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_DEBUGINFO_DWARF_DWARFUNIT_H
11#define LLVM_DEBUGINFO_DWARF_DWARFUNIT_H
12
13#include "llvm/ADT/Optional.h"
14#include "llvm/ADT/STLExtras.h"
15#include "llvm/ADT/SmallVector.h"
16#include "llvm/ADT/StringRef.h"
17#include "llvm/ADT/iterator_range.h"
18#include "llvm/BinaryFormat/Dwarf.h"
19#include "llvm/DebugInfo/DWARF/DWARFDebugInfoEntry.h"
20#include "llvm/DebugInfo/DWARF/DWARFDebugRangeList.h"
21#include "llvm/DebugInfo/DWARF/DWARFDie.h"
22#include "llvm/DebugInfo/DWARF/DWARFRelocMap.h"
23#include "llvm/DebugInfo/DWARF/DWARFSection.h"
24#include "llvm/DebugInfo/DWARF/DWARFUnitIndex.h"
25#include "llvm/Object/Binary.h"
26#include "llvm/Object/ObjectFile.h"
27#include "llvm/Support/DataExtractor.h"
28#include <algorithm>
29#include <cassert>
30#include <cstddef>
31#include <cstdint>
32#include <map>
33#include <memory>
34#include <vector>
35
36namespace llvm {
37
38class DWARFAbbreviationDeclarationSet;
39class DWARFContext;
40class DWARFDebugAbbrev;
41class DWARFUnit;
42
43/// Base class for all DWARFUnitSection classes. This provides the
44/// functionality common to all unit types.
45class DWARFUnitSectionBase {
46public:
47  /// Returns the Unit that contains the given section offset in the
48  /// same section this Unit originated from.
49  virtual DWARFUnit *getUnitForOffset(uint32_t Offset) const = 0;
50
51  void parse(DWARFContext &C, const DWARFSection &Section);
52  void parseDWO(DWARFContext &C, const DWARFSection &DWOSection,
53                DWARFUnitIndex *Index = nullptr);
54
55protected:
56  ~DWARFUnitSectionBase() = default;
57
58  virtual void parseImpl(DWARFContext &Context, const DWARFSection &Section,
59                         const DWARFDebugAbbrev *DA, const DWARFSection *RS,
60                         StringRef SS, const DWARFSection &SOS,
61                         const DWARFSection *AOS, StringRef LS,
62                         bool isLittleEndian, bool isDWO) = 0;
63};
64
65const DWARFUnitIndex &getDWARFUnitIndex(DWARFContext &Context,
66                                        DWARFSectionKind Kind);
67
68/// Concrete instance of DWARFUnitSection, specialized for one Unit type.
69template<typename UnitType>
70class DWARFUnitSection final : public SmallVector<std::unique_ptr<UnitType>, 1>,
71                               public DWARFUnitSectionBase {
72  bool Parsed = false;
73
74public:
75  typedef SmallVectorImpl<std::unique_ptr<UnitType>> UnitVector;
76  typedef typename UnitVector::iterator iterator;
77  typedef llvm::iterator_range<typename UnitVector::iterator> iterator_range;
78
79  UnitType *getUnitForOffset(uint32_t Offset) const override {
80    auto *CU = std::upper_bound(
81        this->begin(), this->end(), Offset,
82        [](uint32_t LHS, const std::unique_ptr<UnitType> &RHS) {
83          return LHS < RHS->getNextUnitOffset();
84        });
85    if (CU != this->end())
86      return CU->get();
87    return nullptr;
88  }
89
90private:
91  void parseImpl(DWARFContext &Context, const DWARFSection &Section,
92                 const DWARFDebugAbbrev *DA, const DWARFSection *RS,
93                 StringRef SS, const DWARFSection &SOS, const DWARFSection *AOS,
94                 StringRef LS, bool LE, bool IsDWO) override {
95    if (Parsed)
96      return;
97    const auto &Index = getDWARFUnitIndex(Context, UnitType::Section);
98    DataExtractor Data(Section.Data, LE, 0);
99    uint32_t Offset = 0;
100    while (Data.isValidOffset(Offset)) {
101      auto U = llvm::make_unique<UnitType>(Context, Section, DA, RS, SS, SOS,
102                                           AOS, LS, LE, IsDWO, *this,
103                                           Index.getFromOffset(Offset));
104      if (!U->extract(Data, &Offset))
105        break;
106      this->push_back(std::move(U));
107      Offset = this->back()->getNextUnitOffset();
108    }
109    Parsed = true;
110  }
111};
112
113class DWARFUnit {
114  DWARFContext &Context;
115  /// Section containing this DWARFUnit.
116  const DWARFSection &InfoSection;
117
118  const DWARFDebugAbbrev *Abbrev;
119  const DWARFSection *RangeSection;
120  uint32_t RangeSectionBase;
121  StringRef LineSection;
122  StringRef StringSection;
123  const DWARFSection &StringOffsetSection;
124  uint64_t StringOffsetSectionBase = 0;
125  const DWARFSection *AddrOffsetSection;
126  uint32_t AddrOffsetSectionBase;
127  bool isLittleEndian;
128  bool isDWO;
129  const DWARFUnitSectionBase &UnitSection;
130
131  uint32_t Offset;
132  uint32_t Length;
133  const DWARFAbbreviationDeclarationSet *Abbrevs;
134  uint16_t Version;
135  uint8_t UnitType;
136  uint8_t AddrSize;
137  uint64_t BaseAddr;
138  /// The compile unit debug information entry items.
139  std::vector<DWARFDebugInfoEntry> DieArray;
140
141  /// Map from range's start address to end address and corresponding DIE.
142  /// IntervalMap does not support range removal, as a result, we use the
143  /// std::map::upper_bound for address range lookup.
144  std::map<uint64_t, std::pair<uint64_t, DWARFDie>> AddrDieMap;
145  typedef iterator_range<std::vector<DWARFDebugInfoEntry>::iterator>
146      die_iterator_range;
147
148  std::shared_ptr<DWARFUnit> DWO;
149
150  const DWARFUnitIndex::Entry *IndexEntry;
151
152  uint32_t getDIEIndex(const DWARFDebugInfoEntry *Die) {
153    auto First = DieArray.data();
154    assert(Die >= First && Die < First + DieArray.size());
155    return Die - First;
156  }
157
158protected:
159  virtual bool extractImpl(DataExtractor debug_info, uint32_t *offset_ptr);
160
161  /// Size in bytes of the unit header.
162  virtual uint32_t getHeaderSize() const { return Version <= 4 ? 11 : 12; }
163
164public:
165  DWARFUnit(DWARFContext &Context, const DWARFSection &Section,
166            const DWARFDebugAbbrev *DA, const DWARFSection *RS, StringRef SS,
167            const DWARFSection &SOS, const DWARFSection *AOS, StringRef LS,
168            bool LE, bool IsDWO, const DWARFUnitSectionBase &UnitSection,
169            const DWARFUnitIndex::Entry *IndexEntry = nullptr);
170
171  virtual ~DWARFUnit();
172
173  DWARFContext& getContext() const { return Context; }
174
175  StringRef getLineSection() const { return LineSection; }
176  StringRef getStringSection() const { return StringSection; }
177  const DWARFSection &getStringOffsetSection() const {
178    return StringOffsetSection;
179  }
180
181  void setAddrOffsetSection(const DWARFSection *AOS, uint32_t Base) {
182    AddrOffsetSection = AOS;
183    AddrOffsetSectionBase = Base;
184  }
185
186  /// Recursively update address to Die map.
187  void updateAddressDieMap(DWARFDie Die);
188
189  void setRangesSection(const DWARFSection *RS, uint32_t Base) {
190    RangeSection = RS;
191    RangeSectionBase = Base;
192  }
193
194  bool getAddrOffsetSectionItem(uint32_t Index, uint64_t &Result) const;
195  // FIXME: Result should be uint64_t in DWARF64.
196  bool getStringOffsetSectionItem(uint32_t Index, uint64_t &Result) const;
197  uint64_t getStringOffsetSectionRelocation(uint32_t Index) const;
198
199  DataExtractor getDebugInfoExtractor() const {
200    return DataExtractor(InfoSection.Data, isLittleEndian, AddrSize);
201  }
202
203  DataExtractor getStringExtractor() const {
204    return DataExtractor(StringSection, false, 0);
205  }
206
207  const RelocAddrMap *getRelocMap() const { return &InfoSection.Relocs; }
208  const RelocAddrMap &getStringOffsetsRelocMap() const {
209    return StringOffsetSection.Relocs;
210  }
211
212  bool extract(DataExtractor debug_info, uint32_t* offset_ptr);
213
214  /// extractRangeList - extracts the range list referenced by this compile
215  /// unit from .debug_ranges section. Returns true on success.
216  /// Requires that compile unit is already extracted.
217  bool extractRangeList(uint32_t RangeListOffset,
218                        DWARFDebugRangeList &RangeList) const;
219  void clear();
220  uint32_t getOffset() const { return Offset; }
221  uint32_t getNextUnitOffset() const { return Offset + Length + 4; }
222  uint32_t getLength() const { return Length; }
223  uint16_t getVersion() const { return Version; }
224
225  dwarf::DwarfFormat getFormat() const {
226    return dwarf::DwarfFormat::DWARF32; // FIXME: Support DWARF64.
227  }
228
229  const DWARFAbbreviationDeclarationSet *getAbbreviations() const {
230    return Abbrevs;
231  }
232
233  uint8_t getUnitType() const { return UnitType; }
234  uint8_t getAddressByteSize() const { return AddrSize; }
235
236  uint8_t getRefAddrByteSize() const {
237    if (Version == 2)
238      return AddrSize;
239    return getDwarfOffsetByteSize();
240  }
241
242  uint8_t getDwarfOffsetByteSize() const {
243    if (getFormat() == dwarf::DwarfFormat::DWARF64)
244      return 8;
245    return 4;
246  }
247
248  uint64_t getBaseAddress() const { return BaseAddr; }
249
250  void setBaseAddress(uint64_t base_addr) {
251    BaseAddr = base_addr;
252  }
253
254  DWARFDie getUnitDIE(bool ExtractUnitDIEOnly = true) {
255    extractDIEsIfNeeded(ExtractUnitDIEOnly);
256    if (DieArray.empty())
257      return DWARFDie();
258    return DWARFDie(this, &DieArray[0]);
259  }
260
261  const char *getCompilationDir();
262  Optional<uint64_t> getDWOId();
263
264  void collectAddressRanges(DWARFAddressRangesVector &CURanges);
265
266  /// getInlinedChainForAddress - fetches inlined chain for a given address.
267  /// Returns empty chain if there is no subprogram containing address. The
268  /// chain is valid as long as parsed compile unit DIEs are not cleared.
269  void getInlinedChainForAddress(uint64_t Address,
270                                 SmallVectorImpl<DWARFDie> &InlinedChain);
271
272  /// getUnitSection - Return the DWARFUnitSection containing this unit.
273  const DWARFUnitSectionBase &getUnitSection() const { return UnitSection; }
274
275  /// \brief Returns the number of DIEs in the unit. Parses the unit
276  /// if necessary.
277  unsigned getNumDIEs() {
278    extractDIEsIfNeeded(false);
279    return DieArray.size();
280  }
281
282  /// \brief Return the index of a DIE inside the unit's DIE vector.
283  ///
284  /// It is illegal to call this method with a DIE that hasn't be
285  /// created by this unit. In other word, it's illegal to call this
286  /// method on a DIE that isn't accessible by following
287  /// children/sibling links starting from this unit's getUnitDIE().
288  uint32_t getDIEIndex(const DWARFDie &D) {
289    return getDIEIndex(D.getDebugInfoEntry());
290  }
291
292  /// \brief Return the DIE object at the given index.
293  DWARFDie getDIEAtIndex(unsigned Index) {
294    assert(Index < DieArray.size());
295    return DWARFDie(this, &DieArray[Index]);
296  }
297
298  DWARFDie getParent(const DWARFDebugInfoEntry *Die);
299  DWARFDie getSibling(const DWARFDebugInfoEntry *Die);
300
301  /// \brief Return the DIE object for a given offset inside the
302  /// unit's DIE vector.
303  ///
304  /// The unit needs to have its DIEs extracted for this method to work.
305  DWARFDie getDIEForOffset(uint32_t Offset) {
306    extractDIEsIfNeeded(false);
307    assert(!DieArray.empty());
308    auto it = std::lower_bound(
309        DieArray.begin(), DieArray.end(), Offset,
310        [](const DWARFDebugInfoEntry &LHS, uint32_t Offset) {
311          return LHS.getOffset() < Offset;
312        });
313    if (it != DieArray.end() && it->getOffset() == Offset)
314      return DWARFDie(this, &*it);
315    return DWARFDie();
316  }
317
318  uint32_t getLineTableOffset() const {
319    if (IndexEntry)
320      if (const auto *Contrib = IndexEntry->getOffset(DW_SECT_LINE))
321        return Contrib->Offset;
322    return 0;
323  }
324
325  die_iterator_range dies() {
326    extractDIEsIfNeeded(false);
327    return die_iterator_range(DieArray.begin(), DieArray.end());
328  }
329
330private:
331  /// Size in bytes of the .debug_info data associated with this compile unit.
332  size_t getDebugInfoSize() const { return Length + 4 - getHeaderSize(); }
333
334  /// extractDIEsIfNeeded - Parses a compile unit and indexes its DIEs if it
335  /// hasn't already been done. Returns the number of DIEs parsed at this call.
336  size_t extractDIEsIfNeeded(bool CUDieOnly);
337
338  /// extractDIEsToVector - Appends all parsed DIEs to a vector.
339  void extractDIEsToVector(bool AppendCUDie, bool AppendNonCUDIEs,
340                           std::vector<DWARFDebugInfoEntry> &DIEs) const;
341
342  /// clearDIEs - Clear parsed DIEs to keep memory usage low.
343  void clearDIEs(bool KeepCUDie);
344
345  /// parseDWO - Parses .dwo file for current compile unit. Returns true if
346  /// it was actually constructed.
347  bool parseDWO();
348
349  /// getSubroutineForAddress - Returns subprogram DIE with address range
350  /// encompassing the provided address. The pointer is alive as long as parsed
351  /// compile unit DIEs are not cleared.
352  DWARFDie getSubroutineForAddress(uint64_t Address);
353};
354
355} // end namespace llvm
356
357#endif // LLVM_DEBUGINFO_DWARF_DWARFUNIT_H
358