vala/valapointertype.vala

   1 /* valapointertype.vala
   2  *
   3  * Copyright (C) 2007-2009  Jürg Billeter
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2.1 of the License, or (at your option) any later version.
   9
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
  18  *
  19  * Author:
  20  *      Jürg Billeter <j@bitron.ch>
  21  */
  22
  23 using GLib;
  24
  25 /**
  26  * A pointer type.
  27  */
  28 public class Vala.PointerType : DataType {
  29         /**
  30          * The base type the pointer is referring to.
  31          */
  32         public DataType base_type {
  33                 get { return _base_type; }
  34                 set {
  35                         _base_type = value;
  36                         _base_type.parent_node = this;
  37                 }
  38         }
  39
  40         private DataType _base_type;
  41
  42         public PointerType (DataType base_type, SourceReference? source_reference = null) {
  43                 this.base_type = base_type;
  44                 nullable = true;
  45                 this.source_reference = source_reference;
  46         }
  47
  48         public override string to_qualified_string (Scope? scope) {
  49                 return base_type.to_qualified_string (scope) + "*";
  50         }
  51
  52         public override DataType copy () {
  53                 return new PointerType (base_type.copy ());
  54         }
  55
  56         public override bool compatible (DataType target_type) {
  57                 if (target_type is PointerType) {
  58                         var tt = target_type as PointerType;
  59
  60                         if (tt.base_type is VoidType || base_type is VoidType) {
  61                                 return true;
  62                         }
  63
  64                         /* dereference only if both types are references or not */
  65                         if (base_type.is_reference_type_or_type_parameter () != tt.base_type.is_reference_type_or_type_parameter ()) {
  66                                 return false;
  67                         }
  68
  69                         return base_type.compatible (tt.base_type);
  70                 }
  71
  72                 if ((target_type.data_type != null && target_type.data_type.get_attribute ("PointerType") != null)) {
  73                         return true;
  74                 }
  75
  76                 /* temporarily ignore type parameters */
  77                 if (target_type.type_parameter != null) {
  78                         return true;
  79                 }
  80
  81                 if (base_type.is_reference_type_or_type_parameter ()) {
  82                         // Object* is compatible with Object if Object is a reference type
  83                         return base_type.compatible (target_type);
  84                 }
  85
  86                 if (target_type.data_type != null && target_type.data_type.is_subtype_of (CodeContext.get ().analyzer.gvalue_type.data_type)) {
  87                         // allow implicit conversion to GValue
  88                         return true;
  89                 }
  90
  91                 return false;
  92         }
  93
  94         public override Symbol? get_member (string member_name) {
  95                 return null;
  96         }
  97
  98         public override Symbol? get_pointer_member (string member_name) {
  99                 Symbol base_symbol = base_type.data_type;
 100
 101                 if (base_symbol == null) {
 102                         return null;
 103                 }
 104
 105                 return SemanticAnalyzer.symbol_lookup_inherited (base_symbol, member_name);
 106         }
 107
 108         public override bool is_accessible (Symbol sym) {
 109                 return base_type.is_accessible (sym);
 110         }
 111
 112         public override void accept_children (CodeVisitor visitor) {
 113                 base_type.accept (visitor);
 114         }
 115
 116         public override void replace_type (DataType old_type, DataType new_type) {
 117                 if (base_type == old_type) {
 118                         base_type = new_type;
 119                 }
 120         }
 121
 122         public override bool is_disposable () {
 123                 return false;
 124         }
 125
 126         public override DataType get_actual_type (DataType? derived_instance_type, List<DataType>? method_type_arguments, CodeNode node_reference) {
 127                 PointerType result = (PointerType) this.copy ();
 128
 129                 if (derived_instance_type == null && method_type_arguments == null) {
 130                         return result;
 131                 }
 132
 133                 if (base_type is GenericType || base_type.has_type_arguments ()) {
 134                         result.base_type = result.base_type.get_actual_type (derived_instance_type, method_type_arguments, node_reference);
 135                 }
 136
 137                 return result;
 138         }
 139
 140         public override DataType? infer_type_argument (TypeParameter type_param, DataType value_type) {
 141                 var pointer_type = value_type as PointerType;
 142                 if (pointer_type != null) {
 143                         return base_type.infer_type_argument (type_param, pointer_type.base_type);
 144                 }
 145
 146                 return null;
 147         }
 148
 149         public override bool check (CodeContext context) {
 150                 error = !base_type.check (context);
 151                 return !error;
 152         }
 153 }