1 //===-- DWARFUnit.h ---------------------------------------------*- C++ -*-===//
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 SymbolFileDWARF_DWARFUnit_h_
10 #define SymbolFileDWARF_DWARFUnit_h_
11 
12 #include "DWARFDIE.h"
13 #include "DWARFDebugInfoEntry.h"
14 #include "lldb/lldb-enumerations.h"
15 #include "llvm/Support/RWMutex.h"
16 #include <atomic>
17 
18 class DWARFUnit;
19 class DWARFCompileUnit;
20 class NameToDIE;
21 class SymbolFileDWARF;
22 class SymbolFileDWARFDwo;
23 
24 typedef std::shared_ptr<DWARFUnit> DWARFUnitSP;
25 
26 enum DWARFProducer {
27   eProducerInvalid = 0,
28   eProducerClang,
29   eProducerGCC,
30   eProducerLLVMGCC,
31   eProcucerOther
32 };
33 
34 /// Base class describing the header of any kind of "unit."  Some information
35 /// is specific to certain unit types.  We separate this class out so we can
36 /// parse the header before deciding what specific kind of unit to construct.
37 class DWARFUnitHeader {
38   dw_offset_t m_offset = 0;
39   dw_offset_t m_length = 0;
40   uint16_t m_version = 0;
41   dw_offset_t m_abbr_offset = 0;
42   uint8_t m_unit_type = 0;
43   uint8_t m_addr_size = 0;
44 
45   uint64_t m_type_hash = 0;
46   uint32_t m_type_offset = 0;
47 
48   uint64_t m_dwo_id = 0;
49 
50   DWARFUnitHeader() = default;
51 
52 public:
53   dw_offset_t GetOffset() const { return m_offset; }
54   uint16_t GetVersion() const { return m_version; }
55   uint16_t GetAddressByteSize() const { return m_addr_size; }
56   dw_offset_t GetLength() const { return m_length; }
57   dw_offset_t GetAbbrOffset() const { return m_abbr_offset; }
58   uint8_t GetUnitType() const { return m_unit_type; }
59   uint64_t GetTypeHash() const { return m_type_hash; }
60   dw_offset_t GetTypeOffset() const { return m_type_offset; }
61   bool IsTypeUnit() const {
62     return m_unit_type == DW_UT_type || m_unit_type == DW_UT_split_type;
63   }
64   uint32_t GetNextUnitOffset() const { return m_offset + m_length + 4; }
65 
66   static llvm::Expected<DWARFUnitHeader>
67   extract(const lldb_private::DWARFDataExtractor &data, DIERef::Section section,
68           lldb::offset_t *offset_ptr);
69 };
70 
71 class DWARFUnit : public lldb_private::UserID {
72   using die_iterator_range =
73       llvm::iterator_range<DWARFDebugInfoEntry::collection::iterator>;
74 
75 public:
76   static llvm::Expected<DWARFUnitSP>
77   extract(SymbolFileDWARF &dwarf2Data, lldb::user_id_t uid,
78           const lldb_private::DWARFDataExtractor &debug_info,
79           DIERef::Section section, lldb::offset_t *offset_ptr);
80   virtual ~DWARFUnit();
81 
82   void ExtractUnitDIEIfNeeded();
83   void ExtractDIEsIfNeeded();
84 
85   class ScopedExtractDIEs {
86     DWARFUnit *m_cu;
87   public:
88     bool m_clear_dies = false;
89     ScopedExtractDIEs(DWARFUnit &cu);
90     ~ScopedExtractDIEs();
91     DISALLOW_COPY_AND_ASSIGN(ScopedExtractDIEs);
92     ScopedExtractDIEs(ScopedExtractDIEs &&rhs);
93     ScopedExtractDIEs &operator=(ScopedExtractDIEs &&rhs);
94   };
95   ScopedExtractDIEs ExtractDIEsScoped();
96 
97   DWARFDIE LookupAddress(const dw_addr_t address);
98   bool Verify(lldb_private::Stream *s) const;
99   virtual void Dump(lldb_private::Stream *s) const = 0;
100   /// Get the data that contains the DIE information for this unit.
101   ///
102   /// This will return the correct bytes that contain the data for
103   /// this DWARFUnit. It could be .debug_info or .debug_types
104   /// depending on where the data for this unit originates.
105   ///
106   /// \return
107   ///   The correct data for the DIE information in this unit.
108   const lldb_private::DWARFDataExtractor &GetData() const;
109 
110   /// Get the size in bytes of the unit header.
111   ///
112   /// \return
113   ///     Byte size of the unit header
114   uint32_t GetHeaderByteSize() const;
115 
116   // Offset of the initial length field.
117   dw_offset_t GetOffset() const { return m_header.GetOffset(); }
118   /// Get the size in bytes of the length field in the header.
119   ///
120   /// In DWARF32 this is just 4 bytes
121   ///
122   /// \return
123   ///     Byte size of the compile unit header length field
124   size_t GetLengthByteSize() const { return 4; }
125 
126   bool ContainsDIEOffset(dw_offset_t die_offset) const {
127     return die_offset >= GetFirstDIEOffset() &&
128            die_offset < GetNextUnitOffset();
129   }
130   dw_offset_t GetFirstDIEOffset() const {
131     return GetOffset() + GetHeaderByteSize();
132   }
133   dw_offset_t GetNextUnitOffset() const { return m_header.GetNextUnitOffset(); }
134   // Size of the CU data (without initial length and without header).
135   size_t GetDebugInfoSize() const;
136   // Size of the CU data incl. header but without initial length.
137   uint32_t GetLength() const { return m_header.GetLength(); }
138   uint16_t GetVersion() const { return m_header.GetVersion(); }
139   const DWARFAbbreviationDeclarationSet *GetAbbreviations() const;
140   dw_offset_t GetAbbrevOffset() const;
141   uint8_t GetAddressByteSize() const { return m_header.GetAddressByteSize(); }
142   dw_addr_t GetAddrBase() const { return m_addr_base; }
143   dw_addr_t GetBaseAddress() const { return m_base_addr; }
144   dw_offset_t GetLineTableOffset();
145   dw_addr_t GetRangesBase() const { return m_ranges_base; }
146   dw_addr_t GetStrOffsetsBase() const { return m_str_offsets_base; }
147   void SetAddrBase(dw_addr_t addr_base);
148   void SetLoclistsBase(dw_addr_t loclists_base);
149   void SetRangesBase(dw_addr_t ranges_base);
150   void SetStrOffsetsBase(dw_offset_t str_offsets_base);
151   virtual void BuildAddressRangeTable(DWARFDebugAranges *debug_aranges) = 0;
152 
153   lldb::ByteOrder GetByteOrder() const;
154 
155   const DWARFDebugAranges &GetFunctionAranges();
156 
157   void SetBaseAddress(dw_addr_t base_addr);
158 
159   DWARFBaseDIE GetUnitDIEOnly() { return DWARFDIE(this, GetUnitDIEPtrOnly()); }
160 
161   DWARFDIE DIE() { return DWARFDIE(this, DIEPtr()); }
162 
163   DWARFDIE GetDIE(dw_offset_t die_offset);
164 
165   DWARFUnit &GetNonSkeletonUnit();
166 
167   static uint8_t GetAddressByteSize(const DWARFUnit *cu);
168 
169   static uint8_t GetDefaultAddressSize();
170 
171   void *GetUserData() const;
172 
173   void SetUserData(void *d);
174 
175   bool Supports_DW_AT_APPLE_objc_complete_type();
176 
177   bool DW_AT_decl_file_attributes_are_invalid();
178 
179   bool Supports_unnamed_objc_bitfields();
180 
181   SymbolFileDWARF &GetSymbolFileDWARF() const { return m_dwarf; }
182 
183   DWARFProducer GetProducer();
184 
185   uint32_t GetProducerVersionMajor();
186 
187   uint32_t GetProducerVersionMinor();
188 
189   uint32_t GetProducerVersionUpdate();
190 
191   uint64_t GetDWARFLanguageType();
192 
193   bool GetIsOptimized();
194 
195   const lldb_private::FileSpec &GetCompilationDirectory();
196   const lldb_private::FileSpec &GetAbsolutePath();
197   lldb_private::FileSpec GetFile(size_t file_idx);
198   lldb_private::FileSpec::Style GetPathStyle();
199 
200   SymbolFileDWARFDwo *GetDwoSymbolFile();
201 
202   die_iterator_range dies() {
203     ExtractDIEsIfNeeded();
204     return die_iterator_range(m_die_array.begin(), m_die_array.end());
205   }
206 
207   DIERef::Section GetDebugSection() const { return m_section; }
208 
209   uint8_t GetUnitType() const { return m_header.GetUnitType(); }
210   bool IsTypeUnit() const { return m_header.IsTypeUnit(); }
211 
212   /// Return a list of address ranges resulting from a (possibly encoded)
213   /// range list starting at a given offset in the appropriate ranges section.
214   llvm::Expected<DWARFRangeList> FindRnglistFromOffset(dw_offset_t offset);
215 
216   /// Return a list of address ranges retrieved from an encoded range
217   /// list whose offset is found via a table lookup given an index (DWARF v5
218   /// and later).
219   llvm::Expected<DWARFRangeList> FindRnglistFromIndex(uint32_t index);
220 
221   /// Return a rangelist's offset based on an index. The index designates
222   /// an entry in the rangelist table's offset array and is supplied by
223   /// DW_FORM_rnglistx.
224   llvm::Optional<uint64_t> GetRnglistOffset(uint32_t Index) const {
225     if (!m_rnglist_table)
226       return llvm::None;
227     if (llvm::Optional<uint64_t> off = m_rnglist_table->getOffsetEntry(Index))
228       return *off + m_ranges_base;
229     return llvm::None;
230   }
231 
232   llvm::Optional<uint64_t> GetLoclistOffset(uint32_t Index) {
233     if (!m_loclist_table_header)
234       return llvm::None;
235 
236     llvm::Optional<uint64_t> Offset =  m_loclist_table_header->getOffsetEntry(Index);
237     if (!Offset)
238       return llvm::None;
239     return *Offset + m_loclists_base;
240   }
241 
242   /// Return the location table for parsing the given location list data. The
243   /// format is chosen according to the unit type. Never returns null.
244   std::unique_ptr<llvm::DWARFLocationTable>
245   GetLocationTable(const lldb_private::DataExtractor &data) const;
246 
247   const lldb_private::DWARFDataExtractor &GetLocationData() const;
248 
249 protected:
250   DWARFUnit(SymbolFileDWARF &dwarf, lldb::user_id_t uid,
251             const DWARFUnitHeader &header,
252             const DWARFAbbreviationDeclarationSet &abbrevs,
253             DIERef::Section section, bool is_dwo);
254 
255   llvm::Error ExtractHeader(SymbolFileDWARF &dwarf,
256                             const lldb_private::DWARFDataExtractor &data,
257                             lldb::offset_t *offset_ptr);
258 
259   // Get the DWARF unit DWARF debug information entry. Parse the single DIE
260   // if needed.
261   const DWARFDebugInfoEntry *GetUnitDIEPtrOnly() {
262     ExtractUnitDIEIfNeeded();
263     // m_first_die_mutex is not required as m_first_die is never cleared.
264     if (!m_first_die)
265       return NULL;
266     return &m_first_die;
267   }
268 
269   // Get all DWARF debug informration entries. Parse all DIEs if needed.
270   const DWARFDebugInfoEntry *DIEPtr() {
271     ExtractDIEsIfNeeded();
272     if (m_die_array.empty())
273       return NULL;
274     return &m_die_array[0];
275   }
276 
277   SymbolFileDWARF &m_dwarf;
278   std::unique_ptr<SymbolFileDWARFDwo> m_dwo_symbol_file;
279   DWARFUnitHeader m_header;
280   const DWARFAbbreviationDeclarationSet *m_abbrevs = nullptr;
281   void *m_user_data = nullptr;
282   // The compile unit debug information entry item
283   DWARFDebugInfoEntry::collection m_die_array;
284   mutable llvm::sys::RWMutex m_die_array_mutex;
285   // It is used for tracking of ScopedExtractDIEs instances.
286   mutable llvm::sys::RWMutex m_die_array_scoped_mutex;
287   // ScopedExtractDIEs instances should not call ClearDIEsRWLocked()
288   // as someone called ExtractDIEsIfNeeded().
289   std::atomic<bool> m_cancel_scopes;
290   // GetUnitDIEPtrOnly() needs to return pointer to the first DIE.
291   // But the first element of m_die_array after ExtractUnitDIEIfNeeded()
292   // would possibly move in memory after later ExtractDIEsIfNeeded().
293   DWARFDebugInfoEntry m_first_die;
294   llvm::sys::RWMutex m_first_die_mutex;
295   // A table similar to the .debug_aranges table, but this one points to the
296   // exact DW_TAG_subprogram DIEs
297   std::unique_ptr<DWARFDebugAranges> m_func_aranges_up;
298   dw_addr_t m_base_addr = 0;
299   DWARFProducer m_producer = eProducerInvalid;
300   uint32_t m_producer_version_major = 0;
301   uint32_t m_producer_version_minor = 0;
302   uint32_t m_producer_version_update = 0;
303   llvm::Optional<uint64_t> m_language_type;
304   lldb_private::LazyBool m_is_optimized = lldb_private::eLazyBoolCalculate;
305   llvm::Optional<lldb_private::FileSpec> m_comp_dir;
306   llvm::Optional<lldb_private::FileSpec> m_file_spec;
307   dw_addr_t m_addr_base = 0;     ///< Value of DW_AT_addr_base.
308   dw_addr_t m_loclists_base = 0; ///< Value of DW_AT_loclists_base.
309   dw_addr_t m_ranges_base = 0;   ///< Value of DW_AT_rnglists_base.
310 
311   /// Value of DW_AT_stmt_list.
312   dw_offset_t m_line_table_offset = DW_INVALID_OFFSET;
313 
314   dw_offset_t m_str_offsets_base = 0; // Value of DW_AT_str_offsets_base.
315 
316   llvm::Optional<llvm::DWARFDebugRnglistTable> m_rnglist_table;
317   llvm::Optional<llvm::DWARFListTableHeader> m_loclist_table_header;
318 
319   const DIERef::Section m_section;
320   bool m_is_dwo;
321 
322 private:
323   void ParseProducerInfo();
324   void ExtractDIEsRWLocked();
325   void ClearDIEsRWLocked();
326 
327   void AddUnitDIE(const DWARFDebugInfoEntry &cu_die);
328 
329   void ComputeCompDirAndGuessPathStyle();
330   void ComputeAbsolutePath();
331 
332   DISALLOW_COPY_AND_ASSIGN(DWARFUnit);
333 };
334 
335 #endif // SymbolFileDWARF_DWARFUnit_h_
336