393 

   394 

   395 /* | function_name [il_operand_list] */

   396 /* NOTE: The parameters 'called_function_declaration' and 'extensible_param_count' are used to pass data between the stage 3 and stage 4. */

   397 // SYM_REF2(il_function_call_c, function_name, il_operand_list, symbol_c *called_function_declaration; int extensible_param_count;)

   398 void *lvalue_check_c::visit(il_function_call_c *symbol) {

   399 	/* The first parameter of a non formal function call in IL will be the 'current value' (i.e. the prev_il_instruction)

   400 	 * In order to be able to handle this without coding special cases, we will simply prepend that symbol

   401 	 * to the il_operand_list, and remove it after calling handle_function_call().

   402 	 *

   403 	 * However, if no further paramters are given, then il_operand_list will be NULL, and we will

   404 	 * need to create a new object to hold the pointer to prev_il_instruction.

   405 	 * This change will also be undone at the end of this method.

   406 	 */

   407 	/* TODO: Copying the location data will result in confusing error message. 

   408 	 *       We need to make this better, by inserting code to handle this special situation explicitly!

   409 	 */

   410 	/* NOTE: When calling a function, using the 'current value' as the first parameter of the function invocation

   411 	 *       implies that we can only call functions whose first parameter is IN. It would not do to pass

   412 	 *       the 'current value' to an OUT or IN_OUT parameter.

   413 	 *       In order to make sure that this will be caught by the check_nonformal_call() function,

   414 	 *       we add a symbol that cannot be an lvalue; in this case, a real_c (REAL literal).

   415 	 */

   416 	real_c param_value(NULL);

   417 	*((symbol_c *)(&param_value)) = *((symbol_c *)symbol); /* copy the symbol location (file, line, offset) data */

   418 	if (NULL == symbol->il_operand_list)  symbol->il_operand_list = new il_operand_list_c;

   419 	if (NULL == symbol->il_operand_list)  ERROR;

   420 	((list_c *)symbol->il_operand_list)->insert_element(&param_value, 0);

   421 

   422 	check_nonformal_call(symbol, symbol->called_function_declaration);

   423 

   424 	/* Undo the changes to the abstract syntax tree we made above... */

   425 	((list_c *)symbol->il_operand_list)->remove_element(0);

   426 	if (((list_c *)symbol->il_operand_list)->n == 0) {

   427 		/* if the list becomes empty, then that means that it did not exist before we made these changes, so we delete it! */

   428 		delete 	symbol->il_operand_list;

   429 		symbol->il_operand_list = NULL;

   430 	}

   431 

   432 	return NULL;

   433 }

   434 

   435 

   436 

   437 

   438 

   439 

   440 /*   il_call_operator prev_declared_fb_name

   441  * | il_call_operator prev_declared_fb_name '(' ')'

   442  * | il_call_operator prev_declared_fb_name '(' eol_list ')'

   443  * | il_call_operator prev_declared_fb_name '(' il_operand_list ')'

   444  * | il_call_operator prev_declared_fb_name '(' eol_list il_param_list ')'

   445  */

   446 /* NOTE: The parameter 'called_fb_declaration'is used to pass data between stage 3 and stage4 (although currently it is not used in stage 4 */

   447 // SYM_REF4(il_fb_call_c, il_call_operator, fb_name, il_operand_list, il_param_list, symbol_c *called_fb_declaration)

   448 void *lvalue_check_c::visit(il_fb_call_c *symbol) {

   449 	if (NULL != symbol->il_operand_list)  check_nonformal_call(symbol, symbol->called_fb_declaration);

   450 	if (NULL != symbol->  il_param_list)     check_formal_call(symbol, symbol->called_fb_declaration);

   451 	return NULL;

   452 }

   453 

   454 

   455 /* | function_name '(' eol_list [il_param_list] ')' */

   456 /* NOTE: The parameter 'called_function_declaration' is used to pass data between the stage 3 and stage 4. */

   457 // SYM_REF2(il_formal_funct_call_c, function_name, il_param_list, symbol_c *called_function_declaration; int extensible_param_count;)

   458 void *lvalue_check_c::visit(il_formal_funct_call_c *symbol) {

   459 	check_formal_call(symbol, symbol->called_function_declaration);

   460 	return NULL;

   461 }

   462 

   463 

   464 

   465 

   466 

   467