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 

    27 /* Determine the data type of a variable.

    28  * The variable may be a simple variable, a function block instance, a

    29  * struture element within a data structured type (a struct or a fb), or

    30  * an array element.

    31  * A mixture of array element of a structure element of a structure element

    32  * of a .... is also suported!

    33  *

    34  * A reference to the relevant base type __definition__ is returned.

    35  * This means that if we find that the variable is of type MY_INT,

    36  * which was previously declared to be

    37  * TYPE MY_INT: INT := 9;

    38  * this class wil return INT, and __not__ MY_INT !!

    39  *

    40  *

    41  *  example:

    42  *    window.points[1].coordinate.x

    43  *    window.points[1].colour

    44  *    etc... ARE ALLOWED!

    45  *

    46  * This class must be passed the scope within which the

    47  * variable was declared, and the variable name...

    48  */

    49 

    50 class search_varfb_instance_type_c: public search_base_type_c {

    51 

    52   private:

    53     search_var_instance_decl_c search_var_instance_decl;

    54     decompose_var_instance_name_c *decompose_var_instance_name;

    55     symbol_c *current_structelement_name;

    56     bool search_base_type;

    57 

    58   public:

    59     search_varfb_instance_type_c(symbol_c *search_scope);

    60     symbol_c *get_type(symbol_c *variable_name, bool base_type = true);

    61 

    62     unsigned int get_vartype(symbol_c *variable_name);

    63 

    64   private:

    65     /* a helper function... */

    66     void *visit_list(list_c *list);

    67 

    68     /* a helper function... */

    69     void *base_type(symbol_c *symbol);

    70 

    71 

    72   private:

    73     /* We override the base class' visitor to identifier_c.

    74      * This is so because the base class does not consider a function block

    75      * to be a type, unlike this class that allows a variable instance

    76      * of a function block type...

    77      */

    78     void *visit(identifier_c *type_name);

    79 

    80     /********************************/

    81     /* B 1.3.3 - Derived data types */

    82     /********************************/

    83     

    84     /*  identifier ':' array_spec_init */

    85     void *visit(array_type_declaration_c *symbol);

    86     

    87     /* array_specification [ASSIGN array_initialization} */

    88     /* array_initialization may be NULL ! */

    89     void *visit(array_spec_init_c *symbol);

    90     

    91     /* ARRAY '[' array_subrange_list ']' OF non_generic_type_name */

    92     void *visit(array_specification_c *symbol);

    93 

    94     /*  structure_type_name ':' structure_specification */

    95     void *visit(structure_type_declaration_c *symbol);

    96 

    97     /* structure_type_name ASSIGN structure_initialization */

    98     /* structure_initialization may be NULL ! */

    99     // SYM_REF2(initialized_structure_c, structure_type_name, structure_initialization)

   100     void *visit(initialized_structure_c *symbol);

   101 

   102     /* helper symbol for structure_declaration */

   103     /* structure_declaration:  STRUCT structure_element_declaration_list END_STRUCT */

   104     /* structure_element_declaration_list structure_element_declaration ';' */

   105     void *visit(structure_element_declaration_list_c *symbol);

   106 

   107     /*  structure_element_name ':' spec_init */

   108     void *visit(structure_element_declaration_c *symbol);

   109 

   110     /* helper symbol for structure_initialization */

   111     /* structure_initialization: '(' structure_element_initialization_list ')' */

   112     /* structure_element_initialization_list ',' structure_element_initialization */

   113     void *visit(structure_element_initialization_list_c *symbol); /* should never get called... */

   114     /*  structure_element_name ASSIGN value */

   115     void *visit(structure_element_initialization_c *symbol); /* should never get called... */

   116 

   117 

   118 

   119     /**************************************/

   120     /* B.1.5 - Program organization units */

   121     /**************************************/

   122     /*****************************/

   123     /* B 1.5.2 - Function Blocks */

   124     /*****************************/

   125     /*  FUNCTION_BLOCK derived_function_block_name io_OR_other_var_declarations function_block_body END_FUNCTION_BLOCK */

   126     // SYM_REF4(function_block_declaration_c, fblock_name, var_declarations, fblock_body, unused)

   127     void *visit(function_block_declaration_c *symbol);

   128 

   129 }; // search_varfb_instance_type_c

   130 

   131 

   132 

   133 

   134 

   135