1

/*

     2

 *  matiec - a compiler for the programming languages defined in IEC 61131-3

     3

 *

     4

 *  Copyright (C) 2003-2011  Mario de Sousa (msousa@fe.up.pt)

     5

 *  Copyright (C) 2007-2011  Laurent Bessard and Edouard Tisserant

     6

 *

     7

 *  This program is free software: you can redistribute it and/or modify

     8

 *  it under the terms of the GNU General Public License as published by

     9

 *  the Free Software Foundation, either version 3 of the License, or

    10

 *  (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, see <http://www.gnu.org/licenses/>.

    19

 *

    20

 *

    21

 * This code is made available on the understanding that it will not be

    22

 * used in safety-critical situations without a full and competent review.

    23

 */

    24

    25

/*

    26

 * An IEC 61131-3 compiler.

    27

 *

    28

 * Based on the

    29

 * FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10)

    30

 *

    31

 */

    32

    33

    34

    35

/* Determine the data type of a variable.

    36

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

    37

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

    38

 * an array element.

    39

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

    40

 * of a .... is also suported!

    41

 *

    42

 *  example:

    43

 *    window.points[1].coordinate.x

    44

 *    window.points[1].colour

    45

 *    etc... ARE ALLOWED!

    46

 *

    47

 * This class must be passed the scope within which the

    48

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

    49

 *

    50

 *

    51

 *

    52

 *

    53

 *

    54

 * This class has several members, depending on the exact data the caller

    55

 * is looking for...

    56

 *

    57

 *    - item i: we can get either the name of the data type(A),

    58

 *              or it's declaration (B)

    59

 *             (notice however that some variables belong to a data type that does

    60

 *              not have a name, only a declaration as in

    61

 *              VAR a: ARRAY [1..3] of INT; END_VAR

    62

 *             )

    63

 *    - item ii: we can get either the direct data type (1), 

    64

 *               or the base type (2)

    65

 * 

    66

 *   By direct type, I mean the data type of the variable. By base type, I 

    67

 * mean the data type on which the direct type is based on. For example, in 

    68

 * a subrange on INT, the direct type is the subrange itself, while the 

    69

 * base type is INT.

    70

 * e.g.

    71

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

    72

 *   which was previously declared to be

    73

 *   TYPE MY_INT: INT := 9;

    74

 *   option (1) will return MY_INT

    75

 *   option (2) will return INT

    76

 * 

    77

 *

    78

 * Member functions:

    79

 * ================

    80

 *   get_basetype_decl()  ---> returns 2B 

    81

 *   get_type_id()        ---> returns 1A

    82

 * 

    83

 *   Since we haven't yet needed them, we don't yet implement

    84

 *   get_basetype_id()    ----> would return 2A

    85

 *   get_type_decl()      ----> would return 1B

    86

 */ 

    87

    88

class search_varfb_instance_type_c: public search_base_type_c {

    89

    90

  private:

    91

    search_var_instance_decl_c search_var_instance_decl;

    92

    decompose_var_instance_name_c *decompose_var_instance_name;

    93

    symbol_c *current_structelement_name;

    95

    bool is_complex;

    96

    97

  public:

    98

    search_varfb_instance_type_c(symbol_c *search_scope);

    99

    symbol_c *get_basetype_decl(symbol_c *variable_name);

   100

    symbol_c *get_type_id(symbol_c *variable_name);

   101

   102

    unsigned int get_vartype(symbol_c *variable_name);

   103

    bool type_is_complex(void);

   104

   105

  private:

   106

    /* a helper function... */

   107

    void *visit_list(list_c *list);

   108

   109

    /* a helper function... */

   110

    void *base_type(symbol_c *symbol);

   111

   112

   113

  private:

   114

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

   115

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

   116

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

   117

     * of a function block type...

   118

     */

   119

    void *visit(identifier_c *type_name);

   120

   121

    /********************************/

   122

    /* B 1.3.3 - Derived data types */

   123

    /********************************/

   124

   125

    /*  identifier ':' array_spec_init */

   126

    void *visit(array_type_declaration_c *symbol);

   127

   128

    /* array_specification [ASSIGN array_initialization} */

   129

    /* array_initialization may be NULL ! */

   130

    void *visit(array_spec_init_c *symbol);

   131

   132

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

   133

    void *visit(array_specification_c *symbol);

   134

   135

    /*  structure_type_name ':' structure_specification */

   136

    void *visit(structure_type_declaration_c *symbol);

   137

   138

    /* structure_type_name ASSIGN structure_initialization */

   139

    /* structure_initialization may be NULL ! */

   140

    // SYM_REF2(initialized_structure_c, structure_type_name, structure_initialization)

   141

    void *visit(initialized_structure_c *symbol);

   142

   143

    /* helper symbol for structure_declaration */

   144

    /* structure_declaration:  STRUCT structure_element_declaration_list END_STRUCT */

   145

    /* structure_element_declaration_list structure_element_declaration ';' */

   146

    void *visit(structure_element_declaration_list_c *symbol);

   147

   148

    /*  structure_element_name ':' spec_init */

   149

    void *visit(structure_element_declaration_c *symbol);

   150

   151

    /* helper symbol for structure_initialization */

   152

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

   153

    /* structure_element_initialization_list ',' structure_element_initialization */

   154

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

   155

    /*  structure_element_name ASSIGN value */

   156

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

   157

   158

   159

   160

    /**************************************/

   161

    /* B.1.5 - Program organization units */

   162

    /**************************************/

   163

    /*****************************/

   164

    /* B 1.5.2 - Function Blocks */

   165

    /*****************************/

   166

    /*  FUNCTION_BLOCK derived_function_block_name io_OR_other_var_declarations function_block_body END_FUNCTION_BLOCK */

   167

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

   168

    void *visit(function_block_declaration_c *symbol);

   169

   170

}; // search_varfb_instance_type_c

   171

   172

   173

   174

   175

   176