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 /* Determine the data type of a specific variable instance, including

    26  * function block instances.

    27  * A reference to the relevant variable declaration is returned.

    28  * The variable instance may NOT be a member of a structure of a memeber

    29  * of a structure of an element of an array of ...

    30  *

    31  * example:

    32  *    window.points[1].coordinate.x

    33  *    window.points[1].colour

    34  *    etc... ARE NOT ALLOWED!

    35  *

    36  * This class must only be passed the name of the variable that will appear

    37  * in the variable declaration. In the above examples, this would be

    38  *   'window' !!

    39  *

    40  *

    41  * If you need to pass a complete name of a variable instance (such as

    42  * 'window.points[1].coordinate.x') use the search_varfb_instance_type_c instead!

    43  */

    44 

    45 /* Note that current_type_decl that this class returns may reference the

    46  * name of a type, or the type declaration itself!

    47  * For an example of the first, consider a variable declared as ...

    48  * x : AAA;

    49  * where the AAA type is previously declared as whatever.

    50  * For an example of the second, consider a variable declared as ...

    51  * x : array of int [10];  ---->  is allowed

    52  *

    53  * If it is the first, we will return a reference to the name, if the second

    54  * we return a reference to the declaration!!

    55  */

    56 #include "absyntax_utils.hh"

    57 

    58 

    59 search_var_instance_decl_c::search_var_instance_decl_c(symbol_c *search_scope) {

    60   this->current_vartype = none_vt;

    61   this->search_scope = search_scope;

    62   this->search_name = NULL;

    63   this->current_type_decl = NULL;

    64 }

    65 

    66 symbol_c *search_var_instance_decl_c::get_decl(symbol_c *variable_instance_name) {

    67   this->search_name = variable_instance_name;

    68   return (symbol_c *)search_scope->accept(*this);

    69 }

    70 

    71 unsigned int search_var_instance_decl_c::get_vartype() {

    72   return current_vartype;

    73 }

    74 

    75 /***************************/

    76 /* B 0 - Programming Model */

    77 /***************************/

    78 void *search_var_instance_decl_c::visit(library_c *symbol) {

    79   /* we do not want to search multiple declaration scopes,

    80    * so we do not visit all the functions, fucntion blocks, etc...

    81    */

    82   return NULL;

    83 }

    84 

    85 

    86 

    87 /******************************************/

    88 /* B 1.4.3 - Declaration & Initialisation */

    89 /******************************************/

    90 /* edge -> The F_EDGE or R_EDGE directive */

    91 // SYM_REF2(edge_declaration_c, edge, var1_list)

    92 // TODO

    93 

    94 void *search_var_instance_decl_c::visit(input_declarations_c *symbol) {

    95   current_vartype = input_vt;

    96   void *res = symbol->input_declaration_list->accept(*this);

    97   if (res == NULL) {

    98     current_vartype = none_vt;

    99   }

   100   return res;

   101 }

   102 

   103 /* VAR_OUTPUT [RETAIN | NON_RETAIN] var_init_decl_list END_VAR */

   104 /* option -> may be NULL ! */

   105 void *search_var_instance_decl_c::visit(output_declarations_c *symbol) {

   106   current_vartype = output_vt;

   107   void *res = symbol->var_init_decl_list->accept(*this);

   108   if (res == NULL) {

   109     current_vartype = none_vt;

   110   }

   111   return res;

   112 }

   113 

   114 /*  VAR_IN_OUT var_declaration_list END_VAR */

   115 void *search_var_instance_decl_c::visit(input_output_declarations_c *symbol) {

   116   current_vartype = inoutput_vt;

   117   void *res = symbol->var_declaration_list->accept(*this);

   118   if (res == NULL) {

   119     current_vartype = none_vt;

   120   }

   121   return res;

   122 }

   123 

   124 /* VAR [CONSTANT] var_init_decl_list END_VAR */

   125 /* option -> may be NULL ! */

   126 /* helper symbol for input_declarations */

   127 void *search_var_instance_decl_c::visit(var_declarations_c *symbol) {

   128   current_vartype = private_vt;

   129   void *res = symbol->var_init_decl_list->accept(*this);

   130   if (res == NULL) {

   131     current_vartype = none_vt;

   132   }

   133   return res;

   134 }

   135 

   136 /*  VAR RETAIN var_init_decl_list END_VAR */

   137 void *search_var_instance_decl_c::visit(retentive_var_declarations_c *symbol) {

   138   current_vartype = private_vt;

   139   void *res = symbol->var_init_decl_list->accept(*this);

   140   if (res == NULL) {

   141     current_vartype = none_vt;

   142   }

   143   return res;

   144 }

   145 

   146 /*  VAR [CONSTANT|RETAIN|NON_RETAIN] located_var_decl_list END_VAR */

   147 /* option -> may be NULL ! */

   148 //SYM_REF2(located_var_declarations_c, option, located_var_decl_list)

   149 void *search_var_instance_decl_c::visit(located_var_declarations_c *symbol) {

   150   current_vartype = located_vt;

   151   void *res = symbol->located_var_decl_list->accept(*this);

   152   if (res == NULL) {

   153     current_vartype = none_vt;

   154   }

   155   return res;

   156 }

   157 

   158 /*| VAR_EXTERNAL [CONSTANT] external_declaration_list END_VAR */

   159 /* option -> may be NULL ! */

   160 //SYM_REF2(external_var_declarations_c, option, external_declaration_list)

   161 void *search_var_instance_decl_c::visit(external_var_declarations_c *symbol) {

   162   current_vartype = external_vt;

   163   void *res = symbol->external_declaration_list->accept(*this);

   164   if (res == NULL) {

   165     current_vartype = none_vt;

   166   }

   167   return res;

   168 }

   169 

   170 /*| VAR_GLOBAL [CONSTANT|RETAIN] global_var_decl_list END_VAR */

   171 /* option -> may be NULL ! */

   172 //SYM_REF2(global_var_declarations_c, option, global_var_decl_list)

   173 void *search_var_instance_decl_c::visit(global_var_declarations_c *symbol) {

   174   current_vartype = global_vt;

   175   void *res = symbol->global_var_decl_list->accept(*this);

   176   if (res == NULL) {

   177     current_vartype = none_vt;

   178   }

   179   return res;

   180 }

   181 

   182 /* var1_list is one of the following...

   183  *    simple_spec_init_c *

   184  *    subrange_spec_init_c *

   185  *    enumerated_spec_init_c *

   186  */

   187 // SYM_REF2(var1_init_decl_c, var1_list, spec_init)

   188 void *search_var_instance_decl_c::visit(var1_init_decl_c *symbol) {

   189   current_type_decl = symbol->spec_init;

   190   return symbol->var1_list->accept(*this);

   191 }

   192 

   193 /* var1_list ',' variable_name */

   194 // SYM_LIST(var1_list_c)

   195 void *search_var_instance_decl_c::visit(var1_list_c *symbol) {

   196   list_c *list = symbol;

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

   198     if (compare_identifiers(list->elements[i], search_name) == 0)

   199    /* by now, current_type_decl should be != NULL */

   200       return current_type_decl;

   201   }

   202   return NULL;

   203 }

   204 

   205 /* name_list ':' function_block_type_name ASSIGN structure_initialization */

   206 /* structure_initialization -> may be NULL ! */

   207 void *search_var_instance_decl_c::visit(fb_name_decl_c *symbol) {

   208   current_type_decl = symbol->function_block_type_name;

   209   return symbol->fb_name_list->accept(*this);

   210 }

   211 

   212 /* name_list ',' fb_name */

   213 void *search_var_instance_decl_c::visit(fb_name_list_c *symbol) {

   214   list_c *list = symbol;

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

   216     if (compare_identifiers(list->elements[i], search_name) == 0)

   217   /* by now, current_fb_declaration should be != NULL */

   218       return current_type_decl;

   219   }

   220   return NULL;

   221 }

   222 

   223 /* var1_list ':' array_spec_init */

   224 // SYM_REF2(array_var_init_decl_c, var1_list, array_spec_init)

   225 void *search_var_instance_decl_c::visit(array_var_init_decl_c *symbol) {

   226   current_type_decl = symbol->array_spec_init;

   227   return symbol->var1_list->accept(*this);

   228 }

   229 

   230 /*  var1_list ':' initialized_structure */

   231 // SYM_REF2(structured_var_init_decl_c, var1_list, initialized_structure)

   232 void *search_var_instance_decl_c::visit(structured_var_init_decl_c *symbol) {

   233   current_type_decl = symbol->initialized_structure;

   234   return symbol->var1_list->accept(*this);

   235 }

   236 

   237 /*  var1_list ':' array_specification */

   238 // SYM_REF2(array_var_declaration_c, var1_list, array_specification)

   239 void *search_var_instance_decl_c::visit(array_var_declaration_c *symbol) {

   240   current_type_decl = symbol->array_specification;

   241   return symbol->var1_list->accept(*this);

   242 }

   243 

   244 /*  var1_list ':' structure_type_name */

   245 // SYM_REF2(structured_var_declaration_c, var1_list, structure_type_name)

   246 void *search_var_instance_decl_c::visit(structured_var_declaration_c *symbol) {

   247   current_type_decl = symbol->structure_type_name;

   248   return symbol->var1_list->accept(*this);

   249 }

   250 

   251 /*  [variable_name] location ':' located_var_spec_init */

   252 /* variable_name -> may be NULL ! */

   253 // SYM_REF4(located_var_decl_c, variable_name, location, located_var_spec_init, unused)

   254 // TODO!!

   255 

   256 /*  global_var_name ':' (simple_specification|subrange_specification|enumerated_specification|array_specification|prev_declared_structure_type_name|function_block_type_name */

   257 // SYM_REF2(external_declaration_c, global_var_name, specification)

   258 void *search_var_instance_decl_c::visit(external_declaration_c *symbol) {

   259   if (compare_identifiers(symbol->global_var_name, search_name) == 0)

   260       return symbol->specification;

   261   return NULL;

   262 }

   263 

   264 /*| global_var_spec ':' [located_var_spec_init|function_block_type_name] */

   265 /* type_specification ->may be NULL ! */

   266 // SYM_REF2(global_var_decl_c, global_var_spec, type_specification)

   267 void *search_var_instance_decl_c::visit(global_var_decl_c *symbol) {

   268   if (symbol->type_specification != NULL) {

   269     current_type_decl = symbol->type_specification;

   270     return symbol->global_var_spec->accept(*this);

   271   }

   272   else

   273     return NULL;

   274 }

   275 

   276 /*| global_var_name location */

   277 //SYM_REF2(global_var_spec_c, global_var_name, location)

   278 void *search_var_instance_decl_c::visit(global_var_spec_c *symbol) {

   279   if (symbol->global_var_name != NULL && compare_identifiers(symbol->global_var_name, search_name) == 0)

   280       return current_type_decl;

   281   else

   282     return symbol->location->accept(*this);

   283 }

   284 

   285 /*| global_var_list ',' global_var_name */

   286 //SYM_LIST(global_var_list_c)

   287 void *search_var_instance_decl_c::visit(global_var_list_c *symbol) {

   288   list_c *list = symbol;

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

   290     if (compare_identifiers(list->elements[i], search_name) == 0)

   291       /* by now, current_type_decl should be != NULL */

   292       return current_type_decl;

   293   }

   294   return NULL;

   295 }

   296 

   297 /*  [variable_name] location ':' located_var_spec_init */

   298 /* variable_name -> may be NULL ! */

   299 //SYM_REF4(located_var_decl_c, variable_name, location, located_var_spec_init, unused)

   300 void *search_var_instance_decl_c::visit(located_var_decl_c *symbol) {

   301   if (symbol->variable_name != NULL && compare_identifiers(symbol->variable_name, search_name) == 0)

   302     return symbol->located_var_spec_init;

   303   else {

   304     current_type_decl = symbol->located_var_spec_init;

   305     return symbol->location->accept(*this);

   306   }

   307 }

   308 

   309 /*| global_var_spec ':' [located_var_spec_init|function_block_type_name] */

   310 /* type_specification ->may be NULL ! */

   311 // SYM_REF2(global_var_decl_c, global_var_spec, type_specification)

   312 // TODO!!

   313 

   314 /*  AT direct_variable */

   315 // SYM_REF2(location_c, direct_variable, unused)

   316 void *search_var_instance_decl_c::visit(location_c *symbol) {

   317   if (compare_identifiers(symbol->direct_variable, search_name) == 0)

   318     return current_type_decl;

   319   else

   320     return NULL;

   321 }

   322         

   323 /*| global_var_list ',' global_var_name */

   324 // SYM_LIST(global_var_list_c)

   325 // TODO!!

   326 

   327 /*  var1_list ':' single_byte_string_spec */

   328 // SYM_REF2(single_byte_string_var_declaration_c, var1_list, single_byte_string_spec)

   329 void *search_var_instance_decl_c::visit(single_byte_string_var_declaration_c *symbol) {

   330   current_type_decl = symbol->single_byte_string_spec;

   331   return symbol->var1_list->accept(*this);

   332 }

   333 

   334 /*  STRING ['[' integer ']'] [ASSIGN single_byte_character_string] */

   335 /* integer ->may be NULL ! */

   336 /* single_byte_character_string ->may be NULL ! */

   337 // SYM_REF2(single_byte_string_spec_c, integer, single_byte_character_string)

   338 // TODO!!

   339 

   340 /*  var1_list ':' double_byte_string_spec */

   341 // SYM_REF2(double_byte_string_var_declaration_c, var1_list, double_byte_string_spec)

   342 void *search_var_instance_decl_c::visit(double_byte_string_var_declaration_c *symbol) {

   343   current_type_decl = symbol->double_byte_string_spec;

   344   return symbol->var1_list->accept(*this);

   345 }

   346 

   347 /*  WSTRING ['[' integer ']'] [ASSIGN double_byte_character_string] */

   348 /* integer ->may be NULL ! */

   349 /* double_byte_character_string ->may be NULL ! */

   350 // SYM_REF2(double_byte_string_spec_c, integer, double_byte_character_string)

   351 // TODO!!

   352 

   353 /*  variable_name incompl_location ':' var_spec */

   354 // SYM_REF4(incompl_located_var_decl_c, variable_name, incompl_location, var_spec, unused)

   355 // TODO!!

   356 

   357 /*  AT incompl_location_token */

   358 // SYM_TOKEN(incompl_location_c)

   359 // TODO!!

   360 

   361 

   362 /**************************************/

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

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

   365 /***********************/

   366 /* B 1.5.1 - Functions */

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

   368 // SYM_REF4(function_declaration_c, derived_function_name, type_name, var_declarations_list, function_body)

   369 void *search_var_instance_decl_c::visit(function_declaration_c *symbol) {

   370   /* functions have a variable named after themselves, to store

   371    * the variable that will be returned!!

   372    */

   373   if (compare_identifiers(symbol->derived_function_name, search_name) == 0)

   374       return symbol->type_name;

   375 

   376   /* no need to search through all the body, so we only

   377    * visit the variable declarations...!

   378    */

   379   return symbol->var_declarations_list->accept(*this);

   380 }

   381 

   382 /*****************************/

   383 /* B 1.5.2 - Function Blocks */

   384 /*****************************/

   385 void *search_var_instance_decl_c::visit(function_block_declaration_c *symbol) {

   386   /* no need to search through all the body, so we only

   387    * visit the variable declarations...!

   388    */

   389   return symbol->var_declarations->accept(*this);

   390 }

   391 

   392 /**********************/

   393 /* B 1.5.3 - Programs */

   394 /**********************/

   395 void *search_var_instance_decl_c::visit(program_declaration_c *symbol) {

   396   /* no need to search through all the body, so we only

   397    * visit the variable declarations...!

   398    */

   399   return symbol->var_declarations->accept(*this);

   400 }

   401 

   402 

   403 /********************************/

   404 /* B 1.7 Configuration elements */

   405 /********************************/

   406 

   407 /*

   408 CONFIGURATION configuration_name

   409    optional_global_var_declarations

   410    (resource_declaration_list | single_resource_declaration)

   411    optional_access_declarations

   412    optional_instance_specific_initializations

   413 END_CONFIGURATION

   414 */

   415 /*

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

   417 */

   418 void *search_var_instance_decl_c::visit(configuration_declaration_c *symbol) {

   419   /* no need to search through all the configuration, so we only

   420    * visit the global variable declarations...!

   421    */

   422   if (symbol->global_var_declarations != NULL)

   423     return symbol->global_var_declarations->accept(*this);

   424   else

   425     return NULL;

   426 }

   427 

   428 /*

   429 RESOURCE resource_name ON resource_type_name

   430    optional_global_var_declarations

   431    single_resource_declaration

   432 END_RESOURCE

   433 */

   434 // SYM_REF4(resource_declaration_c, resource_name, resource_type_name, global_var_declarations, resource_declaration)

   435 void *search_var_instance_decl_c::visit(resource_declaration_c *symbol) {

   436   /* no need to search through all the resource, so we only

   437    * visit the global variable declarations...!

   438    */

   439   if (symbol->global_var_declarations != NULL)

   440     return symbol->global_var_declarations->accept(*this);

   441   else

   442     return NULL;

   443 }

   444 

   445 /* task_configuration_list program_configuration_list */

   446 // SYM_REF2(single_resource_declaration_c, task_configuration_list, program_configuration_list)

   447 void *search_var_instance_decl_c::visit(single_resource_declaration_c *symbol) {

   448   /* no need to search through all the resource,

   449    * and there is no global variable declarations...!

   450    */

   451   return NULL;

   452 }

   453 

   454 #if 0

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

   456 /* B 1.4 - Variables */

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

   458 SYM_REF2(symbolic_variable_c, var_name, unused)

   459 

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

   461 /* B.1.4.1   Directly Represented Variables */

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

   463 SYM_TOKEN(direct_variable_c)

   464 

   465 /*************************************/

   466 /* B.1.4.2   Multi-element Variables */

   467 /*************************************/

   468 /*  subscripted_variable '[' subscript_list ']' */

   469 SYM_REF2(array_variable_c, subscripted_variable, subscript_list)

   470 

   471 /* subscript_list ',' subscript */

   472 SYM_LIST(subscript_list_c)

   473 

   474 /*  record_variable '.' field_selector */

   475 /*  WARNING: input and/or output variables of function blocks

   476  *           may be accessed as fields of a tructured variable!

   477  *           Code handling a structured_variable_c must take

   478  *           this into account!

   479  */

   480 SYM_REF2(structured_variable_c, record_variable, field_selector)

   481 

   482 

   483 

   484 };

   485 #endif