stage4/generate_cc/search_expression_type.cc
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     1 /*
       
     2  * (c) 2003 Mario de Sousa
       
     3  *
       
     4  * Offered to the public under the terms of the GNU General Public License
       
     5  * as published by the Free Software Foundation; either version 2 of the
       
     6  * License, or (at your option) any later version.
       
     7  *
       
     8  * This program is distributed in the hope that it will be useful, but
       
     9  * WITHOUT ANY WARRANTY; without even the implied warranty of
       
    10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
       
    11  * Public License for more details.
       
    12  *
       
    13  * This code is made available on the understanding that it will not be
       
    14  * used in safety-critical situations without a full and competent review.
       
    15  */
       
    16 
       
    17 /*
       
    18  * An IEC 61131-3 IL and ST compiler.
       
    19  *
       
    20  * Based on the
       
    21  * FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10)
       
    22  *
       
    23  */
       
    24 
       
    25 
       
    26 /* Determine the data type of an ST expression.
       
    27  * A reference to the relevant type definition is returned.
       
    28  *
       
    29  * For example:
       
    30  *       2 + 3       -> returns reference to a int_type_name_c object.
       
    31  *       22.2 - 5    -> returns reference to a real_type_name_c object.
       
    32  *       etc...
       
    33  */
       
    34 class search_expression_type_c: public search_constant_type_c {
       
    35   private:
       
    36     search_varfb_instance_type_c *search_varfb_instance_type;
       
    37     search_base_type_c search_base_type;
       
    38 
       
    39   public:
       
    40     search_expression_type_c(symbol_c *search_scope) {
       
    41       search_varfb_instance_type = new search_varfb_instance_type_c(search_scope);
       
    42     }
       
    43 
       
    44     virtual ~search_expression_type_c(void) {
       
    45       delete search_varfb_instance_type;
       
    46     }
       
    47 
       
    48     /* A helper function... */
       
    49     bool is_bool_type(symbol_c *type_symbol) {
       
    50       return (typeid(*type_symbol) == typeid(bool_type_name_c));
       
    51     }
       
    52 
       
    53     /* A helper function... */
       
    54     bool is_time_compatible(symbol_c *type_symbol) {
       
    55       if (typeid(*type_symbol) == typeid(time_type_name_c)) {return true;}
       
    56       if (typeid(*type_symbol) == typeid(date_type_name_c)) {return true;}
       
    57       if (typeid(*type_symbol) == typeid(tod_type_name_c)) {return true;}
       
    58       if (typeid(*type_symbol) == typeid(dt_type_name_c)) {return true;}
       
    59       return false;
       
    60     }
       
    61 
       
    62     /* A helper function... */
       
    63     bool is_numeric_compatible(symbol_c *type_symbol) {
       
    64       if (typeid(*type_symbol) == typeid(sint_type_name_c)) {return true;}
       
    65       if (typeid(*type_symbol) == typeid(int_type_name_c)) {return true;}
       
    66       if (typeid(*type_symbol) == typeid(dint_type_name_c)) {return true;}
       
    67       if (typeid(*type_symbol) == typeid(lint_type_name_c)) {return true;}
       
    68       if (typeid(*type_symbol) == typeid(usint_type_name_c)) {return true;}
       
    69       if (typeid(*type_symbol) == typeid(uint_type_name_c)) {return true;}
       
    70       if (typeid(*type_symbol) == typeid(udint_type_name_c)) {return true;}
       
    71       if (typeid(*type_symbol) == typeid(ulint_type_name_c)) {return true;}
       
    72       if (typeid(*type_symbol) == typeid(real_type_name_c)) {return true;}
       
    73       if (typeid(*type_symbol) == typeid(lreal_type_name_c)) {return true;}
       
    74       if (typeid(*type_symbol) == typeid(byte_type_name_c)) {return true;}
       
    75       if (typeid(*type_symbol) == typeid(word_type_name_c)) {return true;}
       
    76       if (typeid(*type_symbol) == typeid(dword_type_name_c)) {return true;}
       
    77       if (typeid(*type_symbol) == typeid(lword_type_name_c)) {return true;}
       
    78       return false;
       
    79     }
       
    80     
       
    81   private:
       
    82 
       
    83   static bool_type_name_c bool_type_name;
       
    84 
       
    85   /* A helper function... */
       
    86   void *compute_boolean_expression(symbol_c *left_type, symbol_c *right_type) {
       
    87     if (typeid(*left_type) == typeid(bool_type_name_c) and typeid(*right_type) == typeid(bool_type_name_c)) {return (void *)left_type;}
       
    88     if (is_numeric_compatible(left_type) && is_numeric_compatible(right_type)) {return (void *)left_type;}
       
    89     ERROR;
       
    90     return NULL;
       
    91   }
       
    92 
       
    93   /* A helper function... */
       
    94   void *compute_numeric_expression(symbol_c *left_type, symbol_c *right_type) {
       
    95     if (is_numeric_compatible(left_type) && is_numeric_compatible(right_type)) {return (void *)left_type;}
       
    96     ERROR;
       
    97     return NULL;
       
    98   }
       
    99 
       
   100   /* a helper function... */
       
   101   symbol_c *base_type(symbol_c *symbol) {
       
   102     return (symbol_c *)symbol->accept(search_base_type);
       
   103   }
       
   104 
       
   105 /*********************/
       
   106 /* B 1.4 - Variables */
       
   107 /*********************/
       
   108 
       
   109   void *visit(symbolic_variable_c *symbol) {
       
   110     symbol_c *res;
       
   111     
       
   112     /* Nope, now we assume it is a variable, and determine its type... */
       
   113     res = search_varfb_instance_type->get_type(symbol);
       
   114     if (NULL != res) return res;
       
   115     
       
   116     return NULL;
       
   117   }
       
   118 
       
   119 
       
   120 /***************************************/
       
   121 /* B.3 - Language ST (Structured Text) */
       
   122 /***************************************/
       
   123 /***********************/
       
   124 /* B 3.1 - Expressions */
       
   125 /***********************/
       
   126   void *visit(or_expression_c *symbol) {
       
   127     symbol_c *left_type = base_type((symbol_c *)symbol->l_exp->accept(*this));
       
   128     symbol_c *right_type = base_type((symbol_c *)symbol->r_exp->accept(*this));
       
   129     return compute_boolean_expression(left_type, right_type);
       
   130   }
       
   131 
       
   132   void *visit(xor_expression_c *symbol) {
       
   133     symbol_c *left_type = base_type((symbol_c *)symbol->l_exp->accept(*this));
       
   134     symbol_c *right_type = base_type((symbol_c *)symbol->r_exp->accept(*this));
       
   135     return compute_boolean_expression(left_type, right_type);
       
   136   }
       
   137 
       
   138   void *visit(and_expression_c *symbol) {
       
   139     symbol_c *left_type = base_type((symbol_c *)symbol->l_exp->accept(*this));
       
   140     symbol_c *right_type = base_type((symbol_c *)symbol->r_exp->accept(*this));
       
   141     return compute_boolean_expression(left_type, right_type); 
       
   142   }
       
   143 
       
   144   void *visit(equ_expression_c *symbol) {return (void *)&bool_type_name;}
       
   145   void *visit(notequ_expression_c *symbol) {return (void *)&bool_type_name;}
       
   146   void *visit(lt_expression_c *symbol) {return (void *)&bool_type_name;}
       
   147   void *visit(gt_expression_c *symbol) {return (void *)&bool_type_name;}
       
   148   void *visit(le_expression_c *symbol) {return (void *)&bool_type_name;}
       
   149   void *visit(ge_expression_c *symbol) {return (void *)&bool_type_name;}
       
   150 
       
   151   void *visit(add_expression_c *symbol) {
       
   152     symbol_c *left_type = base_type((symbol_c *)symbol->l_exp->accept(*this));
       
   153     symbol_c *right_type = base_type((symbol_c *)symbol->r_exp->accept(*this));
       
   154     if (is_time_compatible(left_type) && is_time_compatible(right_type)) {return left_type;}
       
   155     return compute_numeric_expression(left_type, right_type);
       
   156   }
       
   157 
       
   158   void *visit(sub_expression_c *symbol) {
       
   159     symbol_c *left_type = base_type((symbol_c *)symbol->l_exp->accept(*this));
       
   160     symbol_c *right_type = base_type((symbol_c *)symbol->r_exp->accept(*this));
       
   161     if (is_time_compatible(left_type) && is_time_compatible(right_type)) {return left_type;}
       
   162     return compute_numeric_expression(left_type, right_type);
       
   163   }
       
   164   
       
   165   void *visit(mul_expression_c *symbol) {
       
   166     symbol_c *left_type = base_type((symbol_c *)symbol->l_exp->accept(*this));
       
   167     symbol_c *right_type = base_type((symbol_c *)symbol->r_exp->accept(*this));
       
   168     if (is_time_compatible(left_type) && is_time_compatible(right_type)) {return left_type;}
       
   169     return compute_numeric_expression(left_type, right_type);
       
   170   }
       
   171   
       
   172   void *visit(div_expression_c *symbol) {
       
   173     symbol_c *left_type = base_type((symbol_c *)symbol->l_exp->accept(*this));
       
   174     symbol_c *right_type = base_type((symbol_c *)symbol->r_exp->accept(*this));
       
   175     return compute_numeric_expression(left_type, right_type);
       
   176   }
       
   177 
       
   178   void *visit(mod_expression_c *symbol) {
       
   179     symbol_c *left_type = base_type((symbol_c *)symbol->l_exp->accept(*this));
       
   180     symbol_c *right_type = base_type((symbol_c *)symbol->r_exp->accept(*this));
       
   181     return compute_numeric_expression(left_type, right_type);
       
   182   }
       
   183 
       
   184   void *visit(power_expression_c *symbol) {
       
   185     symbol_c *left_type = base_type((symbol_c *)symbol->l_exp->accept(*this));
       
   186     symbol_c *right_type = base_type((symbol_c *)symbol->r_exp->accept(*this));
       
   187     if (typeid(*left_type) == typeid(real_type_name_c) and typeid(*right_type) == typeid(sint_type_name_c)) {return (void *)left_type;}
       
   188     if (typeid(*left_type) == typeid(real_type_name_c) and typeid(*right_type) == typeid(int_type_name_c)) {return (void *)left_type;}
       
   189     if (typeid(*left_type) == typeid(real_type_name_c) and typeid(*right_type) == typeid(dint_type_name_c)) {return (void *)left_type;}
       
   190     if (typeid(*left_type) == typeid(real_type_name_c) and typeid(*right_type) == typeid(lint_type_name_c)) {return (void *)left_type;}
       
   191     if (typeid(*left_type) == typeid(real_type_name_c) and typeid(*right_type) == typeid(usint_type_name_c)) {return (void *)left_type;}
       
   192     if (typeid(*left_type) == typeid(real_type_name_c) and typeid(*right_type) == typeid(uint_type_name_c)) {return (void *)left_type;}
       
   193     if (typeid(*left_type) == typeid(real_type_name_c) and typeid(*right_type) == typeid(udint_type_name_c)) {return (void *)left_type;}
       
   194     if (typeid(*left_type) == typeid(real_type_name_c) and typeid(*right_type) == typeid(ulint_type_name_c)) {return (void *)left_type;}
       
   195     if (typeid(*left_type) == typeid(lreal_type_name_c) and typeid(*right_type) == typeid(sint_type_name_c)) {return (void *)left_type;}
       
   196     if (typeid(*left_type) == typeid(lreal_type_name_c) and typeid(*right_type) == typeid(int_type_name_c)) {return (void *)left_type;}
       
   197     if (typeid(*left_type) == typeid(lreal_type_name_c) and typeid(*right_type) == typeid(dint_type_name_c)) {return (void *)left_type;}
       
   198     if (typeid(*left_type) == typeid(lreal_type_name_c) and typeid(*right_type) == typeid(lint_type_name_c)) {return (void *)left_type;}
       
   199     if (typeid(*left_type) == typeid(lreal_type_name_c) and typeid(*right_type) == typeid(usint_type_name_c)) {return (void *)left_type;}
       
   200     if (typeid(*left_type) == typeid(lreal_type_name_c) and typeid(*right_type) == typeid(uint_type_name_c)) {return (void *)left_type;}
       
   201     if (typeid(*left_type) == typeid(lreal_type_name_c) and typeid(*right_type) == typeid(udint_type_name_c)) {return (void *)left_type;}
       
   202     if (typeid(*left_type) == typeid(lreal_type_name_c) and typeid(*right_type) == typeid(ulint_type_name_c)) {return (void *)left_type;}
       
   203     ERROR;
       
   204     return NULL;
       
   205   }
       
   206   
       
   207   void *visit(neg_expression_c *symbol) {
       
   208     symbol_c *exp_type = base_type((symbol_c *)symbol->exp->accept(*this));
       
   209     if (typeid(*exp_type) == typeid(sint_type_name_c)) {return (void *)exp_type;}
       
   210     if (typeid(*exp_type) == typeid(int_type_name_c)) {return (void *)exp_type;}
       
   211     if (typeid(*exp_type) == typeid(dint_type_name_c)) {return (void *)exp_type;}
       
   212     if (typeid(*exp_type) == typeid(lint_type_name_c)) {return (void *)exp_type;}
       
   213     if (typeid(*exp_type) == typeid(usint_type_name_c)) {return (void *)exp_type;}
       
   214     if (typeid(*exp_type) == typeid(uint_type_name_c)) {return (void *)exp_type;}
       
   215     if (typeid(*exp_type) == typeid(udint_type_name_c)) {return (void *)exp_type;}
       
   216     if (typeid(*exp_type) == typeid(ulint_type_name_c)) {return (void *)exp_type;}
       
   217     if (typeid(*exp_type) == typeid(real_type_name_c)) {return (void *)exp_type;}
       
   218     if (typeid(*exp_type) == typeid(lreal_type_name_c)) {return (void *)exp_type;}
       
   219     if (typeid(*exp_type) == typeid(time_type_name_c)) {return (void *)exp_type;}
       
   220     ERROR;
       
   221     return NULL;
       
   222   }
       
   223   
       
   224   void *visit(not_expression_c *symbol) {
       
   225     symbol_c *exp_type = base_type((symbol_c *)symbol->exp->accept(*this));
       
   226     if (typeid(*exp_type) == typeid(bool_type_name_c)) {return (void *)exp_type;}
       
   227     ERROR;
       
   228     return NULL;
       
   229   }
       
   230   
       
   231   void *visit(function_invocation_c *symbol) {
       
   232 	  function_declaration_c *f_decl = function_symtable.find_value(symbol->function_name);
       
   233 	
       
   234 	  if (f_decl == function_symtable.end_value())
       
   235 	    /* should never occur. The function being called MUST be in the symtable... */
       
   236 	    ERROR;
       
   237 
       
   238     return base_type(f_decl->type_name);
       
   239   }
       
   240 
       
   241 };
       
   242 
       
   243 bool_type_name_c     search_expression_type_c::bool_type_name;
       
   244