1 //===-- Symbol.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 liblldb_Symbol_h_
10 #define liblldb_Symbol_h_
11 
12 #include "lldb/Core/AddressRange.h"
13 #include "lldb/Core/Mangled.h"
14 #include "lldb/Symbol/SymbolContextScope.h"
15 #include "lldb/Utility/UserID.h"
16 #include "lldb/lldb-private.h"
17 
18 namespace lldb_private {
19 
20 class Symbol : public SymbolContextScope {
21 public:
22   // ObjectFile readers can classify their symbol table entries and searches
23   // can be made on specific types where the symbol values will have
24   // drastically different meanings and sorting requirements.
25   Symbol();
26 
27   Symbol(uint32_t symID, llvm::StringRef name, lldb::SymbolType type,
28          bool external, bool is_debug, bool is_trampoline, bool is_artificial,
29          const lldb::SectionSP &section_sp, lldb::addr_t value,
30          lldb::addr_t size, bool size_is_valid,
31          bool contains_linker_annotations, uint32_t flags);
32 
33   Symbol(uint32_t symID, const Mangled &mangled, lldb::SymbolType type,
34          bool external, bool is_debug, bool is_trampoline, bool is_artificial,
35          const AddressRange &range, bool size_is_valid,
36          bool contains_linker_annotations, uint32_t flags);
37 
38   Symbol(const Symbol &rhs);
39 
40   const Symbol &operator=(const Symbol &rhs);
41 
42   void Clear();
43 
44   bool Compare(ConstString name, lldb::SymbolType type) const;
45 
46   void Dump(Stream *s, Target *target, uint32_t index,
47             Mangled::NamePreference name_preference =
48                 Mangled::ePreferDemangled) const;
49 
50   bool ValueIsAddress() const;
51 
52   // The GetAddressRef() accessor functions should only be called if you
53   // previously call ValueIsAddress() otherwise you might get an reference to
54   // an Address object that contains an constant integer value in
55   // m_addr_range.m_base_addr.m_offset which could be incorrectly used to
56   // represent an absolute address since it has no section.
57   Address &GetAddressRef() { return m_addr_range.GetBaseAddress(); }
58 
59   const Address &GetAddressRef() const { return m_addr_range.GetBaseAddress(); }
60 
61   // Makes sure the symbol's value is an address and returns the file address.
62   // Returns LLDB_INVALID_ADDRESS if the symbol's value isn't an address.
63   lldb::addr_t GetFileAddress() const;
64 
65   // Makes sure the symbol's value is an address and gets the load address
66   // using \a target if it is. Returns LLDB_INVALID_ADDRESS if the symbol's
67   // value isn't an address or if the section isn't loaded in \a target.
68   lldb::addr_t GetLoadAddress(Target *target) const;
69 
70   // Access the address value. Do NOT hand out the AddressRange as an object as
71   // the byte size of the address range may not be filled in and it should be
72   // accessed via GetByteSize().
73   Address GetAddress() const {
74     // Make sure the our value is an address before we hand a copy out. We use
75     // the Address inside m_addr_range to contain the value for symbols that
76     // are not address based symbols so we are using it for more than just
77     // addresses. For example undefined symbols on MacOSX have a nlist.n_value
78     // of 0 (zero) and this will get placed into
79     // m_addr_range.m_base_addr.m_offset and it will have no section. So in the
80     // GetAddress() accessor, we need to hand out an invalid address if the
81     // symbol's value isn't an address.
82     if (ValueIsAddress())
83       return m_addr_range.GetBaseAddress();
84     else
85       return Address();
86   }
87 
88   // When a symbol's value isn't an address, we need to access the raw value.
89   // This function will ensure this symbol's value isn't an address and return
90   // the integer value if this checks out, otherwise it will return
91   // "fail_value" if the symbol is an address value.
92   uint64_t GetIntegerValue(uint64_t fail_value = 0) const {
93     if (ValueIsAddress()) {
94       // This symbol's value is an address. Use Symbol::GetAddress() to get the
95       // address.
96       return fail_value;
97     } else {
98       // The value is stored in the base address' offset
99       return m_addr_range.GetBaseAddress().GetOffset();
100     }
101   }
102 
103   lldb::addr_t ResolveCallableAddress(Target &target) const;
104 
105   ConstString GetName() const;
106 
107   ConstString GetNameNoArguments() const;
108 
109   ConstString GetDisplayName() const;
110 
111   uint32_t GetID() const { return m_uid; }
112 
113   lldb::LanguageType GetLanguage() const {
114     // TODO: See if there is a way to determine the language for a symbol
115     // somehow, for now just return our best guess
116     return m_mangled.GuessLanguage();
117   }
118 
119   void SetID(uint32_t uid) { m_uid = uid; }
120 
121   Mangled &GetMangled() { return m_mangled; }
122 
123   const Mangled &GetMangled() const { return m_mangled; }
124 
125   ConstString GetReExportedSymbolName() const;
126 
127   FileSpec GetReExportedSymbolSharedLibrary() const;
128 
129   void SetReExportedSymbolName(ConstString name);
130 
131   bool SetReExportedSymbolSharedLibrary(const FileSpec &fspec);
132 
133   Symbol *ResolveReExportedSymbol(Target &target) const;
134 
135   uint32_t GetSiblingIndex() const;
136 
137   lldb::SymbolType GetType() const { return (lldb::SymbolType)m_type; }
138 
139   void SetType(lldb::SymbolType type) { m_type = (lldb::SymbolType)type; }
140 
141   const char *GetTypeAsString() const;
142 
143   uint32_t GetFlags() const { return m_flags; }
144 
145   void SetFlags(uint32_t flags) { m_flags = flags; }
146 
147   void GetDescription(Stream *s, lldb::DescriptionLevel level,
148                       Target *target) const;
149 
150   bool IsSynthetic() const { return m_is_synthetic; }
151 
152   void SetIsSynthetic(bool b) { m_is_synthetic = b; }
153 
154   bool GetSizeIsSynthesized() const { return m_size_is_synthesized; }
155 
156   void SetSizeIsSynthesized(bool b) { m_size_is_synthesized = b; }
157 
158   bool IsDebug() const { return m_is_debug; }
159 
160   void SetDebug(bool b) { m_is_debug = b; }
161 
162   bool IsExternal() const { return m_is_external; }
163 
164   void SetExternal(bool b) { m_is_external = b; }
165 
166   bool IsTrampoline() const;
167 
168   bool IsIndirect() const;
169 
170   bool IsWeak() const { return m_is_weak; }
171 
172   void SetIsWeak (bool b) { m_is_weak = b; }
173 
174   bool GetByteSizeIsValid() const { return m_size_is_valid; }
175 
176   lldb::addr_t GetByteSize() const;
177 
178   void SetByteSize(lldb::addr_t size) {
179     m_size_is_valid = size > 0;
180     m_addr_range.SetByteSize(size);
181   }
182 
183   bool GetSizeIsSibling() const { return m_size_is_sibling; }
184 
185   void SetSizeIsSibling(bool b) { m_size_is_sibling = b; }
186 
187   // If m_type is "Code" or "Function" then this will return the prologue size
188   // in bytes, else it will return zero.
189   uint32_t GetPrologueByteSize();
190 
191   bool GetDemangledNameIsSynthesized() const {
192     return m_demangled_is_synthesized;
193   }
194 
195   void SetDemangledNameIsSynthesized(bool b) { m_demangled_is_synthesized = b; }
196 
197   bool ContainsLinkerAnnotations() const {
198     return m_contains_linker_annotations;
199   }
200   void SetContainsLinkerAnnotations(bool b) {
201     m_contains_linker_annotations = b;
202   }
203   /// \copydoc SymbolContextScope::CalculateSymbolContext(SymbolContext*)
204   ///
205   /// \see SymbolContextScope
206   void CalculateSymbolContext(SymbolContext *sc) override;
207 
208   lldb::ModuleSP CalculateSymbolContextModule() override;
209 
210   Symbol *CalculateSymbolContextSymbol() override;
211 
212   /// \copydoc SymbolContextScope::DumpSymbolContext(Stream*)
213   ///
214   /// \see SymbolContextScope
215   void DumpSymbolContext(Stream *s) override;
216 
217   lldb::DisassemblerSP GetInstructions(const ExecutionContext &exe_ctx,
218                                        const char *flavor,
219                                        bool prefer_file_cache);
220 
221   bool GetDisassembly(const ExecutionContext &exe_ctx, const char *flavor,
222                       bool prefer_file_cache, Stream &strm);
223 
224   bool ContainsFileAddress(lldb::addr_t file_addr) const;
225 
226 protected:
227   // This is the internal guts of ResolveReExportedSymbol, it assumes
228   // reexport_name is not null, and that module_spec is valid.  We track the
229   // modules we've already seen to make sure we don't get caught in a cycle.
230 
231   Symbol *ResolveReExportedSymbolInModuleSpec(
232       Target &target, ConstString &reexport_name,
233       lldb_private::ModuleSpec &module_spec,
234       lldb_private::ModuleList &seen_modules) const;
235 
236   uint32_t m_uid;       // User ID (usually the original symbol table index)
237   uint16_t m_type_data; // data specific to m_type
238   uint16_t m_type_data_resolved : 1, // True if the data in m_type_data has
239                                      // already been calculated
240       m_is_synthetic : 1, // non-zero if this symbol is not actually in the
241                           // symbol table, but synthesized from other info in
242                           // the object file.
243       m_is_debug : 1,     // non-zero if this symbol is debug information in a
244                           // symbol
245       m_is_external : 1,  // non-zero if this symbol is globally visible
246       m_size_is_sibling : 1,     // m_size contains the index of this symbol's
247                                  // sibling
248       m_size_is_synthesized : 1, // non-zero if this symbol's size was
249                                  // calculated using a delta between this
250                                  // symbol and the next
251       m_size_is_valid : 1,
252       m_demangled_is_synthesized : 1, // The demangled name was created should
253                                       // not be used for expressions or other
254                                       // lookups
255       m_contains_linker_annotations : 1, // The symbol name contains linker
256                                          // annotations, which are optional when
257                                          // doing name lookups
258       m_is_weak : 1,
259       m_type : 6;            // Values from the lldb::SymbolType enum.
260   Mangled m_mangled;         // uniqued symbol name/mangled name pair
261   AddressRange m_addr_range; // Contains the value, or the section offset
262                              // address when the value is an address in a
263                              // section, and the size (if any)
264   uint32_t m_flags; // A copy of the flags from the original symbol table, the
265                     // ObjectFile plug-in can interpret these
266 };
267 
268 } // namespace lldb_private
269 
270 #endif // liblldb_Symbol_h_
271