LLVM  10.0.0svn
DWARFVerifier.h
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1 //===- DWARFVerifier.h ----------------------------------------------------===//
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_DWARFVERIFIER_H
10 #define LLVM_DEBUGINFO_DWARF_DWARFVERIFIER_H
11 
17 
18 #include <cstdint>
19 #include <map>
20 #include <set>
21 
22 namespace llvm {
23 class raw_ostream;
24 struct DWARFAttribute;
25 class DWARFContext;
26 class DWARFDie;
27 class DWARFUnit;
28 class DWARFCompileUnit;
29 class DWARFDataExtractor;
30 class DWARFDebugAbbrev;
31 class DataExtractor;
32 struct DWARFSection;
33 
34 /// A class that verifies DWARF debug information given a DWARF Context.
36 public:
37  /// A class that keeps the address range information for a single DIE.
38  struct DieRangeInfo {
40 
41  /// Sorted DWARFAddressRanges.
42  std::vector<DWARFAddressRange> Ranges;
43 
44  /// Sorted DWARFAddressRangeInfo.
45  std::set<DieRangeInfo> Children;
46 
47  DieRangeInfo() = default;
48  DieRangeInfo(DWARFDie Die) : Die(Die) {}
49 
50  /// Used for unit testing.
51  DieRangeInfo(std::vector<DWARFAddressRange> Ranges)
52  : Ranges(std::move(Ranges)) {}
53 
54  typedef std::vector<DWARFAddressRange>::const_iterator
56  typedef std::set<DieRangeInfo>::const_iterator die_range_info_iterator;
57 
58  /// Inserts the address range. If the range overlaps with an existing
59  /// range, the range is *not* added and an iterator to the overlapping
60  /// range is returned.
61  ///
62  /// This is used for finding overlapping ranges within the same DIE.
64 
65  /// Finds an address range in the sorted vector of ranges.
67  auto Begin = Ranges.begin();
68  auto End = Ranges.end();
69  auto Iter = std::upper_bound(Begin, End, R);
70  if (Iter != Begin)
71  --Iter;
72  return Iter;
73  }
74 
75  /// Inserts the address range info. If any of its ranges overlaps with a
76  /// range in an existing range info, the range info is *not* added and an
77  /// iterator to the overlapping range info.
78  ///
79  /// This is used for finding overlapping children of the same DIE.
80  die_range_info_iterator insert(const DieRangeInfo &RI);
81 
82  /// Return true if ranges in this object contains all ranges within RHS.
83  bool contains(const DieRangeInfo &RHS) const;
84 
85  /// Return true if any range in this object intersects with any range in
86  /// RHS.
87  bool intersects(const DieRangeInfo &RHS) const;
88  };
89 
90 private:
91  raw_ostream &OS;
92  DWARFContext &DCtx;
93  DIDumpOptions DumpOpts;
94  /// A map that tracks all references (converted absolute references) so we
95  /// can verify each reference points to a valid DIE and not an offset that
96  /// lies between to valid DIEs.
97  std::map<uint64_t, std::set<uint64_t>> ReferenceToDIEOffsets;
98  uint32_t NumDebugLineErrors = 0;
99  // Used to relax some checks that do not currently work portably
100  bool IsObjectFile;
101  bool IsMachOObject;
102 
103  raw_ostream &error() const;
104  raw_ostream &warn() const;
105  raw_ostream &note() const;
106  raw_ostream &dump(const DWARFDie &Die, unsigned indent = 0) const;
107 
108  /// Verifies the abbreviations section.
109  ///
110  /// This function currently checks that:
111  /// --No abbreviation declaration has more than one attributes with the same
112  /// name.
113  ///
114  /// \param Abbrev Pointer to the abbreviations section we are verifying
115  /// Abbrev can be a pointer to either .debug_abbrev or debug_abbrev.dwo.
116  ///
117  /// \returns The number of errors that occurred during verification.
118  unsigned verifyAbbrevSection(const DWARFDebugAbbrev *Abbrev);
119 
120  /// Verifies the header of a unit in a .debug_info or .debug_types section.
121  ///
122  /// This function currently checks for:
123  /// - Unit is in 32-bit DWARF format. The function can be modified to
124  /// support 64-bit format.
125  /// - The DWARF version is valid
126  /// - The unit type is valid (if unit is in version >=5)
127  /// - The unit doesn't extend beyond the containing section
128  /// - The address size is valid
129  /// - The offset in the .debug_abbrev section is valid
130  ///
131  /// \param DebugInfoData The section data
132  /// \param Offset A reference to the offset start of the unit. The offset will
133  /// be updated to point to the next unit in the section
134  /// \param UnitIndex The index of the unit to be verified
135  /// \param UnitType A reference to the type of the unit
136  /// \param isUnitDWARF64 A reference to a flag that shows whether the unit is
137  /// in 64-bit format.
138  ///
139  /// \returns true if the header is verified successfully, false otherwise.
140  bool verifyUnitHeader(const DWARFDataExtractor DebugInfoData,
141  uint64_t *Offset, unsigned UnitIndex, uint8_t &UnitType,
142  bool &isUnitDWARF64);
143 
144  /// Verifies the header of a unit in a .debug_info or .debug_types section.
145  ///
146  /// This function currently verifies:
147  /// - The debug info attributes.
148  /// - The debug info form=s.
149  /// - The presence of a root DIE.
150  /// - That the root DIE is a unit DIE.
151  /// - If a unit type is provided, that the unit DIE matches the unit type.
152  /// - The DIE ranges.
153  /// - That call site entries are only nested within subprograms with a
154  /// DW_AT_call attribute.
155  ///
156  /// \param Unit The DWARF Unit to verify.
157  ///
158  /// \returns The number of errors that occurred during verification.
159  unsigned verifyUnitContents(DWARFUnit &Unit);
160 
161  /// Verifies the unit headers and contents in a .debug_info or .debug_types
162  /// section.
163  ///
164  /// \param S The DWARF Section to verify.
165  /// \param SectionKind The object-file section kind that S comes from.
166  ///
167  /// \returns The number of errors that occurred during verification.
168  unsigned verifyUnitSection(const DWARFSection &S,
170 
171  /// Verifies that a call site entry is nested within a subprogram with a
172  /// DW_AT_call attribute.
173  ///
174  /// \returns Number of errors that occurred during verification.
175  unsigned verifyDebugInfoCallSite(const DWARFDie &Die);
176 
177  /// Verify that all Die ranges are valid.
178  ///
179  /// This function currently checks for:
180  /// - cases in which lowPC >= highPC
181  ///
182  /// \returns Number of errors that occurred during verification.
183  unsigned verifyDieRanges(const DWARFDie &Die, DieRangeInfo &ParentRI);
184 
185  /// Verifies the attribute's DWARF attribute and its value.
186  ///
187  /// This function currently checks for:
188  /// - DW_AT_ranges values is a valid .debug_ranges offset
189  /// - DW_AT_stmt_list is a valid .debug_line offset
190  ///
191  /// \param Die The DWARF DIE that owns the attribute value
192  /// \param AttrValue The DWARF attribute value to check
193  ///
194  /// \returns NumErrors The number of errors occurred during verification of
195  /// attributes' values in a unit
196  unsigned verifyDebugInfoAttribute(const DWARFDie &Die,
197  DWARFAttribute &AttrValue);
198 
199  /// Verifies the attribute's DWARF form.
200  ///
201  /// This function currently checks for:
202  /// - All DW_FORM_ref values that are CU relative have valid CU offsets
203  /// - All DW_FORM_ref_addr values have valid section offsets
204  /// - All DW_FORM_strp values have valid .debug_str offsets
205  ///
206  /// \param Die The DWARF DIE that owns the attribute value
207  /// \param AttrValue The DWARF attribute value to check
208  ///
209  /// \returns NumErrors The number of errors occurred during verification of
210  /// attributes' forms in a unit
211  unsigned verifyDebugInfoForm(const DWARFDie &Die, DWARFAttribute &AttrValue);
212 
213  /// Verifies the all valid references that were found when iterating through
214  /// all of the DIE attributes.
215  ///
216  /// This function will verify that all references point to DIEs whose DIE
217  /// offset matches. This helps to ensure if a DWARF link phase moved things
218  /// around, that it doesn't create invalid references by failing to relocate
219  /// CU relative and absolute references.
220  ///
221  /// \returns NumErrors The number of errors occurred during verification of
222  /// references for the .debug_info and .debug_types sections
223  unsigned verifyDebugInfoReferences();
224 
225  /// Verify the DW_AT_stmt_list encoding and value and ensure that no
226  /// compile units that have the same DW_AT_stmt_list value.
227  void verifyDebugLineStmtOffsets();
228 
229  /// Verify that all of the rows in the line table are valid.
230  ///
231  /// This function currently checks for:
232  /// - addresses within a sequence that decrease in value
233  /// - invalid file indexes
234  void verifyDebugLineRows();
235 
236  /// Verify that an Apple-style accelerator table is valid.
237  ///
238  /// This function currently checks that:
239  /// - The fixed part of the header fits in the section
240  /// - The size of the section is as large as what the header describes
241  /// - There is at least one atom
242  /// - The form for each atom is valid
243  /// - The tag for each DIE in the table is valid
244  /// - The buckets have a valid index, or they are empty
245  /// - Each hashdata offset is valid
246  /// - Each DIE is valid
247  ///
248  /// \param AccelSection pointer to the section containing the acceleration table
249  /// \param StrData pointer to the string section
250  /// \param SectionName the name of the table we're verifying
251  ///
252  /// \returns The number of errors occurred during verification
253  unsigned verifyAppleAccelTable(const DWARFSection *AccelSection,
254  DataExtractor *StrData,
255  const char *SectionName);
256 
257  unsigned verifyDebugNamesCULists(const DWARFDebugNames &AccelTable);
258  unsigned verifyNameIndexBuckets(const DWARFDebugNames::NameIndex &NI,
259  const DataExtractor &StrData);
260  unsigned verifyNameIndexAbbrevs(const DWARFDebugNames::NameIndex &NI);
261  unsigned verifyNameIndexAttribute(const DWARFDebugNames::NameIndex &NI,
262  const DWARFDebugNames::Abbrev &Abbr,
264  unsigned verifyNameIndexEntries(const DWARFDebugNames::NameIndex &NI,
266  unsigned verifyNameIndexCompleteness(const DWARFDie &Die,
267  const DWARFDebugNames::NameIndex &NI);
268 
269  /// Verify that the DWARF v5 accelerator table is valid.
270  ///
271  /// This function currently checks that:
272  /// - Headers individual Name Indices fit into the section and can be parsed.
273  /// - Abbreviation tables can be parsed and contain valid index attributes
274  /// with correct form encodings.
275  /// - The CU lists reference existing compile units.
276  /// - The buckets have a valid index, or they are empty.
277  /// - All names are reachable via the hash table (they have the correct hash,
278  /// and the hash is in the correct bucket).
279  /// - Information in the index entries is complete (all required entries are
280  /// present) and consistent with the debug_info section DIEs.
281  ///
282  /// \param AccelSection section containing the acceleration table
283  /// \param StrData string section
284  ///
285  /// \returns The number of errors occurred during verification
286  unsigned verifyDebugNames(const DWARFSection &AccelSection,
287  const DataExtractor &StrData);
288 
289 public:
292 
293  /// Verify the information in any of the following sections, if available:
294  /// .debug_abbrev, debug_abbrev.dwo
295  ///
296  /// Any errors are reported to the stream that was this object was
297  /// constructed with.
298  ///
299  /// \returns true if .debug_abbrev and .debug_abbrev.dwo verify successfully,
300  /// false otherwise.
301  bool handleDebugAbbrev();
302 
303  /// Verify the information in the .debug_info and .debug_types sections.
304  ///
305  /// Any errors are reported to the stream that this object was
306  /// constructed with.
307  ///
308  /// \returns true if all sections verify successfully, false otherwise.
309  bool handleDebugInfo();
310 
311  /// Verify the information in the .debug_line section.
312  ///
313  /// Any errors are reported to the stream that was this object was
314  /// constructed with.
315  ///
316  /// \returns true if the .debug_line verifies successfully, false otherwise.
317  bool handleDebugLine();
318 
319  /// Verify the information in accelerator tables, if they exist.
320  ///
321  /// Any errors are reported to the stream that was this object was
322  /// constructed with.
323  ///
324  /// \returns true if the existing Apple-style accelerator tables verify
325  /// successfully, false otherwise.
326  bool handleAccelTables();
327 };
328 
329 static inline bool operator<(const DWARFVerifier::DieRangeInfo &LHS,
330  const DWARFVerifier::DieRangeInfo &RHS) {
331  return std::tie(LHS.Ranges, LHS.Die) < std::tie(RHS.Ranges, RHS.Die);
332 }
333 
334 } // end namespace llvm
335 
336 #endif // LLVM_DEBUGINFO_DWARF_DWARFCONTEXT_H
This class represents lattice values for constants.
Definition: AllocatorList.h:23
This class holds an abstract representation of an Accelerator Table, consisting of a sequence of buck...
Definition: AccelTable.h:198
bool handleDebugLine()
Verify the information in the .debug_line section.
#define error(X)
Abbreviation describing the encoding of Name Index entries.
bool handleDebugInfo()
Verify the information in the .debug_info and .debug_types sections.
Definition: BitVector.h:937
Index attribute and its encoding.
std::set< DieRangeInfo > Children
Sorted DWARFAddressRangeInfo.
Definition: DWARFVerifier.h:45
std::vector< DWARFAddressRange > Ranges
Sorted DWARFAddressRanges.
Definition: DWARFVerifier.h:42
Encapsulates a DWARF attribute value and all of the data required to describe the attribute value...
Represents a single accelerator table within the DWARF v5 .debug_names section.
Container for dump options that control which debug information will be dumped.
Definition: DIContext.h:171
address_range_iterator findRange(const DWARFAddressRange &R) const
Finds an address range in the sorted vector of ranges.
Definition: DWARFVerifier.h:66
Utility class that carries the DWARF compile/type unit and the debug info entry in an object...
Definition: DWARFDie.h:42
void dump(const SparseBitVector< ElementSize > &LHS, raw_ostream &out)
DWARFSectionKind
bool handleDebugAbbrev()
Verify the information in any of the following sections, if available: .debug_abbrev, debug_abbrev.dwo.
A class that keeps the address range information for a single DIE.
Definition: DWARFVerifier.h:38
bool contains(const DieRangeInfo &RHS) const
Return true if ranges in this object contains all ranges within RHS.
DieRangeInfo(std::vector< DWARFAddressRange > Ranges)
Used for unit testing.
Definition: DWARFVerifier.h:51
SectionKind - This is a simple POD value that classifies the properties of a section.
Definition: SectionKind.h:22
std::vector< DWARFAddressRange >::const_iterator address_range_iterator
Definition: DWARFVerifier.h:55
UnitType
Constants for unit types in DWARF v5.
Definition: Dwarf.h:319
A DataExtractor (typically for an in-memory copy of an object-file section) plus a relocation map for...
.debug_names section consists of one or more units.
A single entry in the Name Table (DWARF v5 sect.
address_range_iterator insert(const DWARFAddressRange &R)
Inserts the address range.
DWARFContext This data structure is the top level entity that deals with dwarf debug information pars...
Definition: DWARFContext.h:58
static GCRegistry::Add< StatepointGC > D("statepoint-example", "an example strategy for statepoint")
bool intersects(const DieRangeInfo &RHS) const
Return true if any range in this object intersects with any range in RHS.
A class that verifies DWARF debug information given a DWARF Context.
Definition: DWARFVerifier.h:35
bool handleAccelTables()
Verify the information in accelerator tables, if they exist.
std::set< DieRangeInfo >::const_iterator die_range_info_iterator
Definition: DWARFVerifier.h:56
static DIDumpOptions getForSingleDIE()
Return default option set for printing a single DIE without children.
Definition: DIContext.h:186
bool operator<(int64_t V1, const APSInt &V2)
Definition: APSInt.h:343
DWARFVerifier(raw_ostream &S, DWARFContext &D, DIDumpOptions DumpOpts=DIDumpOptions::getForSingleDIE())
This class implements an extremely fast bulk output stream that can only output to a stream...
Definition: raw_ostream.h:45
auto upper_bound(R &&Range, T &&Value) -> decltype(adl_begin(Range))
Provide wrappers to std::upper_bound which take ranges instead of having to pass begin/end explicitly...
Definition: STLExtras.h:1288