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