src/cast.c

   1 /*
   2  * Copyright (C) 2003, 2004, 2005, 2006, 2007
   3  * Robert Lougher <rob@lougher.org.uk>.
   4  *
   5  * This file is part of JamVM.
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * as published by the Free Software Foundation; either version 2,
  10  * or (at your option) any later version.
  11  *
  12  * This program 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 this program; if not, write to the Free Software
  19  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  20  */
  21
  22 #include "jam.h"
  23
  24 char implements(Class *class, Class *test) {
  25     ClassBlock *test_cb = CLASS_CB(test);
  26     int i;
  27
  28     for(i = 0; i < test_cb->interfaces_count; i++)
  29         if((class == test_cb->interfaces[i]) ||
  30                       implements(class, test_cb->interfaces[i]))
  31             return TRUE;
  32
  33     if(test_cb->super)
  34         return implements(class, test_cb->super);
  35
  36     return FALSE;
  37 }
  38
  39 char isSubClassOf(Class *class, Class *test) {
  40     for(; test != NULL && test != class; test = CLASS_CB(test)->super);
  41     return test != NULL;
  42 }
  43
  44 char isInstOfArray0(Class *array_class, Class *test_elem, int test_dim) {
  45     ClassBlock *array_cb = CLASS_CB(array_class);
  46     Class *array_elem = array_cb->element_class;
  47
  48     if(test_dim == array_cb->dim)
  49         return isInstanceOf(array_elem, test_elem);
  50
  51     if(test_dim > array_cb->dim)
  52         return IS_INTERFACE(CLASS_CB(array_elem)) ?
  53                      implements(array_elem, array_class) :
  54                      (array_elem == array_cb->super);
  55
  56     return FALSE;
  57 }
  58
  59 char isInstOfArray(Class *class, Class *test) {
  60     ClassBlock *test_cb = CLASS_CB(test);
  61
  62     if(!IS_ARRAY(CLASS_CB(class)))
  63         return class == test_cb->super;
  64
  65     return isInstOfArray0(class, test_cb->element_class, test_cb->dim);
  66 }
  67
  68 char isInstanceOf(Class *class, Class *test) {
  69     if(class == test)
  70         return TRUE;
  71
  72     if(IS_INTERFACE(CLASS_CB(class)))
  73         return implements(class, test);
  74     else
  75         if(IS_ARRAY(CLASS_CB(test)))
  76             return isInstOfArray(class, test);
  77         else
  78             return isSubClassOf(class, test);
  79 }
  80
  81 char arrayStoreCheck(Class *array_class, Class *test) {
  82     ClassBlock *test_cb = CLASS_CB(test);
  83
  84     if(!IS_ARRAY(test_cb))
  85         return isInstOfArray0(array_class, test, 1);
  86
  87     return isInstOfArray0(array_class, test_cb->element_class, test_cb->dim + 1);
  88 }