mjsousa@959: /*
mjsousa@959:  *  matiec - a compiler for the programming languages defined in IEC 61131-3
mjsousa@959:  *
mjsousa@959:  *  Copyright (C) 2014  Mario de Sousa (msousa@fe.up.pt)
mjsousa@959:  *
mjsousa@959:  *  This program is free software: you can redistribute it and/or modify
mjsousa@959:  *  it under the terms of the GNU General Public License as published by
mjsousa@959:  *  the Free Software Foundation, either version 3 of the License, or
mjsousa@959:  *  (at your option) any later version.
mjsousa@959:  *
mjsousa@959:  *  This program is distributed in the hope that it will be useful,
mjsousa@959:  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
mjsousa@959:  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
mjsousa@959:  *  GNU General Public License for more details.
mjsousa@959:  *
mjsousa@959:  *  You should have received a copy of the GNU General Public License
mjsousa@959:  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
mjsousa@959:  *
mjsousa@959:  *
mjsousa@959:  * This code is made available on the understanding that it will not be
mjsousa@959:  * used in safety-critical situations without a full and competent review.
mjsousa@959:  */
mjsousa@959: 
mjsousa@959: /*
mjsousa@959:  * An IEC 61131-3 compiler.
mjsousa@959:  *
mjsousa@959:  * Based on the
mjsousa@959:  * FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10)
mjsousa@959:  *
mjsousa@959:  */
mjsousa@959: 
mjsousa@959: 
mjsousa@959: /*
mjsousa@959:  * Re-oder the POUs in te library so that no forward references occur.
mjsousa@959:  * 
mjsousa@959:  * Since stage1_2 now suppport POUs that contain references to POUS that are only declared later,
mjsousa@959:  * (e.g. a variable of FB1_t is declared, before the FB1_T function block is itself declared!)
mjsousa@959:  * we may need to re-order all the POUs in the library so that these forward references do not occur.
mjsousa@959:  * 
mjsousa@959:  * This utility class will do just that. However, it does not destroy the original abstract syntax 
mjsousa@959:  * tree (AST). It instead creates a new re-ordered AST, by instantiating a new library_c object.
mjsousa@959:  * This new library_c object will however point to the *same* objects of the original AST, just in 
mjsousa@959:  * a new order. 
mjsousa@959:  * This means that the new and original AST share all the object instances, and only use a distinct
mjsousa@959:  * library_c object!
mjsousa@959:  */
mjsousa@959: 
mjsousa@959: #include "../absyntax/absyntax.hh"
mjsousa@959: #include "../absyntax/visitor.hh"
mjsousa@959: #include "../util/symtable.hh"
mjsousa@959: #include <set>
mjsousa@959: 
mjsousa@959: 
mjsousa@959: class   find_forward_dependencies_c;
mjsousa@971: typedef symtable_c<symbol_c *> identifiers_symbtable_t;
mjsousa@959: 
mjsousa@959: 
mjsousa@959: 
mjsousa@959: 
mjsousa@959: 
mjsousa@959: 
mjsousa@959: 
mjsousa@959: class remove_forward_dependencies_c: public search_visitor_c {
mjsousa@959: 
mjsousa@959:   private:
mjsousa@959:     /* The level of detail that the user wants us to display error messages. */
mjsousa@959:     #define error_level_default (1)
mjsousa@959:     #define error_level_nagging (4)
mjsousa@959:     unsigned int    current_display_error_level;
mjsousa@959:     int             error_count;
mjsousa@959:     bool            warning_found;
mjsousa@959:     library_c      *new_tree;
mjsousa@959:     int             cycle_count; // main algorithm runs in a loop. The nuber of the current cycle...
mjsousa@959:     // NOTE: we need two lists in order to correctly handle overloaded functions
mjsousa@959:     identifiers_symbtable_t      declared_identifiers; // list of identifiers already declared by the symbols in the new tree
mjsousa@959:     std::set <symbol_c *>        inserted_symbols;     // list of symbols already inserted in the new tree 
mjsousa@959:     symbol_c       *current_code_generation_pragma;    // points to any currently 'active' enable_code_generation_pragma_c
mjsousa@959:     find_forward_dependencies_c    *find_forward_dependencies;  
mjsousa@959: 
mjsousa@959:   public:
mjsousa@959:      remove_forward_dependencies_c(void);
mjsousa@959:     ~remove_forward_dependencies_c(void);
mjsousa@959:     library_c *create_new_tree(symbol_c *old_tree);  // create a new tree with POUs ordered so it does not contain forward dependencies...
mjsousa@959:     int        get_error_count(void);
mjsousa@959: 
mjsousa@959:   private:
mjsousa@959:     void *handle_library_symbol(symbol_c *symbol, symbol_c *name, symbol_c *search1, symbol_c *search2 = NULL, symbol_c *search3 = NULL);
mjsousa@959:     void  print_circ_error(library_c *symbol);
mjsousa@959: 
mjsousa@959:     /***************************/
mjsousa@959:     /* B 0 - Programming Model */
mjsousa@959:     /***************************/
mjsousa@959:     void *visit(library_c *symbol);
mjsousa@959:     /**************************************/
mjsousa@959:     /* B.1.5 - Program organization units */
mjsousa@959:     /**************************************/
mjsousa@959:     void *visit(function_declaration_c *symbol);
mjsousa@959:     void *visit(function_block_declaration_c *symbol);
mjsousa@959:     void *visit(program_declaration_c *symbol);
mjsousa@959:     /********************************/
mjsousa@959:     /* B 1.7 Configuration elements */
mjsousa@959:     /********************************/
mjsousa@959:     void *visit(configuration_declaration_c *symbol);
mjsousa@959:     /********************/
mjsousa@959:     /* 2.1.6 - Pragmas  */
mjsousa@959:     /********************/
mjsousa@959:     void *visit(disable_code_generation_pragma_c *symbol);
mjsousa@959:     void *visit(enable_code_generation_pragma_c *symbol);
mjsousa@959:     void *visit(pragma_c *symbol);
mjsousa@959: 
mjsousa@959: };   /* class remove_forward_dependencies_c */
mjsousa@959: 
mjsousa@959: 
mjsousa@959: