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           

   131           if (variable_name2 == NULL) {

   132             en_param_c *en_param = dynamic_cast<en_param_c *>(variable_name);

   133             if (en_param != NULL)

   134               variable_name2 = new identifier_c("EN");

   135           }

   136           

   137           if (variable_name2 == NULL) {

   138             eno_param_c *eno_param = dynamic_cast<eno_param_c *>(variable_name);

   139             if (eno_param != NULL)

   140               variable_name2 = new identifier_c("ENO");

   141           }

   142           

   143           if (variable_name2 == NULL) ERROR;

   144           

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

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

   147             return (void *)expression;

   148           return NULL;

   149           break;

   150       }

   151 

   152       ERROR;

   153       return NULL;

   154     }

   155 

   156 

   157 

   158   public:

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

   160     void reset(void) {

   161       next_param = param_count = 0;

   162     }

   163 

   164     /* initialise the iterator object.

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

   166      * that will be analysed...

   167      */

   168     function_call_param_iterator_c(symbol_c *f_call) {

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

   170        *  program_configuration_c

   171        *  function_invocation_c

   172        *  fb_invocation_c

   173        *  il_function_call_c

   174        *  il_formal_funct_call_c

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

   176        */

   177       this->f_call = f_call;

   178       search_param_name = NULL;

   179       reset();

   180     }

   181 

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

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

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

   185      * reference the first parameter...

   186      *

   187      * Returns whatever is being passed to the parameter!

   188      */

   189     symbol_c *next(void) {

   190       param_count = 0;

   191       next_param++;

   192       current_operation = function_call_param_iterator_c::iterate_op;

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

   194       return (symbol_c *)res;

   195     }

   196 

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

   198     symbol_c *search(symbol_c *param_name) {

   199       if (NULL == param_name) ERROR;

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

   201       if (NULL == search_param_name) ERROR;

   202       current_operation = function_call_param_iterator_c::search_op;

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

   204       return (symbol_c *)res;

   205     }

   206 

   207 

   208 

   209 

   210   private:

   211 /********************************/

   212 /* B 1.7 Configuration elements */

   213 /********************************/

   214 

   215 /*

   216 CONFIGURATION configuration_name

   217    optional_global_var_declarations

   218    (resource_declaration_list | single_resource_declaration)

   219    optional_access_declarations

   220    optional_instance_specific_initializations

   221 END_CONFIGURATION

   222 */

   223 /*

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

   225 */

   226 

   227 /* helper symbol for configuration_declaration */

   228 /*

   229 SYM_LIST(resource_declaration_list_c)

   230 */

   231 

   232 /*

   233 RESOURCE resource_name ON resource_type_name

   234    optional_global_var_declarations

   235    single_resource_declaration

   236 END_RESOURCE

   237 */

   238 /*

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

   240 */

   241 

   242 /* task_configuration_list program_configuration_list */

   243 /*

   244 SYM_REF2(single_resource_declaration_c, task_configuration_list, program_configuration_list)

   245 */

   246 

   247 /* helper symbol for single_resource_declaration */

   248 /*

   249 SYM_LIST(task_configuration_list_c)

   250 */

   251 

   252 /* helper symbol for single_resource_declaration */

   253 /*

   254 SYM_LIST(program_configuration_list_c)

   255 */

   256 

   257 /* helper symbol for

   258  *  - access_path

   259  *  - instance_specific_init

   260  */

   261 /*

   262 SYM_LIST(any_fb_name_list_c)

   263 */

   264 

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

   266 /*

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

   268 */

   269 

   270 /*  prev_declared_program_name '.' symbolic_variable */

   271 /*

   272 SYM_REF2(program_output_reference_c, program_name, symbolic_variable)

   273 */

   274 

   275 /*  TASK task_name task_initialization */

   276 /*

   277 SYM_REF2(task_configuration_c, task_name, task_initialization)

   278 */

   279 

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

   281 /*

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

   283 */

   284 

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

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

   287     void *visit(program_configuration_c *symbol) {

   288       TRACE("program_configuration_c");

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

   290     }

   291 

   292 /* prog_conf_elements ',' prog_conf_element */

   293 // SYM_LIST(prog_conf_elements_c)

   294     void *visit(prog_conf_elements_c *symbol) {

   295       TRACE("prog_conf_elements_c");

   296       return search_list(symbol);

   297     }

   298 

   299 /*  fb_name WITH task_name */

   300 /*

   301 SYM_REF2(fb_task_c, fb_name, task_name)

   302 */

   303 

   304 /*  any_symbolic_variable ASSIGN prog_data_source */

   305 // SYM_REF2(prog_cnxn_assign_c, symbolic_variable, prog_data_source)

   306     void *visit(prog_cnxn_assign_c *symbol) {

   307       TRACE("prog_cnxn_assign_c");

   308 

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

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

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

   312        */

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

   314       if (NULL == symb_var)

   315         ERROR;

   316 

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

   318     }

   319 

   320 /* any_symbolic_variable SENDTO data_sink */

   321 // SYM_REF2(prog_cnxn_sendto_c, symbolic_variable, prog_data_source)

   322     void *visit(prog_cnxn_sendto_c *symbol) {

   323       TRACE("prog_cnxn_sendto_c");

   324 

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

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

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

   328        */

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

   330       if (NULL == symb_var)

   331         ERROR;

   332 

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

   334     }

   335 

   336 /* VAR_CONFIG instance_specific_init_list END_VAR */

   337 /*

   338 SYM_REF2(instance_specific_initializations_c, instance_specific_init_list, unused)

   339 */

   340 

   341 /* helper symbol for instance_specific_initializations */

   342 /*

   343 SYM_LIST(instance_specific_init_list_c)

   344 */

   345 

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

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

   348 */

   349 /*

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

   351 */

   352 

   353 /* helper symbol for instance_specific_init */

   354 /* function_block_type_name ':=' structure_initialization */

   355 /*

   356 SYM_REF2(fb_initialization_c, function_block_type_name, structure_initialization)

   357 */

   358 

   359 

   360 

   361 

   362 

   363 

   364 /****************************************/

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

   366 /****************************************/

   367 /***********************************/

   368 /* B 2.1 Instructions and Operands */

   369 /***********************************/

   370 

   371 /* | function_name [il_operand_list] */

   372 // SYM_REF2(il_function_call_c, function_name, il_operand_list)

   373     void *visit(il_function_call_c *symbol) {

   374       TRACE("il_function_call_c");

   375       if (NULL != symbol->il_operand_list)

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

   377       return NULL;

   378     }

   379 

   380 

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

   382 // SYM_REF2(il_formal_funct_call_c, function_name, il_param_list)

   383     void *visit(il_formal_funct_call_c *symbol) {

   384       TRACE("il_formal_funct_call_c");

   385       if (NULL != symbol->il_param_list)

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

   387       return NULL;

   388     }

   389 

   390 

   391 /*   il_call_operator prev_declared_fb_name

   392  * | il_call_operator prev_declared_fb_name '(' ')'

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

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

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

   396  */

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

   398     void *visit(il_fb_call_c *symbol) {

   399       TRACE("il_fb_call_c");

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

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

   402        * understand the remaining code :-)

   403        */

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

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

   406 

   407       if (NULL != symbol->il_operand_list)

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

   409       if (NULL != symbol->il_param_list)

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

   411       return NULL;

   412     }

   413 

   414 

   415 

   416 /* | il_operand_list ',' il_operand */

   417 // SYM_LIST(il_operand_list_c)

   418     void *visit(il_operand_list_c *symbol) {

   419       TRACE("il_operand_list_c");

   420       return search_list(symbol);

   421     }

   422 

   423 

   424 /* | il_initial_param_list il_param_instruction */

   425 // SYM_LIST(il_param_list_c)

   426     void *visit(il_param_list_c *symbol) {

   427       TRACE("il_param_list_c");

   428       return search_list(symbol);

   429     }

   430 

   431 /*  il_assign_operator il_operand

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

   433  */

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

   435     void *visit(il_param_assignment_c *symbol) {

   436       TRACE("il_param_assignment_c");

   437 

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

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

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

   441 

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

   443     }

   444 

   445 /*  il_assign_out_operator variable */

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

   447     void *visit(il_param_out_assignment_c *symbol) {

   448       TRACE("il_param_out_assignment_c");

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

   450     }

   451 

   452 

   453 /*******************/

   454 /* B 2.2 Operators */

   455 /*******************/

   456 /*| [NOT] any_identifier SENDTO */

   457 // SYM_REF2(il_assign_out_operator_c, option, variable_name)

   458     void *visit(il_assign_out_operator_c *symbol) {

   459       TRACE("il_assign_out_operator_c");

   460 

   461       // TODO : Handle not_param !!!

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

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

   464 

   465       return (void *)symbol->variable_name;

   466     }

   467 

   468 

   469 

   470 

   471 /***************************************/

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

   473 /***************************************/

   474 /***********************/

   475 /* B 3.1 - Expressions */

   476 /***********************/

   477 

   478 /*

   479 SYM_REF2(function_invocation_c, function_name, parameter_assignment_list)

   480 */

   481     void *visit(function_invocation_c *symbol) {

   482       TRACE("function_invocation_c");

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

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

   485       else

   486         return NULL;

   487     }

   488 

   489 

   490 

   491 

   492 /********************/

   493 /* B 3.2 Statements */

   494 /********************/

   495 

   496 /*********************************/

   497 /* B 3.2.1 Assignment Statements */

   498 /*********************************/

   499 /*

   500 SYM_REF2(assignment_statement_c, l_exp, r_exp)

   501 */

   502 

   503 /*****************************************/

   504 /* B 3.2.2 Subprogram Control Statements */

   505 /*****************************************/

   506 /*  RETURN */

   507 // SYM_REF0(return_statement_c)

   508 

   509 

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

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

   512 // SYM_REF2(fb_invocation_c, fb_name, param_assignment_list)

   513     void *visit(fb_invocation_c *symbol) {

   514       TRACE("fb_invocation_c");

   515       if (symbol->param_assignment_list != NULL)

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

   517       else

   518         return NULL;

   519     }

   520 

   521 /* helper symbol for fb_invocation */

   522 /* param_assignment_list ',' param_assignment */

   523 // SYM_LIST(param_assignment_list_c)

   524     void *visit(param_assignment_list_c *symbol) {

   525       TRACE("param_assignment_list_c");

   526       return search_list(symbol);

   527     }

   528 

   529 /*  variable_name ASSIGN expression */

   530 // SYM_REF2(input_variable_param_assignment_c, variable_name, expression)

   531     void *visit(input_variable_param_assignment_c *symbol) {

   532       TRACE("input_variable_param_assignment_c");

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

   534     }

   535 

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

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

   538     void *visit(output_variable_param_assignment_c *symbol) {

   539       TRACE("output_variable_param_assignment_c");

   540       // TODO : Handle not_param !!!

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

   542 

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

   544     }

   545 

   546 /* helper CLASS for output_variable_param_assignment */

   547 // SYM_REF0(not_paramassign_c)

   548 // TODO... ???

   549 

   550 

   551 

   552 

   553 

   554 };

   555 

   556 

   557 

   558 

   559 

   560