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     if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86)
155       CompactUnwindDwarfEHFrameOnly = 0x04000000;
156   }
157 
158   // Debug Information.
159   DwarfAccelNamesSection =
160     Ctx->getMachOSection("__DWARF", "__apple_names",
161                          MCSectionMachO::S_ATTR_DEBUG,
162                          SectionKind::getMetadata());
163   DwarfAccelObjCSection =
164     Ctx->getMachOSection("__DWARF", "__apple_objc",
165                          MCSectionMachO::S_ATTR_DEBUG,
166                          SectionKind::getMetadata());
167   // 16 character section limit...
168   DwarfAccelNamespaceSection =
169     Ctx->getMachOSection("__DWARF", "__apple_namespac",
170                          MCSectionMachO::S_ATTR_DEBUG,
171                          SectionKind::getMetadata());
172   DwarfAccelTypesSection =
173     Ctx->getMachOSection("__DWARF", "__apple_types",
174                          MCSectionMachO::S_ATTR_DEBUG,
175                          SectionKind::getMetadata());
176 
177   DwarfAbbrevSection =
178     Ctx->getMachOSection("__DWARF", "__debug_abbrev",
179                          MCSectionMachO::S_ATTR_DEBUG,
180                          SectionKind::getMetadata());
181   DwarfInfoSection =
182     Ctx->getMachOSection("__DWARF", "__debug_info",
183                          MCSectionMachO::S_ATTR_DEBUG,
184                          SectionKind::getMetadata());
185   DwarfLineSection =
186     Ctx->getMachOSection("__DWARF", "__debug_line",
187                          MCSectionMachO::S_ATTR_DEBUG,
188                          SectionKind::getMetadata());
189   DwarfFrameSection =
190     Ctx->getMachOSection("__DWARF", "__debug_frame",
191                          MCSectionMachO::S_ATTR_DEBUG,
192                          SectionKind::getMetadata());
193   DwarfPubNamesSection =
194     Ctx->getMachOSection("__DWARF", "__debug_pubnames",
195                          MCSectionMachO::S_ATTR_DEBUG,
196                          SectionKind::getMetadata());
197   DwarfPubTypesSection =
198     Ctx->getMachOSection("__DWARF", "__debug_pubtypes",
199                          MCSectionMachO::S_ATTR_DEBUG,
200                          SectionKind::getMetadata());
201   DwarfStrSection =
202     Ctx->getMachOSection("__DWARF", "__debug_str",
203                          MCSectionMachO::S_ATTR_DEBUG,
204                          SectionKind::getMetadata());
205   DwarfLocSection =
206     Ctx->getMachOSection("__DWARF", "__debug_loc",
207                          MCSectionMachO::S_ATTR_DEBUG,
208                          SectionKind::getMetadata());
209   DwarfARangesSection =
210     Ctx->getMachOSection("__DWARF", "__debug_aranges",
211                          MCSectionMachO::S_ATTR_DEBUG,
212                          SectionKind::getMetadata());
213   DwarfRangesSection =
214     Ctx->getMachOSection("__DWARF", "__debug_ranges",
215                          MCSectionMachO::S_ATTR_DEBUG,
216                          SectionKind::getMetadata());
217   DwarfMacroInfoSection =
218     Ctx->getMachOSection("__DWARF", "__debug_macinfo",
219                          MCSectionMachO::S_ATTR_DEBUG,
220                          SectionKind::getMetadata());
221   DwarfDebugInlineSection =
222     Ctx->getMachOSection("__DWARF", "__debug_inlined",
223                          MCSectionMachO::S_ATTR_DEBUG,
224                          SectionKind::getMetadata());
225 
226   TLSExtraDataSection = TLSTLVSection;
227 }
228 
229 void MCObjectFileInfo::InitELFMCObjectFileInfo(Triple T) {
230   if (T.getArch() == Triple::mips ||
231       T.getArch() == Triple::mipsel)
232     FDECFIEncoding = dwarf::DW_EH_PE_sdata4;
233   else if (T.getArch() == Triple::mips64 ||
234            T.getArch() == Triple::mips64el)
235     FDECFIEncoding = dwarf::DW_EH_PE_sdata8;
236   else
237     FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
238 
239   if (T.getArch() == Triple::x86) {
240     PersonalityEncoding = (RelocM == Reloc::PIC_)
241      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
242      : dwarf::DW_EH_PE_absptr;
243     LSDAEncoding = (RelocM == Reloc::PIC_)
244       ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
245       : dwarf::DW_EH_PE_absptr;
246     FDEEncoding = (RelocM == Reloc::PIC_)
247       ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
248       : dwarf::DW_EH_PE_absptr;
249     TTypeEncoding = (RelocM == Reloc::PIC_)
250      ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
251      : dwarf::DW_EH_PE_absptr;
252   } else if (T.getArch() == Triple::x86_64) {
253     if (RelocM == Reloc::PIC_) {
254       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
255         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
256          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
257       LSDAEncoding = dwarf::DW_EH_PE_pcrel |
258         (CMModel == CodeModel::Small
259          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
260       FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
261       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
262         ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
263          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
264     } else {
265       PersonalityEncoding =
266         (CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
267         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
268       LSDAEncoding = (CMModel == CodeModel::Small)
269         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
270       FDEEncoding = dwarf::DW_EH_PE_udata4;
271       TTypeEncoding = (CMModel == CodeModel::Small)
272         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
273     }
274   }  else if (T.getArch() ==  Triple::aarch64) {
275     // The small model guarantees static code/data size < 4GB, but not where it
276     // will be in memory. Most of these could end up >2GB away so even a signed
277     // pc-relative 32-bit address is insufficient, theoretically.
278     if (RelocM == Reloc::PIC_) {
279       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
280         dwarf::DW_EH_PE_sdata8;
281       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8;
282       FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
283       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
284         dwarf::DW_EH_PE_sdata8;
285     } else {
286       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
287       LSDAEncoding = dwarf::DW_EH_PE_absptr;
288       FDEEncoding = dwarf::DW_EH_PE_udata4;
289       TTypeEncoding = dwarf::DW_EH_PE_absptr;
290     }
291   } else if (T.getArch() == Triple::ppc64) {
292     PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
293       dwarf::DW_EH_PE_udata8;
294     LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
295     FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
296     TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
297       dwarf::DW_EH_PE_udata8;
298   } else if (T.getArch() == Triple::systemz) {
299     // All currently-defined code models guarantee that 4-byte PC-relative
300     // values will be in range.
301     if (RelocM == Reloc::PIC_) {
302       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
303         dwarf::DW_EH_PE_sdata4;
304       LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
305       FDEEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
306       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
307         dwarf::DW_EH_PE_sdata4;
308     } else {
309       PersonalityEncoding = dwarf::DW_EH_PE_absptr;
310       LSDAEncoding = dwarf::DW_EH_PE_absptr;
311       FDEEncoding = dwarf::DW_EH_PE_absptr;
312       TTypeEncoding = dwarf::DW_EH_PE_absptr;
313     }
314   }
315 
316   // Solaris requires different flags for .eh_frame to seemingly every other
317   // platform.
318   EHSectionType = ELF::SHT_PROGBITS;
319   EHSectionFlags = ELF::SHF_ALLOC;
320   if (T.getOS() == Triple::Solaris) {
321     if (T.getArch() == Triple::x86_64)
322       EHSectionType = ELF::SHT_X86_64_UNWIND;
323     else
324       EHSectionFlags |= ELF::SHF_WRITE;
325   }
326 
327 
328   // ELF
329   BSSSection =
330     Ctx->getELFSection(".bss", ELF::SHT_NOBITS,
331                        ELF::SHF_WRITE | ELF::SHF_ALLOC,
332                        SectionKind::getBSS());
333 
334   TextSection =
335     Ctx->getELFSection(".text", ELF::SHT_PROGBITS,
336                        ELF::SHF_EXECINSTR |
337                        ELF::SHF_ALLOC,
338                        SectionKind::getText());
339 
340   DataSection =
341     Ctx->getELFSection(".data", ELF::SHT_PROGBITS,
342                        ELF::SHF_WRITE |ELF::SHF_ALLOC,
343                        SectionKind::getDataRel());
344 
345   ReadOnlySection =
346     Ctx->getELFSection(".rodata", ELF::SHT_PROGBITS,
347                        ELF::SHF_ALLOC,
348                        SectionKind::getReadOnly());
349 
350   TLSDataSection =
351     Ctx->getELFSection(".tdata", ELF::SHT_PROGBITS,
352                        ELF::SHF_ALLOC | ELF::SHF_TLS |
353                        ELF::SHF_WRITE,
354                        SectionKind::getThreadData());
355 
356   TLSBSSSection =
357     Ctx->getELFSection(".tbss", ELF::SHT_NOBITS,
358                        ELF::SHF_ALLOC | ELF::SHF_TLS |
359                        ELF::SHF_WRITE,
360                        SectionKind::getThreadBSS());
361 
362   DataRelSection =
363     Ctx->getELFSection(".data.rel", ELF::SHT_PROGBITS,
364                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
365                        SectionKind::getDataRel());
366 
367   DataRelLocalSection =
368     Ctx->getELFSection(".data.rel.local", ELF::SHT_PROGBITS,
369                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
370                        SectionKind::getDataRelLocal());
371 
372   DataRelROSection =
373     Ctx->getELFSection(".data.rel.ro", ELF::SHT_PROGBITS,
374                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
375                        SectionKind::getReadOnlyWithRel());
376 
377   DataRelROLocalSection =
378     Ctx->getELFSection(".data.rel.ro.local", ELF::SHT_PROGBITS,
379                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
380                        SectionKind::getReadOnlyWithRelLocal());
381 
382   MergeableConst4Section =
383     Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS,
384                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
385                        SectionKind::getMergeableConst4());
386 
387   MergeableConst8Section =
388     Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS,
389                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
390                        SectionKind::getMergeableConst8());
391 
392   MergeableConst16Section =
393     Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS,
394                        ELF::SHF_ALLOC |ELF::SHF_MERGE,
395                        SectionKind::getMergeableConst16());
396 
397   StaticCtorSection =
398     Ctx->getELFSection(".ctors", ELF::SHT_PROGBITS,
399                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
400                        SectionKind::getDataRel());
401 
402   StaticDtorSection =
403     Ctx->getELFSection(".dtors", ELF::SHT_PROGBITS,
404                        ELF::SHF_ALLOC |ELF::SHF_WRITE,
405                        SectionKind::getDataRel());
406 
407   // Exception Handling Sections.
408 
409   // FIXME: We're emitting LSDA info into a readonly section on ELF, even though
410   // it contains relocatable pointers.  In PIC mode, this is probably a big
411   // runtime hit for C++ apps.  Either the contents of the LSDA need to be
412   // adjusted or this should be a data section.
413   LSDASection =
414     Ctx->getELFSection(".gcc_except_table", ELF::SHT_PROGBITS,
415                        ELF::SHF_ALLOC,
416                        SectionKind::getReadOnly());
417 
418   // Debug Info Sections.
419   DwarfAbbrevSection =
420     Ctx->getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0,
421                        SectionKind::getMetadata());
422   DwarfInfoSection =
423     Ctx->getELFSection(".debug_info", ELF::SHT_PROGBITS, 0,
424                        SectionKind::getMetadata());
425   DwarfLineSection =
426     Ctx->getELFSection(".debug_line", ELF::SHT_PROGBITS, 0,
427                        SectionKind::getMetadata());
428   DwarfFrameSection =
429     Ctx->getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0,
430                        SectionKind::getMetadata());
431   DwarfPubNamesSection =
432     Ctx->getELFSection(".debug_pubnames", ELF::SHT_PROGBITS, 0,
433                        SectionKind::getMetadata());
434   DwarfPubTypesSection =
435     Ctx->getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0,
436                        SectionKind::getMetadata());
437   DwarfStrSection =
438     Ctx->getELFSection(".debug_str", ELF::SHT_PROGBITS,
439                        ELF::SHF_MERGE | ELF::SHF_STRINGS,
440                        SectionKind::getMergeable1ByteCString());
441   DwarfLocSection =
442     Ctx->getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0,
443                        SectionKind::getMetadata());
444   DwarfARangesSection =
445     Ctx->getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0,
446                        SectionKind::getMetadata());
447   DwarfRangesSection =
448     Ctx->getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0,
449                        SectionKind::getMetadata());
450   DwarfMacroInfoSection =
451     Ctx->getELFSection(".debug_macinfo", ELF::SHT_PROGBITS, 0,
452                        SectionKind::getMetadata());
453 
454   // DWARF5 Experimental Debug Info
455 
456   // Accelerator Tables
457   DwarfAccelNamesSection =
458     Ctx->getELFSection(".apple_names", ELF::SHT_PROGBITS, 0,
459                        SectionKind::getMetadata());
460   DwarfAccelObjCSection =
461     Ctx->getELFSection(".apple_objc", ELF::SHT_PROGBITS, 0,
462                        SectionKind::getMetadata());
463   DwarfAccelNamespaceSection =
464     Ctx->getELFSection(".apple_namespaces", ELF::SHT_PROGBITS, 0,
465                        SectionKind::getMetadata());
466   DwarfAccelTypesSection =
467     Ctx->getELFSection(".apple_types", ELF::SHT_PROGBITS, 0,
468                        SectionKind::getMetadata());
469 
470   // Fission Sections
471   DwarfInfoDWOSection =
472     Ctx->getELFSection(".debug_info.dwo", ELF::SHT_PROGBITS, 0,
473                        SectionKind::getMetadata());
474   DwarfAbbrevDWOSection =
475     Ctx->getELFSection(".debug_abbrev.dwo", ELF::SHT_PROGBITS, 0,
476                        SectionKind::getMetadata());
477   DwarfStrDWOSection =
478     Ctx->getELFSection(".debug_str.dwo", ELF::SHT_PROGBITS,
479                        ELF::SHF_MERGE | ELF::SHF_STRINGS,
480                        SectionKind::getMergeable1ByteCString());
481   DwarfLineDWOSection =
482     Ctx->getELFSection(".debug_line.dwo", ELF::SHT_PROGBITS, 0,
483                        SectionKind::getMetadata());
484   DwarfLocDWOSection =
485     Ctx->getELFSection(".debug_loc.dwo", ELF::SHT_PROGBITS, 0,
486                        SectionKind::getMetadata());
487   DwarfStrOffDWOSection =
488     Ctx->getELFSection(".debug_str_offsets.dwo", ELF::SHT_PROGBITS, 0,
489                        SectionKind::getMetadata());
490   DwarfAddrSection =
491     Ctx->getELFSection(".debug_addr", ELF::SHT_PROGBITS, 0,
492                        SectionKind::getMetadata());
493 }
494 
495 
496 void MCObjectFileInfo::InitCOFFMCObjectFileInfo(Triple T) {
497   // COFF
498   TextSection =
499     Ctx->getCOFFSection(".text",
500                         COFF::IMAGE_SCN_CNT_CODE |
501                         COFF::IMAGE_SCN_MEM_EXECUTE |
502                         COFF::IMAGE_SCN_MEM_READ,
503                         SectionKind::getText());
504   DataSection =
505     Ctx->getCOFFSection(".data",
506                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
507                         COFF::IMAGE_SCN_MEM_READ |
508                         COFF::IMAGE_SCN_MEM_WRITE,
509                         SectionKind::getDataRel());
510   ReadOnlySection =
511     Ctx->getCOFFSection(".rdata",
512                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
513                         COFF::IMAGE_SCN_MEM_READ,
514                         SectionKind::getReadOnly());
515   if (T.getOS() == Triple::Win32) {
516     StaticCtorSection =
517       Ctx->getCOFFSection(".CRT$XCU",
518                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
519                           COFF::IMAGE_SCN_MEM_READ,
520                           SectionKind::getReadOnly());
521   } else {
522     StaticCtorSection =
523       Ctx->getCOFFSection(".ctors",
524                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
525                           COFF::IMAGE_SCN_MEM_READ |
526                           COFF::IMAGE_SCN_MEM_WRITE,
527                           SectionKind::getDataRel());
528   }
529 
530 
531   if (T.getOS() == Triple::Win32) {
532     StaticDtorSection =
533       Ctx->getCOFFSection(".CRT$XTX",
534                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
535                           COFF::IMAGE_SCN_MEM_READ,
536                           SectionKind::getReadOnly());
537   } else {
538     StaticDtorSection =
539       Ctx->getCOFFSection(".dtors",
540                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
541                           COFF::IMAGE_SCN_MEM_READ |
542                           COFF::IMAGE_SCN_MEM_WRITE,
543                           SectionKind::getDataRel());
544   }
545 
546   // FIXME: We're emitting LSDA info into a readonly section on COFF, even
547   // though it contains relocatable pointers.  In PIC mode, this is probably a
548   // big runtime hit for C++ apps.  Either the contents of the LSDA need to be
549   // adjusted or this should be a data section.
550   LSDASection =
551     Ctx->getCOFFSection(".gcc_except_table",
552                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
553                         COFF::IMAGE_SCN_MEM_READ,
554                         SectionKind::getReadOnly());
555 
556   // Debug info.
557   DwarfAbbrevSection =
558     Ctx->getCOFFSection(".debug_abbrev",
559                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
560                         COFF::IMAGE_SCN_MEM_READ,
561                         SectionKind::getMetadata());
562   DwarfInfoSection =
563     Ctx->getCOFFSection(".debug_info",
564                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
565                         COFF::IMAGE_SCN_MEM_READ,
566                         SectionKind::getMetadata());
567   DwarfLineSection =
568     Ctx->getCOFFSection(".debug_line",
569                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
570                         COFF::IMAGE_SCN_MEM_READ,
571                         SectionKind::getMetadata());
572   DwarfFrameSection =
573     Ctx->getCOFFSection(".debug_frame",
574                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
575                         COFF::IMAGE_SCN_MEM_READ,
576                         SectionKind::getMetadata());
577   DwarfPubNamesSection =
578     Ctx->getCOFFSection(".debug_pubnames",
579                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
580                         COFF::IMAGE_SCN_MEM_READ,
581                         SectionKind::getMetadata());
582   DwarfPubTypesSection =
583     Ctx->getCOFFSection(".debug_pubtypes",
584                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
585                         COFF::IMAGE_SCN_MEM_READ,
586                         SectionKind::getMetadata());
587   DwarfStrSection =
588     Ctx->getCOFFSection(".debug_str",
589                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
590                         COFF::IMAGE_SCN_MEM_READ,
591                         SectionKind::getMetadata());
592   DwarfLocSection =
593     Ctx->getCOFFSection(".debug_loc",
594                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
595                         COFF::IMAGE_SCN_MEM_READ,
596                         SectionKind::getMetadata());
597   DwarfARangesSection =
598     Ctx->getCOFFSection(".debug_aranges",
599                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
600                         COFF::IMAGE_SCN_MEM_READ,
601                         SectionKind::getMetadata());
602   DwarfRangesSection =
603     Ctx->getCOFFSection(".debug_ranges",
604                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
605                         COFF::IMAGE_SCN_MEM_READ,
606                         SectionKind::getMetadata());
607   DwarfMacroInfoSection =
608     Ctx->getCOFFSection(".debug_macinfo",
609                         COFF::IMAGE_SCN_MEM_DISCARDABLE |
610                         COFF::IMAGE_SCN_MEM_READ,
611                         SectionKind::getMetadata());
612 
613   DrectveSection =
614     Ctx->getCOFFSection(".drectve",
615                         COFF::IMAGE_SCN_LNK_INFO,
616                         SectionKind::getMetadata());
617 
618   PDataSection =
619     Ctx->getCOFFSection(".pdata",
620                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
621                         COFF::IMAGE_SCN_MEM_READ,
622                         SectionKind::getDataRel());
623 
624   XDataSection =
625     Ctx->getCOFFSection(".xdata",
626                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
627                         COFF::IMAGE_SCN_MEM_READ,
628                         SectionKind::getDataRel());
629   TLSDataSection =
630     Ctx->getCOFFSection(".tls$",
631                         COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
632                         COFF::IMAGE_SCN_MEM_READ |
633                         COFF::IMAGE_SCN_MEM_WRITE,
634                         SectionKind::getDataRel());
635 }
636 
637 void MCObjectFileInfo::InitMCObjectFileInfo(StringRef TT, Reloc::Model relocm,
638                                             CodeModel::Model cm,
639                                             MCContext &ctx) {
640   RelocM = relocm;
641   CMModel = cm;
642   Ctx = &ctx;
643 
644   // Common.
645   CommDirectiveSupportsAlignment = true;
646   SupportsWeakOmittedEHFrame = true;
647   IsFunctionEHFrameSymbolPrivate = true;
648 
649   PersonalityEncoding = LSDAEncoding = FDEEncoding = FDECFIEncoding =
650     TTypeEncoding = dwarf::DW_EH_PE_absptr;
651 
652   CompactUnwindDwarfEHFrameOnly = 0;
653 
654   EHFrameSection = 0;             // Created on demand.
655   CompactUnwindSection = 0;       // Used only by selected targets.
656   DwarfAccelNamesSection = 0;     // Used only by selected targets.
657   DwarfAccelObjCSection = 0;      // Used only by selected targets.
658   DwarfAccelNamespaceSection = 0; // Used only by selected targets.
659   DwarfAccelTypesSection = 0;     // Used only by selected targets.
660 
661   Triple T(TT);
662   Triple::ArchType Arch = T.getArch();
663   // FIXME: Checking for Arch here to filter out bogus triples such as
664   // cellspu-apple-darwin. Perhaps we should fix in Triple?
665   if ((Arch == Triple::x86 || Arch == Triple::x86_64 ||
666        Arch == Triple::arm || Arch == Triple::thumb ||
667        Arch == Triple::ppc || Arch == Triple::ppc64 ||
668        Arch == Triple::UnknownArch) &&
669       (T.isOSDarwin() || T.getEnvironment() == Triple::MachO)) {
670     Env = IsMachO;
671     InitMachOMCObjectFileInfo(T);
672   } else if ((Arch == Triple::x86 || Arch == Triple::x86_64) &&
673              (T.getEnvironment() != Triple::ELF) &&
674              (T.getOS() == Triple::MinGW32 || T.getOS() == Triple::Cygwin ||
675               T.getOS() == Triple::Win32)) {
676     Env = IsCOFF;
677     InitCOFFMCObjectFileInfo(T);
678   } else {
679     Env = IsELF;
680     InitELFMCObjectFileInfo(T);
681   }
682 }
683 
684 void MCObjectFileInfo::InitEHFrameSection() {
685   if (Env == IsMachO)
686     EHFrameSection =
687       Ctx->getMachOSection("__TEXT", "__eh_frame",
688                            MCSectionMachO::S_COALESCED |
689                            MCSectionMachO::S_ATTR_NO_TOC |
690                            MCSectionMachO::S_ATTR_STRIP_STATIC_SYMS |
691                            MCSectionMachO::S_ATTR_LIVE_SUPPORT,
692                            SectionKind::getReadOnly());
693   else if (Env == IsELF)
694     EHFrameSection =
695       Ctx->getELFSection(".eh_frame", EHSectionType,
696                          EHSectionFlags,
697                          SectionKind::getDataRel());
698   else
699     EHFrameSection =
700       Ctx->getCOFFSection(".eh_frame",
701                           COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
702                           COFF::IMAGE_SCN_MEM_READ |
703                           COFF::IMAGE_SCN_MEM_WRITE,
704                           SectionKind::getDataRel());
705 }
706