1 //===-- llvm/BinaryFormat/Dwarf.cpp - Dwarf Framework ------------*- C++-*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file contains support for generic dwarf information.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "llvm/BinaryFormat/Dwarf.h"
14 #include "llvm/ADT/StringSwitch.h"
15 #include "llvm/ADT/Triple.h"
16 #include "llvm/Support/ErrorHandling.h"
17 
18 using namespace llvm;
19 using namespace dwarf;
20 
21 StringRef llvm::dwarf::TagString(unsigned Tag) {
22   switch (Tag) {
23   default:
24     return StringRef();
25 #define HANDLE_DW_TAG(ID, NAME, VERSION, VENDOR)                               \
26   case DW_TAG_##NAME:                                                          \
27     return "DW_TAG_" #NAME;
28 #include "llvm/BinaryFormat/Dwarf.def"
29   }
30 }
31 
32 unsigned llvm::dwarf::getTag(StringRef TagString) {
33   return StringSwitch<unsigned>(TagString)
34 #define HANDLE_DW_TAG(ID, NAME, VERSION, VENDOR)                               \
35   .Case("DW_TAG_" #NAME, DW_TAG_##NAME)
36 #include "llvm/BinaryFormat/Dwarf.def"
37       .Default(DW_TAG_invalid);
38 }
39 
40 unsigned llvm::dwarf::TagVersion(dwarf::Tag Tag) {
41   switch (Tag) {
42   default:
43     return 0;
44 #define HANDLE_DW_TAG(ID, NAME, VERSION, VENDOR)                               \
45   case DW_TAG_##NAME:                                                          \
46     return VERSION;
47 #include "llvm/BinaryFormat/Dwarf.def"
48   }
49 }
50 
51 unsigned llvm::dwarf::TagVendor(dwarf::Tag Tag) {
52   switch (Tag) {
53   default:
54     return 0;
55 #define HANDLE_DW_TAG(ID, NAME, VERSION, VENDOR)                               \
56   case DW_TAG_##NAME:                                                          \
57     return DWARF_VENDOR_##VENDOR;
58 #include "llvm/BinaryFormat/Dwarf.def"
59   }
60 }
61 
62 StringRef llvm::dwarf::ChildrenString(unsigned Children) {
63   switch (Children) {
64   case DW_CHILDREN_no:
65     return "DW_CHILDREN_no";
66   case DW_CHILDREN_yes:
67     return "DW_CHILDREN_yes";
68   }
69   return StringRef();
70 }
71 
72 StringRef llvm::dwarf::AttributeString(unsigned Attribute) {
73   switch (Attribute) {
74   default:
75     return StringRef();
76 #define HANDLE_DW_AT(ID, NAME, VERSION, VENDOR)                                \
77   case DW_AT_##NAME:                                                           \
78     return "DW_AT_" #NAME;
79 #include "llvm/BinaryFormat/Dwarf.def"
80   }
81 }
82 
83 unsigned llvm::dwarf::AttributeVersion(dwarf::Attribute Attribute) {
84   switch (Attribute) {
85   default:
86     return 0;
87 #define HANDLE_DW_AT(ID, NAME, VERSION, VENDOR)                                \
88   case DW_AT_##NAME:                                                           \
89     return VERSION;
90 #include "llvm/BinaryFormat/Dwarf.def"
91   }
92 }
93 
94 unsigned llvm::dwarf::AttributeVendor(dwarf::Attribute Attribute) {
95   switch (Attribute) {
96   default:
97     return 0;
98 #define HANDLE_DW_AT(ID, NAME, VERSION, VENDOR)                                \
99   case DW_AT_##NAME:                                                           \
100     return DWARF_VENDOR_##VENDOR;
101 #include "llvm/BinaryFormat/Dwarf.def"
102   }
103 }
104 
105 StringRef llvm::dwarf::FormEncodingString(unsigned Encoding) {
106   switch (Encoding) {
107   default:
108     return StringRef();
109 #define HANDLE_DW_FORM(ID, NAME, VERSION, VENDOR)                              \
110   case DW_FORM_##NAME:                                                         \
111     return "DW_FORM_" #NAME;
112 #include "llvm/BinaryFormat/Dwarf.def"
113   }
114 }
115 
116 unsigned llvm::dwarf::FormVersion(dwarf::Form Form) {
117   switch (Form) {
118   default:
119     return 0;
120 #define HANDLE_DW_FORM(ID, NAME, VERSION, VENDOR)                              \
121   case DW_FORM_##NAME:                                                         \
122     return VERSION;
123 #include "llvm/BinaryFormat/Dwarf.def"
124   }
125 }
126 
127 unsigned llvm::dwarf::FormVendor(dwarf::Form Form) {
128   switch (Form) {
129   default:
130     return 0;
131 #define HANDLE_DW_FORM(ID, NAME, VERSION, VENDOR)                              \
132   case DW_FORM_##NAME:                                                         \
133     return DWARF_VENDOR_##VENDOR;
134 #include "llvm/BinaryFormat/Dwarf.def"
135   }
136 }
137 
138 StringRef llvm::dwarf::OperationEncodingString(unsigned Encoding) {
139   switch (Encoding) {
140   default:
141     return StringRef();
142 #define HANDLE_DW_OP(ID, NAME, VERSION, VENDOR)                                \
143   case DW_OP_##NAME:                                                           \
144     return "DW_OP_" #NAME;
145 #include "llvm/BinaryFormat/Dwarf.def"
146   case DW_OP_LLVM_fragment:
147     return "DW_OP_LLVM_fragment";
148   }
149 }
150 
151 unsigned llvm::dwarf::getOperationEncoding(StringRef OperationEncodingString) {
152   return StringSwitch<unsigned>(OperationEncodingString)
153 #define HANDLE_DW_OP(ID, NAME, VERSION, VENDOR)                                \
154   .Case("DW_OP_" #NAME, DW_OP_##NAME)
155 #include "llvm/BinaryFormat/Dwarf.def"
156       .Case("DW_OP_LLVM_fragment", DW_OP_LLVM_fragment)
157       .Default(0);
158 }
159 
160 unsigned llvm::dwarf::OperationVersion(dwarf::LocationAtom Op) {
161   switch (Op) {
162   default:
163     return 0;
164 #define HANDLE_DW_OP(ID, NAME, VERSION, VENDOR)                                \
165   case DW_OP_##NAME:                                                           \
166     return VERSION;
167 #include "llvm/BinaryFormat/Dwarf.def"
168   }
169 }
170 
171 unsigned llvm::dwarf::OperationVendor(dwarf::LocationAtom Op) {
172   switch (Op) {
173   default:
174     return 0;
175 #define HANDLE_DW_OP(ID, NAME, VERSION, VENDOR)                                \
176   case DW_OP_##NAME:                                                           \
177     return DWARF_VENDOR_##VENDOR;
178 #include "llvm/BinaryFormat/Dwarf.def"
179   }
180 }
181 
182 StringRef llvm::dwarf::AttributeEncodingString(unsigned Encoding) {
183   switch (Encoding) {
184   default:
185     return StringRef();
186 #define HANDLE_DW_ATE(ID, NAME, VERSION, VENDOR)                               \
187   case DW_ATE_##NAME:                                                          \
188     return "DW_ATE_" #NAME;
189 #include "llvm/BinaryFormat/Dwarf.def"
190   }
191 }
192 
193 unsigned llvm::dwarf::getAttributeEncoding(StringRef EncodingString) {
194   return StringSwitch<unsigned>(EncodingString)
195 #define HANDLE_DW_ATE(ID, NAME, VERSION, VENDOR)                               \
196   .Case("DW_ATE_" #NAME, DW_ATE_##NAME)
197 #include "llvm/BinaryFormat/Dwarf.def"
198       .Default(0);
199 }
200 
201 unsigned llvm::dwarf::AttributeEncodingVersion(dwarf::TypeKind ATE) {
202   switch (ATE) {
203   default:
204     return 0;
205 #define HANDLE_DW_ATE(ID, NAME, VERSION, VENDOR)                               \
206   case DW_ATE_##NAME:                                                          \
207     return VERSION;
208 #include "llvm/BinaryFormat/Dwarf.def"
209   }
210 }
211 
212 unsigned llvm::dwarf::AttributeEncodingVendor(dwarf::TypeKind ATE) {
213   switch (ATE) {
214   default:
215     return 0;
216 #define HANDLE_DW_ATE(ID, NAME, VERSION, VENDOR)                               \
217   case DW_ATE_##NAME:                                                          \
218     return DWARF_VENDOR_##VENDOR;
219 #include "llvm/BinaryFormat/Dwarf.def"
220   }
221 }
222 
223 StringRef llvm::dwarf::DecimalSignString(unsigned Sign) {
224   switch (Sign) {
225   case DW_DS_unsigned:
226     return "DW_DS_unsigned";
227   case DW_DS_leading_overpunch:
228     return "DW_DS_leading_overpunch";
229   case DW_DS_trailing_overpunch:
230     return "DW_DS_trailing_overpunch";
231   case DW_DS_leading_separate:
232     return "DW_DS_leading_separate";
233   case DW_DS_trailing_separate:
234     return "DW_DS_trailing_separate";
235   }
236   return StringRef();
237 }
238 
239 StringRef llvm::dwarf::EndianityString(unsigned Endian) {
240   switch (Endian) {
241   case DW_END_default:
242     return "DW_END_default";
243   case DW_END_big:
244     return "DW_END_big";
245   case DW_END_little:
246     return "DW_END_little";
247   case DW_END_lo_user:
248     return "DW_END_lo_user";
249   case DW_END_hi_user:
250     return "DW_END_hi_user";
251   }
252   return StringRef();
253 }
254 
255 StringRef llvm::dwarf::AccessibilityString(unsigned Access) {
256   switch (Access) {
257   // Accessibility codes
258   case DW_ACCESS_public:
259     return "DW_ACCESS_public";
260   case DW_ACCESS_protected:
261     return "DW_ACCESS_protected";
262   case DW_ACCESS_private:
263     return "DW_ACCESS_private";
264   }
265   return StringRef();
266 }
267 
268 StringRef llvm::dwarf::VisibilityString(unsigned Visibility) {
269   switch (Visibility) {
270   case DW_VIS_local:
271     return "DW_VIS_local";
272   case DW_VIS_exported:
273     return "DW_VIS_exported";
274   case DW_VIS_qualified:
275     return "DW_VIS_qualified";
276   }
277   return StringRef();
278 }
279 
280 StringRef llvm::dwarf::VirtualityString(unsigned Virtuality) {
281   switch (Virtuality) {
282   default:
283     return StringRef();
284 #define HANDLE_DW_VIRTUALITY(ID, NAME)                                         \
285   case DW_VIRTUALITY_##NAME:                                                   \
286     return "DW_VIRTUALITY_" #NAME;
287 #include "llvm/BinaryFormat/Dwarf.def"
288   }
289 }
290 
291 unsigned llvm::dwarf::getVirtuality(StringRef VirtualityString) {
292   return StringSwitch<unsigned>(VirtualityString)
293 #define HANDLE_DW_VIRTUALITY(ID, NAME)                                         \
294   .Case("DW_VIRTUALITY_" #NAME, DW_VIRTUALITY_##NAME)
295 #include "llvm/BinaryFormat/Dwarf.def"
296       .Default(DW_VIRTUALITY_invalid);
297 }
298 
299 StringRef llvm::dwarf::LanguageString(unsigned Language) {
300   switch (Language) {
301   default:
302     return StringRef();
303 #define HANDLE_DW_LANG(ID, NAME, LOWER_BOUND, VERSION, VENDOR)                 \
304   case DW_LANG_##NAME:                                                         \
305     return "DW_LANG_" #NAME;
306 #include "llvm/BinaryFormat/Dwarf.def"
307   }
308 }
309 
310 unsigned llvm::dwarf::getLanguage(StringRef LanguageString) {
311   return StringSwitch<unsigned>(LanguageString)
312 #define HANDLE_DW_LANG(ID, NAME, LOWER_BOUND, VERSION, VENDOR)                 \
313   .Case("DW_LANG_" #NAME, DW_LANG_##NAME)
314 #include "llvm/BinaryFormat/Dwarf.def"
315       .Default(0);
316 }
317 
318 unsigned llvm::dwarf::LanguageVersion(dwarf::SourceLanguage Lang) {
319   switch (Lang) {
320   default:
321     return 0;
322 #define HANDLE_DW_LANG(ID, NAME, LOWER_BOUND, VERSION, VENDOR)                 \
323   case DW_LANG_##NAME:                                                         \
324     return VERSION;
325 #include "llvm/BinaryFormat/Dwarf.def"
326   }
327 }
328 
329 unsigned llvm::dwarf::LanguageVendor(dwarf::SourceLanguage Lang) {
330   switch (Lang) {
331   default:
332     return 0;
333 #define HANDLE_DW_LANG(ID, NAME, LOWER_BOUND, VERSION, VENDOR)                 \
334   case DW_LANG_##NAME:                                                         \
335     return DWARF_VENDOR_##VENDOR;
336 #include "llvm/BinaryFormat/Dwarf.def"
337   }
338 }
339 
340 Optional<unsigned> llvm::dwarf::LanguageLowerBound(dwarf::SourceLanguage Lang) {
341   switch (Lang) {
342   default:
343     return None;
344 #define HANDLE_DW_LANG(ID, NAME, LOWER_BOUND, VERSION, VENDOR)                 \
345   case DW_LANG_##NAME:                                                         \
346     return LOWER_BOUND;
347 #include "llvm/BinaryFormat/Dwarf.def"
348   }
349 }
350 
351 StringRef llvm::dwarf::CaseString(unsigned Case) {
352   switch (Case) {
353   case DW_ID_case_sensitive:
354     return "DW_ID_case_sensitive";
355   case DW_ID_up_case:
356     return "DW_ID_up_case";
357   case DW_ID_down_case:
358     return "DW_ID_down_case";
359   case DW_ID_case_insensitive:
360     return "DW_ID_case_insensitive";
361   }
362   return StringRef();
363 }
364 
365 StringRef llvm::dwarf::ConventionString(unsigned CC) {
366   switch (CC) {
367   default:
368     return StringRef();
369 #define HANDLE_DW_CC(ID, NAME)                                                 \
370   case DW_CC_##NAME:                                                           \
371     return "DW_CC_" #NAME;
372 #include "llvm/BinaryFormat/Dwarf.def"
373   }
374 }
375 
376 unsigned llvm::dwarf::getCallingConvention(StringRef CCString) {
377   return StringSwitch<unsigned>(CCString)
378 #define HANDLE_DW_CC(ID, NAME) .Case("DW_CC_" #NAME, DW_CC_##NAME)
379 #include "llvm/BinaryFormat/Dwarf.def"
380       .Default(0);
381 }
382 
383 StringRef llvm::dwarf::InlineCodeString(unsigned Code) {
384   switch (Code) {
385   case DW_INL_not_inlined:
386     return "DW_INL_not_inlined";
387   case DW_INL_inlined:
388     return "DW_INL_inlined";
389   case DW_INL_declared_not_inlined:
390     return "DW_INL_declared_not_inlined";
391   case DW_INL_declared_inlined:
392     return "DW_INL_declared_inlined";
393   }
394   return StringRef();
395 }
396 
397 StringRef llvm::dwarf::ArrayOrderString(unsigned Order) {
398   switch (Order) {
399   case DW_ORD_row_major:
400     return "DW_ORD_row_major";
401   case DW_ORD_col_major:
402     return "DW_ORD_col_major";
403   }
404   return StringRef();
405 }
406 
407 StringRef llvm::dwarf::LNStandardString(unsigned Standard) {
408   switch (Standard) {
409   default:
410     return StringRef();
411 #define HANDLE_DW_LNS(ID, NAME)                                                \
412   case DW_LNS_##NAME:                                                          \
413     return "DW_LNS_" #NAME;
414 #include "llvm/BinaryFormat/Dwarf.def"
415   }
416 }
417 
418 StringRef llvm::dwarf::LNExtendedString(unsigned Encoding) {
419   switch (Encoding) {
420   default:
421     return StringRef();
422 #define HANDLE_DW_LNE(ID, NAME)                                                \
423   case DW_LNE_##NAME:                                                          \
424     return "DW_LNE_" #NAME;
425 #include "llvm/BinaryFormat/Dwarf.def"
426   }
427 }
428 
429 StringRef llvm::dwarf::MacinfoString(unsigned Encoding) {
430   switch (Encoding) {
431   // Macinfo Type Encodings
432   case DW_MACINFO_define:
433     return "DW_MACINFO_define";
434   case DW_MACINFO_undef:
435     return "DW_MACINFO_undef";
436   case DW_MACINFO_start_file:
437     return "DW_MACINFO_start_file";
438   case DW_MACINFO_end_file:
439     return "DW_MACINFO_end_file";
440   case DW_MACINFO_vendor_ext:
441     return "DW_MACINFO_vendor_ext";
442   case DW_MACINFO_invalid:
443     return "DW_MACINFO_invalid";
444   }
445   return StringRef();
446 }
447 
448 unsigned llvm::dwarf::getMacinfo(StringRef MacinfoString) {
449   return StringSwitch<unsigned>(MacinfoString)
450       .Case("DW_MACINFO_define", DW_MACINFO_define)
451       .Case("DW_MACINFO_undef", DW_MACINFO_undef)
452       .Case("DW_MACINFO_start_file", DW_MACINFO_start_file)
453       .Case("DW_MACINFO_end_file", DW_MACINFO_end_file)
454       .Case("DW_MACINFO_vendor_ext", DW_MACINFO_vendor_ext)
455       .Default(DW_MACINFO_invalid);
456 }
457 
458 StringRef llvm::dwarf::RangeListEncodingString(unsigned Encoding) {
459   switch (Encoding) {
460   default:
461     return StringRef();
462 #define HANDLE_DW_RLE(ID, NAME)                                                \
463   case DW_RLE_##NAME:                                                          \
464     return "DW_RLE_" #NAME;
465 #include "llvm/BinaryFormat/Dwarf.def"
466   }
467 }
468 
469 StringRef llvm::dwarf::CallFrameString(unsigned Encoding,
470     Triple::ArchType Arch) {
471   assert(Arch != llvm::Triple::ArchType::UnknownArch);
472 #define SELECT_AARCH64 (Arch == llvm::Triple::aarch64_be || Arch == llvm::Triple::aarch64)
473 #define SELECT_MIPS64 Arch == llvm::Triple::mips64
474 #define SELECT_SPARC (Arch == llvm::Triple::sparc || Arch == llvm::Triple::sparcv9)
475 #define SELECT_X86 (Arch == llvm::Triple::x86 || Arch == llvm::Triple::x86_64)
476 #define HANDLE_DW_CFA(ID, NAME)
477 #define HANDLE_DW_CFA_PRED(ID, NAME, PRED) \
478   if (ID == Encoding && PRED) \
479     return "DW_CFA_" #NAME;
480 #include "llvm/BinaryFormat/Dwarf.def"
481 
482   switch (Encoding) {
483   default:
484     return StringRef();
485 #define HANDLE_DW_CFA_PRED(ID, NAME, PRED)
486 #define HANDLE_DW_CFA(ID, NAME)                                                \
487   case DW_CFA_##NAME:                                                          \
488     return "DW_CFA_" #NAME;
489 #include "llvm/BinaryFormat/Dwarf.def"
490 
491 #undef SELECT_X86
492 #undef SELECT_SPARC
493 #undef SELECT_MIPS64
494 #undef SELECT_AARCH64
495   }
496 }
497 
498 StringRef llvm::dwarf::ApplePropertyString(unsigned Prop) {
499   switch (Prop) {
500   default:
501     return StringRef();
502 #define HANDLE_DW_APPLE_PROPERTY(ID, NAME)                                     \
503   case DW_APPLE_PROPERTY_##NAME:                                               \
504     return "DW_APPLE_PROPERTY_" #NAME;
505 #include "llvm/BinaryFormat/Dwarf.def"
506   }
507 }
508 
509 StringRef llvm::dwarf::UnitTypeString(unsigned UT) {
510   switch (UT) {
511   default:
512     return StringRef();
513 #define HANDLE_DW_UT(ID, NAME)                                                 \
514   case DW_UT_##NAME:                                                           \
515     return "DW_UT_" #NAME;
516 #include "llvm/BinaryFormat/Dwarf.def"
517   }
518 }
519 
520 StringRef llvm::dwarf::AtomTypeString(unsigned AT) {
521   switch (AT) {
522   case dwarf::DW_ATOM_null:
523     return "DW_ATOM_null";
524   case dwarf::DW_ATOM_die_offset:
525     return "DW_ATOM_die_offset";
526   case DW_ATOM_cu_offset:
527     return "DW_ATOM_cu_offset";
528   case DW_ATOM_die_tag:
529     return "DW_ATOM_die_tag";
530   case DW_ATOM_type_flags:
531   case DW_ATOM_type_type_flags:
532     return "DW_ATOM_type_flags";
533   case DW_ATOM_qual_name_hash:
534     return "DW_ATOM_qual_name_hash";
535   }
536   return StringRef();
537 }
538 
539 StringRef llvm::dwarf::GDBIndexEntryKindString(GDBIndexEntryKind Kind) {
540   switch (Kind) {
541   case GIEK_NONE:
542     return "NONE";
543   case GIEK_TYPE:
544     return "TYPE";
545   case GIEK_VARIABLE:
546     return "VARIABLE";
547   case GIEK_FUNCTION:
548     return "FUNCTION";
549   case GIEK_OTHER:
550     return "OTHER";
551   case GIEK_UNUSED5:
552     return "UNUSED5";
553   case GIEK_UNUSED6:
554     return "UNUSED6";
555   case GIEK_UNUSED7:
556     return "UNUSED7";
557   }
558   llvm_unreachable("Unknown GDBIndexEntryKind value");
559 }
560 
561 StringRef
562 llvm::dwarf::GDBIndexEntryLinkageString(GDBIndexEntryLinkage Linkage) {
563   switch (Linkage) {
564   case GIEL_EXTERNAL:
565     return "EXTERNAL";
566   case GIEL_STATIC:
567     return "STATIC";
568   }
569   llvm_unreachable("Unknown GDBIndexEntryLinkage value");
570 }
571 
572 StringRef llvm::dwarf::AttributeValueString(uint16_t Attr, unsigned Val) {
573   switch (Attr) {
574   case DW_AT_accessibility:
575     return AccessibilityString(Val);
576   case DW_AT_virtuality:
577     return VirtualityString(Val);
578   case DW_AT_language:
579     return LanguageString(Val);
580   case DW_AT_encoding:
581     return AttributeEncodingString(Val);
582   case DW_AT_decimal_sign:
583     return DecimalSignString(Val);
584   case DW_AT_endianity:
585     return EndianityString(Val);
586   case DW_AT_visibility:
587     return VisibilityString(Val);
588   case DW_AT_identifier_case:
589     return CaseString(Val);
590   case DW_AT_calling_convention:
591     return ConventionString(Val);
592   case DW_AT_inline:
593     return InlineCodeString(Val);
594   case DW_AT_ordering:
595     return ArrayOrderString(Val);
596   case DW_AT_APPLE_runtime_class:
597     return LanguageString(Val);
598   }
599 
600   return StringRef();
601 }
602 
603 StringRef llvm::dwarf::AtomValueString(uint16_t Atom, unsigned Val) {
604   switch (Atom) {
605   case DW_ATOM_null:
606     return "NULL";
607   case DW_ATOM_die_tag:
608     return TagString(Val);
609   }
610 
611   return StringRef();
612 }
613 
614 StringRef llvm::dwarf::IndexString(unsigned Idx) {
615   switch (Idx) {
616   default:
617     return StringRef();
618 #define HANDLE_DW_IDX(ID, NAME)                                                \
619   case DW_IDX_##NAME:                                                          \
620     return "DW_IDX_" #NAME;
621 #include "llvm/BinaryFormat/Dwarf.def"
622   }
623 }
624 
625 Optional<uint8_t> llvm::dwarf::getFixedFormByteSize(dwarf::Form Form,
626                                                     FormParams Params) {
627   switch (Form) {
628   case DW_FORM_addr:
629     if (Params)
630       return Params.AddrSize;
631     return None;
632 
633   case DW_FORM_block:          // ULEB128 length L followed by L bytes.
634   case DW_FORM_block1:         // 1 byte length L followed by L bytes.
635   case DW_FORM_block2:         // 2 byte length L followed by L bytes.
636   case DW_FORM_block4:         // 4 byte length L followed by L bytes.
637   case DW_FORM_string:         // C-string with null terminator.
638   case DW_FORM_sdata:          // SLEB128.
639   case DW_FORM_udata:          // ULEB128.
640   case DW_FORM_ref_udata:      // ULEB128.
641   case DW_FORM_indirect:       // ULEB128.
642   case DW_FORM_exprloc:        // ULEB128 length L followed by L bytes.
643   case DW_FORM_strx:           // ULEB128.
644   case DW_FORM_addrx:          // ULEB128.
645   case DW_FORM_loclistx:       // ULEB128.
646   case DW_FORM_rnglistx:       // ULEB128.
647   case DW_FORM_GNU_addr_index: // ULEB128.
648   case DW_FORM_GNU_str_index:  // ULEB128.
649     return None;
650 
651   case DW_FORM_ref_addr:
652     if (Params)
653       return Params.getRefAddrByteSize();
654     return None;
655 
656   case DW_FORM_flag:
657   case DW_FORM_data1:
658   case DW_FORM_ref1:
659   case DW_FORM_strx1:
660   case DW_FORM_addrx1:
661     return 1;
662 
663   case DW_FORM_data2:
664   case DW_FORM_ref2:
665   case DW_FORM_strx2:
666   case DW_FORM_addrx2:
667     return 2;
668 
669   case DW_FORM_strx3:
670     return 3;
671 
672   case DW_FORM_data4:
673   case DW_FORM_ref4:
674   case DW_FORM_ref_sup4:
675   case DW_FORM_strx4:
676   case DW_FORM_addrx4:
677     return 4;
678 
679   case DW_FORM_strp:
680   case DW_FORM_GNU_ref_alt:
681   case DW_FORM_GNU_strp_alt:
682   case DW_FORM_line_strp:
683   case DW_FORM_sec_offset:
684   case DW_FORM_strp_sup:
685     if (Params)
686       return Params.getDwarfOffsetByteSize();
687     return None;
688 
689   case DW_FORM_data8:
690   case DW_FORM_ref8:
691   case DW_FORM_ref_sig8:
692   case DW_FORM_ref_sup8:
693     return 8;
694 
695   case DW_FORM_flag_present:
696     return 0;
697 
698   case DW_FORM_data16:
699     return 16;
700 
701   case DW_FORM_implicit_const:
702     // The implicit value is stored in the abbreviation as a SLEB128, and
703     // there no data in debug info.
704     return 0;
705 
706   default:
707     break;
708   }
709   return None;
710 }
711 
712 bool llvm::dwarf::isValidFormForVersion(Form F, unsigned Version,
713                                         bool ExtensionsOk) {
714   if (FormVendor(F) == DWARF_VENDOR_DWARF) {
715     unsigned FV = FormVersion(F);
716     return FV > 0 && FV <= Version;
717   }
718   return ExtensionsOk;
719 }
720 
721 constexpr char llvm::dwarf::EnumTraits<Attribute>::Type[];
722 constexpr char llvm::dwarf::EnumTraits<Form>::Type[];
723 constexpr char llvm::dwarf::EnumTraits<Index>::Type[];
724 constexpr char llvm::dwarf::EnumTraits<Tag>::Type[];
725