1//===-- DWARFUnit.h ---------------------------------------------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef LLVM_LIB_DEBUGINFO_DWARFUNIT_H
11#define LLVM_LIB_DEBUGINFO_DWARFUNIT_H
12
13#include "llvm/ADT/STLExtras.h"
14#include "llvm/DebugInfo/DWARF/DWARFDebugAbbrev.h"
15#include "llvm/DebugInfo/DWARF/DWARFDebugInfoEntry.h"
16#include "llvm/DebugInfo/DWARF/DWARFDebugRangeList.h"
17#include "llvm/DebugInfo/DWARF/DWARFRelocMap.h"
18#include "llvm/DebugInfo/DWARF/DWARFSection.h"
19#include "llvm/DebugInfo/DWARF/DWARFUnitIndex.h"
20#include <vector>
21
22namespace llvm {
23
24namespace object {
25class ObjectFile;
26}
27
28class DWARFContext;
29class DWARFDebugAbbrev;
30class DWARFUnit;
31class StringRef;
32class raw_ostream;
33
34/// Base class for all DWARFUnitSection classes. This provides the
35/// functionality common to all unit types.
36class DWARFUnitSectionBase {
37public:
38  /// Returns the Unit that contains the given section offset in the
39  /// same section this Unit originated from.
40  virtual DWARFUnit *getUnitForOffset(uint32_t Offset) const = 0;
41
42  void parse(DWARFContext &C, const DWARFSection &Section);
43  void parseDWO(DWARFContext &C, const DWARFSection &DWOSection,
44                DWARFUnitIndex *Index = nullptr);
45
46protected:
47  virtual void parseImpl(DWARFContext &Context, const DWARFSection &Section,
48                         const DWARFDebugAbbrev *DA, StringRef RS, StringRef SS,
49                         StringRef SOS, StringRef AOS, StringRef LS,
50                         bool isLittleEndian) = 0;
51
52  ~DWARFUnitSectionBase() = default;
53};
54
55const DWARFUnitIndex &getDWARFUnitIndex(DWARFContext &Context,
56                                        DWARFSectionKind Kind);
57
58/// Concrete instance of DWARFUnitSection, specialized for one Unit type.
59template<typename UnitType>
60class DWARFUnitSection final : public SmallVector<std::unique_ptr<UnitType>, 1>,
61                               public DWARFUnitSectionBase {
62  bool Parsed;
63
64public:
65  DWARFUnitSection() : Parsed(false) {}
66  DWARFUnitSection(DWARFUnitSection &&DUS) :
67    SmallVector<std::unique_ptr<UnitType>, 1>(std::move(DUS)), Parsed(DUS.Parsed) {}
68
69  typedef llvm::SmallVectorImpl<std::unique_ptr<UnitType>> UnitVector;
70  typedef typename UnitVector::iterator iterator;
71  typedef llvm::iterator_range<typename UnitVector::iterator> iterator_range;
72
73  UnitType *getUnitForOffset(uint32_t Offset) const override {
74    auto *CU = std::upper_bound(
75        this->begin(), this->end(), Offset,
76        [](uint32_t LHS, const std::unique_ptr<UnitType> &RHS) {
77          return LHS < RHS->getNextUnitOffset();
78        });
79    if (CU != this->end())
80      return CU->get();
81    return nullptr;
82  }
83
84private:
85  void parseImpl(DWARFContext &Context, const DWARFSection &Section,
86                 const DWARFDebugAbbrev *DA, StringRef RS, StringRef SS,
87                 StringRef SOS, StringRef AOS, StringRef LS, bool LE) override {
88    if (Parsed)
89      return;
90    const auto &Index = getDWARFUnitIndex(Context, UnitType::Section);
91    DataExtractor Data(Section.Data, LE, 0);
92    uint32_t Offset = 0;
93    while (Data.isValidOffset(Offset)) {
94      auto U = llvm::make_unique<UnitType>(Context, Section, DA, RS, SS, SOS,
95                                           AOS, LS, LE, *this,
96                                           Index.getFromOffset(Offset));
97      if (!U->extract(Data, &Offset))
98        break;
99      this->push_back(std::move(U));
100      Offset = this->back()->getNextUnitOffset();
101    }
102    Parsed = true;
103  }
104};
105
106class DWARFUnit {
107  DWARFContext &Context;
108  // Section containing this DWARFUnit.
109  const DWARFSection &InfoSection;
110
111  const DWARFDebugAbbrev *Abbrev;
112  StringRef RangeSection;
113  uint32_t RangeSectionBase;
114  StringRef LineSection;
115  StringRef StringSection;
116  StringRef StringOffsetSection;
117  StringRef AddrOffsetSection;
118  uint32_t AddrOffsetSectionBase;
119  bool isLittleEndian;
120  const DWARFUnitSectionBase &UnitSection;
121
122  uint32_t Offset;
123  uint32_t Length;
124  uint16_t Version;
125  const DWARFAbbreviationDeclarationSet *Abbrevs;
126  uint8_t AddrSize;
127  uint64_t BaseAddr;
128  // The compile unit debug information entry items.
129  std::vector<DWARFDebugInfoEntryMinimal> DieArray;
130
131  class DWOHolder {
132    object::OwningBinary<object::ObjectFile> DWOFile;
133    std::unique_ptr<DWARFContext> DWOContext;
134    DWARFUnit *DWOU;
135  public:
136    DWOHolder(StringRef DWOPath);
137    DWARFUnit *getUnit() const { return DWOU; }
138  };
139  std::unique_ptr<DWOHolder> DWO;
140
141  const DWARFUnitIndex::Entry *IndexEntry;
142
143protected:
144  virtual bool extractImpl(DataExtractor debug_info, uint32_t *offset_ptr);
145  /// Size in bytes of the unit header.
146  virtual uint32_t getHeaderSize() const { return 11; }
147
148public:
149  DWARFUnit(DWARFContext &Context, const DWARFSection &Section,
150            const DWARFDebugAbbrev *DA, StringRef RS, StringRef SS,
151            StringRef SOS, StringRef AOS, StringRef LS, bool LE,
152            const DWARFUnitSectionBase &UnitSection,
153            const DWARFUnitIndex::Entry *IndexEntry = nullptr);
154
155  virtual ~DWARFUnit();
156
157  DWARFContext& getContext() const { return Context; }
158
159  StringRef getLineSection() const { return LineSection; }
160  StringRef getStringSection() const { return StringSection; }
161  StringRef getStringOffsetSection() const { return StringOffsetSection; }
162  void setAddrOffsetSection(StringRef AOS, uint32_t Base) {
163    AddrOffsetSection = AOS;
164    AddrOffsetSectionBase = Base;
165  }
166  void setRangesSection(StringRef RS, uint32_t Base) {
167    RangeSection = RS;
168    RangeSectionBase = Base;
169  }
170
171  bool getAddrOffsetSectionItem(uint32_t Index, uint64_t &Result) const;
172  // FIXME: Result should be uint64_t in DWARF64.
173  bool getStringOffsetSectionItem(uint32_t Index, uint32_t &Result) const;
174
175  DataExtractor getDebugInfoExtractor() const {
176    return DataExtractor(InfoSection.Data, isLittleEndian, AddrSize);
177  }
178  DataExtractor getStringExtractor() const {
179    return DataExtractor(StringSection, false, 0);
180  }
181
182  const RelocAddrMap *getRelocMap() const { return &InfoSection.Relocs; }
183
184  bool extract(DataExtractor debug_info, uint32_t* offset_ptr);
185
186  /// extractRangeList - extracts the range list referenced by this compile
187  /// unit from .debug_ranges section. Returns true on success.
188  /// Requires that compile unit is already extracted.
189  bool extractRangeList(uint32_t RangeListOffset,
190                        DWARFDebugRangeList &RangeList) const;
191  void clear();
192  uint32_t getOffset() const { return Offset; }
193  uint32_t getNextUnitOffset() const { return Offset + Length + 4; }
194  uint32_t getLength() const { return Length; }
195  uint16_t getVersion() const { return Version; }
196  const DWARFAbbreviationDeclarationSet *getAbbreviations() const {
197    return Abbrevs;
198  }
199  uint8_t getAddressByteSize() const { return AddrSize; }
200  uint64_t getBaseAddress() const { return BaseAddr; }
201
202  void setBaseAddress(uint64_t base_addr) {
203    BaseAddr = base_addr;
204  }
205
206  const DWARFDebugInfoEntryMinimal *getUnitDIE(bool ExtractUnitDIEOnly = true) {
207    extractDIEsIfNeeded(ExtractUnitDIEOnly);
208    return DieArray.empty() ? nullptr : &DieArray[0];
209  }
210
211  const char *getCompilationDir();
212  uint64_t getDWOId();
213
214  void collectAddressRanges(DWARFAddressRangesVector &CURanges);
215
216  /// getInlinedChainForAddress - fetches inlined chain for a given address.
217  /// Returns empty chain if there is no subprogram containing address. The
218  /// chain is valid as long as parsed compile unit DIEs are not cleared.
219  DWARFDebugInfoEntryInlinedChain getInlinedChainForAddress(uint64_t Address);
220
221  /// getUnitSection - Return the DWARFUnitSection containing this unit.
222  const DWARFUnitSectionBase &getUnitSection() const { return UnitSection; }
223
224  /// \brief Returns the number of DIEs in the unit. Parses the unit
225  /// if necessary.
226  unsigned getNumDIEs() {
227    extractDIEsIfNeeded(false);
228    return DieArray.size();
229  }
230
231  /// \brief Return the index of a DIE inside the unit's DIE vector.
232  ///
233  /// It is illegal to call this method with a DIE that hasn't be
234  /// created by this unit. In other word, it's illegal to call this
235  /// method on a DIE that isn't accessible by following
236  /// children/sibling links starting from this unit's getUnitDIE().
237  uint32_t getDIEIndex(const DWARFDebugInfoEntryMinimal *DIE) {
238    assert(!DieArray.empty() && DIE >= &DieArray[0] &&
239           DIE < &DieArray[0] + DieArray.size());
240    return DIE - &DieArray[0];
241  }
242
243  /// \brief Return the DIE object at the given index.
244  const DWARFDebugInfoEntryMinimal *getDIEAtIndex(unsigned Index) const {
245    assert(Index < DieArray.size());
246    return &DieArray[Index];
247  }
248
249  /// \brief Return the DIE object for a given offset inside the
250  /// unit's DIE vector.
251  ///
252  /// The unit needs to have his DIEs extracted for this method to work.
253  const DWARFDebugInfoEntryMinimal *getDIEForOffset(uint32_t Offset) const {
254    assert(!DieArray.empty());
255    auto it = std::lower_bound(
256        DieArray.begin(), DieArray.end(), Offset,
257        [](const DWARFDebugInfoEntryMinimal &LHS, uint32_t Offset) {
258          return LHS.getOffset() < Offset;
259        });
260    return it == DieArray.end() ? nullptr : &*it;
261  }
262
263  uint32_t getLineTableOffset() const {
264    if (IndexEntry)
265      if (const auto *Contrib = IndexEntry->getOffset(DW_SECT_LINE))
266        return Contrib->Offset;
267    return 0;
268  }
269
270private:
271  /// Size in bytes of the .debug_info data associated with this compile unit.
272  size_t getDebugInfoSize() const { return Length + 4 - getHeaderSize(); }
273
274  /// extractDIEsIfNeeded - Parses a compile unit and indexes its DIEs if it
275  /// hasn't already been done. Returns the number of DIEs parsed at this call.
276  size_t extractDIEsIfNeeded(bool CUDieOnly);
277  /// extractDIEsToVector - Appends all parsed DIEs to a vector.
278  void extractDIEsToVector(bool AppendCUDie, bool AppendNonCUDIEs,
279                           std::vector<DWARFDebugInfoEntryMinimal> &DIEs) const;
280  /// setDIERelations - We read in all of the DIE entries into our flat list
281  /// of DIE entries and now we need to go back through all of them and set the
282  /// parent, sibling and child pointers for quick DIE navigation.
283  void setDIERelations();
284  /// clearDIEs - Clear parsed DIEs to keep memory usage low.
285  void clearDIEs(bool KeepCUDie);
286
287  /// parseDWO - Parses .dwo file for current compile unit. Returns true if
288  /// it was actually constructed.
289  bool parseDWO();
290
291  /// getSubprogramForAddress - Returns subprogram DIE with address range
292  /// encompassing the provided address. The pointer is alive as long as parsed
293  /// compile unit DIEs are not cleared.
294  const DWARFDebugInfoEntryMinimal *getSubprogramForAddress(uint64_t Address);
295};
296
297}
298
299#endif
300