xref: /llvm-project/llvm/lib/BinaryFormat/Dwarf.cpp (revision b86ce219f4dabe1ac5ceee79651b05308672064e)
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_convert:
147     return "DW_OP_LLVM_convert";
148   case DW_OP_LLVM_fragment:
149     return "DW_OP_LLVM_fragment";
150   }
151 }
152 
153 unsigned llvm::dwarf::getOperationEncoding(StringRef OperationEncodingString) {
154   return StringSwitch<unsigned>(OperationEncodingString)
155 #define HANDLE_DW_OP(ID, NAME, VERSION, VENDOR)                                \
156   .Case("DW_OP_" #NAME, DW_OP_##NAME)
157 #include "llvm/BinaryFormat/Dwarf.def"
158       .Case("DW_OP_LLVM_convert", DW_OP_LLVM_convert)
159       .Case("DW_OP_LLVM_fragment", DW_OP_LLVM_fragment)
160       .Default(0);
161 }
162 
163 unsigned llvm::dwarf::OperationVersion(dwarf::LocationAtom Op) {
164   switch (Op) {
165   default:
166     return 0;
167 #define HANDLE_DW_OP(ID, NAME, VERSION, VENDOR)                                \
168   case DW_OP_##NAME:                                                           \
169     return VERSION;
170 #include "llvm/BinaryFormat/Dwarf.def"
171   }
172 }
173 
174 unsigned llvm::dwarf::OperationVendor(dwarf::LocationAtom Op) {
175   switch (Op) {
176   default:
177     return 0;
178 #define HANDLE_DW_OP(ID, NAME, VERSION, VENDOR)                                \
179   case DW_OP_##NAME:                                                           \
180     return DWARF_VENDOR_##VENDOR;
181 #include "llvm/BinaryFormat/Dwarf.def"
182   }
183 }
184 
185 StringRef llvm::dwarf::AttributeEncodingString(unsigned Encoding) {
186   switch (Encoding) {
187   default:
188     return StringRef();
189 #define HANDLE_DW_ATE(ID, NAME, VERSION, VENDOR)                               \
190   case DW_ATE_##NAME:                                                          \
191     return "DW_ATE_" #NAME;
192 #include "llvm/BinaryFormat/Dwarf.def"
193   }
194 }
195 
196 unsigned llvm::dwarf::getAttributeEncoding(StringRef EncodingString) {
197   return StringSwitch<unsigned>(EncodingString)
198 #define HANDLE_DW_ATE(ID, NAME, VERSION, VENDOR)                               \
199   .Case("DW_ATE_" #NAME, DW_ATE_##NAME)
200 #include "llvm/BinaryFormat/Dwarf.def"
201       .Default(0);
202 }
203 
204 unsigned llvm::dwarf::AttributeEncodingVersion(dwarf::TypeKind ATE) {
205   switch (ATE) {
206   default:
207     return 0;
208 #define HANDLE_DW_ATE(ID, NAME, VERSION, VENDOR)                               \
209   case DW_ATE_##NAME:                                                          \
210     return VERSION;
211 #include "llvm/BinaryFormat/Dwarf.def"
212   }
213 }
214 
215 unsigned llvm::dwarf::AttributeEncodingVendor(dwarf::TypeKind ATE) {
216   switch (ATE) {
217   default:
218     return 0;
219 #define HANDLE_DW_ATE(ID, NAME, VERSION, VENDOR)                               \
220   case DW_ATE_##NAME:                                                          \
221     return DWARF_VENDOR_##VENDOR;
222 #include "llvm/BinaryFormat/Dwarf.def"
223   }
224 }
225 
226 StringRef llvm::dwarf::DecimalSignString(unsigned Sign) {
227   switch (Sign) {
228   case DW_DS_unsigned:
229     return "DW_DS_unsigned";
230   case DW_DS_leading_overpunch:
231     return "DW_DS_leading_overpunch";
232   case DW_DS_trailing_overpunch:
233     return "DW_DS_trailing_overpunch";
234   case DW_DS_leading_separate:
235     return "DW_DS_leading_separate";
236   case DW_DS_trailing_separate:
237     return "DW_DS_trailing_separate";
238   }
239   return StringRef();
240 }
241 
242 StringRef llvm::dwarf::EndianityString(unsigned Endian) {
243   switch (Endian) {
244   case DW_END_default:
245     return "DW_END_default";
246   case DW_END_big:
247     return "DW_END_big";
248   case DW_END_little:
249     return "DW_END_little";
250   case DW_END_lo_user:
251     return "DW_END_lo_user";
252   case DW_END_hi_user:
253     return "DW_END_hi_user";
254   }
255   return StringRef();
256 }
257 
258 StringRef llvm::dwarf::AccessibilityString(unsigned Access) {
259   switch (Access) {
260   // Accessibility codes
261   case DW_ACCESS_public:
262     return "DW_ACCESS_public";
263   case DW_ACCESS_protected:
264     return "DW_ACCESS_protected";
265   case DW_ACCESS_private:
266     return "DW_ACCESS_private";
267   }
268   return StringRef();
269 }
270 
271 StringRef llvm::dwarf::VisibilityString(unsigned Visibility) {
272   switch (Visibility) {
273   case DW_VIS_local:
274     return "DW_VIS_local";
275   case DW_VIS_exported:
276     return "DW_VIS_exported";
277   case DW_VIS_qualified:
278     return "DW_VIS_qualified";
279   }
280   return StringRef();
281 }
282 
283 StringRef llvm::dwarf::VirtualityString(unsigned Virtuality) {
284   switch (Virtuality) {
285   default:
286     return StringRef();
287 #define HANDLE_DW_VIRTUALITY(ID, NAME)                                         \
288   case DW_VIRTUALITY_##NAME:                                                   \
289     return "DW_VIRTUALITY_" #NAME;
290 #include "llvm/BinaryFormat/Dwarf.def"
291   }
292 }
293 
294 unsigned llvm::dwarf::getVirtuality(StringRef VirtualityString) {
295   return StringSwitch<unsigned>(VirtualityString)
296 #define HANDLE_DW_VIRTUALITY(ID, NAME)                                         \
297   .Case("DW_VIRTUALITY_" #NAME, DW_VIRTUALITY_##NAME)
298 #include "llvm/BinaryFormat/Dwarf.def"
299       .Default(DW_VIRTUALITY_invalid);
300 }
301 
302 StringRef llvm::dwarf::LanguageString(unsigned Language) {
303   switch (Language) {
304   default:
305     return StringRef();
306 #define HANDLE_DW_LANG(ID, NAME, LOWER_BOUND, VERSION, VENDOR)                 \
307   case DW_LANG_##NAME:                                                         \
308     return "DW_LANG_" #NAME;
309 #include "llvm/BinaryFormat/Dwarf.def"
310   }
311 }
312 
313 unsigned llvm::dwarf::getLanguage(StringRef LanguageString) {
314   return StringSwitch<unsigned>(LanguageString)
315 #define HANDLE_DW_LANG(ID, NAME, LOWER_BOUND, VERSION, VENDOR)                 \
316   .Case("DW_LANG_" #NAME, DW_LANG_##NAME)
317 #include "llvm/BinaryFormat/Dwarf.def"
318       .Default(0);
319 }
320 
321 unsigned llvm::dwarf::LanguageVersion(dwarf::SourceLanguage Lang) {
322   switch (Lang) {
323   default:
324     return 0;
325 #define HANDLE_DW_LANG(ID, NAME, LOWER_BOUND, VERSION, VENDOR)                 \
326   case DW_LANG_##NAME:                                                         \
327     return VERSION;
328 #include "llvm/BinaryFormat/Dwarf.def"
329   }
330 }
331 
332 unsigned llvm::dwarf::LanguageVendor(dwarf::SourceLanguage Lang) {
333   switch (Lang) {
334   default:
335     return 0;
336 #define HANDLE_DW_LANG(ID, NAME, LOWER_BOUND, VERSION, VENDOR)                 \
337   case DW_LANG_##NAME:                                                         \
338     return DWARF_VENDOR_##VENDOR;
339 #include "llvm/BinaryFormat/Dwarf.def"
340   }
341 }
342 
343 Optional<unsigned> llvm::dwarf::LanguageLowerBound(dwarf::SourceLanguage Lang) {
344   switch (Lang) {
345   default:
346     return None;
347 #define HANDLE_DW_LANG(ID, NAME, LOWER_BOUND, VERSION, VENDOR)                 \
348   case DW_LANG_##NAME:                                                         \
349     return LOWER_BOUND;
350 #include "llvm/BinaryFormat/Dwarf.def"
351   }
352 }
353 
354 StringRef llvm::dwarf::CaseString(unsigned Case) {
355   switch (Case) {
356   case DW_ID_case_sensitive:
357     return "DW_ID_case_sensitive";
358   case DW_ID_up_case:
359     return "DW_ID_up_case";
360   case DW_ID_down_case:
361     return "DW_ID_down_case";
362   case DW_ID_case_insensitive:
363     return "DW_ID_case_insensitive";
364   }
365   return StringRef();
366 }
367 
368 StringRef llvm::dwarf::ConventionString(unsigned CC) {
369   switch (CC) {
370   default:
371     return StringRef();
372 #define HANDLE_DW_CC(ID, NAME)                                                 \
373   case DW_CC_##NAME:                                                           \
374     return "DW_CC_" #NAME;
375 #include "llvm/BinaryFormat/Dwarf.def"
376   }
377 }
378 
379 unsigned llvm::dwarf::getCallingConvention(StringRef CCString) {
380   return StringSwitch<unsigned>(CCString)
381 #define HANDLE_DW_CC(ID, NAME) .Case("DW_CC_" #NAME, DW_CC_##NAME)
382 #include "llvm/BinaryFormat/Dwarf.def"
383       .Default(0);
384 }
385 
386 StringRef llvm::dwarf::InlineCodeString(unsigned Code) {
387   switch (Code) {
388   case DW_INL_not_inlined:
389     return "DW_INL_not_inlined";
390   case DW_INL_inlined:
391     return "DW_INL_inlined";
392   case DW_INL_declared_not_inlined:
393     return "DW_INL_declared_not_inlined";
394   case DW_INL_declared_inlined:
395     return "DW_INL_declared_inlined";
396   }
397   return StringRef();
398 }
399 
400 StringRef llvm::dwarf::ArrayOrderString(unsigned Order) {
401   switch (Order) {
402   case DW_ORD_row_major:
403     return "DW_ORD_row_major";
404   case DW_ORD_col_major:
405     return "DW_ORD_col_major";
406   }
407   return StringRef();
408 }
409 
410 StringRef llvm::dwarf::LNStandardString(unsigned Standard) {
411   switch (Standard) {
412   default:
413     return StringRef();
414 #define HANDLE_DW_LNS(ID, NAME)                                                \
415   case DW_LNS_##NAME:                                                          \
416     return "DW_LNS_" #NAME;
417 #include "llvm/BinaryFormat/Dwarf.def"
418   }
419 }
420 
421 StringRef llvm::dwarf::LNExtendedString(unsigned Encoding) {
422   switch (Encoding) {
423   default:
424     return StringRef();
425 #define HANDLE_DW_LNE(ID, NAME)                                                \
426   case DW_LNE_##NAME:                                                          \
427     return "DW_LNE_" #NAME;
428 #include "llvm/BinaryFormat/Dwarf.def"
429   }
430 }
431 
432 StringRef llvm::dwarf::MacinfoString(unsigned Encoding) {
433   switch (Encoding) {
434   // Macinfo Type Encodings
435   case DW_MACINFO_define:
436     return "DW_MACINFO_define";
437   case DW_MACINFO_undef:
438     return "DW_MACINFO_undef";
439   case DW_MACINFO_start_file:
440     return "DW_MACINFO_start_file";
441   case DW_MACINFO_end_file:
442     return "DW_MACINFO_end_file";
443   case DW_MACINFO_vendor_ext:
444     return "DW_MACINFO_vendor_ext";
445   case DW_MACINFO_invalid:
446     return "DW_MACINFO_invalid";
447   }
448   return StringRef();
449 }
450 
451 unsigned llvm::dwarf::getMacinfo(StringRef MacinfoString) {
452   return StringSwitch<unsigned>(MacinfoString)
453       .Case("DW_MACINFO_define", DW_MACINFO_define)
454       .Case("DW_MACINFO_undef", DW_MACINFO_undef)
455       .Case("DW_MACINFO_start_file", DW_MACINFO_start_file)
456       .Case("DW_MACINFO_end_file", DW_MACINFO_end_file)
457       .Case("DW_MACINFO_vendor_ext", DW_MACINFO_vendor_ext)
458       .Default(DW_MACINFO_invalid);
459 }
460 
461 StringRef llvm::dwarf::RangeListEncodingString(unsigned Encoding) {
462   switch (Encoding) {
463   default:
464     return StringRef();
465 #define HANDLE_DW_RLE(ID, NAME)                                                \
466   case DW_RLE_##NAME:                                                          \
467     return "DW_RLE_" #NAME;
468 #include "llvm/BinaryFormat/Dwarf.def"
469   }
470 }
471 
472 StringRef llvm::dwarf::CallFrameString(unsigned Encoding,
473     Triple::ArchType Arch) {
474   assert(Arch != llvm::Triple::ArchType::UnknownArch);
475 #define SELECT_AARCH64 (Arch == llvm::Triple::aarch64_be || Arch == llvm::Triple::aarch64)
476 #define SELECT_MIPS64 Arch == llvm::Triple::mips64
477 #define SELECT_SPARC (Arch == llvm::Triple::sparc || Arch == llvm::Triple::sparcv9)
478 #define SELECT_X86 (Arch == llvm::Triple::x86 || Arch == llvm::Triple::x86_64)
479 #define HANDLE_DW_CFA(ID, NAME)
480 #define HANDLE_DW_CFA_PRED(ID, NAME, PRED) \
481   if (ID == Encoding && PRED) \
482     return "DW_CFA_" #NAME;
483 #include "llvm/BinaryFormat/Dwarf.def"
484 
485   switch (Encoding) {
486   default:
487     return StringRef();
488 #define HANDLE_DW_CFA_PRED(ID, NAME, PRED)
489 #define HANDLE_DW_CFA(ID, NAME)                                                \
490   case DW_CFA_##NAME:                                                          \
491     return "DW_CFA_" #NAME;
492 #include "llvm/BinaryFormat/Dwarf.def"
493 
494 #undef SELECT_X86
495 #undef SELECT_SPARC
496 #undef SELECT_MIPS64
497 #undef SELECT_AARCH64
498   }
499 }
500 
501 StringRef llvm::dwarf::ApplePropertyString(unsigned Prop) {
502   switch (Prop) {
503   default:
504     return StringRef();
505 #define HANDLE_DW_APPLE_PROPERTY(ID, NAME)                                     \
506   case DW_APPLE_PROPERTY_##NAME:                                               \
507     return "DW_APPLE_PROPERTY_" #NAME;
508 #include "llvm/BinaryFormat/Dwarf.def"
509   }
510 }
511 
512 StringRef llvm::dwarf::UnitTypeString(unsigned UT) {
513   switch (UT) {
514   default:
515     return StringRef();
516 #define HANDLE_DW_UT(ID, NAME)                                                 \
517   case DW_UT_##NAME:                                                           \
518     return "DW_UT_" #NAME;
519 #include "llvm/BinaryFormat/Dwarf.def"
520   }
521 }
522 
523 StringRef llvm::dwarf::AtomTypeString(unsigned AT) {
524   switch (AT) {
525   case dwarf::DW_ATOM_null:
526     return "DW_ATOM_null";
527   case dwarf::DW_ATOM_die_offset:
528     return "DW_ATOM_die_offset";
529   case DW_ATOM_cu_offset:
530     return "DW_ATOM_cu_offset";
531   case DW_ATOM_die_tag:
532     return "DW_ATOM_die_tag";
533   case DW_ATOM_type_flags:
534   case DW_ATOM_type_type_flags:
535     return "DW_ATOM_type_flags";
536   case DW_ATOM_qual_name_hash:
537     return "DW_ATOM_qual_name_hash";
538   }
539   return StringRef();
540 }
541 
542 StringRef llvm::dwarf::GDBIndexEntryKindString(GDBIndexEntryKind Kind) {
543   switch (Kind) {
544   case GIEK_NONE:
545     return "NONE";
546   case GIEK_TYPE:
547     return "TYPE";
548   case GIEK_VARIABLE:
549     return "VARIABLE";
550   case GIEK_FUNCTION:
551     return "FUNCTION";
552   case GIEK_OTHER:
553     return "OTHER";
554   case GIEK_UNUSED5:
555     return "UNUSED5";
556   case GIEK_UNUSED6:
557     return "UNUSED6";
558   case GIEK_UNUSED7:
559     return "UNUSED7";
560   }
561   llvm_unreachable("Unknown GDBIndexEntryKind value");
562 }
563 
564 StringRef
565 llvm::dwarf::GDBIndexEntryLinkageString(GDBIndexEntryLinkage Linkage) {
566   switch (Linkage) {
567   case GIEL_EXTERNAL:
568     return "EXTERNAL";
569   case GIEL_STATIC:
570     return "STATIC";
571   }
572   llvm_unreachable("Unknown GDBIndexEntryLinkage value");
573 }
574 
575 StringRef llvm::dwarf::AttributeValueString(uint16_t Attr, unsigned Val) {
576   switch (Attr) {
577   case DW_AT_accessibility:
578     return AccessibilityString(Val);
579   case DW_AT_virtuality:
580     return VirtualityString(Val);
581   case DW_AT_language:
582     return LanguageString(Val);
583   case DW_AT_encoding:
584     return AttributeEncodingString(Val);
585   case DW_AT_decimal_sign:
586     return DecimalSignString(Val);
587   case DW_AT_endianity:
588     return EndianityString(Val);
589   case DW_AT_visibility:
590     return VisibilityString(Val);
591   case DW_AT_identifier_case:
592     return CaseString(Val);
593   case DW_AT_calling_convention:
594     return ConventionString(Val);
595   case DW_AT_inline:
596     return InlineCodeString(Val);
597   case DW_AT_ordering:
598     return ArrayOrderString(Val);
599   case DW_AT_APPLE_runtime_class:
600     return LanguageString(Val);
601   }
602 
603   return StringRef();
604 }
605 
606 StringRef llvm::dwarf::AtomValueString(uint16_t Atom, unsigned Val) {
607   switch (Atom) {
608   case DW_ATOM_null:
609     return "NULL";
610   case DW_ATOM_die_tag:
611     return TagString(Val);
612   }
613 
614   return StringRef();
615 }
616 
617 StringRef llvm::dwarf::IndexString(unsigned Idx) {
618   switch (Idx) {
619   default:
620     return StringRef();
621 #define HANDLE_DW_IDX(ID, NAME)                                                \
622   case DW_IDX_##NAME:                                                          \
623     return "DW_IDX_" #NAME;
624 #include "llvm/BinaryFormat/Dwarf.def"
625   }
626 }
627 
628 Optional<uint8_t> llvm::dwarf::getFixedFormByteSize(dwarf::Form Form,
629                                                     FormParams Params) {
630   switch (Form) {
631   case DW_FORM_addr:
632     if (Params)
633       return Params.AddrSize;
634     return None;
635 
636   case DW_FORM_block:          // ULEB128 length L followed by L bytes.
637   case DW_FORM_block1:         // 1 byte length L followed by L bytes.
638   case DW_FORM_block2:         // 2 byte length L followed by L bytes.
639   case DW_FORM_block4:         // 4 byte length L followed by L bytes.
640   case DW_FORM_string:         // C-string with null terminator.
641   case DW_FORM_sdata:          // SLEB128.
642   case DW_FORM_udata:          // ULEB128.
643   case DW_FORM_ref_udata:      // ULEB128.
644   case DW_FORM_indirect:       // ULEB128.
645   case DW_FORM_exprloc:        // ULEB128 length L followed by L bytes.
646   case DW_FORM_strx:           // ULEB128.
647   case DW_FORM_addrx:          // ULEB128.
648   case DW_FORM_loclistx:       // ULEB128.
649   case DW_FORM_rnglistx:       // ULEB128.
650   case DW_FORM_GNU_addr_index: // ULEB128.
651   case DW_FORM_GNU_str_index:  // ULEB128.
652     return None;
653 
654   case DW_FORM_ref_addr:
655     if (Params)
656       return Params.getRefAddrByteSize();
657     return None;
658 
659   case DW_FORM_flag:
660   case DW_FORM_data1:
661   case DW_FORM_ref1:
662   case DW_FORM_strx1:
663   case DW_FORM_addrx1:
664     return 1;
665 
666   case DW_FORM_data2:
667   case DW_FORM_ref2:
668   case DW_FORM_strx2:
669   case DW_FORM_addrx2:
670     return 2;
671 
672   case DW_FORM_strx3:
673     return 3;
674 
675   case DW_FORM_data4:
676   case DW_FORM_ref4:
677   case DW_FORM_ref_sup4:
678   case DW_FORM_strx4:
679   case DW_FORM_addrx4:
680     return 4;
681 
682   case DW_FORM_strp:
683   case DW_FORM_GNU_ref_alt:
684   case DW_FORM_GNU_strp_alt:
685   case DW_FORM_line_strp:
686   case DW_FORM_sec_offset:
687   case DW_FORM_strp_sup:
688     if (Params)
689       return Params.getDwarfOffsetByteSize();
690     return None;
691 
692   case DW_FORM_data8:
693   case DW_FORM_ref8:
694   case DW_FORM_ref_sig8:
695   case DW_FORM_ref_sup8:
696     return 8;
697 
698   case DW_FORM_flag_present:
699     return 0;
700 
701   case DW_FORM_data16:
702     return 16;
703 
704   case DW_FORM_implicit_const:
705     // The implicit value is stored in the abbreviation as a SLEB128, and
706     // there no data in debug info.
707     return 0;
708 
709   default:
710     break;
711   }
712   return None;
713 }
714 
715 bool llvm::dwarf::isValidFormForVersion(Form F, unsigned Version,
716                                         bool ExtensionsOk) {
717   if (FormVendor(F) == DWARF_VENDOR_DWARF) {
718     unsigned FV = FormVersion(F);
719     return FV > 0 && FV <= Version;
720   }
721   return ExtensionsOk;
722 }
723 
724 constexpr char llvm::dwarf::EnumTraits<Attribute>::Type[];
725 constexpr char llvm::dwarf::EnumTraits<Form>::Type[];
726 constexpr char llvm::dwarf::EnumTraits<Index>::Type[];
727 constexpr char llvm::dwarf::EnumTraits<Tag>::Type[];
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