include/llvm/DebugInfo/DWARF/DWARFVerifier.h

   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
  12 #include "llvm/DebugInfo/DIContext.h"
  13 #include "llvm/DebugInfo/DWARF/DWARFAcceleratorTable.h"
  14 #include "llvm/DebugInfo/DWARF/DWARFAddressRange.h"
  15 #include "llvm/DebugInfo/DWARF/DWARFDie.h"
  16 #include "llvm/DebugInfo/DWARF/DWARFUnitIndex.h"
  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.
  35 class DWARFVerifier {
  36 public:
  37   /// A class that keeps the address range information for a single DIE.
  38   struct DieRangeInfo {
  39     DWARFDie Die;
  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
  55         address_range_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.
  63     address_range_iterator insert(const DWARFAddressRange &R);
  64
  65     /// Finds an address range in the sorted vector of ranges.
  66     address_range_iterator findRange(const DWARFAddressRange &R) const {
  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,
 169                              DWARFSectionKind SectionKind);
 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,
 263                                     DWARFDebugNames::AttributeEncoding AttrEnc);
 264   unsigned verifyNameIndexEntries(const DWARFDebugNames::NameIndex &NI,
 265                                   const DWARFDebugNames::NameTableEntry &NTE);
 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:
 290   DWARFVerifier(raw_ostream &S, DWARFContext &D,
 291                 DIDumpOptions DumpOpts = DIDumpOptions::getForSingleDIE());
 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