1

/*

     2

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

     3

 *

     4

 *  Copyright (C) 2009-2012  Mario de Sousa (msousa@fe.up.pt)

     5

 *  Copyright (C) 2012       Manuele Conti  (conti.ma@alice.it)

     6

 *

     7

 *

     8

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

     9

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

    10

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

    11

 *  (at your option) any later version.

    12

 *

    13

 *  This program is distributed in the hope that it will be useful,

    14

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

    15

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    16

 *  GNU General Public License for more details.

    17

 *

    18

 *  You should have received a copy of the GNU General Public License

    19

 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.

    20

 *

    21

 *

    22

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

    23

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

    24

 */

    25

    26

/*

    27

 * An IEC 61131-3 compiler.

    28

 *

    29

 * Based on the

    30

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

    31

 *

    32

 */

    33

    34

#include <vector>

    35

#include "../absyntax_utils/absyntax_utils.hh"

    36

#include "datatype_functions.hh"

    37

    38

    39

/* Expressions on the left hand side of assignment statements have aditional restrictions on their datatype.

    40

 * For example, they cannot be literals, CONSTANT type variables, function invocations, etc...

    41

 * This class wil do those checks.

    42

 * 

    43

 * Note that assignment may also be done when passing variables to OUTPUT or IN_OUT function parameters,so we check those too.

    44

 */

    45

    46

    47

    48

class lvalue_check_c: public iterator_visitor_c {

    49

    50

  private:

    51

    search_varfb_instance_type_c *search_varfb_instance_type;

    52

    search_var_instance_decl_c *search_var_instance_decl;

    53

    int error_count;

    54

    int current_display_error_level;

    55

    std::vector <token_c *> control_variables;

    56

    symbol_c *current_il_operand;

    57

    58

    void verify_is_lvalue              (symbol_c *lvalue);

    59

    void check_assignment_to_controlvar(symbol_c *lvalue);

    60

    void check_assignment_to_output    (symbol_c *lvalue);

    61

    void check_assignment_to_constant  (symbol_c *lvalue);

    62

    void check_assignment_to_expression(symbol_c *lvalue);

    63

    void check_formal_call   (symbol_c *f_call, symbol_c *f_decl);

    64

    void check_nonformal_call(symbol_c *f_call, symbol_c *f_decl);

    65

    66

    67

  public:

    68

    lvalue_check_c(symbol_c *ignore);

    69

    virtual ~lvalue_check_c(void);

    70

    int get_error_count();

    71

    72

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

    73

    /* B 1.5 - Program organisation units */

    74

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

    75

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

    76

    /* B 1.5.1 - Functions */

    77

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

    78

    void *visit(function_declaration_c *symbol);

    79

    80

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

    81

    /* B 1.5.2 - Function blocks */

    82

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

    83

    void *visit(function_block_declaration_c *symbol);

    84

    85

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

    86

    /* B 1.5.3 - Programs */

    87

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

    88

    void *visit(program_declaration_c *symbol);

    89

    90

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

    91

    /* B.2 - Language IL (Instruction List) */

    92

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

    93

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

    94

    /* B 2.1 Instructions and Operands */

    95

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

    96

    void *visit(il_instruction_c *symbol);

    97

    void *visit(il_simple_operation_c *symbol);

    98

    void *visit(il_function_call_c *symbol);

    99

    void *visit(il_fb_call_c *symbol);

   100

    void *visit(il_formal_funct_call_c *symbol);

   101

   102

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

   103

    /* B 2.2 Operators */

   104

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

   105

    void *visit(ST_operator_c *symbol);

   106

    void *visit(STN_operator_c *symbol);

   107

    void *visit(S_operator_c *symbol);

   108

    void *visit(R_operator_c *symbol);

   109

   110

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

   111

    /* B.3 - Language ST (Structured Text) */

   112

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

   113

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

   114

    /* B 3.1 - Expressions */

   115

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

   116

    void *visit(function_invocation_c *symbol);

   117

   118

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

   119

    /* B 3.2.1 Assignment Statements */

   120

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

   121

    void *visit(assignment_statement_c *symbol);

   122

   123

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

   124

    /* B 3.2.2 Subprogram Control Statements */

   125

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

   126

    void *visit(fb_invocation_c *symbol);

   127

   128

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

   129

    /* B 3.2.4 Iteration Statements */

   130

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

   131

    void *visit(for_statement_c *symbol);

   132

   133

}; /* lvalue_check_c */

   134

   135

   136

   137

   138

   139

   140