1 | //===- DWARFDie.h -----------------------------------------------*- 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 | #ifndef LLVM_DEBUGINFO_DWARF_DWARFDIE_H |
10 | #define LLVM_DEBUGINFO_DWARF_DWARFDIE_H |
11 | |
12 | #include "llvm/ADT/ArrayRef.h" |
13 | #include "llvm/ADT/iterator.h" |
14 | #include "llvm/ADT/iterator_range.h" |
15 | #include "llvm/BinaryFormat/Dwarf.h" |
16 | #include "llvm/DebugInfo/DIContext.h" |
17 | #include "llvm/DebugInfo/DWARF/DWARFAddressRange.h" |
18 | #include "llvm/DebugInfo/DWARF/DWARFAttribute.h" |
19 | #include "llvm/DebugInfo/DWARF/DWARFDebugInfoEntry.h" |
20 | #include "llvm/DebugInfo/DWARF/DWARFLocationExpression.h" |
21 | #include <cassert> |
22 | #include <cstdint> |
23 | #include <iterator> |
24 | |
25 | namespace llvm { |
26 | |
27 | class DWARFUnit; |
28 | class raw_ostream; |
29 | |
30 | //===----------------------------------------------------------------------===// |
31 | /// Utility class that carries the DWARF compile/type unit and the debug info |
32 | /// entry in an object. |
33 | /// |
34 | /// When accessing information from a debug info entry we always need to DWARF |
35 | /// compile/type unit in order to extract the info correctly as some information |
36 | /// is relative to the compile/type unit. Prior to this class the DWARFUnit and |
37 | /// the DWARFDebugInfoEntry was passed around separately and there was the |
38 | /// possibility for error if the wrong DWARFUnit was used to extract a unit |
39 | /// relative offset. This class helps to ensure that this doesn't happen and |
40 | /// also simplifies the attribute extraction calls by not having to specify the |
41 | /// DWARFUnit for each call. |
42 | class DWARFDie { |
43 | DWARFUnit *U = nullptr; |
44 | const DWARFDebugInfoEntry *Die = nullptr; |
45 | |
46 | public: |
47 | DWARFDie() = default; |
48 | DWARFDie(DWARFUnit *Unit, const DWARFDebugInfoEntry *D) : U(Unit), Die(D) {} |
49 | |
50 | bool isValid() const { return U && Die; } |
51 | explicit operator bool() const { return isValid(); } |
52 | const DWARFDebugInfoEntry *getDebugInfoEntry() const { return Die; } |
53 | DWARFUnit *getDwarfUnit() const { return U; } |
54 | |
55 | /// Get the abbreviation declaration for this DIE. |
56 | /// |
57 | /// \returns the abbreviation declaration or NULL for null tags. |
58 | const DWARFAbbreviationDeclaration *getAbbreviationDeclarationPtr() const { |
59 | assert(isValid() && "must check validity prior to calling" ); |
60 | return Die->getAbbreviationDeclarationPtr(); |
61 | } |
62 | |
63 | /// Get the absolute offset into the debug info or types section. |
64 | /// |
65 | /// \returns the DIE offset or -1U if invalid. |
66 | uint64_t getOffset() const { |
67 | assert(isValid() && "must check validity prior to calling" ); |
68 | return Die->getOffset(); |
69 | } |
70 | |
71 | dwarf::Tag getTag() const { |
72 | auto AbbrevDecl = getAbbreviationDeclarationPtr(); |
73 | if (AbbrevDecl) |
74 | return AbbrevDecl->getTag(); |
75 | return dwarf::DW_TAG_null; |
76 | } |
77 | |
78 | bool hasChildren() const { |
79 | assert(isValid() && "must check validity prior to calling" ); |
80 | return Die->hasChildren(); |
81 | } |
82 | |
83 | /// Returns true for a valid DIE that terminates a sibling chain. |
84 | bool isNULL() const { return getAbbreviationDeclarationPtr() == nullptr; } |
85 | |
86 | /// Returns true if DIE represents a subprogram (not inlined). |
87 | bool isSubprogramDIE() const; |
88 | |
89 | /// Returns true if DIE represents a subprogram or an inlined subroutine. |
90 | bool isSubroutineDIE() const; |
91 | |
92 | /// Get the parent of this DIE object. |
93 | /// |
94 | /// \returns a valid DWARFDie instance if this object has a parent or an |
95 | /// invalid DWARFDie instance if it doesn't. |
96 | DWARFDie getParent() const; |
97 | |
98 | /// Get the sibling of this DIE object. |
99 | /// |
100 | /// \returns a valid DWARFDie instance if this object has a sibling or an |
101 | /// invalid DWARFDie instance if it doesn't. |
102 | DWARFDie getSibling() const; |
103 | |
104 | /// Get the previous sibling of this DIE object. |
105 | /// |
106 | /// \returns a valid DWARFDie instance if this object has a sibling or an |
107 | /// invalid DWARFDie instance if it doesn't. |
108 | DWARFDie getPreviousSibling() const; |
109 | |
110 | /// Get the first child of this DIE object. |
111 | /// |
112 | /// \returns a valid DWARFDie instance if this object has children or an |
113 | /// invalid DWARFDie instance if it doesn't. |
114 | DWARFDie getFirstChild() const; |
115 | |
116 | /// Get the last child of this DIE object. |
117 | /// |
118 | /// \returns a valid null DWARFDie instance if this object has children or an |
119 | /// invalid DWARFDie instance if it doesn't. |
120 | DWARFDie getLastChild() const; |
121 | |
122 | /// Dump the DIE and all of its attributes to the supplied stream. |
123 | /// |
124 | /// \param OS the stream to use for output. |
125 | /// \param indent the number of characters to indent each line that is output. |
126 | void dump(raw_ostream &OS, unsigned indent = 0, |
127 | DIDumpOptions DumpOpts = DIDumpOptions()) const; |
128 | |
129 | /// Convenience zero-argument overload for debugging. |
130 | LLVM_DUMP_METHOD void dump() const; |
131 | |
132 | /// Extract the specified attribute from this DIE. |
133 | /// |
134 | /// Extract an attribute value from this DIE only. This call doesn't look |
135 | /// for the attribute value in any DW_AT_specification or |
136 | /// DW_AT_abstract_origin referenced DIEs. |
137 | /// |
138 | /// \param Attr the attribute to extract. |
139 | /// \returns an optional DWARFFormValue that will have the form value if the |
140 | /// attribute was successfully extracted. |
141 | std::optional<DWARFFormValue> find(dwarf::Attribute Attr) const; |
142 | |
143 | /// Extract the first value of any attribute in Attrs from this DIE. |
144 | /// |
145 | /// Extract the first attribute that matches from this DIE only. This call |
146 | /// doesn't look for the attribute value in any DW_AT_specification or |
147 | /// DW_AT_abstract_origin referenced DIEs. The attributes will be searched |
148 | /// linearly in the order they are specified within Attrs. |
149 | /// |
150 | /// \param Attrs an array of DWARF attribute to look for. |
151 | /// \returns an optional that has a valid DWARFFormValue for the first |
152 | /// matching attribute in Attrs, or std::nullopt if none of the attributes in |
153 | /// Attrs exist in this DIE. |
154 | std::optional<DWARFFormValue> find(ArrayRef<dwarf::Attribute> Attrs) const; |
155 | |
156 | /// Extract the first value of any attribute in Attrs from this DIE and |
157 | /// recurse into any DW_AT_specification or DW_AT_abstract_origin referenced |
158 | /// DIEs. |
159 | /// |
160 | /// \param Attrs an array of DWARF attribute to look for. |
161 | /// \returns an optional that has a valid DWARFFormValue for the first |
162 | /// matching attribute in Attrs, or std::nullopt if none of the attributes in |
163 | /// Attrs exist in this DIE or in any DW_AT_specification or |
164 | /// DW_AT_abstract_origin DIEs. |
165 | std::optional<DWARFFormValue> |
166 | findRecursively(ArrayRef<dwarf::Attribute> Attrs) const; |
167 | |
168 | /// Extract the specified attribute from this DIE as the referenced DIE. |
169 | /// |
170 | /// Regardless of the reference type, return the correct DWARFDie instance if |
171 | /// the attribute exists. The returned DWARFDie object might be from another |
172 | /// DWARFUnit, but that is all encapsulated in the new DWARFDie object. |
173 | /// |
174 | /// Extract an attribute value from this DIE only. This call doesn't look |
175 | /// for the attribute value in any DW_AT_specification or |
176 | /// DW_AT_abstract_origin referenced DIEs. |
177 | /// |
178 | /// \param Attr the attribute to extract. |
179 | /// \returns a valid DWARFDie instance if the attribute exists, or an invalid |
180 | /// DWARFDie object if it doesn't. |
181 | DWARFDie getAttributeValueAsReferencedDie(dwarf::Attribute Attr) const; |
182 | DWARFDie getAttributeValueAsReferencedDie(const DWARFFormValue &V) const; |
183 | |
184 | DWARFDie resolveTypeUnitReference() const; |
185 | |
186 | /// Extract the range base attribute from this DIE as absolute section offset. |
187 | /// |
188 | /// This is a utility function that checks for either the DW_AT_rnglists_base |
189 | /// or DW_AT_GNU_ranges_base attribute. |
190 | /// |
191 | /// \returns anm optional absolute section offset value for the attribute. |
192 | std::optional<uint64_t> getRangesBaseAttribute() const; |
193 | std::optional<uint64_t> getLocBaseAttribute() const; |
194 | |
195 | /// Get the DW_AT_high_pc attribute value as an address. |
196 | /// |
197 | /// In DWARF version 4 and later the high PC can be encoded as an offset from |
198 | /// the DW_AT_low_pc. This function takes care of extracting the value as an |
199 | /// address or offset and adds it to the low PC if needed and returns the |
200 | /// value as an optional in case the DIE doesn't have a DW_AT_high_pc |
201 | /// attribute. |
202 | /// |
203 | /// \param LowPC the low PC that might be needed to calculate the high PC. |
204 | /// \returns an optional address value for the attribute. |
205 | std::optional<uint64_t> getHighPC(uint64_t LowPC) const; |
206 | |
207 | /// Retrieves DW_AT_low_pc and DW_AT_high_pc from CU. |
208 | /// Returns true if both attributes are present. |
209 | bool getLowAndHighPC(uint64_t &LowPC, uint64_t &HighPC, |
210 | uint64_t &SectionIndex) const; |
211 | |
212 | /// Get the address ranges for this DIE. |
213 | /// |
214 | /// Get the hi/low PC range if both attributes are available or exrtracts the |
215 | /// non-contiguous address ranges from the DW_AT_ranges attribute. |
216 | /// |
217 | /// Extracts the range information from this DIE only. This call doesn't look |
218 | /// for the range in any DW_AT_specification or DW_AT_abstract_origin DIEs. |
219 | /// |
220 | /// \returns a address range vector that might be empty if no address range |
221 | /// information is available. |
222 | Expected<DWARFAddressRangesVector> getAddressRanges() const; |
223 | |
224 | bool addressRangeContainsAddress(const uint64_t Address) const; |
225 | |
226 | Expected<DWARFLocationExpressionsVector> |
227 | getLocations(dwarf::Attribute Attr) const; |
228 | |
229 | /// If a DIE represents a subprogram (or inlined subroutine), returns its |
230 | /// mangled name (or short name, if mangled is missing). This name may be |
231 | /// fetched from specification or abstract origin for this subprogram. |
232 | /// Returns null if no name is found. |
233 | const char *getSubroutineName(DINameKind Kind) const; |
234 | |
235 | /// Return the DIE name resolving DW_AT_specification or DW_AT_abstract_origin |
236 | /// references if necessary. For the LinkageName case it additionaly searches |
237 | /// for ShortName if LinkageName is not found. |
238 | /// Returns null if no name is found. |
239 | const char *getName(DINameKind Kind) const; |
240 | void getFullName(raw_string_ostream &, |
241 | std::string *OriginalFullName = nullptr) const; |
242 | |
243 | /// Return the DIE short name resolving DW_AT_specification or |
244 | /// DW_AT_abstract_origin references if necessary. Returns null if no name |
245 | /// is found. |
246 | const char *getShortName() const; |
247 | |
248 | /// Return the DIE linkage name resolving DW_AT_specification or |
249 | /// DW_AT_abstract_origin references if necessary. Returns null if no name |
250 | /// is found. |
251 | const char *getLinkageName() const; |
252 | |
253 | /// Returns the declaration line (start line) for a DIE, assuming it specifies |
254 | /// a subprogram. This may be fetched from specification or abstract origin |
255 | /// for this subprogram by resolving DW_AT_sepcification or |
256 | /// DW_AT_abstract_origin references if necessary. |
257 | uint64_t getDeclLine() const; |
258 | std::string getDeclFile(DILineInfoSpecifier::FileLineInfoKind Kind) const; |
259 | |
260 | /// Retrieves values of DW_AT_call_file, DW_AT_call_line and DW_AT_call_column |
261 | /// from DIE (or zeroes if they are missing). This function looks for |
262 | /// DW_AT_call attributes in this DIE only, it will not resolve the attribute |
263 | /// values in any DW_AT_specification or DW_AT_abstract_origin DIEs. |
264 | /// \param CallFile filled in with non-zero if successful, zero if there is no |
265 | /// DW_AT_call_file attribute in this DIE. |
266 | /// \param CallLine filled in with non-zero if successful, zero if there is no |
267 | /// DW_AT_call_line attribute in this DIE. |
268 | /// \param CallColumn filled in with non-zero if successful, zero if there is |
269 | /// no DW_AT_call_column attribute in this DIE. |
270 | /// \param CallDiscriminator filled in with non-zero if successful, zero if |
271 | /// there is no DW_AT_GNU_discriminator attribute in this DIE. |
272 | void getCallerFrame(uint32_t &CallFile, uint32_t &CallLine, |
273 | uint32_t &CallColumn, uint32_t &CallDiscriminator) const; |
274 | |
275 | class attribute_iterator; |
276 | |
277 | /// Get an iterator range to all attributes in the current DIE only. |
278 | /// |
279 | /// \returns an iterator range for the attributes of the current DIE. |
280 | iterator_range<attribute_iterator> attributes() const; |
281 | |
282 | /// Gets the type size (in bytes) for this DIE. |
283 | /// |
284 | /// \param PointerSize the pointer size of the containing CU. |
285 | /// \returns if this is a type DIE, or this DIE contains a DW_AT_type, returns |
286 | /// the size of the type. |
287 | std::optional<uint64_t> getTypeSize(uint64_t PointerSize); |
288 | |
289 | class iterator; |
290 | |
291 | iterator begin() const; |
292 | iterator end() const; |
293 | |
294 | std::reverse_iterator<iterator> rbegin() const; |
295 | std::reverse_iterator<iterator> rend() const; |
296 | |
297 | iterator_range<iterator> children() const; |
298 | }; |
299 | |
300 | class DWARFDie::attribute_iterator |
301 | : public iterator_facade_base<attribute_iterator, std::forward_iterator_tag, |
302 | const DWARFAttribute> { |
303 | /// The DWARF DIE we are extracting attributes from. |
304 | DWARFDie Die; |
305 | /// The value vended to clients via the operator*() or operator->(). |
306 | DWARFAttribute AttrValue; |
307 | /// The attribute index within the abbreviation declaration in Die. |
308 | uint32_t Index; |
309 | |
310 | friend bool operator==(const attribute_iterator &LHS, |
311 | const attribute_iterator &RHS); |
312 | |
313 | /// Update the attribute index and attempt to read the attribute value. If the |
314 | /// attribute is able to be read, update AttrValue and the Index member |
315 | /// variable. If the attribute value is not able to be read, an appropriate |
316 | /// error will be set if the Err member variable is non-NULL and the iterator |
317 | /// will be set to the end value so iteration stops. |
318 | void updateForIndex(const DWARFAbbreviationDeclaration &AbbrDecl, uint32_t I); |
319 | |
320 | public: |
321 | attribute_iterator() = delete; |
322 | explicit attribute_iterator(DWARFDie D, bool End); |
323 | |
324 | attribute_iterator &operator++(); |
325 | attribute_iterator &operator--(); |
326 | explicit operator bool() const { return AttrValue.isValid(); } |
327 | const DWARFAttribute &operator*() const { return AttrValue; } |
328 | }; |
329 | |
330 | inline bool operator==(const DWARFDie::attribute_iterator &LHS, |
331 | const DWARFDie::attribute_iterator &RHS) { |
332 | return LHS.Index == RHS.Index; |
333 | } |
334 | |
335 | inline bool operator!=(const DWARFDie::attribute_iterator &LHS, |
336 | const DWARFDie::attribute_iterator &RHS) { |
337 | return !(LHS == RHS); |
338 | } |
339 | |
340 | inline bool operator==(const DWARFDie &LHS, const DWARFDie &RHS) { |
341 | return LHS.getDebugInfoEntry() == RHS.getDebugInfoEntry() && |
342 | LHS.getDwarfUnit() == RHS.getDwarfUnit(); |
343 | } |
344 | |
345 | inline bool operator!=(const DWARFDie &LHS, const DWARFDie &RHS) { |
346 | return !(LHS == RHS); |
347 | } |
348 | |
349 | inline bool operator<(const DWARFDie &LHS, const DWARFDie &RHS) { |
350 | return LHS.getOffset() < RHS.getOffset(); |
351 | } |
352 | |
353 | class DWARFDie::iterator |
354 | : public iterator_facade_base<iterator, std::bidirectional_iterator_tag, |
355 | const DWARFDie> { |
356 | DWARFDie Die; |
357 | |
358 | friend std::reverse_iterator<llvm::DWARFDie::iterator>; |
359 | friend bool operator==(const DWARFDie::iterator &LHS, |
360 | const DWARFDie::iterator &RHS); |
361 | |
362 | public: |
363 | iterator() = default; |
364 | |
365 | explicit iterator(DWARFDie D) : Die(D) {} |
366 | |
367 | iterator &operator++() { |
368 | Die = Die.getSibling(); |
369 | return *this; |
370 | } |
371 | |
372 | iterator &operator--() { |
373 | Die = Die.getPreviousSibling(); |
374 | return *this; |
375 | } |
376 | |
377 | const DWARFDie &operator*() const { return Die; } |
378 | }; |
379 | |
380 | inline bool operator==(const DWARFDie::iterator &LHS, |
381 | const DWARFDie::iterator &RHS) { |
382 | return LHS.Die == RHS.Die; |
383 | } |
384 | |
385 | // These inline functions must follow the DWARFDie::iterator definition above |
386 | // as they use functions from that class. |
387 | inline DWARFDie::iterator DWARFDie::begin() const { |
388 | return iterator(getFirstChild()); |
389 | } |
390 | |
391 | inline DWARFDie::iterator DWARFDie::end() const { |
392 | return iterator(getLastChild()); |
393 | } |
394 | |
395 | inline iterator_range<DWARFDie::iterator> DWARFDie::children() const { |
396 | return make_range(x: begin(), y: end()); |
397 | } |
398 | |
399 | } // end namespace llvm |
400 | |
401 | namespace std { |
402 | |
403 | template <> |
404 | class reverse_iterator<llvm::DWARFDie::iterator> |
405 | : public llvm::iterator_facade_base< |
406 | reverse_iterator<llvm::DWARFDie::iterator>, |
407 | bidirectional_iterator_tag, const llvm::DWARFDie> { |
408 | |
409 | private: |
410 | llvm::DWARFDie Die; |
411 | bool AtEnd; |
412 | |
413 | public: |
414 | reverse_iterator(llvm::DWARFDie::iterator It) |
415 | : Die(It.Die), AtEnd(!It.Die.getPreviousSibling()) { |
416 | if (!AtEnd) |
417 | Die = Die.getPreviousSibling(); |
418 | } |
419 | |
420 | llvm::DWARFDie::iterator base() const { |
421 | return llvm::DWARFDie::iterator(AtEnd ? Die : Die.getSibling()); |
422 | } |
423 | |
424 | reverse_iterator<llvm::DWARFDie::iterator> &operator++() { |
425 | assert(!AtEnd && "Incrementing rend" ); |
426 | llvm::DWARFDie D = Die.getPreviousSibling(); |
427 | if (D) |
428 | Die = D; |
429 | else |
430 | AtEnd = true; |
431 | return *this; |
432 | } |
433 | |
434 | reverse_iterator<llvm::DWARFDie::iterator> &operator--() { |
435 | if (AtEnd) { |
436 | AtEnd = false; |
437 | return *this; |
438 | } |
439 | Die = Die.getSibling(); |
440 | assert(!Die.isNULL() && "Decrementing rbegin" ); |
441 | return *this; |
442 | } |
443 | |
444 | const llvm::DWARFDie &operator*() const { |
445 | assert(Die.isValid()); |
446 | return Die; |
447 | } |
448 | |
449 | // FIXME: We should be able to specify the equals operator as a friend, but |
450 | // that causes the compiler to think the operator overload is ambiguous |
451 | // with the friend declaration and the actual definition as candidates. |
452 | bool equals(const reverse_iterator<llvm::DWARFDie::iterator> &RHS) const { |
453 | return Die == RHS.Die && AtEnd == RHS.AtEnd; |
454 | } |
455 | }; |
456 | |
457 | } // namespace std |
458 | |
459 | namespace llvm { |
460 | |
461 | inline bool operator==(const std::reverse_iterator<DWARFDie::iterator> &LHS, |
462 | const std::reverse_iterator<DWARFDie::iterator> &RHS) { |
463 | return LHS.equals(RHS); |
464 | } |
465 | |
466 | inline bool operator!=(const std::reverse_iterator<DWARFDie::iterator> &LHS, |
467 | const std::reverse_iterator<DWARFDie::iterator> &RHS) { |
468 | return !(LHS == RHS); |
469 | } |
470 | |
471 | inline std::reverse_iterator<DWARFDie::iterator> DWARFDie::rbegin() const { |
472 | return std::make_reverse_iterator(i: end()); |
473 | } |
474 | |
475 | inline std::reverse_iterator<DWARFDie::iterator> DWARFDie::rend() const { |
476 | return std::make_reverse_iterator(i: begin()); |
477 | } |
478 | |
479 | void dumpTypeQualifiedName(const DWARFDie &DIE, raw_ostream &OS); |
480 | void dumpTypeUnqualifiedName(const DWARFDie &DIE, raw_ostream &OS, |
481 | std::string *OriginalFullName = nullptr); |
482 | |
483 | } // end namespace llvm |
484 | |
485 | #endif // LLVM_DEBUGINFO_DWARF_DWARFDIE_H |
486 | |