1 // symtab.h -- the gold symbol table -*- C++ -*-
10 #include "stringpool.h"
20 template<int size, bool big_endian>
23 template<int size, bool big_endian>
26 // The base class of an entry in the symbol table. The symbol table
27 // can have a lot of entries, so we don't want this class to big.
28 // Size dependent fields can be found in the template class
29 // Sized_symbol. Targets may support their own derived classes.
34 // Return the symbol name.
37 { return this->name_; }
39 // Return the symbol version. This will return NULL for an
40 // unversioned symbol.
43 { return this->version_; }
45 // Return the object with which this symbol is associated.
48 { return this->object_; }
50 // Return the symbol binding.
53 { return this->binding_; }
55 // Return the symbol type.
58 { return this->type_; }
60 // Return the symbol visibility.
63 { return this->visibility_; }
65 // Return the non-visibility part of the st_other field.
68 { return this->other_; }
70 // Return the section index.
73 { return this->shnum_; }
75 // Return whether this symbol is a forwarder. This will never be
76 // true of a symbol found in the hash table, but may be true of
77 // symbol pointers attached to object files.
80 { return this->is_forwarder_; }
82 // Mark this symbol as a forwarder.
85 { this->is_forwarder_ = true; }
87 // Return whether this symbol was seen in a dynamic object.
90 { return this->in_dyn_; }
92 // Mark this symbol as seen in a dynamic object.
95 { this->in_dyn_ = true; }
98 // Instances of this class should always be created at a specific
103 // Initialize fields from an ELF symbol in OBJECT.
104 template<int size, bool big_endian>
106 init_base(const char *name, const char* version, Object* object,
107 const elfcpp::Sym<size, big_endian>&);
109 // Override existing symbol.
110 template<int size, bool big_endian>
112 override_base(const elfcpp::Sym<size, big_endian>&, Object* object);
115 Symbol(const Symbol&);
116 Symbol& operator=(const Symbol&);
118 // Symbol name (expected to point into a Stringpool).
120 // Symbol version (expected to point into a Stringpool). This may
122 const char* version_;
123 // Object in which symbol is defined, or in which it was first seen.
125 // Section number in object_ in which symbol is defined.
128 elfcpp::STT type_ : 4;
130 elfcpp::STB binding_ : 4;
131 // Symbol visibility.
132 elfcpp::STV visibility_ : 2;
133 // Rest of symbol st_other field.
134 unsigned int other_ : 6;
135 // True if this symbol always requires special target-specific
137 bool is_special_ : 1;
138 // True if this is the default version of the symbol.
140 // True if this symbol really forwards to another symbol. This is
141 // used when we discover after the fact that two different entries
142 // in the hash table really refer to the same symbol. This will
143 // never be set for a symbol found in the hash table, but may be set
144 // for a symbol found in the list of symbols attached to an Object.
145 // It forwards to the symbol found in the forwarders_ map of
147 bool is_forwarder_ : 1;
148 // True if we've seen this symbol in a dynamic object.
152 // The parts of a symbol which are size specific. Using a template
153 // derived class like this helps us use less space on a 32-bit system.
156 class Sized_symbol : public Symbol
159 typedef typename elfcpp::Elf_types<size>::Elf_Addr Value_type;
160 typedef typename elfcpp::Elf_types<size>::Elf_WXword Size_type;
165 // Initialize fields from an ELF symbol in OBJECT.
166 template<bool big_endian>
168 init(const char *name, const char* version, Object* object,
169 const elfcpp::Sym<size, big_endian>&);
171 // Override existing symbol.
172 template<bool big_endian>
174 override(const elfcpp::Sym<size, big_endian>&, Object* object);
176 // Return the symbol's value.
179 { return this->value_; }
181 // Return the symbol's size (we can't call this 'size' because that
182 // is a template parameter).
185 { return this->size_; }
188 Sized_symbol(const Sized_symbol&);
189 Sized_symbol& operator=(const Sized_symbol&);
197 // The main linker symbol table.
206 // Add COUNT external symbols from OBJECT to the symbol table. SYMS
207 // is the symbols, SYM_NAMES is their names, SYM_NAME_SIZE is the
208 // size of SYM_NAMES. This sets SYMPOINTERS to point to the symbols
209 // in the symbol table.
210 template<int size, bool big_endian>
212 add_from_object(Sized_object<size, big_endian>* object,
213 const elfcpp::Sym<size, big_endian>* syms,
214 size_t count, const char* sym_names, size_t sym_name_size,
215 Symbol** sympointers);
217 // Return the real symbol associated with the forwarder symbol FROM.
219 resolve_forwards(Symbol* from) const;
221 // Return the size of the symbols in the table.
224 { return this->size_; }
226 // Return the sized version of a symbol in this table.
229 get_sized_symbol(Symbol*);
232 const Sized_symbol<size>*
233 get_sized_symbol(const Symbol*);
236 Symbol_table(const Symbol_table&);
237 Symbol_table& operator=(const Symbol_table&);
239 // Set the size of the symbols in the table.
242 { this->size_ = size; }
244 // Make FROM a forwarder symbol to TO.
246 make_forwarder(Symbol* from, Symbol* to);
249 template<int size, bool big_endian>
251 add_from_object(Sized_object<size, big_endian>*, const char *name,
252 const char *version, bool def,
253 const elfcpp::Sym<size, big_endian>& sym);
256 template<int size, bool big_endian>
258 resolve(Sized_symbol<size>* to,
259 const elfcpp::Sym<size, big_endian>& sym,
262 template<int size, bool big_endian>
264 resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from);
266 typedef std::pair<const char*, const char*> Symbol_table_key;
268 struct Symbol_table_hash
271 operator()(const Symbol_table_key&) const;
274 struct Symbol_table_eq
277 operator()(const Symbol_table_key&, const Symbol_table_key&) const;
280 typedef Unordered_map<Symbol_table_key, Symbol*, Symbol_table_hash,
281 Symbol_table_eq> Symbol_table_type;
283 // The size of the symbols in the symbol table (32 or 64).
286 // The symbol table itself.
287 Symbol_table_type table_;
289 // A pool of symbol names.
290 Stringpool namepool_;
292 // Forwarding symbols.
293 Unordered_map<Symbol*, Symbol*> forwarders_;
296 // We inline get_sized_symbol for efficiency.
300 Symbol_table::get_sized_symbol(Symbol* sym)
302 assert(size == this->get_size());
303 return static_cast<Sized_symbol<size>*>(sym);
307 const Sized_symbol<size>*
308 Symbol_table::get_sized_symbol(const Symbol* sym)
310 assert(size == this->get_size());
311 return static_cast<const Sized_symbol<size>*>(sym);
314 } // End namespace gold.
316 #endif // !defined(GOLD_SYMTAB_H)