1 //===-- llvm/BinaryFormat/Dwarf.h ---Dwarf Constants-------------*- 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 /// \file
10 /// This file contains constants used for implementing Dwarf
11 /// debug support.
12 ///
13 /// For details on the Dwarf specfication see the latest DWARF Debugging
14 /// Information Format standard document on http://www.dwarfstd.org. This
15 /// file often includes support for non-released standard features.
16 //
17 //===----------------------------------------------------------------------===//
18 
19 #ifndef LLVM_BINARYFORMAT_DWARF_H
20 #define LLVM_BINARYFORMAT_DWARF_H
21 
22 #include "llvm/Support/Compiler.h"
23 #include "llvm/Support/DataTypes.h"
24 #include "llvm/Support/ErrorHandling.h"
25 #include "llvm/Support/Format.h"
26 #include "llvm/Support/FormatVariadicDetails.h"
27 #include "llvm/ADT/Triple.h"
28 
29 #include <limits>
30 
31 namespace llvm {
32 class StringRef;
33 
34 namespace dwarf {
35 
36 //===----------------------------------------------------------------------===//
37 // DWARF constants as gleaned from the DWARF Debugging Information Format V.5
38 // reference manual http://www.dwarfstd.org/.
39 //
40 
41 // Do not mix the following two enumerations sets.  DW_TAG_invalid changes the
42 // enumeration base type.
43 
44 enum LLVMConstants : uint32_t {
45   /// LLVM mock tags (see also llvm/BinaryFormat/Dwarf.def).
46   /// \{
47   DW_TAG_invalid = ~0U,        ///< Tag for invalid results.
48   DW_VIRTUALITY_invalid = ~0U, ///< Virtuality for invalid results.
49   DW_MACINFO_invalid = ~0U,    ///< Macinfo type for invalid results.
50   /// \}
51 
52   /// Special values for an initial length field.
53   /// \{
54   DW_LENGTH_lo_reserved = 0xfffffff0, ///< Lower bound of the reserved range.
55   DW_LENGTH_DWARF64 = 0xffffffff,     ///< Indicator of 64-bit DWARF format.
56   DW_LENGTH_hi_reserved = 0xffffffff, ///< Upper bound of the reserved range.
57   /// \}
58 
59   /// Other constants.
60   /// \{
61   DWARF_VERSION = 4,       ///< Default dwarf version we output.
62   DW_PUBTYPES_VERSION = 2, ///< Section version number for .debug_pubtypes.
63   DW_PUBNAMES_VERSION = 2, ///< Section version number for .debug_pubnames.
64   DW_ARANGES_VERSION = 2,  ///< Section version number for .debug_aranges.
65   /// \}
66 
67   /// Identifiers we use to distinguish vendor extensions.
68   /// \{
69   DWARF_VENDOR_DWARF = 0, ///< Defined in v2 or later of the DWARF standard.
70   DWARF_VENDOR_APPLE = 1,
71   DWARF_VENDOR_BORLAND = 2,
72   DWARF_VENDOR_GNU = 3,
73   DWARF_VENDOR_GOOGLE = 4,
74   DWARF_VENDOR_LLVM = 5,
75   DWARF_VENDOR_MIPS = 6,
76   DWARF_VENDOR_WASM = 7,
77   DWARF_VENDOR_ALTIUM,
78   DWARF_VENDOR_COMPAQ,
79   DWARF_VENDOR_GHS,
80   DWARF_VENDOR_GO,
81   DWARF_VENDOR_HP,
82   DWARF_VENDOR_IBM,
83   DWARF_VENDOR_INTEL,
84   DWARF_VENDOR_PGI,
85   DWARF_VENDOR_SUN,
86   DWARF_VENDOR_UPC,
87   ///\}
88 };
89 
90 /// Constants that define the DWARF format as 32 or 64 bit.
91 enum DwarfFormat : uint8_t { DWARF32, DWARF64 };
92 
93 /// Special ID values that distinguish a CIE from a FDE in DWARF CFI.
94 /// Not inside an enum because a 64-bit value is needed.
95 /// @{
96 const uint32_t DW_CIE_ID = UINT32_MAX;
97 const uint64_t DW64_CIE_ID = UINT64_MAX;
98 /// @}
99 
100 /// Identifier of an invalid DIE offset in the .debug_info section.
101 const uint32_t DW_INVALID_OFFSET = UINT32_MAX;
102 
103 enum Tag : uint16_t {
104 #define HANDLE_DW_TAG(ID, NAME, VERSION, VENDOR, KIND) DW_TAG_##NAME = ID,
105 #include "llvm/BinaryFormat/Dwarf.def"
106   DW_TAG_lo_user = 0x4080,
107   DW_TAG_hi_user = 0xffff,
108   DW_TAG_user_base = 0x1000 ///< Recommended base for user tags.
109 };
110 
isType(Tag T)111 inline bool isType(Tag T) {
112   switch (T) {
113   default:
114     return false;
115 #define HANDLE_DW_TAG(ID, NAME, VERSION, VENDOR, KIND)                         \
116   case DW_TAG_##NAME:                                                          \
117     return (KIND == DW_KIND_TYPE);
118 #include "llvm/BinaryFormat/Dwarf.def"
119   }
120 }
121 
122 /// Attributes.
123 enum Attribute : uint16_t {
124 #define HANDLE_DW_AT(ID, NAME, VERSION, VENDOR) DW_AT_##NAME = ID,
125 #include "llvm/BinaryFormat/Dwarf.def"
126   DW_AT_lo_user = 0x2000,
127   DW_AT_hi_user = 0x3fff,
128 };
129 
130 enum Form : uint16_t {
131 #define HANDLE_DW_FORM(ID, NAME, VERSION, VENDOR) DW_FORM_##NAME = ID,
132 #include "llvm/BinaryFormat/Dwarf.def"
133   DW_FORM_lo_user = 0x1f00, ///< Not specified by DWARF.
134 };
135 
136 enum LocationAtom {
137 #define HANDLE_DW_OP(ID, NAME, VERSION, VENDOR) DW_OP_##NAME = ID,
138 #include "llvm/BinaryFormat/Dwarf.def"
139   DW_OP_lo_user = 0xe0,
140   DW_OP_hi_user = 0xff,
141   DW_OP_LLVM_fragment = 0x1000,         ///< Only used in LLVM metadata.
142   DW_OP_LLVM_convert = 0x1001,          ///< Only used in LLVM metadata.
143   DW_OP_LLVM_tag_offset = 0x1002,       ///< Only used in LLVM metadata.
144   DW_OP_LLVM_entry_value = 0x1003,      ///< Only used in LLVM metadata.
145   DW_OP_LLVM_implicit_pointer = 0x1004, ///< Only used in LLVM metadata.
146   DW_OP_LLVM_arg = 0x1005,              ///< Only used in LLVM metadata.
147 };
148 
149 enum TypeKind : uint8_t {
150 #define HANDLE_DW_ATE(ID, NAME, VERSION, VENDOR) DW_ATE_##NAME = ID,
151 #include "llvm/BinaryFormat/Dwarf.def"
152   DW_ATE_lo_user = 0x80,
153   DW_ATE_hi_user = 0xff
154 };
155 
156 enum DecimalSignEncoding {
157   // Decimal sign attribute values
158   DW_DS_unsigned = 0x01,
159   DW_DS_leading_overpunch = 0x02,
160   DW_DS_trailing_overpunch = 0x03,
161   DW_DS_leading_separate = 0x04,
162   DW_DS_trailing_separate = 0x05
163 };
164 
165 enum EndianityEncoding {
166   // Endianity attribute values
167 #define HANDLE_DW_END(ID, NAME) DW_END_##NAME = ID,
168 #include "llvm/BinaryFormat/Dwarf.def"
169   DW_END_lo_user = 0x40,
170   DW_END_hi_user = 0xff
171 };
172 
173 enum AccessAttribute {
174   // Accessibility codes
175   DW_ACCESS_public = 0x01,
176   DW_ACCESS_protected = 0x02,
177   DW_ACCESS_private = 0x03
178 };
179 
180 enum VisibilityAttribute {
181   // Visibility codes
182   DW_VIS_local = 0x01,
183   DW_VIS_exported = 0x02,
184   DW_VIS_qualified = 0x03
185 };
186 
187 enum VirtualityAttribute {
188 #define HANDLE_DW_VIRTUALITY(ID, NAME) DW_VIRTUALITY_##NAME = ID,
189 #include "llvm/BinaryFormat/Dwarf.def"
190   DW_VIRTUALITY_max = 0x02
191 };
192 
193 enum DefaultedMemberAttribute {
194 #define HANDLE_DW_DEFAULTED(ID, NAME) DW_DEFAULTED_##NAME = ID,
195 #include "llvm/BinaryFormat/Dwarf.def"
196   DW_DEFAULTED_max = 0x02
197 };
198 
199 enum SourceLanguage {
200 #define HANDLE_DW_LANG(ID, NAME, LOWER_BOUND, VERSION, VENDOR)                 \
201   DW_LANG_##NAME = ID,
202 #include "llvm/BinaryFormat/Dwarf.def"
203   DW_LANG_lo_user = 0x8000,
204   DW_LANG_hi_user = 0xffff
205 };
206 
isCPlusPlus(SourceLanguage S)207 inline bool isCPlusPlus(SourceLanguage S) {
208   bool result = false;
209   // Deliberately enumerate all the language options so we get a warning when
210   // new language options are added (-Wswitch) that'll hopefully help keep this
211   // switch up-to-date when new C++ versions are added.
212   switch (S) {
213   case DW_LANG_C_plus_plus:
214   case DW_LANG_C_plus_plus_03:
215   case DW_LANG_C_plus_plus_11:
216   case DW_LANG_C_plus_plus_14:
217   case DW_LANG_C_plus_plus_17:
218   case DW_LANG_C_plus_plus_20:
219     result = true;
220     break;
221   case DW_LANG_C89:
222   case DW_LANG_C:
223   case DW_LANG_Ada83:
224   case DW_LANG_Cobol74:
225   case DW_LANG_Cobol85:
226   case DW_LANG_Fortran77:
227   case DW_LANG_Fortran90:
228   case DW_LANG_Pascal83:
229   case DW_LANG_Modula2:
230   case DW_LANG_Java:
231   case DW_LANG_C99:
232   case DW_LANG_Ada95:
233   case DW_LANG_Fortran95:
234   case DW_LANG_PLI:
235   case DW_LANG_ObjC:
236   case DW_LANG_ObjC_plus_plus:
237   case DW_LANG_UPC:
238   case DW_LANG_D:
239   case DW_LANG_Python:
240   case DW_LANG_OpenCL:
241   case DW_LANG_Go:
242   case DW_LANG_Modula3:
243   case DW_LANG_Haskell:
244   case DW_LANG_OCaml:
245   case DW_LANG_Rust:
246   case DW_LANG_C11:
247   case DW_LANG_Swift:
248   case DW_LANG_Julia:
249   case DW_LANG_Dylan:
250   case DW_LANG_Fortran03:
251   case DW_LANG_Fortran08:
252   case DW_LANG_RenderScript:
253   case DW_LANG_BLISS:
254   case DW_LANG_Mips_Assembler:
255   case DW_LANG_GOOGLE_RenderScript:
256   case DW_LANG_BORLAND_Delphi:
257   case DW_LANG_lo_user:
258   case DW_LANG_hi_user:
259   case DW_LANG_Kotlin:
260   case DW_LANG_Zig:
261   case DW_LANG_Crystal:
262   case DW_LANG_C17:
263   case DW_LANG_Fortran18:
264   case DW_LANG_Ada2005:
265   case DW_LANG_Ada2012:
266     result = false;
267     break;
268   }
269 
270   return result;
271 }
272 
isFortran(SourceLanguage S)273 inline bool isFortran(SourceLanguage S) {
274   bool result = false;
275   // Deliberately enumerate all the language options so we get a warning when
276   // new language options are added (-Wswitch) that'll hopefully help keep this
277   // switch up-to-date when new Fortran versions are added.
278   switch (S) {
279   case DW_LANG_Fortran77:
280   case DW_LANG_Fortran90:
281   case DW_LANG_Fortran95:
282   case DW_LANG_Fortran03:
283   case DW_LANG_Fortran08:
284   case DW_LANG_Fortran18:
285     result = true;
286     break;
287   case DW_LANG_C89:
288   case DW_LANG_C:
289   case DW_LANG_Ada83:
290   case DW_LANG_C_plus_plus:
291   case DW_LANG_Cobol74:
292   case DW_LANG_Cobol85:
293   case DW_LANG_Pascal83:
294   case DW_LANG_Modula2:
295   case DW_LANG_Java:
296   case DW_LANG_C99:
297   case DW_LANG_Ada95:
298   case DW_LANG_PLI:
299   case DW_LANG_ObjC:
300   case DW_LANG_ObjC_plus_plus:
301   case DW_LANG_UPC:
302   case DW_LANG_D:
303   case DW_LANG_Python:
304   case DW_LANG_OpenCL:
305   case DW_LANG_Go:
306   case DW_LANG_Modula3:
307   case DW_LANG_Haskell:
308   case DW_LANG_C_plus_plus_03:
309   case DW_LANG_C_plus_plus_11:
310   case DW_LANG_OCaml:
311   case DW_LANG_Rust:
312   case DW_LANG_C11:
313   case DW_LANG_Swift:
314   case DW_LANG_Julia:
315   case DW_LANG_Dylan:
316   case DW_LANG_C_plus_plus_14:
317   case DW_LANG_RenderScript:
318   case DW_LANG_BLISS:
319   case DW_LANG_Mips_Assembler:
320   case DW_LANG_GOOGLE_RenderScript:
321   case DW_LANG_BORLAND_Delphi:
322   case DW_LANG_lo_user:
323   case DW_LANG_hi_user:
324   case DW_LANG_Kotlin:
325   case DW_LANG_Zig:
326   case DW_LANG_Crystal:
327   case DW_LANG_C_plus_plus_17:
328   case DW_LANG_C_plus_plus_20:
329   case DW_LANG_C17:
330   case DW_LANG_Ada2005:
331   case DW_LANG_Ada2012:
332     result = false;
333     break;
334   }
335 
336   return result;
337 }
338 
isC(SourceLanguage S)339 inline bool isC(SourceLanguage S) {
340   // Deliberately enumerate all the language options so we get a warning when
341   // new language options are added (-Wswitch) that'll hopefully help keep this
342   // switch up-to-date when new C++ versions are added.
343   switch (S) {
344   case DW_LANG_C11:
345   case DW_LANG_C17:
346   case DW_LANG_C89:
347   case DW_LANG_C99:
348   case DW_LANG_C:
349   case DW_LANG_ObjC:
350     return true;
351   case DW_LANG_C_plus_plus:
352   case DW_LANG_C_plus_plus_03:
353   case DW_LANG_C_plus_plus_11:
354   case DW_LANG_C_plus_plus_14:
355   case DW_LANG_C_plus_plus_17:
356   case DW_LANG_C_plus_plus_20:
357   case DW_LANG_Ada83:
358   case DW_LANG_Cobol74:
359   case DW_LANG_Cobol85:
360   case DW_LANG_Fortran77:
361   case DW_LANG_Fortran90:
362   case DW_LANG_Pascal83:
363   case DW_LANG_Modula2:
364   case DW_LANG_Java:
365   case DW_LANG_Ada95:
366   case DW_LANG_Fortran95:
367   case DW_LANG_PLI:
368   case DW_LANG_ObjC_plus_plus:
369   case DW_LANG_UPC:
370   case DW_LANG_D:
371   case DW_LANG_Python:
372   case DW_LANG_OpenCL:
373   case DW_LANG_Go:
374   case DW_LANG_Modula3:
375   case DW_LANG_Haskell:
376   case DW_LANG_OCaml:
377   case DW_LANG_Rust:
378   case DW_LANG_Swift:
379   case DW_LANG_Julia:
380   case DW_LANG_Dylan:
381   case DW_LANG_Fortran03:
382   case DW_LANG_Fortran08:
383   case DW_LANG_RenderScript:
384   case DW_LANG_BLISS:
385   case DW_LANG_Mips_Assembler:
386   case DW_LANG_GOOGLE_RenderScript:
387   case DW_LANG_BORLAND_Delphi:
388   case DW_LANG_lo_user:
389   case DW_LANG_hi_user:
390   case DW_LANG_Kotlin:
391   case DW_LANG_Zig:
392   case DW_LANG_Crystal:
393   case DW_LANG_Fortran18:
394   case DW_LANG_Ada2005:
395   case DW_LANG_Ada2012:
396     return false;
397   }
398   llvm_unreachable("Unknown language kind.");
399 }
400 
getArrayIndexTypeEncoding(SourceLanguage S)401 inline TypeKind getArrayIndexTypeEncoding(SourceLanguage S) {
402   return isFortran(S) ? DW_ATE_signed : DW_ATE_unsigned;
403 }
404 
405 enum CaseSensitivity {
406   // Identifier case codes
407   DW_ID_case_sensitive = 0x00,
408   DW_ID_up_case = 0x01,
409   DW_ID_down_case = 0x02,
410   DW_ID_case_insensitive = 0x03
411 };
412 
413 enum CallingConvention {
414 // Calling convention codes
415 #define HANDLE_DW_CC(ID, NAME) DW_CC_##NAME = ID,
416 #include "llvm/BinaryFormat/Dwarf.def"
417   DW_CC_lo_user = 0x40,
418   DW_CC_hi_user = 0xff
419 };
420 
421 enum InlineAttribute {
422   // Inline codes
423   DW_INL_not_inlined = 0x00,
424   DW_INL_inlined = 0x01,
425   DW_INL_declared_not_inlined = 0x02,
426   DW_INL_declared_inlined = 0x03
427 };
428 
429 enum ArrayDimensionOrdering {
430   // Array ordering
431   DW_ORD_row_major = 0x00,
432   DW_ORD_col_major = 0x01
433 };
434 
435 enum DiscriminantList {
436   // Discriminant descriptor values
437   DW_DSC_label = 0x00,
438   DW_DSC_range = 0x01
439 };
440 
441 /// Line Number Standard Opcode Encodings.
442 enum LineNumberOps : uint8_t {
443 #define HANDLE_DW_LNS(ID, NAME) DW_LNS_##NAME = ID,
444 #include "llvm/BinaryFormat/Dwarf.def"
445 };
446 
447 /// Line Number Extended Opcode Encodings.
448 enum LineNumberExtendedOps {
449 #define HANDLE_DW_LNE(ID, NAME) DW_LNE_##NAME = ID,
450 #include "llvm/BinaryFormat/Dwarf.def"
451   DW_LNE_lo_user = 0x80,
452   DW_LNE_hi_user = 0xff
453 };
454 
455 enum LineNumberEntryFormat {
456 #define HANDLE_DW_LNCT(ID, NAME) DW_LNCT_##NAME = ID,
457 #include "llvm/BinaryFormat/Dwarf.def"
458   DW_LNCT_lo_user = 0x2000,
459   DW_LNCT_hi_user = 0x3fff,
460 };
461 
462 enum MacinfoRecordType {
463   // Macinfo Type Encodings
464   DW_MACINFO_define = 0x01,
465   DW_MACINFO_undef = 0x02,
466   DW_MACINFO_start_file = 0x03,
467   DW_MACINFO_end_file = 0x04,
468   DW_MACINFO_vendor_ext = 0xff
469 };
470 
471 /// DWARF v5 macro information entry type encodings.
472 enum MacroEntryType {
473 #define HANDLE_DW_MACRO(ID, NAME) DW_MACRO_##NAME = ID,
474 #include "llvm/BinaryFormat/Dwarf.def"
475   DW_MACRO_lo_user = 0xe0,
476   DW_MACRO_hi_user = 0xff
477 };
478 
479 /// GNU .debug_macro macro information entry type encodings.
480 enum GnuMacroEntryType {
481 #define HANDLE_DW_MACRO_GNU(ID, NAME) DW_MACRO_GNU_##NAME = ID,
482 #include "llvm/BinaryFormat/Dwarf.def"
483   DW_MACRO_GNU_lo_user = 0xe0,
484   DW_MACRO_GNU_hi_user = 0xff
485 };
486 
487 /// DWARF v5 range list entry encoding values.
488 enum RnglistEntries {
489 #define HANDLE_DW_RLE(ID, NAME) DW_RLE_##NAME = ID,
490 #include "llvm/BinaryFormat/Dwarf.def"
491 };
492 
493 /// DWARF v5 loc list entry encoding values.
494 enum LoclistEntries {
495 #define HANDLE_DW_LLE(ID, NAME) DW_LLE_##NAME = ID,
496 #include "llvm/BinaryFormat/Dwarf.def"
497 };
498 
499 /// Call frame instruction encodings.
500 enum CallFrameInfo {
501 #define HANDLE_DW_CFA(ID, NAME) DW_CFA_##NAME = ID,
502 #define HANDLE_DW_CFA_PRED(ID, NAME, ARCH) DW_CFA_##NAME = ID,
503 #include "llvm/BinaryFormat/Dwarf.def"
504   DW_CFA_extended = 0x00,
505 
506   DW_CFA_lo_user = 0x1c,
507   DW_CFA_hi_user = 0x3f
508 };
509 
510 enum Constants {
511   // Children flag
512   DW_CHILDREN_no = 0x00,
513   DW_CHILDREN_yes = 0x01,
514 
515   DW_EH_PE_absptr = 0x00,
516   DW_EH_PE_omit = 0xff,
517   DW_EH_PE_uleb128 = 0x01,
518   DW_EH_PE_udata2 = 0x02,
519   DW_EH_PE_udata4 = 0x03,
520   DW_EH_PE_udata8 = 0x04,
521   DW_EH_PE_sleb128 = 0x09,
522   DW_EH_PE_sdata2 = 0x0A,
523   DW_EH_PE_sdata4 = 0x0B,
524   DW_EH_PE_sdata8 = 0x0C,
525   DW_EH_PE_signed = 0x08,
526   DW_EH_PE_pcrel = 0x10,
527   DW_EH_PE_textrel = 0x20,
528   DW_EH_PE_datarel = 0x30,
529   DW_EH_PE_funcrel = 0x40,
530   DW_EH_PE_aligned = 0x50,
531   DW_EH_PE_indirect = 0x80
532 };
533 
534 /// Constants for the DW_APPLE_PROPERTY_attributes attribute.
535 /// Keep this list in sync with clang's DeclObjCCommon.h
536 /// ObjCPropertyAttribute::Kind!
537 enum ApplePropertyAttributes {
538 #define HANDLE_DW_APPLE_PROPERTY(ID, NAME) DW_APPLE_PROPERTY_##NAME = ID,
539 #include "llvm/BinaryFormat/Dwarf.def"
540 };
541 
542 /// Constants for unit types in DWARF v5.
543 enum UnitType : unsigned char {
544 #define HANDLE_DW_UT(ID, NAME) DW_UT_##NAME = ID,
545 #include "llvm/BinaryFormat/Dwarf.def"
546   DW_UT_lo_user = 0x80,
547   DW_UT_hi_user = 0xff
548 };
549 
550 enum Index {
551 #define HANDLE_DW_IDX(ID, NAME) DW_IDX_##NAME = ID,
552 #include "llvm/BinaryFormat/Dwarf.def"
553   DW_IDX_lo_user = 0x2000,
554   DW_IDX_hi_user = 0x3fff
555 };
556 
isUnitType(uint8_t UnitType)557 inline bool isUnitType(uint8_t UnitType) {
558   switch (UnitType) {
559   case DW_UT_compile:
560   case DW_UT_type:
561   case DW_UT_partial:
562   case DW_UT_skeleton:
563   case DW_UT_split_compile:
564   case DW_UT_split_type:
565     return true;
566   default:
567     return false;
568   }
569 }
570 
isUnitType(dwarf::Tag T)571 inline bool isUnitType(dwarf::Tag T) {
572   switch (T) {
573   case DW_TAG_compile_unit:
574   case DW_TAG_type_unit:
575   case DW_TAG_partial_unit:
576   case DW_TAG_skeleton_unit:
577     return true;
578   default:
579     return false;
580   }
581 }
582 
583 // Constants for the DWARF v5 Accelerator Table Proposal
584 enum AcceleratorTable {
585   // Data layout descriptors.
586   DW_ATOM_null = 0u,       ///  Marker as the end of a list of atoms.
587   DW_ATOM_die_offset = 1u, // DIE offset in the debug_info section.
588   DW_ATOM_cu_offset = 2u, // Offset of the compile unit header that contains the
589                           // item in question.
590   DW_ATOM_die_tag = 3u,   // A tag entry.
591   DW_ATOM_type_flags = 4u, // Set of flags for a type.
592 
593   DW_ATOM_type_type_flags = 5u, // Dsymutil type extension.
594   DW_ATOM_qual_name_hash = 6u,  // Dsymutil qualified hash extension.
595 
596   // DW_ATOM_type_flags values.
597 
598   // Always set for C++, only set for ObjC if this is the @implementation for a
599   // class.
600   DW_FLAG_type_implementation = 2u,
601 
602   // Hash functions.
603 
604   // Daniel J. Bernstein hash.
605   DW_hash_function_djb = 0u
606 };
607 
608 // Constants for the GNU pubnames/pubtypes extensions supporting gdb index.
609 enum GDBIndexEntryKind {
610   GIEK_NONE,
611   GIEK_TYPE,
612   GIEK_VARIABLE,
613   GIEK_FUNCTION,
614   GIEK_OTHER,
615   GIEK_UNUSED5,
616   GIEK_UNUSED6,
617   GIEK_UNUSED7
618 };
619 
620 enum GDBIndexEntryLinkage { GIEL_EXTERNAL, GIEL_STATIC };
621 
622 /// \defgroup DwarfConstantsDumping Dwarf constants dumping functions
623 ///
624 /// All these functions map their argument's value back to the
625 /// corresponding enumerator name or return an empty StringRef if the value
626 /// isn't known.
627 ///
628 /// @{
629 StringRef TagString(unsigned Tag);
630 StringRef ChildrenString(unsigned Children);
631 StringRef AttributeString(unsigned Attribute);
632 StringRef FormEncodingString(unsigned Encoding);
633 StringRef OperationEncodingString(unsigned Encoding);
634 StringRef AttributeEncodingString(unsigned Encoding);
635 StringRef DecimalSignString(unsigned Sign);
636 StringRef EndianityString(unsigned Endian);
637 StringRef AccessibilityString(unsigned Access);
638 StringRef DefaultedMemberString(unsigned DefaultedEncodings);
639 StringRef VisibilityString(unsigned Visibility);
640 StringRef VirtualityString(unsigned Virtuality);
641 StringRef LanguageString(unsigned Language);
642 StringRef CaseString(unsigned Case);
643 StringRef ConventionString(unsigned Convention);
644 StringRef InlineCodeString(unsigned Code);
645 StringRef ArrayOrderString(unsigned Order);
646 StringRef LNStandardString(unsigned Standard);
647 StringRef LNExtendedString(unsigned Encoding);
648 StringRef MacinfoString(unsigned Encoding);
649 StringRef MacroString(unsigned Encoding);
650 StringRef GnuMacroString(unsigned Encoding);
651 StringRef RangeListEncodingString(unsigned Encoding);
652 StringRef LocListEncodingString(unsigned Encoding);
653 StringRef CallFrameString(unsigned Encoding, Triple::ArchType Arch);
654 StringRef ApplePropertyString(unsigned);
655 StringRef UnitTypeString(unsigned);
656 StringRef AtomTypeString(unsigned Atom);
657 StringRef GDBIndexEntryKindString(GDBIndexEntryKind Kind);
658 StringRef GDBIndexEntryLinkageString(GDBIndexEntryLinkage Linkage);
659 StringRef IndexString(unsigned Idx);
660 StringRef FormatString(DwarfFormat Format);
661 StringRef FormatString(bool IsDWARF64);
662 StringRef RLEString(unsigned RLE);
663 /// @}
664 
665 /// \defgroup DwarfConstantsParsing Dwarf constants parsing functions
666 ///
667 /// These functions map their strings back to the corresponding enumeration
668 /// value or return 0 if there is none, except for these exceptions:
669 ///
670 /// \li \a getTag() returns \a DW_TAG_invalid on invalid input.
671 /// \li \a getVirtuality() returns \a DW_VIRTUALITY_invalid on invalid input.
672 /// \li \a getMacinfo() returns \a DW_MACINFO_invalid on invalid input.
673 ///
674 /// @{
675 unsigned getTag(StringRef TagString);
676 unsigned getOperationEncoding(StringRef OperationEncodingString);
677 unsigned getVirtuality(StringRef VirtualityString);
678 unsigned getLanguage(StringRef LanguageString);
679 unsigned getCallingConvention(StringRef LanguageString);
680 unsigned getAttributeEncoding(StringRef EncodingString);
681 unsigned getMacinfo(StringRef MacinfoString);
682 unsigned getMacro(StringRef MacroString);
683 /// @}
684 
685 /// \defgroup DwarfConstantsVersioning Dwarf version for constants
686 ///
687 /// For constants defined by DWARF, returns the DWARF version when the constant
688 /// was first defined. For vendor extensions, if there is a version-related
689 /// policy for when to emit it, returns a version number for that policy.
690 /// Otherwise returns 0.
691 ///
692 /// @{
693 unsigned TagVersion(Tag T);
694 unsigned AttributeVersion(Attribute A);
695 unsigned FormVersion(Form F);
696 unsigned OperationVersion(LocationAtom O);
697 unsigned AttributeEncodingVersion(TypeKind E);
698 unsigned LanguageVersion(SourceLanguage L);
699 /// @}
700 
701 /// \defgroup DwarfConstantsVendor Dwarf "vendor" for constants
702 ///
703 /// These functions return an identifier describing "who" defined the constant,
704 /// either the DWARF standard itself or the vendor who defined the extension.
705 ///
706 /// @{
707 unsigned TagVendor(Tag T);
708 unsigned AttributeVendor(Attribute A);
709 unsigned FormVendor(Form F);
710 unsigned OperationVendor(LocationAtom O);
711 unsigned AttributeEncodingVendor(TypeKind E);
712 unsigned LanguageVendor(SourceLanguage L);
713 /// @}
714 
715 std::optional<unsigned> LanguageLowerBound(SourceLanguage L);
716 
717 /// The size of a reference determined by the DWARF 32/64-bit format.
getDwarfOffsetByteSize(DwarfFormat Format)718 inline uint8_t getDwarfOffsetByteSize(DwarfFormat Format) {
719   switch (Format) {
720   case DwarfFormat::DWARF32:
721     return 4;
722   case DwarfFormat::DWARF64:
723     return 8;
724   }
725   llvm_unreachable("Invalid Format value");
726 }
727 
728 /// A helper struct providing information about the byte size of DW_FORM
729 /// values that vary in size depending on the DWARF version, address byte
730 /// size, or DWARF32/DWARF64.
731 struct FormParams {
732   uint16_t Version;
733   uint8_t AddrSize;
734   DwarfFormat Format;
735   /// True if DWARF v2 output generally uses relocations for references
736   /// to other .debug_* sections.
737   bool DwarfUsesRelocationsAcrossSections = false;
738 
739   /// The definition of the size of form DW_FORM_ref_addr depends on the
740   /// version. In DWARF v2 it's the size of an address; after that, it's the
741   /// size of a reference.
getRefAddrByteSizeFormParams742   uint8_t getRefAddrByteSize() const {
743     if (Version == 2)
744       return AddrSize;
745     return getDwarfOffsetByteSize();
746   }
747 
748   /// The size of a reference is determined by the DWARF 32/64-bit format.
getDwarfOffsetByteSizeFormParams749   uint8_t getDwarfOffsetByteSize() const {
750     return dwarf::getDwarfOffsetByteSize(Format);
751   }
752 
753   explicit operator bool() const { return Version && AddrSize; }
754 };
755 
756 /// Get the byte size of the unit length field depending on the DWARF format.
getUnitLengthFieldByteSize(DwarfFormat Format)757 inline uint8_t getUnitLengthFieldByteSize(DwarfFormat Format) {
758   switch (Format) {
759   case DwarfFormat::DWARF32:
760     return 4;
761   case DwarfFormat::DWARF64:
762     return 12;
763   }
764   llvm_unreachable("Invalid Format value");
765 }
766 
767 /// Get the fixed byte size for a given form.
768 ///
769 /// If the form has a fixed byte size, then an Optional with a value will be
770 /// returned. If the form is always encoded using a variable length storage
771 /// format (ULEB or SLEB numbers or blocks) then std::nullopt will be returned.
772 ///
773 /// \param Form DWARF form to get the fixed byte size for.
774 /// \param Params DWARF parameters to help interpret forms.
775 /// \returns std::optional<uint8_t> value with the fixed byte size or
776 /// std::nullopt if \p Form doesn't have a fixed byte size.
777 std::optional<uint8_t> getFixedFormByteSize(dwarf::Form Form,
778                                             FormParams Params);
779 
780 /// Tells whether the specified form is defined in the specified version,
781 /// or is an extension if extensions are allowed.
782 bool isValidFormForVersion(Form F, unsigned Version, bool ExtensionsOk = true);
783 
784 /// Returns the symbolic string representing Val when used as a value
785 /// for attribute Attr.
786 StringRef AttributeValueString(uint16_t Attr, unsigned Val);
787 
788 /// Returns the symbolic string representing Val when used as a value
789 /// for atom Atom.
790 StringRef AtomValueString(uint16_t Atom, unsigned Val);
791 
792 /// Describes an entry of the various gnu_pub* debug sections.
793 ///
794 /// The gnu_pub* kind looks like:
795 ///
796 /// 0-3  reserved
797 /// 4-6  symbol kind
798 /// 7    0 == global, 1 == static
799 ///
800 /// A gdb_index descriptor includes the above kind, shifted 24 bits up with the
801 /// offset of the cu within the debug_info section stored in those 24 bits.
802 struct PubIndexEntryDescriptor {
803   GDBIndexEntryKind Kind;
804   GDBIndexEntryLinkage Linkage;
PubIndexEntryDescriptorPubIndexEntryDescriptor805   PubIndexEntryDescriptor(GDBIndexEntryKind Kind, GDBIndexEntryLinkage Linkage)
806       : Kind(Kind), Linkage(Linkage) {}
PubIndexEntryDescriptorPubIndexEntryDescriptor807   /* implicit */ PubIndexEntryDescriptor(GDBIndexEntryKind Kind)
808       : Kind(Kind), Linkage(GIEL_EXTERNAL) {}
PubIndexEntryDescriptorPubIndexEntryDescriptor809   explicit PubIndexEntryDescriptor(uint8_t Value)
810       : Kind(
811             static_cast<GDBIndexEntryKind>((Value & KIND_MASK) >> KIND_OFFSET)),
812         Linkage(static_cast<GDBIndexEntryLinkage>((Value & LINKAGE_MASK) >>
813                                                   LINKAGE_OFFSET)) {}
toBitsPubIndexEntryDescriptor814   uint8_t toBits() const {
815     return Kind << KIND_OFFSET | Linkage << LINKAGE_OFFSET;
816   }
817 
818 private:
819   enum {
820     KIND_OFFSET = 4,
821     KIND_MASK = 7 << KIND_OFFSET,
822     LINKAGE_OFFSET = 7,
823     LINKAGE_MASK = 1 << LINKAGE_OFFSET
824   };
825 };
826 
827 template <typename Enum> struct EnumTraits : public std::false_type {};
828 
829 template <> struct EnumTraits<Attribute> : public std::true_type {
830   static constexpr char Type[3] = "AT";
831   static constexpr StringRef (*StringFn)(unsigned) = &AttributeString;
832 };
833 
834 template <> struct EnumTraits<Form> : public std::true_type {
835   static constexpr char Type[5] = "FORM";
836   static constexpr StringRef (*StringFn)(unsigned) = &FormEncodingString;
837 };
838 
839 template <> struct EnumTraits<Index> : public std::true_type {
840   static constexpr char Type[4] = "IDX";
841   static constexpr StringRef (*StringFn)(unsigned) = &IndexString;
842 };
843 
844 template <> struct EnumTraits<Tag> : public std::true_type {
845   static constexpr char Type[4] = "TAG";
846   static constexpr StringRef (*StringFn)(unsigned) = &TagString;
847 };
848 
849 template <> struct EnumTraits<LineNumberOps> : public std::true_type {
850   static constexpr char Type[4] = "LNS";
851   static constexpr StringRef (*StringFn)(unsigned) = &LNStandardString;
852 };
853 
854 template <> struct EnumTraits<LocationAtom> : public std::true_type {
855   static constexpr char Type[3] = "OP";
856   static constexpr StringRef (*StringFn)(unsigned) = &OperationEncodingString;
857 };
858 
859 inline uint64_t computeTombstoneAddress(uint8_t AddressByteSize) {
860   return std::numeric_limits<uint64_t>::max() >> (8 - AddressByteSize) * 8;
861 }
862 
863 } // End of namespace dwarf
864 
865 /// Dwarf constants format_provider
866 ///
867 /// Specialization of the format_provider template for dwarf enums. Unlike the
868 /// dumping functions above, these format unknown enumerator values as
869 /// DW_TYPE_unknown_1234 (e.g. DW_TAG_unknown_ffff).
870 template <typename Enum>
871 struct format_provider<Enum, std::enable_if_t<dwarf::EnumTraits<Enum>::value>> {
872   static void format(const Enum &E, raw_ostream &OS, StringRef Style) {
873     StringRef Str = dwarf::EnumTraits<Enum>::StringFn(E);
874     if (Str.empty()) {
875       OS << "DW_" << dwarf::EnumTraits<Enum>::Type << "_unknown_"
876          << llvm::format("%x", E);
877     } else
878       OS << Str;
879   }
880 };
881 } // End of namespace llvm
882 
883 #endif
884