vala/valasymbolresolver.vala

   1 /* valasymbolresolver.vala
   2  *
   3  * Copyright (C) 2006-2010  Jürg Billeter
   4  * Copyright (C) 2006-2008  Raffaele Sandrini
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
  19  *
  20  * Author:
  21  *      Jürg Billeter <j@bitron.ch>
  22  *      Raffaele Sandrini <raffaele@sandrini.ch>
  23  */
  24
  25 using GLib;
  26
  27 /**
  28  * Code visitor resolving symbol names.
  29  */
  30 public class Vala.SymbolResolver : CodeVisitor {
  31         CodeContext context;
  32         Symbol root_symbol;
  33         Scope current_scope;
  34
  35         /**
  36          * Resolve symbol names in the specified code context.
  37          *
  38          * @param context a code context
  39          */
  40         public void resolve (CodeContext context) {
  41                 this.context = context;
  42                 root_symbol = context.root;
  43
  44                 context.root.accept (this);
  45         }
  46
  47         public override void visit_namespace (Namespace ns) {
  48                 var old_scope = current_scope;
  49                 current_scope = ns.scope;
  50
  51                 ns.accept_children (this);
  52
  53                 current_scope = old_scope;
  54         }
  55
  56         public override void visit_class (Class cl) {
  57                 current_scope = cl.scope;
  58
  59                 cl.accept_children (this);
  60
  61                 cl.base_class = null;
  62                 foreach (DataType type in cl.get_base_types ()) {
  63                         if (type.data_type is Class) {
  64                                 if (cl.base_class != null) {
  65                                         cl.error = true;
  66                                         Report.error (type.source_reference, "%s: Classes cannot have multiple base classes (`%s' and `%s')".printf (cl.get_full_name (), cl.base_class.get_full_name (), type.data_type.get_full_name ()));
  67                                         return;
  68                                 }
  69                                 cl.base_class = (Class) type.data_type;
  70                                 if (cl.base_class.is_subtype_of (cl)) {
  71                                         cl.error = true;
  72                                         Report.error (type.source_reference, "Base class cycle (`%s' and `%s')".printf (cl.get_full_name (), cl.base_class.get_full_name ()));
  73                                         return;
  74                                 }
  75                         }
  76                 }
  77
  78                 current_scope = current_scope.parent_scope;
  79         }
  80
  81         public override void visit_struct (Struct st) {
  82                 current_scope = st.scope;
  83
  84                 st.accept_children (this);
  85
  86                 if (st.base_type != null) {
  87                         var base_type = st.base_struct;
  88                         if (base_type != null) {
  89                                 if (base_type.is_subtype_of (st)) {
  90                                         st.error = true;
  91                                         Report.error (base_type.source_reference, "Base struct cycle (`%s' and `%s')".printf (st.get_full_name (), base_type.get_full_name ()));
  92                                         return;
  93                                 }
  94                         }
  95                 }
  96
  97                 current_scope = current_scope.parent_scope;
  98         }
  99
 100         public override void visit_interface (Interface iface) {
 101                 current_scope = iface.scope;
 102
 103                 iface.accept_children (this);
 104
 105                 foreach (DataType type in iface.get_prerequisites ()) {
 106                         if (type.data_type != null && type.data_type.is_subtype_of (iface)) {
 107                                 iface.error = true;
 108                                 Report.error (type.source_reference, "Prerequisite cycle (`%s' and `%s')".printf (iface.get_full_name (), type.data_type.get_full_name ()));
 109                                 return;
 110                         }
 111                 }
 112
 113                 current_scope = current_scope.parent_scope;
 114         }
 115
 116         public override void visit_enum (Enum en) {
 117                 current_scope = en.scope;
 118
 119                 en.accept_children (this);
 120
 121                 current_scope = current_scope.parent_scope;
 122         }
 123
 124         public override void visit_error_domain (ErrorDomain ed) {
 125                 current_scope = ed.scope;
 126
 127                 ed.accept_children (this);
 128
 129                 current_scope = current_scope.parent_scope;
 130         }
 131
 132         public override void visit_delegate (Delegate cb) {
 133                 current_scope = cb.scope;
 134
 135                 cb.accept_children (this);
 136
 137                 current_scope = current_scope.parent_scope;
 138         }
 139
 140         public override void visit_constant (Constant c) {
 141                 var old_scope = current_scope;
 142                 if (!(c.parent_symbol is Block)) {
 143                         // non-local constant
 144                         current_scope = c.scope;
 145                 }
 146
 147                 c.accept_children (this);
 148
 149                 current_scope = old_scope;
 150         }
 151
 152         public override void visit_field (Field f) {
 153                 current_scope = f.scope;
 154
 155                 f.accept_children (this);
 156
 157                 current_scope = current_scope.parent_scope;
 158         }
 159
 160         public override void visit_method (Method m) {
 161                 current_scope = m.scope;
 162
 163                 m.accept_children (this);
 164
 165                 current_scope = current_scope.parent_scope;
 166         }
 167
 168         public override void visit_creation_method (CreationMethod m) {
 169                 m.accept_children (this);
 170         }
 171
 172         public override void visit_formal_parameter (Parameter p) {
 173                 p.accept_children (this);
 174         }
 175
 176         public override void visit_property (Property prop) {
 177                 prop.accept_children (this);
 178         }
 179
 180         public override void visit_property_accessor (PropertyAccessor acc) {
 181                 acc.accept_children (this);
 182         }
 183
 184         public override void visit_signal (Signal sig) {
 185                 sig.accept_children (this);
 186         }
 187
 188         public override void visit_constructor (Constructor c) {
 189                 c.accept_children (this);
 190         }
 191
 192         public override void visit_destructor (Destructor d) {
 193                 d.accept_children (this);
 194         }
 195
 196         public override void visit_block (Block b) {
 197                 b.accept_children (this);
 198         }
 199
 200         public override void visit_using_directive (UsingDirective ns) {
 201                 var unresolved_symbol = ns.namespace_symbol as UnresolvedSymbol;
 202                 if (unresolved_symbol != null) {
 203                         ns.namespace_symbol = resolve_symbol (unresolved_symbol);
 204                         if (!(ns.namespace_symbol is Namespace)) {
 205                                 ns.error = true;
 206                                 Report.error (ns.source_reference, "The namespace name `%s' could not be found".printf (unresolved_symbol.to_string ()));
 207                                 return;
 208                         }
 209                 }
 210         }
 211
 212         private Symbol? resolve_symbol (UnresolvedSymbol unresolved_symbol) {
 213                 if (unresolved_symbol.qualified) {
 214                         // qualified access to global symbol
 215                         return root_symbol.scope.lookup (unresolved_symbol.name);
 216                 } else if (unresolved_symbol.inner == null) {
 217                         Symbol sym = null;
 218                         Scope scope = current_scope;
 219                         while (sym == null && scope != null) {
 220                                 sym = scope.lookup (unresolved_symbol.name);
 221
 222                                 // only look for types and type containers
 223                                 if (!(sym is Namespace || sym is TypeSymbol || sym is TypeParameter)) {
 224                                         sym = null;
 225                                 }
 226
 227                                 scope = scope.parent_scope;
 228                         }
 229                         if (sym == null && unresolved_symbol.source_reference != null) {
 230                                 foreach (UsingDirective ns in unresolved_symbol.source_reference.using_directives) {
 231                                         if (ns.error || ns.namespace_symbol is UnresolvedSymbol) {
 232                                                 continue;
 233                                         }
 234
 235                                         var local_sym = ns.namespace_symbol.scope.lookup (unresolved_symbol.name);
 236
 237                                         // only look for types and type containers
 238                                         if (!(local_sym is Namespace || local_sym is TypeSymbol || sym is TypeParameter)) {
 239                                                 local_sym = null;
 240                                         }
 241
 242                                         if (local_sym != null) {
 243                                                 if (sym != null && sym != local_sym) {
 244                                                         unresolved_symbol.error = true;
 245                                                         Report.error (unresolved_symbol.source_reference, "`%s' is an ambiguous reference between `%s' and `%s'".printf (unresolved_symbol.name, sym.get_full_name (), local_sym.get_full_name ()));
 246                                                         return null;
 247                                                 }
 248                                                 sym = local_sym;
 249                                         }
 250                                 }
 251                         }
 252                         return sym;
 253                 } else {
 254                         var parent_symbol = resolve_symbol (unresolved_symbol.inner);
 255                         if (parent_symbol == null) {
 256                                 unresolved_symbol.error = true;
 257                                 Report.error (unresolved_symbol.inner.source_reference, "The symbol `%s' could not be found".printf (unresolved_symbol.inner.name));
 258                                 return null;
 259                         }
 260                         parent_symbol.used = true;
 261
 262                         return parent_symbol.scope.lookup (unresolved_symbol.name);
 263                 }
 264         }
 265
 266         DataType get_type_for_struct (Struct st, Struct base_struct) {
 267                 if (st.base_type != null) {
 268                         // make sure that base type is resolved
 269
 270                         var old_scope = current_scope;
 271                         current_scope = st.scope;
 272
 273                         st.base_type.accept (this);
 274
 275                         current_scope = old_scope;
 276                 }
 277
 278                 if (base_struct.base_struct != null) {
 279                         return get_type_for_struct (st, base_struct.base_struct);
 280                 }
 281
 282                 // attributes are not processed yet, access them directly
 283                 if (base_struct.get_attribute ("BooleanType") != null) {
 284                         return new BooleanType (st);
 285                 } else if (base_struct.get_attribute ("IntegerType") != null) {
 286                         return new IntegerType (st);
 287                 } else if (base_struct.get_attribute ("FloatingType") != null) {
 288                         return new FloatingType (st);
 289                 } else {
 290                         return new StructValueType (st);
 291                 }
 292         }
 293
 294         private DataType resolve_type (UnresolvedType unresolved_type) {
 295                 DataType type = null;
 296
 297                 // still required for vapigen
 298                 if (unresolved_type.unresolved_symbol.name == "void") {
 299                         return new VoidType ();
 300                 }
 301
 302                 var sym = resolve_symbol (unresolved_type.unresolved_symbol);
 303                 if (sym == null) {
 304                         // don't report same error twice
 305                         if (!unresolved_type.unresolved_symbol.error) {
 306                                 Report.error (unresolved_type.source_reference, "The type name `%s' could not be found".printf (unresolved_type.unresolved_symbol.to_string ()));
 307                         }
 308                         return new InvalidType ();
 309                 }
 310
 311                 if (sym is TypeParameter) {
 312                         type = new GenericType ((TypeParameter) sym);
 313                 } else if (sym is TypeSymbol) {
 314                         if (sym is Delegate) {
 315                                 type = new DelegateType ((Delegate) sym);
 316                         } else if (sym is Class) {
 317                                 var cl = (Class) sym;
 318                                 if (cl.is_error_base) {
 319                                         type = new ErrorType (null, null, unresolved_type.source_reference);
 320                                 } else {
 321                                         type = new ObjectType (cl);
 322                                 }
 323                         } else if (sym is Interface) {
 324                                 type = new ObjectType ((Interface) sym);
 325                         } else if (sym is Struct) {
 326                                 type = get_type_for_struct ((Struct) sym, (Struct) sym);
 327                         } else if (sym is Enum) {
 328                                 type = new EnumValueType ((Enum) sym);
 329                         } else if (sym is ErrorDomain) {
 330                                 type = new ErrorType ((ErrorDomain) sym, null, unresolved_type.source_reference);
 331                         } else if (sym is ErrorCode) {
 332                                 type = new ErrorType ((ErrorDomain) sym.parent_symbol, (ErrorCode) sym, unresolved_type.source_reference);
 333                         } else {
 334                                 Report.error (unresolved_type.source_reference, "internal error: `%s' is not a supported type".printf (sym.get_full_name ()));
 335                                 return new InvalidType ();
 336                         }
 337                 } else {
 338                         Report.error (unresolved_type.source_reference, "`%s' is not a type".printf (sym.get_full_name ()));
 339                         return new InvalidType ();
 340                 }
 341
 342                 type.source_reference = unresolved_type.source_reference;
 343                 type.value_owned = unresolved_type.value_owned;
 344                 sym.used = true;
 345
 346                 if (type is GenericType) {
 347                         // type parameters are always considered nullable
 348                         // actual type argument may or may not be nullable
 349                         type.nullable = true;
 350                 } else {
 351                         type.nullable = unresolved_type.nullable;
 352                 }
 353
 354                 type.is_dynamic = unresolved_type.is_dynamic;
 355                 foreach (DataType type_arg in unresolved_type.get_type_arguments ()) {
 356                         type.add_type_argument (type_arg);
 357                 }
 358
 359                 return type;
 360         }
 361
 362         public override void visit_data_type (DataType data_type) {
 363                 data_type.accept_children (this);
 364
 365                 if (!(data_type is UnresolvedType)) {
 366                         return;
 367                 }
 368
 369                 var unresolved_type = (UnresolvedType) data_type;
 370
 371                 unresolved_type.parent_node.replace_type (unresolved_type, resolve_type (unresolved_type));
 372         }
 373
 374         public override void visit_declaration_statement (DeclarationStatement stmt) {
 375                 stmt.accept_children (this);
 376         }
 377
 378         public override void visit_local_variable (LocalVariable local) {
 379                 local.accept_children (this);
 380                 if (!context.experimental_non_null) {
 381                         // local reference variables are considered nullable
 382                         // except when using experimental non-null enhancements
 383                         if (local.variable_type is ReferenceType) {
 384                                 var array_type = local.variable_type as ArrayType;
 385                                 if (array_type != null && array_type.fixed_length) {
 386                                         // local fixed length arrays are not nullable
 387                                 } else {
 388                                         local.variable_type.nullable = true;
 389                                 }
 390                         }
 391                 }
 392         }
 393
 394         public override void visit_initializer_list (InitializerList list) {
 395                 list.accept_children (this);
 396         }
 397
 398         public override void visit_expression_statement (ExpressionStatement stmt) {
 399                 stmt.accept_children (this);
 400         }
 401
 402         public override void visit_if_statement (IfStatement stmt) {
 403                 stmt.accept_children (this);
 404         }
 405
 406         public override void visit_switch_statement (SwitchStatement stmt) {
 407                 stmt.accept_children (this);
 408         }
 409
 410         public override void visit_switch_section (SwitchSection section) {
 411                 section.accept_children (this);
 412         }
 413
 414         public override void visit_switch_label (SwitchLabel label) {
 415                 label.accept_children (this);
 416         }
 417
 418         public override void visit_loop (Loop stmt) {
 419                 stmt.accept_children (this);
 420         }
 421
 422         public override void visit_while_statement (WhileStatement stmt) {
 423                 stmt.accept_children (this);
 424         }
 425
 426         public override void visit_do_statement (DoStatement stmt) {
 427                 stmt.accept_children (this);
 428         }
 429
 430         public override void visit_for_statement (ForStatement stmt) {
 431                 stmt.accept_children (this);
 432         }
 433
 434         public override void visit_foreach_statement (ForeachStatement stmt) {
 435                 stmt.accept_children (this);
 436         }
 437
 438         public override void visit_return_statement (ReturnStatement stmt) {
 439                 stmt.accept_children (this);
 440         }
 441
 442         public override void visit_yield_statement (YieldStatement stmt) {
 443                 stmt.accept_children (this);
 444         }
 445
 446         public override void visit_throw_statement (ThrowStatement stmt) {
 447                 stmt.accept_children (this);
 448         }
 449
 450         public override void visit_try_statement (TryStatement stmt) {
 451                 stmt.accept_children (this);
 452         }
 453
 454         public override void visit_delete_statement (DeleteStatement stmt) {
 455                 stmt.accept_children (this);
 456         }
 457
 458         public override void visit_catch_clause (CatchClause clause) {
 459                 clause.accept_children (this);
 460         }
 461
 462         public override void visit_array_creation_expression (ArrayCreationExpression e) {
 463                 e.accept_children (this);
 464         }
 465
 466         public override void visit_template (Template tmpl) {
 467                 tmpl.accept_children (this);
 468         }
 469
 470         public override void visit_tuple (Tuple tuple) {
 471                 tuple.accept_children (this);
 472         }
 473
 474         public override void visit_member_access (MemberAccess expr) {
 475                 expr.accept_children (this);
 476         }
 477
 478         public override void visit_method_call (MethodCall expr) {
 479                 expr.accept_children (this);
 480         }
 481
 482         public override void visit_element_access (ElementAccess expr) {
 483                 expr.accept_children (this);
 484         }
 485
 486         public override void visit_slice_expression (SliceExpression expr) {
 487                 expr.accept_children (this);
 488         }
 489
 490         public override void visit_postfix_expression (PostfixExpression expr) {
 491                 expr.accept_children (this);
 492         }
 493
 494         public override void visit_object_creation_expression (ObjectCreationExpression expr) {
 495                 expr.accept_children (this);
 496         }
 497
 498         public override void visit_sizeof_expression (SizeofExpression expr) {
 499                 expr.accept_children (this);
 500         }
 501
 502         public override void visit_typeof_expression (TypeofExpression expr) {
 503                 expr.accept_children (this);
 504         }
 505
 506         public override void visit_unary_expression (UnaryExpression expr) {
 507                 expr.accept_children (this);
 508         }
 509
 510         public override void visit_cast_expression (CastExpression expr) {
 511                 expr.accept_children (this);
 512         }
 513
 514         public override void visit_addressof_expression (AddressofExpression expr) {
 515                 expr.accept_children (this);
 516         }
 517
 518         public override void visit_reference_transfer_expression (ReferenceTransferExpression expr) {
 519                 expr.accept_children (this);
 520         }
 521
 522         public override void visit_binary_expression (BinaryExpression expr) {
 523                 expr.accept_children (this);
 524         }
 525
 526         public override void visit_type_check (TypeCheck expr) {
 527                 expr.accept_children (this);
 528         }
 529
 530         public override void visit_conditional_expression (ConditionalExpression expr) {
 531                 expr.accept_children (this);
 532         }
 533
 534         public override void visit_lambda_expression (LambdaExpression l) {
 535                 l.accept_children (this);
 536         }
 537
 538         public override void visit_assignment (Assignment a) {
 539                 a.accept_children (this);
 540         }
 541 }