX() && !T.isMacOSXVersionLT(10, 6))
149     CompactUnwindSection =
150       Ctx->getMachOSection("__LD", "__compact_unwind",
151                            MCSectionMachO::S_ATTR_DEBUG,
152                            SectionKind::getReadOnly());
153 
154   // Debug Information.
155   DwarfAccelNamesSection =
156     Ctx->getMachOSection("__DWARF", "__apple_names",
157                          MCSectionMachO::S_ATTR_DEBUG,
158                          SectionKind::getMetadata());
159   DwarfAccelObjCSection =
160     Ctx->getMachOSection("__DWARF", "__apple_objc",
161                          MCSectionMachO::S_ATTR_DEBUG,
162                          SectionKind::getMetadata());
163   // 16 character section limit...
164   DwarfAccelNamespaceSection =
165     Ctx->getMachOSection("__DWARF", "__apple_namespac",
166                          MCSectionMachO::S_ATTR_DEBUG,
167                          SectionKind::getMetadata());
168   DwarfAccelTypesSection =
169     Ctx->getMachOSection("__DWARF", "__apple_types",
170                          MCSectionMachO::S_ATTR_DEBUG,
171                          SectionKind::getMetadata());
172 
173   DwarfAbbrevSection =
174     Ctx->getMachOSection("__DWARF", "__debug_abbrev",
175                          MCSectionMachO::S_ATTR_DEBUG,
176                          SectionKind::getMetadata());
177   DwarfInfoSection =
178     Ctx->getMachOSection("__DWARF", "__debug_info",
179                          MCSectionMachO::S_ATTR_DEBUG,
180                          SectionKind::getMetadata());
181   DwarfLineSection =
182     Ctx->getMachOSection("__DWARF", "__debug_line",
183                          MCSectionMachO::S_ATTR_DEBUG,
184                          SectionKind::getMetadata());
185   DwarfFrameSection =
186     Ctx->getMachOSection("__DWARF", "__debug_frame",
187                          MCSectionMachO::S_ATTR_DEBUG,
188                          SectionKind::getMetadata());
189   DwarfPubTypesSection =
190     Ctx->getMachOSection("__DWARF", "__debug_pubtypes",
191                          MCSectionMachO::S_ATTR_DEBUG,
192                          SectionKind::getMetadata());
193   DwarfStrSection =
194     Ctx->getMachOSection("__DWARF", "__debug_str",
195                          MCSectionMachO::S_ATTR_DEBUG,
196                          SectionKind::getMetadata());
197   DwarfLocSection =
198     Ctx->getMachOSection("__DWARF", "__debug_loc",
199                          MCSectionMachO::S_ATTR_DEBUG,
200                          SectionKind::getMetadata());
201   DwarfARangesSection =
202     Ctx->getMachOSection("__DWARF", "__debug_aranges",
203                          MCSectionMachO::S_ATTR_DEBUG,
204                          SectionKind::getMetadata());
205   DwarfRangesSection =
206     Ctx->getMachOSection("__DWARF", "__debug_ranges",
207                          MCSectionMachO::S_ATTR_DEBUG,
208                          SectionKind::getMetadata());
209   DwarfMacroInfoSection =
210     Ctx->getMachOSection("__DWARF", "__debug_macinfo",
211                          MCSectionMachO::S_ATTR_DEBUG,
212                          SectionKind::getMetadata());
213   DwarfDebugInlineSection =
214     Ctx->getMachOSection("__DWARF", "__debug_inlined",
215                          MCSectionMachO::S_ATTR_DEBUG,
216                          SectionKind::getMetadata());
217 
218   TLSExtraDataSection = TLSTLVSection;
219 }
220 
221 void MCObjectFileInfo::InitELFMCObjectFileInfo(Triple T) {
222   if (T.getArch() == Triple::x86) {
223     PersonalityEncoding = (RelocM == Reloc::PIC_)
224      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
225      : dwarf::DW_EH_PE_absptr;
226     LSDAEncoding = (RelocM == Reloc::PIC_)
227       ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
228       : dwarf::DW_EH_PE_absptr;
229     FDEEncoding = FDECFIEncoding = (RelocM == Reloc::PIC_)
230       ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
231       : dwarf::DW_EH_PE_absptr;
232     TTypeEncoding = (RelocM == Reloc::PIC_)
233      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
234      : dwarf::DW_EH_PE_absptr;
235   } else if (T.getArch() == Triple::x86_64) {
236     FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
237 
238     if (RelocM == Reloc::PIC_) {
239       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
240         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
241          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
242       LSDAEncoding = dwarf::DW_EH_PE_pcrel |
243         (CMModel == CodeModel::Small
244          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
245       FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
246       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
247         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
248          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
249     } else {
250       PersonalityEncoding =
251         (CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
252         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
253       LSDAEncoding = (CMModel == CodeModel::Small)
254         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
255       FDEEncoding = dwarf::DW_EH_PE_udata4;
256       TTypeEncoding = (CMModel == CodeModel::Small)
257         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
258     }
259   } else if (T.getArch() == Triple::ppc64) {
260     PersonalityEncoding = dwarf::DW_EH_PE_udata8;
261     PersonalityEncoding |= (RelocM == Reloc::PIC_)
262      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel
263      : dwarf::DW_EH_PE_absptr;
264     unsigned PICFlag = (RelocM == Reloc::PIC_) ? dwarf::DW_EH_PE_pcrel
265      : dwarf::DW_EH_PE_absptr;
266     FDECFIEncoding = PICFlag | dwarf::DW_EH_PE_sdata4;
267     LSDAEncoding = PICFlag | dwarf::DW_EH_PE_udata8;
268     FDEEncoding = PICFlag | dwarf::DW_EH_PE_sdata4;
269     TTypeEncoding = PICFlag | dwarf::DW_EH_PE_sdata4;
270   }
271 
272   // Solaris requires different flags for .eh_frame to seemingly every other
273   // platform.
274   EHSectionType = ELF::SHT_PROGBITS;
275   EHSectionFlags = ELF::SHF_ALLOC;
276   if (T.getOS() == Triple::Solaris) {
277     if (T.getArch() == Triple::x86_64)
278       EHSectionType = ELF::SHT_X86_64_UNWIND;
279     else
280       EHSectionFlags |= ELF::SHF_WRITE;
281   }
282 
283 
284   // ELF
285   BSSSection =
286     Ctx->getELFSection(".bss", ELF::SHT_NOBITS,
287                        ELF::SHF_WRITE | ELF::SHF_ALLOC,
288                        SectionKind::getBSS());
289 
290   TextSection =
291     Ctx->getELFSection(".text", ELF::SHT_PROGBITS,
292                        ELF::SHF_EXECINSTR |
293                        ELF::SHF_ALLOC,
294                        SectionKind::getText());
295 
296   DataSection =
297     Ctx->getELFSection(".data", ELF::SHT_PROGBITS,
298                        ELF::SHF_WRITE |ELF::SHF_ALLOC,
299                        SectionKind::getDataRel());
300 
301   ReadOnlySection =
302     Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS,
303                        ELF::SHF_ALLOC,
304                        SectionKind::getReadOnly());
305 
306   TLSDataSection =
307     Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS,
308                        ELF::SHF_ALLOC | ELF::SHF_TLS |
309                        ELF::SHF_WRITE,
310                        SectionKind::getThreadData());
311 
312   TLSBSSSection =
313     Ctx->getELFSection(".tbss", ELF::SHT_NOBITS,
314                        ELF::SHF_ALLOC | ELF::SHF_TLS |
315                        ELF::SHF_WRITE,
316                        SectionKind::getThreadBSS());
317 
318   DataRelSection =
319     Ctx->getELFSection(".data.rel", ELF::SHT_PROGBITS,
320                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
321                        SectionKind::getDataRel());
322 
323   DataRelLocalSection =
324     Ctx->getELFSection(".data.rel.local", ELF::SHT_PROGBITS,
325                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
326                        SectionKind::getDataRelLocal());
327 
328   DataRelROSection =
329     Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS,
330                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
331                        SectionKind::getReadOnlyWithRel());
332 
333   DataRelROLocalSection =
334     Ctx->getELFSection(".data.rel.ro.local", ELF::SHT_PROGBITS,
335                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
336                        SectionKind::getReadOnlyWithRelLocal());
337 
338   MergeableConst4Section =
339     Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS,
340                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
341                        SectionKind::getMergeableConst4());
342 
343   MergeableConst8Section =
344     Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS,
345                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
346                        SectionKind::getMergeableConst8());
347 
348   MergeableConst16Section =
349     Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS,
350                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
351                        SectionKind::getMergeableConst16());
352 
353   StaticCtorSection =
354     Ctx->getELFSection(".ctors", ELF::SHT_PROGBITS,
355                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
356                        SectionKind::getDataRel());
357 
358   StaticDtorSection =
359     Ctx->getELFSection(".dtors", ELF::SHT_PROGBITS,
360                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
361                        SectionKind::getDataRel());
362 
363   // Exception Handling Sections.
364 
365   // FIXME: We're emitting LSDA info into a readonly section on ELF, even though
366   // it contains relocatable pointers.  In PIC mode, this is probably a big
367   // runtime hit for C++ apps.  Either the contents of the LSDA need to be
368   // adjusted or this should be a data section.
369   LSDASection =
370     Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS,
371                        ELF::SHF_ALLOC,
372                        SectionKind::getReadOnly());
373 
374   // Debug Info Sections.
375   DwarfAbbrevSection =
376     Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0,
377                        SectionKind::getMetadata());
378   DwarfInfoSection =
379     Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0,
380                        SectionKind::getMetadata());
381   DwarfLineSection =
382     Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0,
383                        SectionKind::getMetadata());
384   DwarfFrameSection =
385     Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0,
386                        SectionKind::getMetadata());
387   DwarfPubTypesSection =
388     Ctx->getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0,
389                        SectionKind::getMetadata());
390   DwarfStrSection =
391     Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS,
392                        ELF::SHF_MERGE | ELF::SHF_STRINGS,
393                        SectionKind::getMergeable1ByteCString());
394   DwarfLocSection =
395     Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0,
396                        SectionKind::getMetadata());
397   DwarfARangesSection =
398     Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0,
399                        SectionKind::getMetadata());
400   DwarfRangesSection =
401     Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0,
402                        SectionKind::getMetadata());
403   DwarfMacroInfoSection =
404     Ctx->getELFSection(".debug_macinfo", ELF::SHT_PROGBITS, 0,
405                        SectionKind::getMetadata());
406 
407   // DWARF5 Experimental Debug Info
408 
409   // Accelerator Tables
410   DwarfAccelNamesSection =
411     Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0,
412                        SectionKind::getMetadata());
413   DwarfAccelObjCSection =
414     Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0,
415                        SectionKind::getMetadata());
416   DwarfAccelNamespaceSection =
417     Ctx->getELFSection(".apple_namespaces", ELF::SHT_PROGBITS, 0,
418                        SectionKind::getMetadata());
419   DwarfAccelTypesSection =
420     Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0,
421                        SectionKind::getMetadata());
422 
423   // Fission Sections
424   DwarfInfoDWOSection =
425     Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0,
426                        SectionKind::getMetadata());
427   DwarfAbbrevDWOSection =
428     Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0,
429                        SectionKind::getMetadata());
430   DwarfStrDWOSection =
431     Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS,
432                        ELF::SHF_MERGE | ELF::SHF_STRINGS,
433                        SectionKind::getMergeable1ByteCString());
434   DwarfLineDWOSection =
435     Ctx->getELFSection(".debug_line.dwo", ELF::SHT_PROGBITS, 0,
436                        SectionKind::getMetadata());
437   DwarfLocDWOSection =
438     Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0,
439                        SectionKind::getMetadata());
440   DwarfStrOffDWOSection =
441     Ctx->getELFSection(".debug_str_offsets.dwo", ELF::SHT_PROGBITS, 0,
442                        SectionKind::getMetadata());
443 }
444 
445 
446 void MCObjectFileInfo::InitCOFFMCObjectFileInfo(Triple T) {
447   // COFF
448   TextSection =
449     Ctx->getCOFFSection(".text",
450                         COFF::IMAGE_SCN_CNT_CODE |
451                         COFF::IMAGE_SCN_MEM_EXECUTE |
452                         COFF::IMAGE_SCN_MEM_READ,
453                         SectionKind::getText());
454   DataSection =
455     Ctx->getCOFFSection(".data",
456                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
457                         COFF::IMAGE_SCN_MEM_READ |
458                         COFF::IMAGE_SCN_MEM_WRITE,
459                         SectionKind::getDataRel());
460   ReadOnlySection =
461     Ctx->getCOFFSection(".rdata",
462                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
463                         COFF::IMAGE_SCN_MEM_READ,
464                         SectionKind::getReadOnly());
465   if (T.getOS() == Triple::Win32) {
466     StaticCtorSection =
467       Ctx->getCOFFSection(".CRT$XCU",
468                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
469                           COFF::IMAGE_SCN_MEM_READ,
470                           SectionKind::getReadOnly());
471   } else {
472     StaticCtorSection =
473       Ctx->getCOFFSection(".ctors",
474                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
475                           COFF::IMAGE_SCN_MEM_READ |
476                           COFF::IMAGE_SCN_MEM_WRITE,
477                           SectionKind::getDataRel());
478   }
479 
480 
481   if (T.getOS() == Triple::Win32) {
482     StaticDtorSection =
483       Ctx->getCOFFSection(".CRT$XTX",
484                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
485                           COFF::IMAGE_SCN_MEM_READ,
486                           SectionKind::getReadOnly());
487   } else {
488     StaticDtorSection =
489       Ctx->getCOFFSection(".dtors",
490                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
491                           COFF::IMAGE_SCN_MEM_READ |
492                           COFF::IMAGE_SCN_MEM_WRITE,
493                           SectionKind::getDataRel());
494   }
495 
496   // FIXME: We're emitting LSDA info into a readonly section on COFF, even
497   // though it contains relocatable pointers.  In PIC mode, this is probably a
498   // big runtime hit for C++ apps.  Either the contents of the LSDA need to be
499   // adjusted or this should be a data section.
500   LSDASection =
501     Ctx->getCOFFSection(".gcc_except_table",
502                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
503                         COFF::IMAGE_SCN_MEM_READ,
504                         SectionKind::getReadOnly());
505 
506   // Debug info.
507   DwarfAbbrevSection =
508     Ctx->getCOFFSection(".debug_abbrev",
509                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
510                         COFF::IMAGE_SCN_MEM_READ,
511                         SectionKind::getMetadata());
512   DwarfInfoSection =
513     Ctx->getCOFFSection(".debug_info",
514                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
515                         COFF::IMAGE_SCN_MEM_READ,
516                         SectionKind::getMetadata());
517   DwarfLineSection =
518     Ctx->getCOFFSection(".debug_line",
519                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
520                         COFF::IMAGE_SCN_MEM_READ,
521                         SectionKind::getMetadata());
522   DwarfFrameSection =
523     Ctx->getCOFFSection(".debug_frame",
524                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
525                         COFF::IMAGE_SCN_MEM_READ,
526                         SectionKind::getMetadata());
527   DwarfPubTypesSection =
528     Ctx->getCOFFSection(".debug_pubtypes",
529                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
530                         COFF::IMAGE_SCN_MEM_READ,
531                         SectionKind::getMetadata());
532   DwarfStrSection =
533     Ctx->getCOFFSection(".debug_str",
534                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
535                         COFF::IMAGE_SCN_MEM_READ,
536                         SectionKind::getMetadata());
537   DwarfLocSection =
538     Ctx->getCOFFSection(".debug_loc",
539                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
540                         COFF::IMAGE_SCN_MEM_READ,
541                         SectionKind::getMetadata());
542   DwarfARangesSection =
543     Ctx->getCOFFSection(".debug_aranges",
544                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
545                         COFF::IMAGE_SCN_MEM_READ,
546                         SectionKind::getMetadata());
547   DwarfRangesSection =
548     Ctx->getCOFFSection(".debug_ranges",
549                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
550                         COFF::IMAGE_SCN_MEM_READ,
551                         SectionKind::getMetadata());
552   DwarfMacroInfoSection =
553     Ctx->getCOFFSection(".debug_macinfo",
554                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
555                         COFF::IMAGE_SCN_MEM_READ,
556                         SectionKind::getMetadata());
557 
558   DrectveSection =
559     Ctx->getCOFFSection(".drectve",
560                         COFF::IMAGE_SCN_LNK_INFO,
561                         SectionKind::getMetadata());
562 
563   PDataSection =
564     Ctx->getCOFFSection(".pdata",
565                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
566                         COFF::IMAGE_SCN_MEM_READ,
567                         SectionKind::getDataRel());
568 
569   XDataSection =
570     Ctx->getCOFFSection(".xdata",
571                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
572                         COFF::IMAGE_SCN_MEM_READ,
573                         SectionKind::getDataRel());
574   TLSDataSection =
575     Ctx->getCOFFSection(".tls$",
576                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
577                         COFF::IMAGE_SCN_MEM_READ |
578                         COFF::IMAGE_SCN_MEM_WRITE,
579                         SectionKind::getDataRel());
580 }
581 
582 void MCObjectFileInfo::InitMCObjectFileInfo(StringRef TT, Reloc::Model relocm,
583                                             CodeModel::Model cm,
584                                             MCContext &ctx) {
585   RelocM = relocm;
586   CMModel = cm;
587   Ctx = &ctx;
588 
589   // Common.
590   CommDirectiveSupportsAlignment = true;
591   SupportsWeakOmittedEHFrame = true;
592   IsFunctionEHFrameSymbolPrivate = true;
593 
594   PersonalityEncoding = LSDAEncoding = FDEEncoding = FDECFIEncoding =
595     TTypeEncoding = dwarf::DW_EH_PE_absptr;
596 
597   EHFrameSection = 0;             // Created on demand.
598   CompactUnwindSection = 0;       // Used only by selected targets.
599   DwarfAccelNamesSection = 0;     // Used only by selected targets.
600   DwarfAccelObjCSection = 0;      // Used only by selected targets.
601   DwarfAccelNamespaceSection = 0; // Used only by selected targets.
602   DwarfAccelTypesSection = 0;     // Used only by selected targets.
603 
604   Triple T(TT);
605   Triple::ArchType Arch = T.getArch();
606   // FIXME: Checking for Arch here to filter out bogus triples such as
607   // cellspu-apple-darwin. Perhaps we should fix in Triple?
608   if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
609        Arch == Triple::arm || Arch == Triple::thumb ||
610        Arch == Triple::ppc || Arch == Triple::ppc64 ||
611        Arch == Triple::UnknownArch) &&
612       (T.isOSDarwin() || T.getEnvironment() == Triple::MachO)) {
613     Env = IsMachO;
614     InitMachOMCObjectFileInfo(T);
615   } else if ((Arch == Triple::x86 || Arch == Triple::x86_64) &&
616              (T.getEnvironment() != Triple::ELF) &&
617              (T.getOS() == Triple::MinGW32 || T.getOS() == Triple::Cygwin ||
618               T.getOS() == Triple::Win32)) {
619     Env = IsCOFF;
620     InitCOFFMCObjectFileInfo(T);
621   } else {
622     Env = IsELF;
623     InitELFMCObjectFileInfo(T);
624   }
625 }
626 
627 void MCObjectFileInfo::InitEHFrameSection() {
628   if (Env == IsMachO)
629     EHFrameSection =
630       Ctx->getMachOSection("__TEXT", "__eh_frame",
631                            MCSectionMachO::S_COALESCED |
632                            MCSectionMachO::S_ATTR_NO_TOC |
633                            MCSectionMachO::S_ATTR_STRIP_STATIC_SYMS |
634                            MCSectionMachO::S_ATTR_LIVE_SUPPORT,
635                            SectionKind::getReadOnly());
636   else if (Env == IsELF)
637     EHFrameSection =
638       Ctx->getELFSection(".eh_frame", EHSectionType,
639                          EHSectionFlags,
640                          SectionKind::getDataRel());
641   else
642     EHFrameSection =
643       Ctx->getCOFFSection(".eh_frame",
644                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
645                           COFF::IMAGE_SCN_MEM_READ |
646                           COFF::IMAGE_SCN_MEM_WRITE,
647                           SectionKind::getDataRel());
648 }
649