Yi Kong | 7bf2a68 | 2019-04-18 17:30:49 -0700 | [diff] [blame] | 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_DWARFDIE_H |
| 10 | #define LLVM_DEBUGINFO_DWARFDIE_H |
| 11 | |
| 12 | #include "llvm/ADT/ArrayRef.h" |
| 13 | #include "llvm/ADT/Optional.h" |
| 14 | #include "llvm/ADT/iterator.h" |
| 15 | #include "llvm/ADT/iterator_range.h" |
| 16 | #include "llvm/BinaryFormat/Dwarf.h" |
| 17 | #include "llvm/DebugInfo/DIContext.h" |
| 18 | #include "llvm/DebugInfo/DWARF/DWARFAddressRange.h" |
| 19 | #include "llvm/DebugInfo/DWARF/DWARFAttribute.h" |
| 20 | #include "llvm/DebugInfo/DWARF/DWARFDebugInfoEntry.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 | uint32_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 | 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 None if none of the attributes in Attrs |
| 153 | /// exist in this DIE. |
| 154 | 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 None if none of the attributes in Attrs |
| 163 | /// exist in this DIE or in any DW_AT_specification or DW_AT_abstract_origin |
| 164 | /// DIEs. |
| 165 | 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 | /// Extract the range base attribute from this DIE as absolute section offset. |
| 185 | /// |
| 186 | /// This is a utility function that checks for either the DW_AT_rnglists_base |
| 187 | /// or DW_AT_GNU_ranges_base attribute. |
| 188 | /// |
| 189 | /// \returns anm optional absolute section offset value for the attribute. |
| 190 | Optional<uint64_t> getRangesBaseAttribute() const; |
| 191 | |
| 192 | /// Get the DW_AT_high_pc attribute value as an address. |
| 193 | /// |
| 194 | /// In DWARF version 4 and later the high PC can be encoded as an offset from |
| 195 | /// the DW_AT_low_pc. This function takes care of extracting the value as an |
| 196 | /// address or offset and adds it to the low PC if needed and returns the |
| 197 | /// value as an optional in case the DIE doesn't have a DW_AT_high_pc |
| 198 | /// attribute. |
| 199 | /// |
| 200 | /// \param LowPC the low PC that might be needed to calculate the high PC. |
| 201 | /// \returns an optional address value for the attribute. |
| 202 | Optional<uint64_t> getHighPC(uint64_t LowPC) const; |
| 203 | |
| 204 | /// Retrieves DW_AT_low_pc and DW_AT_high_pc from CU. |
| 205 | /// Returns true if both attributes are present. |
| 206 | bool getLowAndHighPC(uint64_t &LowPC, uint64_t &HighPC, |
| 207 | uint64_t &SectionIndex) const; |
| 208 | |
| 209 | /// Get the address ranges for this DIE. |
| 210 | /// |
| 211 | /// Get the hi/low PC range if both attributes are available or exrtracts the |
| 212 | /// non-contiguous address ranges from the DW_AT_ranges attribute. |
| 213 | /// |
| 214 | /// Extracts the range information from this DIE only. This call doesn't look |
| 215 | /// for the range in any DW_AT_specification or DW_AT_abstract_origin DIEs. |
| 216 | /// |
| 217 | /// \returns a address range vector that might be empty if no address range |
| 218 | /// information is available. |
| 219 | Expected<DWARFAddressRangesVector> getAddressRanges() const; |
| 220 | |
| 221 | /// Get all address ranges for any DW_TAG_subprogram DIEs in this DIE or any |
| 222 | /// of its children. |
| 223 | /// |
| 224 | /// Get the hi/low PC range if both attributes are available or exrtracts the |
| 225 | /// non-contiguous address ranges from the DW_AT_ranges attribute for this DIE |
| 226 | /// and all children. |
| 227 | /// |
| 228 | /// \param Ranges the addres range vector to fill in. |
| 229 | void collectChildrenAddressRanges(DWARFAddressRangesVector &Ranges) const; |
| 230 | |
| 231 | bool addressRangeContainsAddress(const uint64_t Address) const; |
| 232 | |
| 233 | /// If a DIE represents a subprogram (or inlined subroutine), returns its |
| 234 | /// mangled name (or short name, if mangled is missing). This name may be |
| 235 | /// fetched from specification or abstract origin for this subprogram. |
| 236 | /// Returns null if no name is found. |
| 237 | const char *getSubroutineName(DINameKind Kind) const; |
| 238 | |
| 239 | /// Return the DIE name resolving DW_AT_sepcification or DW_AT_abstract_origin |
| 240 | /// references if necessary. Returns null if no name is found. |
| 241 | const char *getName(DINameKind Kind) const; |
| 242 | |
| 243 | /// Returns the declaration line (start line) for a DIE, assuming it specifies |
| 244 | /// a subprogram. This may be fetched from specification or abstract origin |
| 245 | /// for this subprogram by resolving DW_AT_sepcification or |
| 246 | /// DW_AT_abstract_origin references if necessary. |
| 247 | uint64_t getDeclLine() const; |
| 248 | |
| 249 | /// Retrieves values of DW_AT_call_file, DW_AT_call_line and DW_AT_call_column |
| 250 | /// from DIE (or zeroes if they are missing). This function looks for |
| 251 | /// DW_AT_call attributes in this DIE only, it will not resolve the attribute |
| 252 | /// values in any DW_AT_specification or DW_AT_abstract_origin DIEs. |
| 253 | /// \param CallFile filled in with non-zero if successful, zero if there is no |
| 254 | /// DW_AT_call_file attribute in this DIE. |
| 255 | /// \param CallLine filled in with non-zero if successful, zero if there is no |
| 256 | /// DW_AT_call_line attribute in this DIE. |
| 257 | /// \param CallColumn filled in with non-zero if successful, zero if there is |
| 258 | /// no DW_AT_call_column attribute in this DIE. |
| 259 | /// \param CallDiscriminator filled in with non-zero if successful, zero if |
| 260 | /// there is no DW_AT_GNU_discriminator attribute in this DIE. |
| 261 | void getCallerFrame(uint32_t &CallFile, uint32_t &CallLine, |
| 262 | uint32_t &CallColumn, uint32_t &CallDiscriminator) const; |
| 263 | |
| 264 | class attribute_iterator; |
| 265 | |
| 266 | /// Get an iterator range to all attributes in the current DIE only. |
| 267 | /// |
| 268 | /// \returns an iterator range for the attributes of the current DIE. |
| 269 | iterator_range<attribute_iterator> attributes() const; |
| 270 | |
| 271 | class iterator; |
| 272 | |
| 273 | iterator begin() const; |
| 274 | iterator end() const; |
| 275 | |
| 276 | std::reverse_iterator<iterator> rbegin() const; |
| 277 | std::reverse_iterator<iterator> rend() const; |
| 278 | |
| 279 | iterator_range<iterator> children() const; |
| 280 | }; |
| 281 | |
| 282 | class DWARFDie::attribute_iterator |
| 283 | : public iterator_facade_base<attribute_iterator, std::forward_iterator_tag, |
| 284 | const DWARFAttribute> { |
| 285 | /// The DWARF DIE we are extracting attributes from. |
| 286 | DWARFDie Die; |
| 287 | /// The value vended to clients via the operator*() or operator->(). |
| 288 | DWARFAttribute AttrValue; |
| 289 | /// The attribute index within the abbreviation declaration in Die. |
| 290 | uint32_t Index; |
| 291 | |
| 292 | friend bool operator==(const attribute_iterator &LHS, |
| 293 | const attribute_iterator &RHS); |
| 294 | |
| 295 | /// Update the attribute index and attempt to read the attribute value. If the |
| 296 | /// attribute is able to be read, update AttrValue and the Index member |
| 297 | /// variable. If the attribute value is not able to be read, an appropriate |
| 298 | /// error will be set if the Err member variable is non-NULL and the iterator |
| 299 | /// will be set to the end value so iteration stops. |
| 300 | void updateForIndex(const DWARFAbbreviationDeclaration &AbbrDecl, uint32_t I); |
| 301 | |
| 302 | public: |
| 303 | attribute_iterator() = delete; |
| 304 | explicit attribute_iterator(DWARFDie D, bool End); |
| 305 | |
| 306 | attribute_iterator &operator++(); |
| 307 | attribute_iterator &operator--(); |
| 308 | explicit operator bool() const { return AttrValue.isValid(); } |
| 309 | const DWARFAttribute &operator*() const { return AttrValue; } |
| 310 | }; |
| 311 | |
| 312 | inline bool operator==(const DWARFDie::attribute_iterator &LHS, |
| 313 | const DWARFDie::attribute_iterator &RHS) { |
| 314 | return LHS.Index == RHS.Index; |
| 315 | } |
| 316 | |
| 317 | inline bool operator!=(const DWARFDie::attribute_iterator &LHS, |
| 318 | const DWARFDie::attribute_iterator &RHS) { |
| 319 | return !(LHS == RHS); |
| 320 | } |
| 321 | |
| 322 | inline bool operator==(const DWARFDie &LHS, const DWARFDie &RHS) { |
| 323 | return LHS.getDebugInfoEntry() == RHS.getDebugInfoEntry() && |
| 324 | LHS.getDwarfUnit() == RHS.getDwarfUnit(); |
| 325 | } |
| 326 | |
| 327 | inline bool operator!=(const DWARFDie &LHS, const DWARFDie &RHS) { |
| 328 | return !(LHS == RHS); |
| 329 | } |
| 330 | |
| 331 | inline bool operator<(const DWARFDie &LHS, const DWARFDie &RHS) { |
| 332 | return LHS.getOffset() < RHS.getOffset(); |
| 333 | } |
| 334 | |
| 335 | class DWARFDie::iterator |
| 336 | : public iterator_facade_base<iterator, std::bidirectional_iterator_tag, |
| 337 | const DWARFDie> { |
| 338 | DWARFDie Die; |
| 339 | |
| 340 | friend std::reverse_iterator<llvm::DWARFDie::iterator>; |
| 341 | friend bool operator==(const DWARFDie::iterator &LHS, |
| 342 | const DWARFDie::iterator &RHS); |
| 343 | |
| 344 | public: |
| 345 | iterator() = default; |
| 346 | |
| 347 | explicit iterator(DWARFDie D) : Die(D) {} |
| 348 | |
| 349 | iterator &operator++() { |
| 350 | Die = Die.getSibling(); |
| 351 | return *this; |
| 352 | } |
| 353 | |
| 354 | iterator &operator--() { |
| 355 | Die = Die.getPreviousSibling(); |
| 356 | return *this; |
| 357 | } |
| 358 | |
| 359 | const DWARFDie &operator*() const { return Die; } |
| 360 | }; |
| 361 | |
| 362 | inline bool operator==(const DWARFDie::iterator &LHS, |
| 363 | const DWARFDie::iterator &RHS) { |
| 364 | return LHS.Die == RHS.Die; |
| 365 | } |
| 366 | |
| 367 | inline bool operator!=(const DWARFDie::iterator &LHS, |
| 368 | const DWARFDie::iterator &RHS) { |
| 369 | return !(LHS == RHS); |
| 370 | } |
| 371 | |
| 372 | // These inline functions must follow the DWARFDie::iterator definition above |
| 373 | // as they use functions from that class. |
| 374 | inline DWARFDie::iterator DWARFDie::begin() const { |
| 375 | return iterator(getFirstChild()); |
| 376 | } |
| 377 | |
| 378 | inline DWARFDie::iterator DWARFDie::end() const { |
| 379 | return iterator(getLastChild()); |
| 380 | } |
| 381 | |
| 382 | inline iterator_range<DWARFDie::iterator> DWARFDie::children() const { |
| 383 | return make_range(begin(), end()); |
| 384 | } |
| 385 | |
| 386 | } // end namespace llvm |
| 387 | |
| 388 | namespace std { |
| 389 | |
| 390 | template <> |
| 391 | class reverse_iterator<llvm::DWARFDie::iterator> |
| 392 | : public llvm::iterator_facade_base< |
| 393 | reverse_iterator<llvm::DWARFDie::iterator>, |
| 394 | bidirectional_iterator_tag, const llvm::DWARFDie> { |
| 395 | |
| 396 | private: |
| 397 | llvm::DWARFDie Die; |
| 398 | bool AtEnd; |
| 399 | |
| 400 | public: |
| 401 | reverse_iterator(llvm::DWARFDie::iterator It) |
| 402 | : Die(It.Die), AtEnd(!It.Die.getPreviousSibling()) { |
| 403 | if (!AtEnd) |
| 404 | Die = Die.getPreviousSibling(); |
| 405 | } |
| 406 | |
| 407 | llvm::DWARFDie::iterator base() const { |
| 408 | return llvm::DWARFDie::iterator(AtEnd ? Die : Die.getSibling()); |
| 409 | } |
| 410 | |
| 411 | reverse_iterator<llvm::DWARFDie::iterator> &operator++() { |
| 412 | assert(!AtEnd && "Incrementing rend"); |
| 413 | llvm::DWARFDie D = Die.getPreviousSibling(); |
| 414 | if (D) |
| 415 | Die = D; |
| 416 | else |
| 417 | AtEnd = true; |
| 418 | return *this; |
| 419 | } |
| 420 | |
| 421 | reverse_iterator<llvm::DWARFDie::iterator> &operator--() { |
| 422 | if (AtEnd) { |
| 423 | AtEnd = false; |
| 424 | return *this; |
| 425 | } |
| 426 | Die = Die.getSibling(); |
| 427 | assert(!Die.isNULL() && "Decrementing rbegin"); |
| 428 | return *this; |
| 429 | } |
| 430 | |
| 431 | const llvm::DWARFDie &operator*() const { |
| 432 | assert(Die.isValid()); |
| 433 | return Die; |
| 434 | } |
| 435 | |
| 436 | // FIXME: We should be able to specify the equals operator as a friend, but |
| 437 | // that causes the compiler to think the operator overload is ambiguous |
| 438 | // with the friend declaration and the actual definition as candidates. |
| 439 | bool equals(const reverse_iterator<llvm::DWARFDie::iterator> &RHS) const { |
| 440 | return Die == RHS.Die && AtEnd == RHS.AtEnd; |
| 441 | } |
| 442 | }; |
| 443 | |
| 444 | } // namespace std |
| 445 | |
| 446 | namespace llvm { |
| 447 | |
| 448 | inline bool operator==(const std::reverse_iterator<DWARFDie::iterator> &LHS, |
| 449 | const std::reverse_iterator<DWARFDie::iterator> &RHS) { |
| 450 | return LHS.equals(RHS); |
| 451 | } |
| 452 | |
| 453 | inline bool operator!=(const std::reverse_iterator<DWARFDie::iterator> &LHS, |
| 454 | const std::reverse_iterator<DWARFDie::iterator> &RHS) { |
| 455 | return !(LHS == RHS); |
| 456 | } |
| 457 | |
| 458 | inline std::reverse_iterator<DWARFDie::iterator> DWARFDie::rbegin() const { |
| 459 | return llvm::make_reverse_iterator(end()); |
| 460 | } |
| 461 | |
| 462 | inline std::reverse_iterator<DWARFDie::iterator> DWARFDie::rend() const { |
| 463 | return llvm::make_reverse_iterator(begin()); |
| 464 | } |
| 465 | |
| 466 | } // end namespace llvm |
| 467 | |
| 468 | #endif // LLVM_DEBUGINFO_DWARFDIE_H |