65 

    66 /****************************************************************************************************/

    67 /****************************************************************************************************/

    69 /****************************************************************************************************/

    70 /****************************************************************************************************/

   285 /*********************************************************/

   286 /*********************************************************/

   287 /* get the datatype of a field inside a struct data type */

   288 /*********************************************************/

   289 /*********************************************************/

   290 

   291 class get_struct_info_c : null_visitor_c {

   292   private:

   293     symbol_c *current_field;

   294     /* singleton class! */

   295     static get_struct_info_c *singleton;

   296 

   297   public:

   298     get_struct_info_c(void) {current_field = NULL;}

   299 

   300     static symbol_c *get_field_type_id(symbol_c *struct_type, symbol_c *field_name) {

   301       if (NULL == singleton)    singleton = new get_struct_info_c;

   302       if (NULL == singleton)    ERROR;

   303       singleton->current_field = field_name;

   304       return (symbol_c *)struct_type->accept(*singleton);

   305     }

   306 

   307 

   308   private:

   309     /*************************/

   310     /* B.1 - Common elements */

   311     /*************************/

   312     /********************************/

   313     /* B 1.3.3 - Derived data types */

   314     /********************************/

   315     /*  structure_type_name ':' structure_specification */

   316     /* NOTE: this is only used inside a TYPE ... END_TYPE declaration.  It is never used directly when declaring a new variable! */

   317     /* NOTE: structure_specification will point to either initialized_structure_c  OR  structure_element_declaration_list_c */

   318     void *visit(structure_type_declaration_c *symbol) {return symbol->structure_specification->accept(*this);}

   319 

   320     /* structure_type_name ASSIGN structure_initialization */

   321     /* structure_initialization may be NULL ! */

   322     // SYM_REF2(initialized_structure_c, structure_type_name, structure_initialization)

   323     /* NOTE: only the initialized structure is never used when declaring a new variable instance */

   324     void *visit(initialized_structure_c *symbol) {return symbol->structure_type_name->accept(*this);}

   325 

   326     /* helper symbol for structure_declaration */

   327     /* structure_declaration:  STRUCT structure_element_declaration_list END_STRUCT */

   328     /* structure_element_declaration_list structure_element_declaration ';' */

   329     void *visit(structure_element_declaration_list_c *symbol) {

   330       /* now search the structure declaration */

   331       for(int i = 0; i < symbol->n; i++) {

   332         void *tmp = symbol->elements[i]->accept(*this);

   333         if (NULL != tmp) return tmp;

   334       }

   335       return NULL; // not found!!

   336     }  

   337 

   338     /*  structure_element_name ':' spec_init */

   339     void *visit(structure_element_declaration_c *symbol) {

   340       if (compare_identifiers(symbol->structure_element_name, current_field) == 0)

   341         return symbol->spec_init; /* found the type of the element we were looking for! */

   342       return NULL;   /* not the element we are looking for! */

   343     }

   344       

   345 

   346     /* helper symbol for structure_initialization */

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

   348     /* structure_element_initialization_list ',' structure_element_initialization */

   349     void *visit(structure_element_initialization_list_c *symbol) {ERROR; return NULL;} /* should never get called... */

   350     /*  structure_element_name ASSIGN value */

   351     void *visit(structure_element_initialization_c *symbol) {ERROR; return NULL;} /* should never get called... */

   352 

   353 

   354     /**************************************/

   355     /* B.1.5 - Program organization units */

   356     /**************************************/

   357     /*****************************/

   358     /* B 1.5.2 - Function Blocks */

   359     /*****************************/

   360     /*  FUNCTION_BLOCK derived_function_block_name io_OR_other_var_declarations function_block_body END_FUNCTION_BLOCK */

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

   362     void *visit(function_block_declaration_c *symbol) {

   363       /* now search the function block declaration for the variable... */

   364       search_var_instance_decl_c search_decl(symbol);

   365       return search_decl.get_decl(current_field);

   366     }

   367       

   368     /*********************************************/

   369     /* B.1.6  Sequential function chart elements */

   370     /*********************************************/

   371     /* INITIAL_STEP step_name ':' action_association_list END_STEP */

   372     // SYM_REF2(initial_step_c, step_name, action_association_list)

   373     void *visit(initial_step_c *symbol) {

   374       identifier_c T("T");  identifier_c X("X");

   375       /* Hard code the datatypes of the implicit variables Stepname.X and Stepname.T */

   376       if (compare_identifiers(&T, current_field) == 0)  return &get_datatype_info_c::time_type_name;

   377       if (compare_identifiers(&X, current_field) == 0)  return &get_datatype_info_c::bool_type_name;

   378       return NULL;

   379     }

   380       

   381     /* STEP step_name ':' action_association_list END_STEP */

   382     // SYM_REF2(step_c, step_name, action_association_list)

   383     /* The code here should be identicial to the code in the visit(initial_step_c *) visitor! So we simply call the other visitor! */

   384     void *visit(step_c *symbol) {initial_step_c initial_step(NULL, NULL); return initial_step.accept(*this);}

   385       

   386 }; // get_struct_info_c

   387 

   388 get_struct_info_c *get_struct_info_c::singleton = NULL;

   389 

   390 

   391 

   392 

   393 

   415 

   416 symbol_c *get_datatype_info_c::get_struct_field_type_id(symbol_c *struct_datatype, symbol_c *struct_fieldname) {

   417   return get_struct_info_c::get_field_type_id(struct_datatype, struct_fieldname);

   418 }