1 /* Declarations for C++ name lookup routines. 2 Copyright (C) 2003-2013 Free Software Foundation, Inc. 3 Contributed by Gabriel Dos Reis <gdr (at) integrable-solutions.net> 4 5 This file is part of GCC. 6 7 GCC is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 3, or (at your option) 10 any later version. 11 12 GCC is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with GCC; see the file COPYING3. If not see 19 <http://www.gnu.org/licenses/>. */ 20 21 #ifndef GCC_CP_NAME_LOOKUP_H 22 #define GCC_CP_NAME_LOOKUP_H 23 24 #include "c-family/c-common.h" 25 26 /* The type of dictionary used to map names to types declared at 27 a given scope. */ 28 typedef struct binding_table_s *binding_table; 29 typedef struct binding_entry_s *binding_entry; 30 31 /* The type of a routine repeatedly called by binding_table_foreach. */ 32 typedef void (*bt_foreach_proc) (binding_entry, void *); 33 34 struct GTY(()) binding_entry_s { 35 binding_entry chain; 36 tree name; 37 tree type; 38 }; 39 40 /* These macros indicate the initial chains count for binding_table. */ 41 #define SCOPE_DEFAULT_HT_SIZE (1 << 3) 42 #define CLASS_SCOPE_HT_SIZE (1 << 3) 43 #define NAMESPACE_ORDINARY_HT_SIZE (1 << 5) 44 #define NAMESPACE_STD_HT_SIZE (1 << 8) 45 #define GLOBAL_SCOPE_HT_SIZE (1 << 8) 46 47 extern void binding_table_foreach (binding_table, bt_foreach_proc, void *); 48 extern binding_entry binding_table_find (binding_table, tree); 49 50 /* Datatype that represents binding established by a declaration between 52 a name and a C++ entity. */ 53 typedef struct cxx_binding cxx_binding; 54 55 /* The datatype used to implement C++ scope. */ 56 typedef struct cp_binding_level cp_binding_level; 57 58 /* Nonzero if this binding is for a local scope, as opposed to a class 59 or namespace scope. */ 60 #define LOCAL_BINDING_P(NODE) ((NODE)->is_local) 61 62 /* True if NODE->value is from a base class of the class which is 63 currently being defined. */ 64 #define INHERITED_VALUE_BINDING_P(NODE) ((NODE)->value_is_inherited) 65 66 struct GTY(()) cxx_binding { 67 /* Link to chain together various bindings for this name. */ 68 cxx_binding *previous; 69 /* The non-type entity this name is bound to. */ 70 tree value; 71 /* The type entity this name is bound to. */ 72 tree type; 73 /* The scope at which this binding was made. */ 74 cp_binding_level *scope; 75 unsigned value_is_inherited : 1; 76 unsigned is_local : 1; 77 }; 78 79 /* Datatype used to temporarily save C++ bindings (for implicit 80 instantiations purposes and like). Implemented in decl.c. */ 81 typedef struct GTY(()) cxx_saved_binding { 82 /* The name of the current binding. */ 83 tree identifier; 84 /* The binding we're saving. */ 85 cxx_binding *binding; 86 tree real_type_value; 87 } cxx_saved_binding; 88 89 90 extern tree identifier_type_value (tree); 91 extern void set_identifier_type_value (tree, tree); 92 extern void pop_binding (tree, tree); 93 extern tree constructor_name (tree); 94 extern bool constructor_name_p (tree, tree); 95 96 /* The kinds of scopes we recognize. */ 98 typedef enum scope_kind { 99 sk_block = 0, /* An ordinary block scope. This enumerator must 100 have the value zero because "cp_binding_level" 101 is initialized by using "memset" to set the 102 contents to zero, and the default scope kind 103 is "sk_block". */ 104 sk_cleanup, /* A scope for (pseudo-)scope for cleanup. It is 105 pseudo in that it is transparent to name lookup 106 activities. */ 107 sk_try, /* A try-block. */ 108 sk_catch, /* A catch-block. */ 109 sk_for, /* The scope of the variable declared in a 110 for-init-statement. */ 111 sk_cond, /* The scope of the variable declared in the condition 112 of an if or switch statement. */ 113 sk_function_parms, /* The scope containing function parameters. */ 114 sk_class, /* The scope containing the members of a class. */ 115 sk_scoped_enum, /* The scope containing the enumertors of a C++0x 116 scoped enumeration. */ 117 sk_namespace, /* The scope containing the members of a 118 namespace, including the global scope. */ 119 sk_template_parms, /* A scope for template parameters. */ 120 sk_template_spec, /* Like sk_template_parms, but for an explicit 121 specialization. Since, by definition, an 122 explicit specialization is introduced by 123 "template <>", this scope is always empty. */ 124 sk_omp /* An OpenMP structured block. */ 125 } scope_kind; 126 127 /* The scope where the class/struct/union/enum tag applies. */ 128 typedef enum tag_scope { 129 ts_current = 0, /* Current scope only. This is for the 130 class-key identifier; 131 case mentioned in [basic.lookup.elab]/2, 132 or the class/enum definition 133 class-key identifier { ... }; */ 134 ts_global = 1, /* All scopes. This is the 3.4.1 135 [basic.lookup.unqual] lookup mentioned 136 in [basic.lookup.elab]/2. */ 137 ts_within_enclosing_non_class = 2, /* Search within enclosing non-class 138 only, for friend class lookup 139 according to [namespace.memdef]/3 140 and [class.friend]/9. */ 141 ts_lambda = 3 /* Declaring a lambda closure. */ 142 } tag_scope; 143 144 typedef struct GTY(()) cp_class_binding { 145 cxx_binding *base; 146 /* The bound name. */ 147 tree identifier; 148 } cp_class_binding; 149 150 151 typedef struct GTY(()) cp_label_binding { 152 /* The bound LABEL_DECL. */ 153 tree label; 154 /* The previous IDENTIFIER_LABEL_VALUE. */ 155 tree prev_value; 156 } cp_label_binding; 157 158 159 /* For each binding contour we allocate a binding_level structure 160 which records the names defined in that contour. 161 Contours include: 162 0) the global one 163 1) one for each function definition, 164 where internal declarations of the parameters appear. 165 2) one for each compound statement, 166 to record its declarations. 167 168 The current meaning of a name can be found by searching the levels 169 from the current one out to the global one. 170 171 Off to the side, may be the class_binding_level. This exists only 172 to catch class-local declarations. It is otherwise nonexistent. 173 174 Also there may be binding levels that catch cleanups that must be 175 run when exceptions occur. Thus, to see whether a name is bound in 176 the current scope, it is not enough to look in the 177 CURRENT_BINDING_LEVEL. You should use lookup_name_current_level 178 instead. */ 179 180 /* Note that the information in the `names' component of the global contour 181 is duplicated in the IDENTIFIER_GLOBAL_VALUEs of all identifiers. */ 182 183 struct GTY(()) cp_binding_level { 184 /* A chain of _DECL nodes for all variables, constants, functions, 185 and typedef types. These are in the reverse of the order 186 supplied. There may be OVERLOADs on this list, too, but they 187 are wrapped in TREE_LISTs; the TREE_VALUE is the OVERLOAD. */ 188 tree names; 189 190 /* A chain of NAMESPACE_DECL nodes. */ 191 tree namespaces; 192 193 /* An array of static functions and variables (for namespaces only) */ 194 vec<tree, va_gc> *static_decls; 195 196 /* A list of USING_DECL nodes. */ 197 tree usings; 198 199 /* A list of used namespaces. PURPOSE is the namespace, 200 VALUE the common ancestor with this binding_level's namespace. */ 201 tree using_directives; 202 203 /* For the binding level corresponding to a class, the entities 204 declared in the class or its base classes. */ 205 vec<cp_class_binding, va_gc> *class_shadowed; 206 207 /* Similar to class_shadowed, but for IDENTIFIER_TYPE_VALUE, and 208 is used for all binding levels. The TREE_PURPOSE is the name of 209 the entity, the TREE_TYPE is the associated type. In addition 210 the TREE_VALUE is the IDENTIFIER_TYPE_VALUE before we entered 211 the class. */ 212 tree type_shadowed; 213 214 /* Similar to class_shadowed, but for IDENTIFIER_LABEL_VALUE, and 215 used for all binding levels. */ 216 vec<cp_label_binding, va_gc> *shadowed_labels; 217 218 /* For each level (except not the global one), 219 a chain of BLOCK nodes for all the levels 220 that were entered and exited one level down. */ 221 tree blocks; 222 223 /* The entity (namespace, class, function) the scope of which this 224 binding contour corresponds to. Otherwise NULL. */ 225 tree this_entity; 226 227 /* The binding level which this one is contained in (inherits from). */ 228 cp_binding_level *level_chain; 229 230 /* List of VAR_DECLS saved from a previous for statement. 231 These would be dead in ISO-conforming code, but might 232 be referenced in ARM-era code. */ 233 vec<tree, va_gc> *dead_vars_from_for; 234 235 /* STATEMENT_LIST for statements in this binding contour. 236 Only used at present for SK_CLEANUP temporary bindings. */ 237 tree statement_list; 238 239 /* Binding depth at which this level began. */ 240 int binding_depth; 241 242 /* The kind of scope that this object represents. However, a 243 SK_TEMPLATE_SPEC scope is represented with KIND set to 244 SK_TEMPLATE_PARMS and EXPLICIT_SPEC_P set to true. */ 245 ENUM_BITFIELD (scope_kind) kind : 4; 246 247 /* True if this scope is an SK_TEMPLATE_SPEC scope. This field is 248 only valid if KIND == SK_TEMPLATE_PARMS. */ 249 BOOL_BITFIELD explicit_spec_p : 1; 250 251 /* true means make a BLOCK for this level regardless of all else. */ 252 unsigned keep : 1; 253 254 /* Nonzero if this level can safely have additional 255 cleanup-needing variables added to it. */ 256 unsigned more_cleanups_ok : 1; 257 unsigned have_cleanups : 1; 258 259 /* 24 bits left to fill a 32-bit word. */ 260 }; 261 262 /* The binding level currently in effect. */ 263 264 #define current_binding_level \ 265 (*(cfun && cp_function_chain && cp_function_chain->bindings \ 266 ? &cp_function_chain->bindings \ 267 : &scope_chain->bindings)) 268 269 /* The binding level of the current class, if any. */ 270 271 #define class_binding_level scope_chain->class_bindings 272 273 /* The tree node representing the global scope. */ 274 extern GTY(()) tree global_namespace; 275 extern GTY(()) tree global_scope_name; 276 277 /* Indicates that there is a type value in some namespace, although 278 that is not necessarily in scope at the moment. */ 279 280 extern GTY(()) tree global_type_node; 281 282 /* True if SCOPE designates the global scope binding contour. */ 283 #define global_scope_p(SCOPE) \ 284 ((SCOPE) == NAMESPACE_LEVEL (global_namespace)) 285 286 extern cp_binding_level *leave_scope (void); 287 extern bool kept_level_p (void); 288 extern bool global_bindings_p (void); 289 extern bool toplevel_bindings_p (void); 290 extern bool namespace_bindings_p (void); 291 extern bool local_bindings_p (void); 292 extern bool template_parm_scope_p (void); 293 extern scope_kind innermost_scope_kind (void); 294 extern cp_binding_level *begin_scope (scope_kind, tree); 295 extern void print_binding_stack (void); 296 extern void push_to_top_level (void); 297 extern void pop_from_top_level (void); 298 extern void pop_everything (void); 299 extern void keep_next_level (bool); 300 extern bool is_ancestor (tree, tree); 301 extern tree push_scope (tree); 302 extern void pop_scope (tree); 303 extern tree push_inner_scope (tree); 304 extern void pop_inner_scope (tree, tree); 305 extern void push_binding_level (cp_binding_level *); 306 307 extern void push_namespace (tree); 309 extern void pop_namespace (void); 310 extern void push_nested_namespace (tree); 311 extern void pop_nested_namespace (tree); 312 extern bool handle_namespace_attrs (tree, tree); 313 extern void pushlevel_class (void); 314 extern void poplevel_class (void); 315 extern tree pushdecl_with_scope (tree, cp_binding_level *, bool); 316 extern tree lookup_name_prefer_type (tree, int); 317 extern tree lookup_name_real (tree, int, int, bool, int, int); 318 extern tree lookup_type_scope (tree, tag_scope); 319 extern tree namespace_binding (tree, tree); 320 extern void set_namespace_binding (tree, tree, tree); 321 extern bool hidden_name_p (tree); 322 extern tree remove_hidden_names (tree); 323 extern tree lookup_qualified_name (tree, tree, bool, bool); 324 extern tree lookup_name_nonclass (tree); 325 extern tree lookup_name_innermost_nonclass_level (tree); 326 extern bool is_local_extern (tree); 327 extern tree lookup_function_nonclass (tree, vec<tree, va_gc> *, bool); 328 extern void push_local_binding (tree, tree, int); 329 extern bool pushdecl_class_level (tree); 330 extern tree pushdecl_namespace_level (tree, bool); 331 extern bool push_class_level_binding (tree, tree); 332 extern tree getdecls (void); 333 extern int function_parm_depth (void); 334 extern tree cp_namespace_decls (tree); 335 extern void set_decl_namespace (tree, tree, bool); 336 extern void push_decl_namespace (tree); 337 extern void pop_decl_namespace (void); 338 extern void do_namespace_alias (tree, tree); 339 extern void do_toplevel_using_decl (tree, tree, tree); 340 extern void do_local_using_decl (tree, tree, tree); 341 extern tree do_class_using_decl (tree, tree); 342 extern void do_using_directive (tree); 343 extern tree lookup_arg_dependent (tree, tree, vec<tree, va_gc> *, bool); 344 extern bool is_associated_namespace (tree, tree); 345 extern void parse_using_directive (tree, tree); 346 extern tree innermost_non_namespace_value (tree); 347 extern cxx_binding *outer_binding (tree, cxx_binding *, bool); 348 extern void cp_emit_debug_info_for_using (tree, tree); 349 350 /* Set *DECL to the (non-hidden) declaration for ID at global scope, 351 if present and return true; otherwise return false. */ 352 353 static inline bool 354 get_global_value_if_present (tree id, tree *decl) 355 { 356 tree global_value = namespace_binding (id, global_namespace); 357 if (global_value) 358 *decl = global_value; 359 return global_value != NULL; 360 } 361 362 /* True is the binding of IDENTIFIER at global scope names a type. */ 363 364 static inline bool 365 is_typename_at_global_scope (tree id) 366 { 367 tree global_value = namespace_binding (id, global_namespace); 368 369 return global_value && TREE_CODE (global_value) == TYPE_DECL; 370 } 371 372 #endif /* GCC_CP_NAME_LOOKUP_H */ 373
