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_indirect | dwarf::DW_EH_PE_pcrel |
261       dwarf::DW_EH_PE_udata8;
262     FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
263     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
264     FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
265     TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
266       dwarf::DW_EH_PE_udata8;
267   }
268 
269   // Solaris requires different flags for .eh_frame to seemingly every other
270   // platform.
271   EHSectionType = ELF::SHT_PROGBITS;
272   EHSectionFlags = ELF::SHF_ALLOC;
273   if (T.getOS() == Triple::Solaris) {
274     if (T.getArch() == Triple::x86_64)
275       EHSectionType = ELF::SHT_X86_64_UNWIND;
276     else
277       EHSectionFlags |= ELF::SHF_WRITE;
278   }
279 
280 
281   // ELF
282   BSSSection =
283     Ctx->getELFSection(".bss", ELF::SHT_NOBITS,
284                        ELF::SHF_WRITE | ELF::SHF_ALLOC,
285                        SectionKind::getBSS());
286 
287   TextSection =
288     Ctx->getELFSection(".text", ELF::SHT_PROGBITS,
289                        ELF::SHF_EXECINSTR |
290                        ELF::SHF_ALLOC,
291                        SectionKind::getText());
292 
293   DataSection =
294     Ctx->getELFSection(".data", ELF::SHT_PROGBITS,
295                        ELF::SHF_WRITE |ELF::SHF_ALLOC,
296                        SectionKind::getDataRel());
297 
298   ReadOnlySection =
299     Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS,
300                        ELF::SHF_ALLOC,
301                        SectionKind::getReadOnly());
302 
303   TLSDataSection =
304     Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS,
305                        ELF::SHF_ALLOC | ELF::SHF_TLS |
306                        ELF::SHF_WRITE,
307                        SectionKind::getThreadData());
308 
309   TLSBSSSection =
310     Ctx->getELFSection(".tbss", ELF::SHT_NOBITS,
311                        ELF::SHF_ALLOC | ELF::SHF_TLS |
312                        ELF::SHF_WRITE,
313                        SectionKind::getThreadBSS());
314 
315   DataRelSection =
316     Ctx->getELFSection(".data.rel", ELF::SHT_PROGBITS,
317                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
318                        SectionKind::getDataRel());
319 
320   DataRelLocalSection =
321     Ctx->getELFSection(".data.rel.local", ELF::SHT_PROGBITS,
322                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
323                        SectionKind::getDataRelLocal());
324 
325   DataRelROSection =
326     Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS,
327                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
328                        SectionKind::getReadOnlyWithRel());
329 
330   DataRelROLocalSection =
331     Ctx->getELFSection(".data.rel.ro.local", ELF::SHT_PROGBITS,
332                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
333                        SectionKind::getReadOnlyWithRelLocal());
334 
335   MergeableConst4Section =
336     Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS,
337                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
338                        SectionKind::getMergeableConst4());
339 
340   MergeableConst8Section =
341     Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS,
342                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
343                        SectionKind::getMergeableConst8());
344 
345   MergeableConst16Section =
346     Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS,
347                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
348                        SectionKind::getMergeableConst16());
349 
350   StaticCtorSection =
351     Ctx->getELFSection(".ctors", ELF::SHT_PROGBITS,
352                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
353                        SectionKind::getDataRel());
354 
355   StaticDtorSection =
356     Ctx->getELFSection(".dtors", ELF::SHT_PROGBITS,
357                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
358                        SectionKind::getDataRel());
359 
360   // Exception Handling Sections.
361 
362   // FIXME: We're emitting LSDA info into a readonly section on ELF, even though
363   // it contains relocatable pointers.  In PIC mode, this is probably a big
364   // runtime hit for C++ apps.  Either the contents of the LSDA need to be
365   // adjusted or this should be a data section.
366   LSDASection =
367     Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS,
368                        ELF::SHF_ALLOC,
369                        SectionKind::getReadOnly());
370 
371   // Debug Info Sections.
372   DwarfAbbrevSection =
373     Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0,
374                        SectionKind::getMetadata());
375   DwarfInfoSection =
376     Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0,
377                        SectionKind::getMetadata());
378   DwarfLineSection =
379     Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0,
380                        SectionKind::getMetadata());
381   DwarfFrameSection =
382     Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0,
383                        SectionKind::getMetadata());
384   DwarfPubTypesSection =
385     Ctx->getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0,
386                        SectionKind::getMetadata());
387   DwarfStrSection =
388     Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS,
389                        ELF::SHF_MERGE | ELF::SHF_STRINGS,
390                        SectionKind::getMergeable1ByteCString());
391   DwarfLocSection =
392     Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0,
393                        SectionKind::getMetadata());
394   DwarfARangesSection =
395     Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0,
396                        SectionKind::getMetadata());
397   DwarfRangesSection =
398     Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0,
399                        SectionKind::getMetadata());
400   DwarfMacroInfoSection =
401     Ctx->getELFSection(".debug_macinfo", ELF::SHT_PROGBITS, 0,
402                        SectionKind::getMetadata());
403 
404   // DWARF5 Experimental Debug Info
405 
406   // Accelerator Tables
407   DwarfAccelNamesSection =
408     Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0,
409                        SectionKind::getMetadata());
410   DwarfAccelObjCSection =
411     Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0,
412                        SectionKind::getMetadata());
413   DwarfAccelNamespaceSection =
414     Ctx->getELFSection(".apple_namespaces", ELF::SHT_PROGBITS, 0,
415                        SectionKind::getMetadata());
416   DwarfAccelTypesSection =
417     Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0,
418                        SectionKind::getMetadata());
419 
420   // Fission Sections
421   DwarfInfoDWOSection =
422     Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0,
423                        SectionKind::getMetadata());
424   DwarfAbbrevDWOSection =
425     Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0,
426                        SectionKind::getMetadata());
427   DwarfStrDWOSection =
428     Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS,
429                        ELF::SHF_MERGE | ELF::SHF_STRINGS,
430                        SectionKind::getMergeable1ByteCString());
431   DwarfLineDWOSection =
432     Ctx->getELFSection(".debug_line.dwo", ELF::SHT_PROGBITS, 0,
433                        SectionKind::getMetadata());
434   DwarfLocDWOSection =
435     Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0,
436                        SectionKind::getMetadata());
437   DwarfStrOffDWOSection =
438     Ctx->getELFSection(".debug_str_offsets.dwo", ELF::SHT_PROGBITS, 0,
439                        SectionKind::getMetadata());
440 }
441 
442 
443 void MCObjectFileInfo::InitCOFFMCObjectFileInfo(Triple T) {
444   // COFF
445   TextSection =
446     Ctx->getCOFFSection(".text",
447                         COFF::IMAGE_SCN_CNT_CODE |
448                         COFF::IMAGE_SCN_MEM_EXECUTE |
449                         COFF::IMAGE_SCN_MEM_READ,
450                         SectionKind::getText());
451   DataSection =
452     Ctx->getCOFFSection(".data",
453                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
454                         COFF::IMAGE_SCN_MEM_READ |
455                         COFF::IMAGE_SCN_MEM_WRITE,
456                         SectionKind::getDataRel());
457   ReadOnlySection =
458     Ctx->getCOFFSection(".rdata",
459                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
460                         COFF::IMAGE_SCN_MEM_READ,
461                         SectionKind::getReadOnly());
462   if (T.getOS() == Triple::Win32) {
463     StaticCtorSection =
464       Ctx->getCOFFSection(".CRT$XCU",
465                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
466                           COFF::IMAGE_SCN_MEM_READ,
467                           SectionKind::getReadOnly());
468   } else {
469     StaticCtorSection =
470       Ctx->getCOFFSection(".ctors",
471                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
472                           COFF::IMAGE_SCN_MEM_READ |
473                           COFF::IMAGE_SCN_MEM_WRITE,
474                           SectionKind::getDataRel());
475   }
476 
477 
478   if (T.getOS() == Triple::Win32) {
479     StaticDtorSection =
480       Ctx->getCOFFSection(".CRT$XTX",
481                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
482                           COFF::IMAGE_SCN_MEM_READ,
483                           SectionKind::getReadOnly());
484   } else {
485     StaticDtorSection =
486       Ctx->getCOFFSection(".dtors",
487                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
488                           COFF::IMAGE_SCN_MEM_READ |
489                           COFF::IMAGE_SCN_MEM_WRITE,
490                           SectionKind::getDataRel());
491   }
492 
493   // FIXME: We're emitting LSDA info into a readonly section on COFF, even
494   // though it contains relocatable pointers.  In PIC mode, this is probably a
495   // big runtime hit for C++ apps.  Either the contents of the LSDA need to be
496   // adjusted or this should be a data section.
497   LSDASection =
498     Ctx->getCOFFSection(".gcc_except_table",
499                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
500                         COFF::IMAGE_SCN_MEM_READ,
501                         SectionKind::getReadOnly());
502 
503   // Debug info.
504   DwarfAbbrevSection =
505     Ctx->getCOFFSection(".debug_abbrev",
506                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
507                         COFF::IMAGE_SCN_MEM_READ,
508                         SectionKind::getMetadata());
509   DwarfInfoSection =
510     Ctx->getCOFFSection(".debug_info",
511                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
512                         COFF::IMAGE_SCN_MEM_READ,
513                         SectionKind::getMetadata());
514   DwarfLineSection =
515     Ctx->getCOFFSection(".debug_line",
516                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
517                         COFF::IMAGE_SCN_MEM_READ,
518                         SectionKind::getMetadata());
519   DwarfFrameSection =
520     Ctx->getCOFFSection(".debug_frame",
521                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
522                         COFF::IMAGE_SCN_MEM_READ,
523                         SectionKind::getMetadata());
524   DwarfPubTypesSection =
525     Ctx->getCOFFSection(".debug_pubtypes",
526                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
527                         COFF::IMAGE_SCN_MEM_READ,
528                         SectionKind::getMetadata());
529   DwarfStrSection =
530     Ctx->getCOFFSection(".debug_str",
531                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
532                         COFF::IMAGE_SCN_MEM_READ,
533                         SectionKind::getMetadata());
534   DwarfLocSection =
535     Ctx->getCOFFSection(".debug_loc",
536                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
537                         COFF::IMAGE_SCN_MEM_READ,
538                         SectionKind::getMetadata());
539   DwarfARangesSection =
540     Ctx->getCOFFSection(".debug_aranges",
541                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
542                         COFF::IMAGE_SCN_MEM_READ,
543                         SectionKind::getMetadata());
544   DwarfRangesSection =
545     Ctx->getCOFFSection(".debug_ranges",
546                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
547                         COFF::IMAGE_SCN_MEM_READ,
548                         SectionKind::getMetadata());
549   DwarfMacroInfoSection =
550     Ctx->getCOFFSection(".debug_macinfo",
551                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
552                         COFF::IMAGE_SCN_MEM_READ,
553                         SectionKind::getMetadata());
554 
555   DrectveSection =
556     Ctx->getCOFFSection(".drectve",
557                         COFF::IMAGE_SCN_LNK_INFO,
558                         SectionKind::getMetadata());
559 
560   PDataSection =
561     Ctx->getCOFFSection(".pdata",
562                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
563                         COFF::IMAGE_SCN_MEM_READ,
564                         SectionKind::getDataRel());
565 
566   XDataSection =
567     Ctx->getCOFFSection(".xdata",
568                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
569                         COFF::IMAGE_SCN_MEM_READ,
570                         SectionKind::getDataRel());
571   TLSDataSection =
572     Ctx->getCOFFSection(".tls$",
573                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
574                         COFF::IMAGE_SCN_MEM_READ |
575                         COFF::IMAGE_SCN_MEM_WRITE,
576                         SectionKind::getDataRel());
577 }
578 
579 void MCObjectFileInfo::InitMCObjectFileInfo(StringRef TT, Reloc::Model relocm,
580                                             CodeModel::Model cm,
581                                             MCContext &ctx) {
582   RelocM = relocm;
583   CMModel = cm;
584   Ctx = &ctx;
585 
586   // Common.
587   CommDirectiveSupportsAlignment = true;
588   SupportsWeakOmittedEHFrame = true;
589   IsFunctionEHFrameSymbolPrivate = true;
590 
591   PersonalityEncoding = LSDAEncoding = FDEEncoding = FDECFIEncoding =
592     TTypeEncoding = dwarf::DW_EH_PE_absptr;
593 
594   EHFrameSection = 0;             // Created on demand.
595   CompactUnwindSection = 0;       // Used only by selected targets.
596   DwarfAccelNamesSection = 0;     // Used only by selected targets.
597   DwarfAccelObjCSection = 0;      // Used only by selected targets.
598   DwarfAccelNamespaceSection = 0; // Used only by selected targets.
599   DwarfAccelTypesSection = 0;     // Used only by selected targets.
600 
601   Triple T(TT);
602   Triple::ArchType Arch = T.getArch();
603   // FIXME: Checking for Arch here to filter out bogus triples such as
604   // cellspu-apple-darwin. Perhaps we should fix in Triple?
605   if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
606        Arch == Triple::arm || Arch == Triple::thumb ||
607        Arch == Triple::ppc || Arch == Triple::ppc64 ||
608        Arch == Triple::UnknownArch) &&
609       (T.isOSDarwin() || T.getEnvironment() == Triple::MachO)) {
610     Env = IsMachO;
611     InitMachOMCObjectFileInfo(T);
612   } else if ((Arch == Triple::x86 || Arch == Triple::x86_64) &&
613              (T.getEnvironment() != Triple::ELF) &&
614              (T.getOS() == Triple::MinGW32 || T.getOS() == Triple::Cygwin ||
615               T.getOS() == Triple::Win32)) {
616     Env = IsCOFF;
617     InitCOFFMCObjectFileInfo(T);
618   } else {
619     Env = IsELF;
620     InitELFMCObjectFileInfo(T);
621   }
622 }
623 
624 void MCObjectFileInfo::InitEHFrameSection() {
625   if (Env == IsMachO)
626     EHFrameSection =
627       Ctx->getMachOSection("__TEXT", "__eh_frame",
628                            MCSectionMachO::S_COALESCED |
629                            MCSectionMachO::S_ATTR_NO_TOC |
630                            MCSectionMachO::S_ATTR_STRIP_STATIC_SYMS |
631                            MCSectionMachO::S_ATTR_LIVE_SUPPORT,
632                            SectionKind::getReadOnly());
633   else if (Env == IsELF)
634     EHFrameSection =
635       Ctx->getELFSection(".eh_frame", EHSectionType,
636                          EHSectionFlags,
637                          SectionKind::getDataRel());
638   else
639     EHFrameSection =
640       Ctx->getCOFFSection(".eh_frame",
641                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
642                           COFF::IMAGE_SCN_MEM_READ |
643                           COFF::IMAGE_SCN_MEM_WRITE,
644                           SectionKind::getDataRel());
645 }
646