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/*

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

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 *

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

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

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 *

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

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

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

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 *  (at your option) any later version.

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 *

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

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

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 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

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 *  GNU General Public License for more details.

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 *

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

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

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 *

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 *

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

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

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 */

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/*

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 * An IEC 61131-3 compiler.

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 *

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 * Based on the

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

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 *

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 */

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/* Determine the data type of an ST expression.

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 * A reference to the relevant type definition is returned.

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 *

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 * For example:

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 *       2 + 3       -> returns reference to a int_type_name_c object.

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 *       22.2 - 5    -> returns reference to a real_type_name_c object.

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 *       etc...

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 */

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/* WARNING   WARNING  WARNING

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 *

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 * When taking into consideration calls to functions, this search_expression_type_c

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 * class will use internal atributes (i.e. anotation) in the function_invocation_c symbol 

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 * in the abstract syntax tree.

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 *

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 * Since this anotation/atribute is only set/populated with the correct value

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 * during stage3 (semantic verification), this class will only work correctly

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 * after the semantic verification in stage 3 has been executed

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 * (to be more exact, the data type checking of stage 3).

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 */

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class search_expression_type_c: public search_constant_type_c {

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  private:

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    search_varfb_instance_type_c *search_varfb_instance_type;

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    search_base_type_c search_base_type;

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  public:

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    search_expression_type_c(symbol_c *search_scope);

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    virtual ~search_expression_type_c(void);

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    /* A helper function... */

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    bool is_bool_type(symbol_c *type_symbol);

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    bool is_time_type(symbol_c *type_symbol);

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    bool is_string_type(symbol_c *type_symbol);

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    bool is_literal_integer_type(symbol_c *type_symbol);

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    bool is_integer_type(symbol_c *type_symbol);

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    bool is_literal_real_type(symbol_c *type_symbol);

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    bool is_real_type(symbol_c *type_symbol);

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    bool is_num_type(symbol_c *type_symbol);

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    bool is_nbinary_type(symbol_c *type_symbol);

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    bool is_binary_type(symbol_c *type_symbol);

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    bool is_same_type(symbol_c *first_type, symbol_c *second_type);

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    symbol_c* common_type(symbol_c *first_type, symbol_c *second_type);

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    symbol_c* default_literal_type(symbol_c *symbol);

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    /*

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    #include "search_type_code.c"

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    */

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    void *compute_standard_function_default(function_invocation_c *st_symbol, il_formal_funct_call_c *il_symbol);

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    void *compute_standard_function_il(il_function_call_c *symbol, symbol_c *param_data_type);

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    /*static bool_type_name_c bool_type_name;*/

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    /* A helper function... */

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    void *compute_boolean_expression(symbol_c *left_type, symbol_c *right_type);

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    /* A helper function... */

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    void *compute_numeric_expression(symbol_c *left_type, symbol_c *right_type);

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    /* a helper function... */

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    symbol_c *base_type(symbol_c *symbol);

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

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    /* B 1.4 - Variables */

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

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    void *visit(symbolic_variable_c *symbol);

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

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    /* B 1.4.1 - Directly Represented Variables */

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

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    void *visit(direct_variable_c *symbol);

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

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    /* B 1.4.2 - Multi-element variables */

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

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    void *visit(array_variable_c *symbol);

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    void *visit(structured_variable_c *symbol);

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

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

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

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

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    /* B 3.1 - Expressions */

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

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    void *visit(or_expression_c *symbol);

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    void *visit(xor_expression_c *symbol);

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    void *visit(and_expression_c *symbol);

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    void *visit(equ_expression_c *symbol);

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    void *visit(notequ_expression_c *symbol);

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    void *visit(lt_expression_c *symbol);

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    void *visit(gt_expression_c *symbol);

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    void *visit(le_expression_c *symbol);

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    void *visit(ge_expression_c *symbol);

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    void *visit(add_expression_c *symbol);

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    void *visit(sub_expression_c *symbol);

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    void *visit(mul_expression_c *symbol);

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    void *visit(div_expression_c *symbol);

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    void *visit(mod_expression_c *symbol);

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    void *visit(power_expression_c *symbol);

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    void *visit(neg_expression_c *symbol);

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    void *visit(not_expression_c *symbol);

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    void *visit(function_invocation_c *symbol);

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    static integer_c integer;

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}; // search_expression_type_c

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