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/*

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 * (c) 2003 Mario de Sousa

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 *

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 * 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

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 * License, or (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, but

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 * WITHOUT ANY WARRANTY; without even the implied warranty of

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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General

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 * Public License for more details.

    12

 *

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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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 */

    16

    17

/*

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 * An IEC 61131-3 IL and ST 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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 */

    24

    25

    26

/*

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 * Conversion of il statements (i.e. IL code).

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 *

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 * This is part of the 4th stage that generates

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 * a c++ source program equivalent to the IL and ST

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 * code.

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 */

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

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

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

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

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    42

/* Returns the data type of an il_operand.

    43

 *

    44

 * Note that the il_operand may be a variable, in which case

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 * we return the type of the variable instance.

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 * The il_operand may also be a constant, in which case

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 * we return the data type of that constant.

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 *

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 * The variable instance may be a member of a structured variable,

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 * or an element in an array, or any combination of the two.

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 *

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 * The class constructor must be given the search scope

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 * (function, function block or program within which

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 * the possible il_operand variable instance was declared).

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 */

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

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

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

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

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/* A new class to ouput the il default variable to c++ code

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 * We use this class, inheriting from symbol_c, so it may be used

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 * as any other symbol_c object in the intermediate parse tree,

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 * more specifically, so it can be used as any other il operand.

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 * This makes the rest of the code much easier...

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 *

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 * Nevertheless, the basic visitor class visitor_c does not know

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 * how to visit this new il_default_variable_c class, so we have

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 * to extend that too.

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 * In reality extending the basic symbols doesn't quite work out

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 * as cleanly as desired (we need to use dynamic_cast in the

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 * accept method of the il_default_variable_c), but it is cleaner

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 * than the alternative...

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 */

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class il_default_variable_c;

    78

    79

/* This visitor class is not really required, we could place the

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 * visit() method directly in genertae_cc_il_c, but doing it in

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 * a seperate class makes the architecture more evident...

    82

 */

    83

class il_default_variable_visitor_c {

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  public:

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    virtual void *visit(il_default_variable_c *symbol) = 0;

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    87

    virtual ~il_default_variable_visitor_c(void) {return;}

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};

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    90

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/* A class to print out to the resulting C++ code

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 * the IL default variable name.

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 *

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 * It includes a reference to its name,

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 * and the data type of the data currently stored

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 * in this C++ variable... This is required because the

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 * C++ variable is a union, and we must know which member

    98

 * of the union top reference!!

    99

 *

   100

 * Note that we also need to keep track of the data type of

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 * the value currently being stored in the default variable.

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 * This is required so we can process parenthesis,

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 *

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 * e.g. :

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 *         LD var1

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 *         AND (

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 *         LD var2

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 *         OR var3

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 *         )

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 *

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 * Note that we only execute the 'AND (' operation when we come across

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 * the ')', i.e. once we have evaluated the result of the

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 * instructions inside the parenthesis.

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 * When we do execute the 'AND (' operation, we need to know the data type

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 * of the operand, which in this case is the result of the evaluation of the

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 * instruction list inside the parenthesis. We can only know this if we

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 * keep track of the data type currently stored in the default variable!

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 *

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 * We use the current_type inside the generate_c_il::default_variable_name variable

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 * to track this!

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 */

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class il_default_variable_c: public symbol_c {

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  public:

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    symbol_c *var_name;  /* in principle, this should point to an indentifier_c */

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    symbol_c *current_type;

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   127

  public:

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    il_default_variable_c(const char *var_name_str, symbol_c *current_type);

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    virtual void *accept(visitor_c &visitor);

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};

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

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

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

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

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class generate_c_il_c: public generate_c_typedecl_c, il_default_variable_visitor_c {

   141

   142

  public:

   143

    typedef enum {

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      expression_vg,

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      assignment_vg,

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      complextype_base_vg,

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      complextype_suffix_vg,

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      fparam_output_vg

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    } variablegeneration_t;

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   151

  private:

   152

    /* When compiling il code, it becomes necessary to determine the

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     * data type of il operands. To do this, we must first find the

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     * il operand's declaration, within the scope of the function block

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     * or function currently being processed.

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     * The following object does just that...

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     * This object instance will then later be called while the

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     * remaining il code is being handled.

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     */

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    search_expression_type_c *search_expression_type;

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   162

    /* The initial value that should be given to the IL default variable

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     * imediately after a parenthesis is opened.

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     * This variable is only used to pass data from the

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     * il_expression_c visitor to the simple_instr_list_c visitor.

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     *

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     * e.g.:

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     *         LD var1

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     *         AND ( var2

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     *         OR var3

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     *         )

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     *

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     * In the above code sample, the line 'AND ( var2' constitutes

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     * an il_expression_c, where var2 should be loaded into the

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     * il default variable before continuing with the expression

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     * inside the parenthesis.

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     * Unfortunately, only the simple_instr_list_c may do the

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     * initial laoding of the var2 bariable following the parenthesis,

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     * so the il_expression_c visitor will have to pass 'var2' as a

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     * parameter to the simple_instr_list_c visitor.

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     * Ergo, the existance of the following parameter...!

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     */

   183

    symbol_c *il_default_variable_init_value;

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    /* Operand to the IL operation currently being processed... */

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    /* These variables are used to pass data from the

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     * il_simple_operation_c and il_expression_c visitors

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     * to the il operator visitors (i.e. LD_operator_c,

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     * LDN_operator_c, ST_operator_c, STN_operator_c, ...)

   190

     */

   191

    symbol_c *current_operand;

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    symbol_c *current_operand_type;

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   194

    /* Label to which the current IL jump operation should jump to... */

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    /* This variable is used to pass data from the

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     * il_jump_operation_c visitor

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     * to the il jump operator visitors (i.e. JMP_operator_c,

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     * JMPC_operator_c, JMPCN_operator_c, ...)

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     */

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    symbol_c *jump_label;

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    /* The result of the comparison IL operations (GT, EQ, LT, ...)

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     * is a boolean variable.

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     * This class keeps track of the current data type stored in the

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     * il default variable. This is usually done by keeping a reference

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     * to the data type of the last operand. Nevertheless, in the case of

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     * the comparison IL operators, the data type of the result (a boolean)

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     * is not the data type of the operand. We therefore need an object

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     * of the boolean data type to keep as a reference of the current

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     * data type.

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     * The following object is it...

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     */

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    bool_type_name_c bool_type;

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    lint_type_name_c lint_type;

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    lword_type_name_c lword_type;

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    lreal_type_name_c lreal_type;

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    /* the data type of the IL default variable... */

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    #define IL_DEFVAR_T VAR_LEADER "IL_DEFVAR_T"

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    /* The name of the IL default variable... */

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    #define IL_DEFVAR   VAR_LEADER "IL_DEFVAR"

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    /* The name of the variable used to pass the result of a

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     * parenthesised instruction list to the immediately preceding

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     * scope ...

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     */

   226

    #define IL_DEFVAR_BACK   VAR_LEADER "IL_DEFVAR_BACK"

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    il_default_variable_c default_variable_name;

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    il_default_variable_c default_variable_back_name;

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   230

    /* When calling a function block, we must first find it's type,

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     * by searching through the declarations of the variables currently

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     * in scope.

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     * This class does just that...

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     * A new class is instantiated whenever we begin generating the code

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     * for a function block type declaration, or a program declaration.

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     * This object instance will then later be called while the

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     * function block's or the program's body is being handled.

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     *

   239

     * Note that functions cannot contain calls to function blocks,

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     * so we do not create an object instance when handling

   241

     * a function declaration.

   242

     */

   243

    search_fb_instance_decl_c *search_fb_instance_decl;

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   245

    search_varfb_instance_type_c *search_varfb_instance_type;

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   247

    search_base_type_c search_base_type;

   248

   249

    symbol_c* current_array_type;

   250

    symbol_c* current_param_type;

   251

   252

    int fcall_number;

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    symbol_c *fbname;

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   255

    variablegeneration_t wanted_variablegeneration;

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   257

  public:

   258

    generate_c_il_c(stage4out_c *s4o_ptr, symbol_c *name, symbol_c *scope, const char *variable_prefix = NULL)

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    : generate_c_typedecl_c(s4o_ptr),

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      default_variable_name(IL_DEFVAR, NULL),

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      default_variable_back_name(IL_DEFVAR_BACK, NULL)

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    {

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      search_expression_type = new search_expression_type_c(scope);

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      search_fb_instance_decl = new search_fb_instance_decl_c(scope);

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      search_varfb_instance_type = new search_varfb_instance_type_c(scope);

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      current_operand = NULL;

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      current_operand_type = NULL;

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      il_default_variable_init_value = NULL;

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      current_array_type = NULL;

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      current_param_type = NULL;

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      fcall_number = 0;

   272

      fbname = name;

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      wanted_variablegeneration = expression_vg;

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      this->set_variable_prefix(variable_prefix);

   275

    }

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   277

    virtual ~generate_c_il_c(void) {

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      delete search_fb_instance_decl;

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      delete search_expression_type;

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      delete search_varfb_instance_type;

   281

    }

   282

   283

    void generate(instruction_list_c *il) {

   284

      il->accept(*this);

   285

    }

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   287

    /* Declare the backup to the default variable, that will store the result

   288

     * of the IL operations executed inside a parenthesis...

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     */

   290

    void declare_backup_variable(void) {

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      s4o.print(s4o.indent_spaces);

   292

      s4o.print(IL_DEFVAR_T);

   293

      s4o.print(" ");

   294

      print_backup_variable();

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      s4o.print(";\n");

   296

    }

   297

   298

    void print_backup_variable(void) {

   299

      this->default_variable_back_name.accept(*this);

   300

    }

   301

   302

  private:

   303

    /* A helper function... */

   304

    /*

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    bool is_bool_type(symbol_c *type_symbol) {

   306

      return (NULL != dynamic_cast<bool_type_name_c *>(type_symbol));

   307

    }

   308

    */

   309

   310

    /* A helper function... */

   311

    void *XXX_operator(symbol_c *lo, const char *op, symbol_c *ro) {

   312

      if ((NULL == lo) || (NULL == ro)) ERROR;

   313

      if (NULL == op) ERROR;

   314

   315

      lo->accept(*this);

   316

      s4o.print(op);

   317

      ro->accept(*this);

   318

      return NULL;

   319

    }

   320

   321

    /* A helper function... */

   322

    void *XXX_function(const char *func, symbol_c *lo, symbol_c *ro) {

   323

      if ((NULL == lo) || (NULL == ro)) ERROR;

   324

      if (NULL == func) ERROR;

   325

   326

      lo->accept(*this);

   327

      s4o.print(" = ");

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      s4o.print(func);

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      s4o.print("(");

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      lo->accept(*this);

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      s4o.print(", ");

   332

      ro->accept(*this);

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      s4o.print(")");

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      return NULL;

   335

    }

   336

   337

    /* A helper function... */

   338

    void *XXX_CAL_operator(const char *param_name, symbol_c *fb_name) {

   339

      if (NULL == fb_name) ERROR;

   340

      symbolic_variable_c *sv = dynamic_cast<symbolic_variable_c *>(fb_name);

   341

      if (NULL == sv) ERROR;

   342

      identifier_c *id = dynamic_cast<identifier_c *>(sv->var_name);

   343

      if (NULL == id) ERROR;

   344

   345

      identifier_c param(param_name);

   346

   347

      //SYM_REF3(il_param_assignment_c, il_assign_operator, il_operand, simple_instr_list)

   348

      il_assign_operator_c il_assign_operator(&param);

   349

      il_param_assignment_c il_param_assignment(&il_assign_operator, &this->default_variable_name, NULL);

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      // SYM_LIST(il_param_list_c)

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      il_param_list_c il_param_list;   

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      il_param_list.add_element(&il_param_assignment);

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      CAL_operator_c CAL_operator;

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      // SYM_REF4(il_fb_call_c, il_call_operator, fb_name, il_operand_list, il_param_list)

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      il_fb_call_c il_fb_call(&CAL_operator, id, NULL, &il_param_list);

   356

   357

      il_fb_call.accept(*this);

   358

      return NULL;

   359

    }

   360

   361

    /* A helper function... */

   362

    void *CMP_operator(symbol_c *o, const char *operation) {

   363

      if (NULL == o) ERROR;

   364

      if (NULL == this->default_variable_name.current_type) ERROR;

   365

   366

      symbol_c *backup = this->default_variable_name.current_type;

   367

      this->default_variable_name.current_type = &(this->bool_type);

   368

      this->default_variable_name.accept(*this);

   369

      this->default_variable_name.current_type = backup;

   370

   371

      s4o.print(" = ");

   372

      s4o.print(operation);

   373

      this->default_variable_name.current_type->accept(*this);

   374

      s4o.print("(__BOOL_LITERAL(TRUE), NULL, 2, ");

   375

      this->default_variable_name.accept(*this);

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      s4o.print(", ");

   377

      o->accept(*this);

   378

      s4o.print(")");

   379

   380

      /* the data type resulting from this operation... */

   381

      this->default_variable_name.current_type = &(this->bool_type);

   382

      return NULL;

   383

    }

   384

   385

   386

    /* A helper function... */

   387

    void C_modifier(void) {

   388

      if (search_expression_type->is_bool_type(default_variable_name.current_type)) {

   389

        s4o.print("if (");

   390

        this->default_variable_name.accept(*this);

   391

        s4o.print(") ");

   392

      }

   393

      else {ERROR;}

   394

    }

   395

   396

    /* A helper function... */

   397

    void CN_modifier(void) {

   398

      if (search_expression_type->is_bool_type(default_variable_name.current_type)) {

   399

        s4o.print("if (!");

   400

        this->default_variable_name.accept(*this);

   401

        s4o.print(") ");

   402

      }

   403

      else {ERROR;}

   404

    }

   405

   406

    void BYTE_operator_result_type(void) {

   407

      if (search_expression_type->is_literal_integer_type(this->default_variable_name.current_type)) {

   408

        if (search_expression_type->is_literal_integer_type(this->current_operand_type))

   409

          this->default_variable_name.current_type = &(this->lword_type);

   410

        else

   411

          this->default_variable_name.current_type = this->current_operand_type;

   412

      }

   413

      else if (search_expression_type->is_literal_integer_type(this->current_operand_type))

   414

    	  this->current_operand_type = this->default_variable_name.current_type;

   415

    }

   416

   417

    void NUM_operator_result_type(void) {

   418

      if (search_expression_type->is_literal_real_type(this->default_variable_name.current_type)) {

   419

        if (search_expression_type->is_literal_integer_type(this->current_operand_type) ||

   420

            search_expression_type->is_literal_real_type(this->current_operand_type))

   421

          this->default_variable_name.current_type = &(this->lreal_type);

   422

        else

   423

          this->default_variable_name.current_type = this->current_operand_type;

   424

      }

   425

      else if (search_expression_type->is_literal_integer_type(this->default_variable_name.current_type)) {

   426

        if (search_expression_type->is_literal_integer_type(this->current_operand_type))

   427

          this->default_variable_name.current_type = &(this->lint_type);

   428

        else if (search_expression_type->is_literal_real_type(this->current_operand_type))

   429

          this->default_variable_name.current_type = &(this->lreal_type);

   430

        else

   431

          this->default_variable_name.current_type = this->current_operand_type;

   432

      }

   433

      else if (search_expression_type->is_literal_integer_type(this->current_operand_type) ||

   434

               search_expression_type->is_literal_real_type(this->current_operand_type))

   435

        this->current_operand_type = this->default_variable_name.current_type;

   436

    }

   437

   438

    void *print_getter(symbol_c *symbol) {

   439

      unsigned int vartype = search_varfb_instance_type->get_vartype(symbol);

   440

      if (wanted_variablegeneration == fparam_output_vg) {

   441

      	if (vartype == search_var_instance_decl_c::external_vt)

   442

          s4o.print(GET_EXTERNAL_BY_REF);

   443

        else if (vartype == search_var_instance_decl_c::located_vt)

   444

          s4o.print(GET_LOCATED_BY_REF);

   445

        else

   446

          s4o.print(GET_VAR_BY_REF);

   447

      }

   448

      else {

   449

    	if (vartype == search_var_instance_decl_c::external_vt)

   450

    	  s4o.print(GET_EXTERNAL);

   451

    	else if (vartype == search_var_instance_decl_c::located_vt)

   452

    	  s4o.print(GET_LOCATED);

   453

    	else

   454

    	  s4o.print(GET_VAR);

   455

      }

   456

      s4o.print("(");

   457

   458

      variablegeneration_t old_wanted_variablegeneration = wanted_variablegeneration;

   459

      wanted_variablegeneration = complextype_base_vg;

   460

      symbol->accept(*this);

   461

      if (search_varfb_instance_type->type_is_complex())

   462

        s4o.print(",");

   463

      wanted_variablegeneration = complextype_suffix_vg;

   464

      symbol->accept(*this);

   465

      s4o.print(")");

   466

      wanted_variablegeneration = old_wanted_variablegeneration;

   467

      return NULL;

   468

    }

   469

   470

    void *print_setter(symbol_c* symbol,

   471

    		symbol_c* type,

   472

    		symbol_c* value,

   473

    		symbol_c* fb_symbol = NULL,

   474

    		symbol_c* fb_value = NULL,

   475

    		bool negative = false) {

   476

      unsigned int vartype = search_varfb_instance_type->get_vartype(symbol);

   477

      if (vartype == search_var_instance_decl_c::external_vt) {

   478

        symbolic_variable_c *variable = dynamic_cast<symbolic_variable_c *>(symbol);

   479

        /* TODO Find a solution for forcing global complex variables */

   480

        if (variable != NULL) {

   481

          s4o.print(SET_EXTERNAL);

   482

          s4o.print("(");

   483

          variable->var_name->accept(*this);

   484

          s4o.print(",");

   485

        }

   486

        else {

   487

          s4o.print(SET_COMPLEX_EXTERNAL);

   488

          s4o.print("(");

   489

        }

   490

      }

   491

      else {

   492

        if (vartype == search_var_instance_decl_c::located_vt)

   493

          s4o.print(SET_LOCATED);

   494

        else

   495

          s4o.print(SET_VAR);

   496

        s4o.print("(");

   497

      }

   498

   499

      if (fb_symbol != NULL) {

   500

        print_variable_prefix();

   501

        fb_symbol->accept(*this);

   502

        s4o.print(".");

   503

      }

   504

      else

   505

        wanted_variablegeneration = complextype_base_vg;

   506

      symbol->accept(*this);

   507

      s4o.print(",");

   508

      if (negative) {

   509

	    if (search_expression_type->is_bool_type(this->current_operand_type))

   510

		  s4o.print("!");

   511

	    else

   512

		  s4o.print("~");

   513

      }

   514

      wanted_variablegeneration = expression_vg;

   515

      print_check_function(type, value, fb_value);

   516

      if (search_varfb_instance_type->type_is_complex()) {

   517

        s4o.print(",");