1 //===-- SymbolFile.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 LLDB_SYMBOL_SYMBOLFILE_H
10 #define LLDB_SYMBOL_SYMBOLFILE_H
11 
12 #include "lldb/Core/PluginInterface.h"
13 #include "lldb/Symbol/CompilerDecl.h"
14 #include "lldb/Symbol/CompilerDeclContext.h"
15 #include "lldb/Symbol/CompilerType.h"
16 #include "lldb/Symbol/Function.h"
17 #include "lldb/Symbol/SourceModule.h"
18 #include "lldb/Symbol/Type.h"
19 #include "lldb/Symbol/TypeList.h"
20 #include "lldb/Symbol/TypeSystem.h"
21 #include "lldb/Utility/XcodeSDK.h"
22 #include "lldb/lldb-private.h"
23 #include "llvm/ADT/DenseSet.h"
24 #include "llvm/Support/Errc.h"
25 
26 #include <mutex>
27 
28 #if defined(LLDB_CONFIGURATION_DEBUG)
29 #define ASSERT_MODULE_LOCK(expr) (expr->AssertModuleLock())
30 #else
31 #define ASSERT_MODULE_LOCK(expr) ((void)0)
32 #endif
33 
34 namespace lldb_private {
35 
36 class SymbolFile : public PluginInterface {
37   /// LLVM RTTI support.
38   static char ID;
39 
40 public:
41   /// LLVM RTTI support.
42   /// \{
43   virtual bool isA(const void *ClassID) const { return ClassID == &ID; }
44   static bool classof(const SymbolFile *obj) { return obj->isA(&ID); }
45   /// \}
46 
47   // Symbol file ability bits.
48   //
49   // Each symbol file can claim to support one or more symbol file abilities.
50   // These get returned from SymbolFile::GetAbilities(). These help us to
51   // determine which plug-in will be best to load the debug information found
52   // in files.
53   enum Abilities {
54     CompileUnits = (1u << 0),
55     LineTables = (1u << 1),
56     Functions = (1u << 2),
57     Blocks = (1u << 3),
58     GlobalVariables = (1u << 4),
59     LocalVariables = (1u << 5),
60     VariableTypes = (1u << 6),
61     kAllAbilities = ((1u << 7) - 1u)
62   };
63 
64   static SymbolFile *FindPlugin(lldb::ObjectFileSP objfile_sp);
65 
66   // Constructors and Destructors
67   SymbolFile(lldb::ObjectFileSP objfile_sp)
68       : m_objfile_sp(std::move(objfile_sp)), m_abilities(0),
69         m_calculated_abilities(false) {}
70 
71   ~SymbolFile() override {}
72 
73   /// Get a mask of what this symbol file supports for the object file
74   /// that it was constructed with.
75   ///
76   /// Each symbol file gets to respond with a mask of abilities that
77   /// it supports for each object file. This happens when we are
78   /// trying to figure out which symbol file plug-in will get used
79   /// for a given object file. The plug-in that responds with the
80   /// best mix of "SymbolFile::Abilities" bits set, will get chosen to
81   /// be the symbol file parser. This allows each plug-in to check for
82   /// sections that contain data a symbol file plug-in would need. For
83   /// example the DWARF plug-in requires DWARF sections in a file that
84   /// contain debug information. If the DWARF plug-in doesn't find
85   /// these sections, it won't respond with many ability bits set, and
86   /// we will probably fall back to the symbol table SymbolFile plug-in
87   /// which uses any information in the symbol table. Also, plug-ins
88   /// might check for some specific symbols in a symbol table in the
89   /// case where the symbol table contains debug information (STABS
90   /// and COFF). Not a lot of work should happen in these functions
91   /// as the plug-in might not get selected due to another plug-in
92   /// having more abilities. Any initialization work should be saved
93   /// for "void SymbolFile::InitializeObject()" which will get called
94   /// on the SymbolFile object with the best set of abilities.
95   ///
96   /// \return
97   ///     A uint32_t mask containing bits from the SymbolFile::Abilities
98   ///     enumeration. Any bits that are set represent an ability that
99   ///     this symbol plug-in can parse from the object file.
100   uint32_t GetAbilities() {
101     if (!m_calculated_abilities) {
102       m_abilities = CalculateAbilities();
103       m_calculated_abilities = true;
104     }
105 
106     return m_abilities;
107   }
108 
109   virtual uint32_t CalculateAbilities() = 0;
110 
111   /// Symbols file subclasses should override this to return the Module that
112   /// owns the TypeSystem that this symbol file modifies type information in.
113   virtual std::recursive_mutex &GetModuleMutex() const;
114 
115   /// Initialize the SymbolFile object.
116   ///
117   /// The SymbolFile object with the best set of abilities (detected
118   /// in "uint32_t SymbolFile::GetAbilities()) will have this function
119   /// called if it is chosen to parse an object file. More complete
120   /// initialization can happen in this function which will get called
121   /// prior to any other functions in the SymbolFile protocol.
122   virtual void InitializeObject() {}
123 
124   // Compile Unit function calls
125   // Approach 1 - iterator
126   uint32_t GetNumCompileUnits();
127   lldb::CompUnitSP GetCompileUnitAtIndex(uint32_t idx);
128 
129   Symtab *GetSymtab();
130 
131   virtual lldb::LanguageType ParseLanguage(CompileUnit &comp_unit) = 0;
132   /// Return the Xcode SDK comp_unit was compiled against.
133   virtual XcodeSDK ParseXcodeSDK(CompileUnit &comp_unit) { return {}; }
134   virtual size_t ParseFunctions(CompileUnit &comp_unit) = 0;
135   virtual bool ParseLineTable(CompileUnit &comp_unit) = 0;
136   virtual bool ParseDebugMacros(CompileUnit &comp_unit) = 0;
137 
138   /// Apply a lambda to each external lldb::Module referenced by this
139   /// \p comp_unit. Recursively also descends into the referenced external
140   /// modules of any encountered compilation unit.
141   ///
142   /// This function can be used to traverse Clang -gmodules debug
143   /// information, which is stored in DWARF files separate from the
144   /// object files.
145   ///
146   /// \param comp_unit
147   ///     When this SymbolFile consists of multiple auxilliary
148   ///     SymbolFiles, for example, a Darwin debug map that references
149   ///     multiple .o files, comp_unit helps choose the auxilliary
150   ///     file. In most other cases comp_unit's symbol file is
151   ///     identical with *this.
152   ///
153   /// \param[in] lambda
154   ///     The lambda that should be applied to every function. The lambda can
155   ///     return true if the iteration should be aborted earlier.
156   ///
157   /// \param visited_symbol_files
158   ///     A set of SymbolFiles that were already visited to avoid
159   ///     visiting one file more than once.
160   ///
161   /// \return
162   ///     If the lambda early-exited, this function returns true to
163   ///     propagate the early exit.
164   virtual bool ForEachExternalModule(
165       lldb_private::CompileUnit &comp_unit,
166       llvm::DenseSet<lldb_private::SymbolFile *> &visited_symbol_files,
167       llvm::function_ref<bool(Module &)> lambda) {
168     return false;
169   }
170   virtual bool ParseSupportFiles(CompileUnit &comp_unit,
171                                  FileSpecList &support_files) = 0;
172   virtual size_t ParseTypes(CompileUnit &comp_unit) = 0;
173   virtual bool ParseIsOptimized(CompileUnit &comp_unit) { return false; }
174 
175   virtual bool
176   ParseImportedModules(const SymbolContext &sc,
177                        std::vector<SourceModule> &imported_modules) = 0;
178   virtual size_t ParseBlocksRecursive(Function &func) = 0;
179   virtual size_t ParseVariablesForContext(const SymbolContext &sc) = 0;
180   virtual Type *ResolveTypeUID(lldb::user_id_t type_uid) = 0;
181 
182 
183   /// The characteristics of an array type.
184   struct ArrayInfo {
185     int64_t first_index = 0;
186     llvm::SmallVector<uint64_t, 1> element_orders;
187     uint32_t byte_stride = 0;
188     uint32_t bit_stride = 0;
189   };
190   /// If \c type_uid points to an array type, return its characteristics.
191   /// To support variable-length array types, this function takes an
192   /// optional \p ExecutionContext. If \c exe_ctx is non-null, the
193   /// dynamic characteristics for that context are returned.
194   virtual llvm::Optional<ArrayInfo>
195   GetDynamicArrayInfoForUID(lldb::user_id_t type_uid,
196                             const lldb_private::ExecutionContext *exe_ctx) = 0;
197 
198   virtual bool CompleteType(CompilerType &compiler_type) = 0;
199   virtual void ParseDeclsForContext(CompilerDeclContext decl_ctx) {}
200   virtual CompilerDecl GetDeclForUID(lldb::user_id_t uid) {
201     return CompilerDecl();
202   }
203   virtual CompilerDeclContext GetDeclContextForUID(lldb::user_id_t uid) {
204     return CompilerDeclContext();
205   }
206   virtual CompilerDeclContext GetDeclContextContainingUID(lldb::user_id_t uid) {
207     return CompilerDeclContext();
208   }
209   virtual uint32_t ResolveSymbolContext(const Address &so_addr,
210                                         lldb::SymbolContextItem resolve_scope,
211                                         SymbolContext &sc) = 0;
212   virtual uint32_t ResolveSymbolContext(const FileSpec &file_spec,
213                                         uint32_t line, bool check_inlines,
214                                         lldb::SymbolContextItem resolve_scope,
215                                         SymbolContextList &sc_list);
216 
217   virtual void DumpClangAST(Stream &s) {}
218   virtual void FindGlobalVariables(ConstString name,
219                                    const CompilerDeclContext &parent_decl_ctx,
220                                    uint32_t max_matches,
221                                    VariableList &variables);
222   virtual void FindGlobalVariables(const RegularExpression &regex,
223                                    uint32_t max_matches,
224                                    VariableList &variables);
225   virtual void FindFunctions(ConstString name,
226                              const CompilerDeclContext &parent_decl_ctx,
227                              lldb::FunctionNameType name_type_mask,
228                              bool include_inlines, SymbolContextList &sc_list);
229   virtual void FindFunctions(const RegularExpression &regex,
230                              bool include_inlines, SymbolContextList &sc_list);
231   virtual void
232   FindTypes(ConstString name, const CompilerDeclContext &parent_decl_ctx,
233             uint32_t max_matches,
234             llvm::DenseSet<lldb_private::SymbolFile *> &searched_symbol_files,
235             TypeMap &types);
236 
237   /// Find types specified by a CompilerContextPattern.
238   /// \param languages
239   ///     Only return results in these languages.
240   /// \param searched_symbol_files
241   ///     Prevents one file from being visited multiple times.
242   virtual void
243   FindTypes(llvm::ArrayRef<CompilerContext> pattern, LanguageSet languages,
244             llvm::DenseSet<lldb_private::SymbolFile *> &searched_symbol_files,
245             TypeMap &types);
246 
247   virtual void
248   GetMangledNamesForFunction(const std::string &scope_qualified_name,
249                              std::vector<ConstString> &mangled_names);
250 
251   virtual void GetTypes(lldb_private::SymbolContextScope *sc_scope,
252                         lldb::TypeClass type_mask,
253                         lldb_private::TypeList &type_list) = 0;
254 
255   virtual void PreloadSymbols();
256 
257   virtual llvm::Expected<lldb_private::TypeSystem &>
258   GetTypeSystemForLanguage(lldb::LanguageType language);
259 
260   virtual CompilerDeclContext
261   FindNamespace(ConstString name, const CompilerDeclContext &parent_decl_ctx) {
262     return CompilerDeclContext();
263   }
264 
265   ObjectFile *GetObjectFile() { return m_objfile_sp.get(); }
266   const ObjectFile *GetObjectFile() const { return m_objfile_sp.get(); }
267   ObjectFile *GetMainObjectFile();
268 
269   virtual std::vector<std::unique_ptr<CallEdge>>
270   ParseCallEdgesInFunction(UserID func_id) {
271     return {};
272   }
273 
274   virtual void AddSymbols(Symtab &symtab) {}
275 
276   /// Notify the SymbolFile that the file addresses in the Sections
277   /// for this module have been changed.
278   virtual void SectionFileAddressesChanged();
279 
280   struct RegisterInfoResolver {
281     virtual ~RegisterInfoResolver(); // anchor
282 
283     virtual const RegisterInfo *ResolveName(llvm::StringRef name) const = 0;
284     virtual const RegisterInfo *ResolveNumber(lldb::RegisterKind kind,
285                                               uint32_t number) const = 0;
286   };
287   virtual lldb::UnwindPlanSP
288   GetUnwindPlan(const Address &address, const RegisterInfoResolver &resolver) {
289     return nullptr;
290   }
291 
292   /// Return the number of stack bytes taken up by the parameters to this
293   /// function.
294   virtual llvm::Expected<lldb::addr_t> GetParameterStackSize(Symbol &symbol) {
295     return llvm::createStringError(make_error_code(llvm::errc::not_supported),
296                                    "Operation not supported.");
297   }
298 
299   virtual void Dump(Stream &s);
300 
301 protected:
302   void AssertModuleLock();
303   virtual uint32_t CalculateNumCompileUnits() = 0;
304   virtual lldb::CompUnitSP ParseCompileUnitAtIndex(uint32_t idx) = 0;
305   virtual TypeList &GetTypeList() { return m_type_list; }
306 
307   void SetCompileUnitAtIndex(uint32_t idx, const lldb::CompUnitSP &cu_sp);
308 
309   lldb::ObjectFileSP m_objfile_sp; // Keep a reference to the object file in
310                                    // case it isn't the same as the module
311                                    // object file (debug symbols in a separate
312                                    // file)
313   llvm::Optional<std::vector<lldb::CompUnitSP>> m_compile_units;
314   TypeList m_type_list;
315   Symtab *m_symtab = nullptr;
316   uint32_t m_abilities;
317   bool m_calculated_abilities;
318 
319 private:
320   SymbolFile(const SymbolFile &) = delete;
321   const SymbolFile &operator=(const SymbolFile &) = delete;
322 };
323 
324 } // namespace lldb_private
325 
326 #endif // LLDB_SYMBOL_SYMBOLFILE_H
327