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

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

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 *

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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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#include <vector>

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

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#include "datatype_functions.hh"

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

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

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 * This class wil do those checks.

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 * 

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

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 */

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class lvalue_check_c: public iterator_visitor_c {

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  private:

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    search_varfb_instance_type_c *search_varfb_instance_type;

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    search_var_instance_decl_c *search_var_instance_decl;

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    int error_count;

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    int current_display_error_level;

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    std::vector <token_c *> control_variables;

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    symbol_c *current_il_operand;

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    void verify_is_lvalue              (symbol_c *lvalue);

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    void check_assignment_to_controlvar(symbol_c *lvalue);

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    void check_assignment_to_output    (symbol_c *lvalue);

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    void check_assignment_to_constant  (symbol_c *lvalue);

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    void check_assignment_to_expression(symbol_c *lvalue);

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    void check_assignment_to_il_list   (symbol_c *lvalue);

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

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

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  public:

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    lvalue_check_c(symbol_c *ignore);

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    virtual ~lvalue_check_c(void);

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    int get_error_count();

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

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    /* B 1.5 - Program organisation units */

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

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

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    /* B 1.5.1 - Functions */

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

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    void *visit(function_declaration_c *symbol);

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

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    /* B 1.5.2 - Function blocks */

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

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    void *visit(function_block_declaration_c *symbol);

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

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    /* B 1.5.3 - Programs */

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

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    void *visit(program_declaration_c *symbol);

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

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

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

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

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    /* B 2.1 Instructions and Operands */

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

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    void *visit(il_instruction_c *symbol);

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    void *visit(il_simple_operation_c *symbol);

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    void *visit(il_function_call_c *symbol);

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    void *visit(il_fb_call_c *symbol);

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    void *visit(il_formal_funct_call_c *symbol);

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

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    /* B 2.2 Operators */

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

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    void *visit(ST_operator_c *symbol);

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    void *visit(STN_operator_c *symbol);

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    void *visit(S_operator_c *symbol);

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    void *visit(R_operator_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(function_invocation_c *symbol);

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

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    /* B 3.2.1 Assignment Statements */

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

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    void *visit(assignment_statement_c *symbol);

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

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    /* B 3.2.2 Subprogram Control Statements */

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

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    void *visit(fb_invocation_c *symbol);

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

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    /* B 3.2.4 Iteration Statements */

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

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    void *visit(for_statement_c *symbol);

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}; /* lvalue_check_c */

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