1 //===-- llvm/BinaryFormat/Dwarf.cpp - Dwarf Framework ------------*- C++-*-===//
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 // This file contains support for generic dwarf information.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "llvm/BinaryFormat/Dwarf.h"
15 #include "llvm/ADT/StringSwitch.h"
16 #include "llvm/ADT/Triple.h"
17 #include "llvm/Support/ErrorHandling.h"
18 
19 using namespace llvm;
20 using namespace dwarf;
21 
22 StringRef llvm::dwarf::TagString(unsigned Tag) {
23   switch (Tag) {
24   default:
25     return StringRef();
26 #define HANDLE_DW_TAG(ID, NAME, VERSION, VENDOR)                               \
27   case DW_TAG_##NAME:                                                          \
28     return "DW_TAG_" #NAME;
29 #include "llvm/BinaryFormat/Dwarf.def"
30   }
31 }
32 
33 unsigned llvm::dwarf::getTag(StringRef TagString) {
34   return StringSwitch<unsigned>(TagString)
35 #define HANDLE_DW_TAG(ID, NAME, VERSION, VENDOR)                               \
36   .Case("DW_TAG_" #NAME, DW_TAG_##NAME)
37 #include "llvm/BinaryFormat/Dwarf.def"
38       .Default(DW_TAG_invalid);
39 }
40 
41 unsigned llvm::dwarf::TagVersion(dwarf::Tag Tag) {
42   switch (Tag) {
43   default:
44     return 0;
45 #define HANDLE_DW_TAG(ID, NAME, VERSION, VENDOR)                               \
46   case DW_TAG_##NAME:                                                          \
47     return VERSION;
48 #include "llvm/BinaryFormat/Dwarf.def"
49   }
50 }
51 
52 unsigned llvm::dwarf::TagVendor(dwarf::Tag Tag) {
53   switch (Tag) {
54   default:
55     return 0;
56 #define HANDLE_DW_TAG(ID, NAME, VERSION, VENDOR)                               \
57   case DW_TAG_##NAME:                                                          \
58     return DWARF_VENDOR_##VENDOR;
59 #include "llvm/BinaryFormat/Dwarf.def"
60   }
61 }
62 
63 StringRef llvm::dwarf::ChildrenString(unsigned Children) {
64   switch (Children) {
65   case DW_CHILDREN_no:
66     return "DW_CHILDREN_no";
67   case DW_CHILDREN_yes:
68     return "DW_CHILDREN_yes";
69   }
70   return StringRef();
71 }
72 
73 StringRef llvm::dwarf::AttributeString(unsigned Attribute) {
74   switch (Attribute) {
75   default:
76     return StringRef();
77 #define HANDLE_DW_AT(ID, NAME, VERSION, VENDOR)                                \
78   case DW_AT_##NAME:                                                           \
79     return "DW_AT_" #NAME;
80 #include "llvm/BinaryFormat/Dwarf.def"
81   }
82 }
83 
84 unsigned llvm::dwarf::AttributeVersion(dwarf::Attribute Attribute) {
85   switch (Attribute) {
86   default:
87     return 0;
88 #define HANDLE_DW_AT(ID, NAME, VERSION, VENDOR)                                \
89   case DW_AT_##NAME:                                                           \
90     return VERSION;
91 #include "llvm/BinaryFormat/Dwarf.def"
92   }
93 }
94 
95 unsigned llvm::dwarf::AttributeVendor(dwarf::Attribute Attribute) {
96   switch (Attribute) {
97   default:
98     return 0;
99 #define HANDLE_DW_AT(ID, NAME, VERSION, VENDOR)                                \
100   case DW_AT_##NAME:                                                           \
101     return DWARF_VENDOR_##VENDOR;
102 #include "llvm/BinaryFormat/Dwarf.def"
103   }
104 }
105 
106 StringRef llvm::dwarf::FormEncodingString(unsigned Encoding) {
107   switch (Encoding) {
108   default:
109     return StringRef();
110 #define HANDLE_DW_FORM(ID, NAME, VERSION, VENDOR)                              \
111   case DW_FORM_##NAME:                                                         \
112     return "DW_FORM_" #NAME;
113 #include "llvm/BinaryFormat/Dwarf.def"
114   }
115 }
116 
117 unsigned llvm::dwarf::FormVersion(dwarf::Form Form) {
118   switch (Form) {
119   default:
120     return 0;
121 #define HANDLE_DW_FORM(ID, NAME, VERSION, VENDOR)                              \
122   case DW_FORM_##NAME:                                                         \
123     return VERSION;
124 #include "llvm/BinaryFormat/Dwarf.def"
125   }
126 }
127 
128 unsigned llvm::dwarf::FormVendor(dwarf::Form Form) {
129   switch (Form) {
130   default:
131     return 0;
132 #define HANDLE_DW_FORM(ID, NAME, VERSION, VENDOR)                              \
133   case DW_FORM_##NAME:                                                         \
134     return DWARF_VENDOR_##VENDOR;
135 #include "llvm/BinaryFormat/Dwarf.def"
136   }
137 }
138 
139 StringRef llvm::dwarf::OperationEncodingString(unsigned Encoding) {
140   switch (Encoding) {
141   default:
142     return StringRef();
143 #define HANDLE_DW_OP(ID, NAME, VERSION, VENDOR)                                \
144   case DW_OP_##NAME:                                                           \
145     return "DW_OP_" #NAME;
146 #include "llvm/BinaryFormat/Dwarf.def"
147   case DW_OP_LLVM_fragment:
148     return "DW_OP_LLVM_fragment";
149   }
150 }
151 
152 unsigned llvm::dwarf::getOperationEncoding(StringRef OperationEncodingString) {
153   return StringSwitch<unsigned>(OperationEncodingString)
154 #define HANDLE_DW_OP(ID, NAME, VERSION, VENDOR)                                \
155   .Case("DW_OP_" #NAME, DW_OP_##NAME)
156 #include "llvm/BinaryFormat/Dwarf.def"
157       .Case("DW_OP_LLVM_fragment", DW_OP_LLVM_fragment)
158       .Default(0);
159 }
160 
161 unsigned llvm::dwarf::OperationVersion(dwarf::LocationAtom Op) {
162   switch (Op) {
163   default:
164     return 0;
165 #define HANDLE_DW_OP(ID, NAME, VERSION, VENDOR)                                \
166   case DW_OP_##NAME:                                                           \
167     return VERSION;
168 #include "llvm/BinaryFormat/Dwarf.def"
169   }
170 }
171 
172 unsigned llvm::dwarf::OperationVendor(dwarf::LocationAtom Op) {
173   switch (Op) {
174   default:
175     return 0;
176 #define HANDLE_DW_OP(ID, NAME, VERSION, VENDOR)                                \
177   case DW_OP_##NAME:                                                           \
178     return DWARF_VENDOR_##VENDOR;
179 #include "llvm/BinaryFormat/Dwarf.def"
180   }
181 }
182 
183 StringRef llvm::dwarf::AttributeEncodingString(unsigned Encoding) {
184   switch (Encoding) {
185   default:
186     return StringRef();
187 #define HANDLE_DW_ATE(ID, NAME, VERSION, VENDOR)                               \
188   case DW_ATE_##NAME:                                                          \
189     return "DW_ATE_" #NAME;
190 #include "llvm/BinaryFormat/Dwarf.def"
191   }
192 }
193 
194 unsigned llvm::dwarf::getAttributeEncoding(StringRef EncodingString) {
195   return StringSwitch<unsigned>(EncodingString)
196 #define HANDLE_DW_ATE(ID, NAME, VERSION, VENDOR)                               \
197   .Case("DW_ATE_" #NAME, DW_ATE_##NAME)
198 #include "llvm/BinaryFormat/Dwarf.def"
199       .Default(0);
200 }
201 
202 unsigned llvm::dwarf::AttributeEncodingVersion(dwarf::TypeKind ATE) {
203   switch (ATE) {
204   default:
205     return 0;
206 #define HANDLE_DW_ATE(ID, NAME, VERSION, VENDOR)                               \
207   case DW_ATE_##NAME:                                                          \
208     return VERSION;
209 #include "llvm/BinaryFormat/Dwarf.def"
210   }
211 }
212 
213 unsigned llvm::dwarf::AttributeEncodingVendor(dwarf::TypeKind ATE) {
214   switch (ATE) {
215   default:
216     return 0;
217 #define HANDLE_DW_ATE(ID, NAME, VERSION, VENDOR)                               \
218   case DW_ATE_##NAME:                                                          \
219     return DWARF_VENDOR_##VENDOR;
220 #include "llvm/BinaryFormat/Dwarf.def"
221   }
222 }
223 
224 StringRef llvm::dwarf::DecimalSignString(unsigned Sign) {
225   switch (Sign) {
226   case DW_DS_unsigned:
227     return "DW_DS_unsigned";
228   case DW_DS_leading_overpunch:
229     return "DW_DS_leading_overpunch";
230   case DW_DS_trailing_overpunch:
231     return "DW_DS_trailing_overpunch";
232   case DW_DS_leading_separate:
233     return "DW_DS_leading_separate";
234   case DW_DS_trailing_separate:
235     return "DW_DS_trailing_separate";
236   }
237   return StringRef();
238 }
239 
240 StringRef llvm::dwarf::EndianityString(unsigned Endian) {
241   switch (Endian) {
242   case DW_END_default:
243     return "DW_END_default";
244   case DW_END_big:
245     return "DW_END_big";
246   case DW_END_little:
247     return "DW_END_little";
248   case DW_END_lo_user:
249     return "DW_END_lo_user";
250   case DW_END_hi_user:
251     return "DW_END_hi_user";
252   }
253   return StringRef();
254 }
255 
256 StringRef llvm::dwarf::AccessibilityString(unsigned Access) {
257   switch (Access) {
258   // Accessibility codes
259   case DW_ACCESS_public:
260     return "DW_ACCESS_public";
261   case DW_ACCESS_protected:
262     return "DW_ACCESS_protected";
263   case DW_ACCESS_private:
264     return "DW_ACCESS_private";
265   }
266   return StringRef();
267 }
268 
269 StringRef llvm::dwarf::VisibilityString(unsigned Visibility) {
270   switch (Visibility) {
271   case DW_VIS_local:
272     return "DW_VIS_local";
273   case DW_VIS_exported:
274     return "DW_VIS_exported";
275   case DW_VIS_qualified:
276     return "DW_VIS_qualified";
277   }
278   return StringRef();
279 }
280 
281 StringRef llvm::dwarf::VirtualityString(unsigned Virtuality) {
282   switch (Virtuality) {
283   default:
284     return StringRef();
285 #define HANDLE_DW_VIRTUALITY(ID, NAME)                                         \
286   case DW_VIRTUALITY_##NAME:                                                   \
287     return "DW_VIRTUALITY_" #NAME;
288 #include "llvm/BinaryFormat/Dwarf.def"
289   }
290 }
291 
292 unsigned llvm::dwarf::getVirtuality(StringRef VirtualityString) {
293   return StringSwitch<unsigned>(VirtualityString)
294 #define HANDLE_DW_VIRTUALITY(ID, NAME)                                         \
295   .Case("DW_VIRTUALITY_" #NAME, DW_VIRTUALITY_##NAME)
296 #include "llvm/BinaryFormat/Dwarf.def"
297       .Default(DW_VIRTUALITY_invalid);
298 }
299 
300 StringRef llvm::dwarf::LanguageString(unsigned Language) {
301   switch (Language) {
302   default:
303     return StringRef();
304 #define HANDLE_DW_LANG(ID, NAME, VERSION, VENDOR)                              \
305   case DW_LANG_##NAME:                                                         \
306     return "DW_LANG_" #NAME;
307 #include "llvm/BinaryFormat/Dwarf.def"
308   }
309 }
310 
311 unsigned llvm::dwarf::getLanguage(StringRef LanguageString) {
312   return StringSwitch<unsigned>(LanguageString)
313 #define HANDLE_DW_LANG(ID, NAME, VERSION, VENDOR)                              \
314   .Case("DW_LANG_" #NAME, DW_LANG_##NAME)
315 #include "llvm/BinaryFormat/Dwarf.def"
316       .Default(0);
317 }
318 
319 unsigned llvm::dwarf::LanguageVersion(dwarf::SourceLanguage Lang) {
320   switch (Lang) {
321   default:
322     return 0;
323 #define HANDLE_DW_LANG(ID, NAME, VERSION, VENDOR)                              \
324   case DW_LANG_##NAME:                                                         \
325     return VERSION;
326 #include "llvm/BinaryFormat/Dwarf.def"
327   }
328 }
329 
330 unsigned llvm::dwarf::LanguageVendor(dwarf::SourceLanguage Lang) {
331   switch (Lang) {
332   default:
333     return 0;
334 #define HANDLE_DW_LANG(ID, NAME, VERSION, VENDOR)                              \
335   case DW_LANG_##NAME:                                                         \
336     return DWARF_VENDOR_##VENDOR;
337 #include "llvm/BinaryFormat/Dwarf.def"
338   }
339 }
340 
341 StringRef llvm::dwarf::CaseString(unsigned Case) {
342   switch (Case) {
343   case DW_ID_case_sensitive:
344     return "DW_ID_case_sensitive";
345   case DW_ID_up_case:
346     return "DW_ID_up_case";
347   case DW_ID_down_case:
348     return "DW_ID_down_case";
349   case DW_ID_case_insensitive:
350     return "DW_ID_case_insensitive";
351   }
352   return StringRef();
353 }
354 
355 StringRef llvm::dwarf::ConventionString(unsigned CC) {
356   switch (CC) {
357   default:
358     return StringRef();
359 #define HANDLE_DW_CC(ID, NAME)                                                 \
360   case DW_CC_##NAME:                                                           \
361     return "DW_CC_" #NAME;
362 #include "llvm/BinaryFormat/Dwarf.def"
363   }
364 }
365 
366 unsigned llvm::dwarf::getCallingConvention(StringRef CCString) {
367   return StringSwitch<unsigned>(CCString)
368 #define HANDLE_DW_CC(ID, NAME) .Case("DW_CC_" #NAME, DW_CC_##NAME)
369 #include "llvm/BinaryFormat/Dwarf.def"
370       .Default(0);
371 }
372 
373 StringRef llvm::dwarf::InlineCodeString(unsigned Code) {
374   switch (Code) {
375   case DW_INL_not_inlined:
376     return "DW_INL_not_inlined";
377   case DW_INL_inlined:
378     return "DW_INL_inlined";
379   case DW_INL_declared_not_inlined:
380     return "DW_INL_declared_not_inlined";
381   case DW_INL_declared_inlined:
382     return "DW_INL_declared_inlined";
383   }
384   return StringRef();
385 }
386 
387 StringRef llvm::dwarf::ArrayOrderString(unsigned Order) {
388   switch (Order) {
389   case DW_ORD_row_major:
390     return "DW_ORD_row_major";
391   case DW_ORD_col_major:
392     return "DW_ORD_col_major";
393   }
394   return StringRef();
395 }
396 
397 StringRef llvm::dwarf::LNStandardString(unsigned Standard) {
398   switch (Standard) {
399   default:
400     return StringRef();
401 #define HANDLE_DW_LNS(ID, NAME)                                                \
402   case DW_LNS_##NAME:                                                          \
403     return "DW_LNS_" #NAME;
404 #include "llvm/BinaryFormat/Dwarf.def"
405   }
406 }
407 
408 StringRef llvm::dwarf::LNExtendedString(unsigned Encoding) {
409   switch (Encoding) {
410   default:
411     return StringRef();
412 #define HANDLE_DW_LNE(ID, NAME)                                                \
413   case DW_LNE_##NAME:                                                          \
414     return "DW_LNE_" #NAME;
415 #include "llvm/BinaryFormat/Dwarf.def"
416   }
417 }
418 
419 StringRef llvm::dwarf::MacinfoString(unsigned Encoding) {
420   switch (Encoding) {
421   // Macinfo Type Encodings
422   case DW_MACINFO_define:
423     return "DW_MACINFO_define";
424   case DW_MACINFO_undef:
425     return "DW_MACINFO_undef";
426   case DW_MACINFO_start_file:
427     return "DW_MACINFO_start_file";
428   case DW_MACINFO_end_file:
429     return "DW_MACINFO_end_file";
430   case DW_MACINFO_vendor_ext:
431     return "DW_MACINFO_vendor_ext";
432   case DW_MACINFO_invalid:
433     return "DW_MACINFO_invalid";
434   }
435   return StringRef();
436 }
437 
438 unsigned llvm::dwarf::getMacinfo(StringRef MacinfoString) {
439   return StringSwitch<unsigned>(MacinfoString)
440       .Case("DW_MACINFO_define", DW_MACINFO_define)
441       .Case("DW_MACINFO_undef", DW_MACINFO_undef)
442       .Case("DW_MACINFO_start_file", DW_MACINFO_start_file)
443       .Case("DW_MACINFO_end_file", DW_MACINFO_end_file)
444       .Case("DW_MACINFO_vendor_ext", DW_MACINFO_vendor_ext)
445       .Default(DW_MACINFO_invalid);
446 }
447 
448 StringRef llvm::dwarf::RangeListEncodingString(unsigned Encoding) {
449   switch (Encoding) {
450   default:
451     return StringRef();
452 #define HANDLE_DW_RLE(ID, NAME)                                                \
453   case DW_RLE_##NAME:                                                          \
454     return "DW_RLE_" #NAME;
455 #include "llvm/BinaryFormat/Dwarf.def"
456   }
457 }
458 
459 StringRef llvm::dwarf::CallFrameString(unsigned Encoding,
460     Triple::ArchType Arch) {
461   assert(Arch != llvm::Triple::ArchType::UnknownArch);
462 #define SELECT_AARCH64 (Arch == llvm::Triple::aarch64_be || Arch == llvm::Triple::aarch64)
463 #define SELECT_MIPS64 Arch == llvm::Triple::mips64
464 #define SELECT_SPARC (Arch == llvm::Triple::sparc || Arch == llvm::Triple::sparcv9)
465 #define SELECT_X86 (Arch == llvm::Triple::x86 || Arch == llvm::Triple::x86_64)
466 #define HANDLE_DW_CFA(ID, NAME)
467 #define HANDLE_DW_CFA_PRED(ID, NAME, PRED) \
468   if (ID == Encoding && PRED) \
469     return "DW_CFA_" #NAME;
470 #include "llvm/BinaryFormat/Dwarf.def"
471 
472   switch (Encoding) {
473   default:
474     return StringRef();
475 #define HANDLE_DW_CFA_PRED(ID, NAME, PRED)
476 #define HANDLE_DW_CFA(ID, NAME)                                                \
477   case DW_CFA_##NAME:                                                          \
478     return "DW_CFA_" #NAME;
479 #include "llvm/BinaryFormat/Dwarf.def"
480 
481 #undef SELECT_X86
482 #undef SELECT_SPARC
483 #undef SELECT_MIPS64
484 #undef SELECT_AARCH64
485   }
486 }
487 
488 StringRef llvm::dwarf::ApplePropertyString(unsigned Prop) {
489   switch (Prop) {
490   default:
491     return StringRef();
492 #define HANDLE_DW_APPLE_PROPERTY(ID, NAME)                                     \
493   case DW_APPLE_PROPERTY_##NAME:                                               \
494     return "DW_APPLE_PROPERTY_" #NAME;
495 #include "llvm/BinaryFormat/Dwarf.def"
496   }
497 }
498 
499 StringRef llvm::dwarf::UnitTypeString(unsigned UT) {
500   switch (UT) {
501   default:
502     return StringRef();
503 #define HANDLE_DW_UT(ID, NAME)                                                 \
504   case DW_UT_##NAME:                                                           \
505     return "DW_UT_" #NAME;
506 #include "llvm/BinaryFormat/Dwarf.def"
507   }
508 }
509 
510 StringRef llvm::dwarf::AtomTypeString(unsigned AT) {
511   switch (AT) {
512   case dwarf::DW_ATOM_null:
513     return "DW_ATOM_null";
514   case dwarf::DW_ATOM_die_offset:
515     return "DW_ATOM_die_offset";
516   case DW_ATOM_cu_offset:
517     return "DW_ATOM_cu_offset";
518   case DW_ATOM_die_tag:
519     return "DW_ATOM_die_tag";
520   case DW_ATOM_type_flags:
521   case DW_ATOM_type_type_flags:
522     return "DW_ATOM_type_flags";
523   case DW_ATOM_qual_name_hash:
524     return "DW_ATOM_qual_name_hash";
525   }
526   return StringRef();
527 }
528 
529 StringRef llvm::dwarf::GDBIndexEntryKindString(GDBIndexEntryKind Kind) {
530   switch (Kind) {
531   case GIEK_NONE:
532     return "NONE";
533   case GIEK_TYPE:
534     return "TYPE";
535   case GIEK_VARIABLE:
536     return "VARIABLE";
537   case GIEK_FUNCTION:
538     return "FUNCTION";
539   case GIEK_OTHER:
540     return "OTHER";
541   case GIEK_UNUSED5:
542     return "UNUSED5";
543   case GIEK_UNUSED6:
544     return "UNUSED6";
545   case GIEK_UNUSED7:
546     return "UNUSED7";
547   }
548   llvm_unreachable("Unknown GDBIndexEntryKind value");
549 }
550 
551 StringRef
552 llvm::dwarf::GDBIndexEntryLinkageString(GDBIndexEntryLinkage Linkage) {
553   switch (Linkage) {
554   case GIEL_EXTERNAL:
555     return "EXTERNAL";
556   case GIEL_STATIC:
557     return "STATIC";
558   }
559   llvm_unreachable("Unknown GDBIndexEntryLinkage value");
560 }
561 
562 StringRef llvm::dwarf::AttributeValueString(uint16_t Attr, unsigned Val) {
563   switch (Attr) {
564   case DW_AT_accessibility:
565     return AccessibilityString(Val);
566   case DW_AT_virtuality:
567     return VirtualityString(Val);
568   case DW_AT_language:
569     return LanguageString(Val);
570   case DW_AT_encoding:
571     return AttributeEncodingString(Val);
572   case DW_AT_decimal_sign:
573     return DecimalSignString(Val);
574   case DW_AT_endianity:
575     return EndianityString(Val);
576   case DW_AT_visibility:
577     return VisibilityString(Val);
578   case DW_AT_identifier_case:
579     return CaseString(Val);
580   case DW_AT_calling_convention:
581     return ConventionString(Val);
582   case DW_AT_inline:
583     return InlineCodeString(Val);
584   case DW_AT_ordering:
585     return ArrayOrderString(Val);
586   case DW_AT_APPLE_runtime_class:
587     return LanguageString(Val);
588   }
589 
590   return StringRef();
591 }
592 
593 StringRef llvm::dwarf::AtomValueString(uint16_t Atom, unsigned Val) {
594   switch (Atom) {
595   case DW_ATOM_null:
596     return "NULL";
597   case DW_ATOM_die_tag:
598     return TagString(Val);
599   }
600 
601   return StringRef();
602 }
603 
604 StringRef llvm::dwarf::IndexString(unsigned Idx) {
605   switch (Idx) {
606   default:
607     return StringRef();
608 #define HANDLE_DW_IDX(ID, NAME)                                                \
609   case DW_IDX_##NAME:                                                          \
610     return "DW_IDX_" #NAME;
611 #include "llvm/BinaryFormat/Dwarf.def"
612   }
613 }
614 
615 Optional<uint8_t> llvm::dwarf::getFixedFormByteSize(dwarf::Form Form,
616                                                     FormParams Params) {
617   switch (Form) {
618   case DW_FORM_addr:
619     if (Params)
620       return Params.AddrSize;
621     return None;
622 
623   case DW_FORM_block:          // ULEB128 length L followed by L bytes.
624   case DW_FORM_block1:         // 1 byte length L followed by L bytes.
625   case DW_FORM_block2:         // 2 byte length L followed by L bytes.
626   case DW_FORM_block4:         // 4 byte length L followed by L bytes.
627   case DW_FORM_string:         // C-string with null terminator.
628   case DW_FORM_sdata:          // SLEB128.
629   case DW_FORM_udata:          // ULEB128.
630   case DW_FORM_ref_udata:      // ULEB128.
631   case DW_FORM_indirect:       // ULEB128.
632   case DW_FORM_exprloc:        // ULEB128 length L followed by L bytes.
633   case DW_FORM_strx:           // ULEB128.
634   case DW_FORM_addrx:          // ULEB128.
635   case DW_FORM_loclistx:       // ULEB128.
636   case DW_FORM_rnglistx:       // ULEB128.
637   case DW_FORM_GNU_addr_index: // ULEB128.
638   case DW_FORM_GNU_str_index:  // ULEB128.
639     return None;
640 
641   case DW_FORM_ref_addr:
642     if (Params)
643       return Params.getRefAddrByteSize();
644     return None;
645 
646   case DW_FORM_flag:
647   case DW_FORM_data1:
648   case DW_FORM_ref1:
649   case DW_FORM_strx1:
650   case DW_FORM_addrx1:
651     return 1;
652 
653   case DW_FORM_data2:
654   case DW_FORM_ref2:
655   case DW_FORM_strx2:
656   case DW_FORM_addrx2:
657     return 2;
658 
659   case DW_FORM_strx3:
660     return 3;
661 
662   case DW_FORM_data4:
663   case DW_FORM_ref4:
664   case DW_FORM_ref_sup4:
665   case DW_FORM_strx4:
666   case DW_FORM_addrx4:
667     return 4;
668 
669   case DW_FORM_strp:
670   case DW_FORM_GNU_ref_alt:
671   case DW_FORM_GNU_strp_alt:
672   case DW_FORM_line_strp:
673   case DW_FORM_sec_offset:
674   case DW_FORM_strp_sup:
675     if (Params)
676       return Params.getDwarfOffsetByteSize();
677     return None;
678 
679   case DW_FORM_data8:
680   case DW_FORM_ref8:
681   case DW_FORM_ref_sig8:
682   case DW_FORM_ref_sup8:
683     return 8;
684 
685   case DW_FORM_flag_present:
686     return 0;
687 
688   case DW_FORM_data16:
689     return 16;
690 
691   case DW_FORM_implicit_const:
692     // The implicit value is stored in the abbreviation as a SLEB128, and
693     // there no data in debug info.
694     return 0;
695 
696   default:
697     break;
698   }
699   return None;
700 }
701 
702 bool llvm::dwarf::isValidFormForVersion(Form F, unsigned Version,
703                                         bool ExtensionsOk) {
704   if (FormVendor(F) == DWARF_VENDOR_DWARF) {
705     unsigned FV = FormVersion(F);
706     return FV > 0 && FV <= Version;
707   }
708   return ExtensionsOk;
709 }
710 
711 constexpr char llvm::dwarf::EnumTraits<Attribute>::Type[];
712 constexpr char llvm::dwarf::EnumTraits<Form>::Type[];
713 constexpr char llvm::dwarf::EnumTraits<Index>::Type[];
714 constexpr char llvm::dwarf::EnumTraits<Tag>::Type[];
715