1 /*

     2  * (c) 2003 Mario de Sousa

     3  *

     4  * 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

     6  * License, or (at your option) any later version.

     7  *

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

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

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

    11  * Public License for more details.

    12  *

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

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

    15  */

    16 

    17 /*

    18  * An IEC 61131-3 IL and ST compiler.

    19  *

    20  * Based on the

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

    22  *

    23  */

    24 

    25 

    26 /*

    27  * Function call parameter iterator.

    28  * It will iterate through the formal parameters of a function call

    29  * (i.e. function calls using the foo(<param1>, <param2>, ...) syntax).

    30  * and/or search through the non-formal parameters of a function call

    31  * (i.e. function calls using the foo(<name1> = <param1>, <name2> = <param2>, ...) syntax).

    32  *

    33  * Calls to function blocks and programs are also supported.

    34  *

    35  * This is part of the 4th stage that generates

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

    37  * code.

    38  */

    39 

    40 

    41 

    42 

    43 

    44 

    45 //#include <stdio.h>  /* required for NULL */

    46 //#include <string>

    47 //#include <iostream>

    48 

    49 //#include "../../util/symtable.hh"

    50 

    51 //#include "generate_c.hh"

    52 

    53 

    54 #include "../../absyntax/visitor.hh"

    55 

    56 

    57 /*

    58  * Function call parameter iterator.

    59  * It will iterate through the formal parameters of a function call

    60  * (i.e. function calls using the foo(<param1>, <param2>, ...) syntax).

    61  * and/or search through the non-formal parameters of a function call

    62  * (i.e. function calls using the foo(<name1> = <param1>, <name2> = <param2>, ...) syntax).

    63  *

    64  * Calls to function blocks and programs are also supported.

    65  *

    66  * Note that calls to next() will only iterate through formal parameters,

    67  * and calls to search()  will only serach through non-formal parameters.

    68  */

    69 

    70 class function_call_param_iterator_c : public null_visitor_c {

    71   private:

    72       /* a pointer to the function call

    73        * (or function block or program call!)

    74        */

    75     symbol_c *f_call;

    76     int next_param, param_count;

    77     identifier_c *search_param_name;

    78 

    79     /* Which operation of the class was called...

    80      * Search a parameter, or iterate to the next parameter.

    81      */

    82     typedef enum {iterate_op, search_op} operation_t;

    83     operation_t current_operation;

    84 

    85   private:

    86     void *search_list(list_c *list) {

    87       switch (current_operation) {

    88         case iterate_op:

    89           for(int i = 0; i < list->n; i++) {

    90             void *res = list->elements[i]->accept(*this);

    91             if (NULL != res) {

    92               /* It went through the handle_parameter_assignment() function,

    93                * and is therefore a parameter assignment (<param> = <value>),

    94                * and not a simple expression (<value>).

    95                */

    96               /* we do nothing... */

    97             } else {

    98               param_count++;

    99               if (param_count == next_param) {

   100                 return list->elements[i];

   101               }

   102             }

   103           }

   104           return NULL;

   105           break;

   106 

   107         case search_op:

   108           for(int i = 0; i < list->n; i++) {

   109             void *res = list->elements[i]->accept(*this);

   110             if (res != NULL)

   111               return res;

   112           }

   113           return NULL;

   114           break;

   115       } /* switch */

   116       return NULL;

   117     }

   118 

   119 

   120 

   121     void *handle_parameter_assignment(symbol_c *variable_name, symbol_c *expression) {

   122       switch (current_operation) {

   123         case iterate_op:

   124 	        /* UGLY HACK -> this will be detected in the search_list() function */

   125           return (void *)this; /* anything, as long as it is not NULL!! */

   126           break;

   127 

   128         case search_op:

   129           identifier_c *variable_name2 = dynamic_cast<identifier_c *>(variable_name);

   130           if (variable_name2 == NULL) ERROR;

   131           if (strcasecmp(search_param_name->value, variable_name2->value) == 0)

   132             /* FOUND! This is the same parameter!! */

   133             return (void *)expression;

   134           return NULL;

   135           break;

   136       }

   137 

   138       ERROR;

   139       return NULL;

   140     }

   141 

   142 

   143 

   144   public:

   145     /* start off at the first parameter once again... */

   146     void reset(void) {

   147       next_param = param_count = 0;

   148     }

   149 

   150     /* initialise the iterator object.

   151      * We must be given a reference to the function/program/function block call

   152      * that will be analysed...

   153      */

   154     function_call_param_iterator_c(symbol_c *f_call) {

   155       /* It is expected that f_call will reference one of the following:

   156        *  program_configuration_c

   157        *  function_invocation_c

   158        *  fb_invocation_c

   159        *  il_function_call_c

   160        *  il_formal_funct_call_c

   161        *  ... (have I missed any?)

   162        */

   163       this->f_call = f_call;

   164       search_param_name = NULL;

   165       reset();

   166     }

   167 

   168     /* Skip to the next parameter. After object creation,

   169      * the object references on parameter _before_ the first, so

   170      * this function must be called once to get the object to

   171      * reference the first parameter...

   172      *

   173      * Returns whatever is being passed to the parameter!

   174      */

   175     symbol_c *next(void) {

   176       param_count = 0;

   177       next_param++;

   178       current_operation = function_call_param_iterator_c::iterate_op;

   179       void *res = f_call->accept(*this);

   180       return (symbol_c *)res;

   181     }

   182 

   183     /* Search for the value passed to the parameter named <param_name>...  */

   184     symbol_c *search(symbol_c *param_name) {

   185       if (NULL == param_name) ERROR;

   186       search_param_name = dynamic_cast<identifier_c *>(param_name);

   187       if (NULL == search_param_name) ERROR;

   188       current_operation = function_call_param_iterator_c::search_op;

   189       void *res = f_call->accept(*this);

   190       return (symbol_c *)res;

   191     }

   192 

   193 

   194 

   195 

   196   private:

   197 /********************************/

   198 /* B 1.7 Configuration elements */

   199 /********************************/

   200 

   201 /*

   202 CONFIGURATION configuration_name

   203    optional_global_var_declarations

   204    (resource_declaration_list | single_resource_declaration)

   205    optional_access_declarations

   206    optional_instance_specific_initializations

   207 END_CONFIGURATION

   208 */

   209 /*

   210 SYM_REF6(configuration_declaration_c, configuration_name, global_var_declarations, resource_declarations, access_declarations, instance_specific_initializations, unused)

   211 */

   212 

   213 /* helper symbol for configuration_declaration */

   214 /*

   215 SYM_LIST(resource_declaration_list_c)

   216 */

   217 

   218 /*

   219 RESOURCE resource_name ON resource_type_name

   220    optional_global_var_declarations

   221    single_resource_declaration

   222 END_RESOURCE

   223 */

   224 /*

   225 SYM_REF4(resource_declaration_c, resource_name, resource_type_name, global_var_declarations, resource_declaration)

   226 */

   227 

   228 /* task_configuration_list program_configuration_list */

   229 /*

   230 SYM_REF2(single_resource_declaration_c, task_configuration_list, program_configuration_list)

   231 */

   232 

   233 /* helper symbol for single_resource_declaration */

   234 /*

   235 SYM_LIST(task_configuration_list_c)

   236 */

   237 

   238 /* helper symbol for single_resource_declaration */

   239 /*

   240 SYM_LIST(program_configuration_list_c)

   241 */

   242 

   243 /* helper symbol for

   244  *  - access_path

   245  *  - instance_specific_init

   246  */

   247 /*

   248 SYM_LIST(any_fb_name_list_c)

   249 */

   250 

   251 /*  [resource_name '.'] global_var_name ['.' structure_element_name] */

   252 /*

   253 SYM_REF4(global_var_reference_c, resource_name, global_var_name, structure_element_name, unused)

   254 */

   255 

   256 /*  prev_declared_program_name '.' symbolic_variable */

   257 /*

   258 SYM_REF2(program_output_reference_c, program_name, symbolic_variable)

   259 */

   260 

   261 /*  TASK task_name task_initialization */

   262 /*

   263 SYM_REF2(task_configuration_c, task_name, task_initialization)

   264 */

   265 

   266 /*  '(' [SINGLE ASSIGN data_source ','] [INTERVAL ASSIGN data_source ','] PRIORITY ASSIGN integer ')' */

   267 /*

   268 SYM_REF4(task_initialization_c, single_data_source, interval_data_source, priority_data_source, unused)

   269 */

   270 

   271 /*  PROGRAM [RETAIN | NON_RETAIN] program_name [WITH task_name] ':' program_type_name ['(' prog_conf_elements ')'] */

   272 // SYM_REF6(program_configuration_c, retain_option, program_name, task_name, program_type_name, prog_conf_elements, unused)

   273     void *visit(program_configuration_c *symbol) {

   274       TRACE("program_configuration_c");

   275       return symbol->prog_conf_elements->accept(*this);

   276     }

   277 

   278 /* prog_conf_elements ',' prog_conf_element */

   279 // SYM_LIST(prog_conf_elements_c)

   280     void *visit(prog_conf_elements_c *symbol) {

   281       TRACE("prog_conf_elements_c");

   282       return search_list(symbol);

   283     }

   284 

   285 /*  fb_name WITH task_name */

   286 /*

   287 SYM_REF2(fb_task_c, fb_name, task_name)

   288 */

   289 

   290 /*  any_symbolic_variable ASSIGN prog_data_source */

   291 // SYM_REF2(prog_cnxn_assign_c, symbolic_variable, prog_data_source)

   292     void *visit(prog_cnxn_assign_c *symbol) {

   293       TRACE("prog_cnxn_assign_c");

   294 

   295       /* NOTE: symbolic_variable may be something other than a symbolic_variable_c, but I (Mario)

   296        *       do not understand the semantics that should be implmeneted if it is not a

   297        *        symbolic_variable, so for the moment we simply give up!

   298        */

   299       symbolic_variable_c *symb_var = dynamic_cast<symbolic_variable_c *>(symbol->symbolic_variable);

   300       if (NULL == symb_var)

   301         ERROR;

   302 

   303       return handle_parameter_assignment(symb_var->var_name, symbol->prog_data_source);

   304     }

   305 

   306 /* any_symbolic_variable SENDTO data_sink */

   307 // SYM_REF2(prog_cnxn_sendto_c, symbolic_variable, prog_data_source)

   308     void *visit(prog_cnxn_sendto_c *symbol) {

   309       TRACE("prog_cnxn_sendto_c");

   310 

   311       /* NOTE: symbolic_variable may be something other than a symbolic_variable_c, but I (Mario)

   312        *       do not understand the semantics that should be implmeneted if it is not a

   313        *        symbolic_variable, so for the moment we simply give up!

   314        */

   315       symbolic_variable_c *symb_var = dynamic_cast<symbolic_variable_c *>(symbol->symbolic_variable);

   316       if (NULL == symb_var)

   317         ERROR;

   318 

   319       return handle_parameter_assignment(symb_var->var_name, symbol->data_sink);

   320     }

   321 

   322 /* VAR_CONFIG instance_specific_init_list END_VAR */

   323 /*

   324 SYM_REF2(instance_specific_initializations_c, instance_specific_init_list, unused)

   325 */

   326 

   327 /* helper symbol for instance_specific_initializations */

   328 /*

   329 SYM_LIST(instance_specific_init_list_c)

   330 */

   331 

   332 /* resource_name '.' program_name '.' {fb_name '.'}

   333     ((variable_name [location] ':' located_var_spec_init) | (fb_name ':' fb_initialization))

   334 */

   335 /*

   336 SYM_REF6(instance_specific_init_c, resource_name, program_name, any_fb_name_list, variable_name, location, initialization)

   337 */

   338 

   339 /* helper symbol for instance_specific_init */

   340 /* function_block_type_name ':=' structure_initialization */

   341 /*

   342 SYM_REF2(fb_initialization_c, function_block_type_name, structure_initialization)

   343 */

   344 

   345 

   346 

   347 

   348 

   349 

   350 /****************************************/

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

   352 /****************************************/

   353 /***********************************/

   354 /* B 2.1 Instructions and Operands */

   355 /***********************************/

   356 

   357 /* | function_name [il_operand_list] */

   358 // SYM_REF2(il_function_call_c, function_name, il_operand_list)

   359     void *visit(il_function_call_c *symbol) {

   360       TRACE("il_function_call_c");

   361       if (NULL != symbol->il_operand_list)

   362         return symbol->il_operand_list->accept(*this);

   363       return NULL;

   364     }

   365 

   366 

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

   368 // SYM_REF2(il_formal_funct_call_c, function_name, il_param_list)

   369     void *visit(il_formal_funct_call_c *symbol) {

   370       TRACE("il_formal_funct_call_c");

   371       if (NULL != symbol->il_param_list)

   372         return symbol->il_param_list->accept(*this);

   373       return NULL;

   374     }

   375 

   376 

   377 /*   il_call_operator prev_declared_fb_name

   378  * | il_call_operator prev_declared_fb_name '(' ')'

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

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

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

   382  */

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

   384     void *visit(il_fb_call_c *symbol) {

   385       TRACE("il_fb_call_c");

   386       /* the following should never occur. In reality the syntax parser

   387        * will guarantee that they never occur, but it makes it easier to

   388        * understand the remaining code :-)

   389        */

   390       //if ((NULL == symbol->il_operand_list) && (NULL == symbol->il_param_list)) ERROR;

   391       //if ((NULL != symbol->il_operand_list) && (NULL != symbol->il_param_list)) ERROR;

   392 

   393       if (NULL != symbol->il_operand_list)

   394         return symbol->il_operand_list->accept(*this);

   395       if (NULL != symbol->il_param_list)

   396         return symbol->il_param_list->accept(*this);

   397       return NULL;

   398     }

   399 

   400 

   401 

   402 /* | il_operand_list ',' il_operand */

   403 // SYM_LIST(il_operand_list_c)

   404     void *visit(il_operand_list_c *symbol) {

   405       TRACE("il_operand_list_c");

   406       return search_list(symbol);

   407     }

   408 

   409 

   410 /* | il_initial_param_list il_param_instruction */

   411 // SYM_LIST(il_param_list_c)

   412     void *visit(il_param_list_c *symbol) {

   413       TRACE("il_param_list_c");

   414       return search_list(symbol);

   415     }

   416 

   417 /*  il_assign_operator il_operand

   418  * | il_assign_operator '(' eol_list simple_instr_list ')'

   419  */

   420 // SYM_REF4(il_param_assignment_c, il_assign_operator, il_operand, simple_instr_list, unused)

   421     void *visit(il_param_assignment_c *symbol) {

   422       TRACE("il_param_assignment_c");

   423 

   424       // TODO : We do not yet handle a instruction list passed as parameter !!!

   425       // since we do not yet support it, it is best to simply stop than to fail silently...

   426       if (NULL != symbol->simple_instr_list) ERROR;

   427 

   428       return handle_parameter_assignment(symbol->il_assign_operator, symbol->il_operand);

   429     }

   430 

   431 /*  il_assign_out_operator variable */

   432 // SYM_REF2(il_param_out_assignment_c, il_assign_out_operator, variable);

   433     void *visit(il_param_out_assignment_c *symbol) {

   434       TRACE("il_param_out_assignment_c");

   435       return handle_parameter_assignment((symbol_c *)symbol->il_assign_out_operator->accept(*this), symbol->variable);

   436     }

   437 

   438 

   439 /*******************/

   440 /* B 2.2 Operators */

   441 /*******************/

   442 /*| [NOT] any_identifier SENDTO */

   443 // SYM_REF2(il_assign_out_operator_c, option, variable_name)

   444     void *visit(il_assign_out_operator_c *symbol) {

   445       TRACE("il_assign_out_operator_c");

   446 

   447       // TODO : Handle not_param !!!

   448       // we do not yet support it, so it is best to simply stop than to fail silently...

   449       if (NULL != symbol->option) ERROR;

   450 

   451       return (void *)symbol->variable_name;

   452     }

   453 

   454 

   455 

   456 

   457 /***************************************/

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

   459 /***************************************/

   460 /***********************/

   461 /* B 3.1 - Expressions */

   462 /***********************/

   463 

   464 /*

   465 SYM_REF2(function_invocation_c, function_name, parameter_assignment_list)

   466 */

   467     void *visit(function_invocation_c *symbol) {

   468       TRACE("function_invocation_c");

   469       if ((symbol_c *)symbol == f_call && symbol->parameter_assignment_list != NULL)

   470         return symbol->parameter_assignment_list->accept(*this);

   471       else

   472         return NULL;

   473     }

   474 

   475 

   476 

   477 

   478 /********************/

   479 /* B 3.2 Statements */

   480 /********************/

   481 

   482 /*********************************/

   483 /* B 3.2.1 Assignment Statements */

   484 /*********************************/

   485 /*

   486 SYM_REF2(assignment_statement_c, l_exp, r_exp)

   487 */

   488 

   489 /*****************************************/

   490 /* B 3.2.2 Subprogram Control Statements */

   491 /*****************************************/

   492 /*  RETURN */

   493 // SYM_REF0(return_statement_c)

   494 

   495 

   496 /* fb_name '(' [param_assignment_list] ')' */

   497 /* param_assignment_list -> may be NULL ! */

   498 // SYM_REF2(fb_invocation_c, fb_name, param_assignment_list)

   499     void *visit(fb_invocation_c *symbol) {

   500       TRACE("fb_invocation_c");

   501       if (symbol->param_assignment_list != NULL)

   502         return symbol->param_assignment_list->accept(*this);

   503       else

   504         return NULL;

   505     }

   506 

   507 /* helper symbol for fb_invocation */

   508 /* param_assignment_list ',' param_assignment */

   509 // SYM_LIST(param_assignment_list_c)

   510     void *visit(param_assignment_list_c *symbol) {

   511       TRACE("param_assignment_list_c");

   512       return search_list(symbol);

   513     }

   514 

   515 /*  variable_name ASSIGN expression */

   516 // SYM_REF2(input_variable_param_assignment_c, variable_name, expression)

   517     void *visit(input_variable_param_assignment_c *symbol) {

   518       TRACE("input_variable_param_assignment_c");

   519       return handle_parameter_assignment(symbol->variable_name, symbol->expression);

   520     }

   521 

   522 /* [NOT] variable_name '=>' variable */

   523 // SYM_REF4(output_variable_param_assignment_c, not_param, variable_name, variable, unused)

   524     void *visit(output_variable_param_assignment_c *symbol) {

   525       TRACE("output_variable_param_assignment_c");

   526       // TODO : Handle not_param !!!

   527       if (NULL != symbol->not_param) ERROR;  // we do not yet support it, so it is best to simply stop than to fail silently...

   528 

   529       return handle_parameter_assignment(symbol->variable_name, symbol->variable);

   530     }

   531 

   532 /* helper CLASS for output_variable_param_assignment */

   533 // SYM_REF0(not_paramassign_c)

   534 // TODO... ???

   535 

   536 

   537 

   538 

   539 

   540 };

   541 

   542 

   543 

   544 

   545 

   546