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  * A generic symbol table.

    28  *

    29  * This is used to create symbol tables such as a list of

    30  * variables currently in scope, a list of previously defined

    31  * functions, etc...

    32  */

    33 

    34 

    35 

    36 #ifndef _SYMTABLE_HH

    37 #define _SYMTABLE_HH

    38 

    39 #include "../absyntax/absyntax.hh"

    40 

    41 #include <map>

    42 #include <string>

    43 

    44 

    45 

    46 

    47 template<typename value_type, value_type null_value> class symtable_c {

    48   /* Case insensitive string compare copied from

    49    * "The C++ Programming Language" - 3rd Edition

    50    * by Bjarne Stroustrup, ISBN 0201889544.

    51    */

    52   class nocase_c {

    53     public:

    54       bool operator() (const std::string& x, const std::string& y) const {

    55         std::string::const_iterator ix = x.begin();

    56         std::string::const_iterator iy = y.begin();

    57 

    58         for(; (ix != x.end()) && (iy != y.end()) && (toupper(*ix) == toupper(*iy)); ++ix, ++iy);

    59         if (ix == x.end()) return (iy != y.end());

    60         if (iy == y.end()) return false;

    61         return (toupper(*ix) < toupper(*iy));

    62       };

    63   };

    64 

    65   public:

    66     typedef value_type value_t;

    67 

    68   private:

    69     /* Comparison between identifiers must ignore case, therefore the use of nocase_c */

    70     typedef std::map<std::string, value_t, nocase_c> base_t;

    71     base_t _base;

    72 

    73   public:

    74   typedef typename base_t::iterator iterator;

    75   typedef typename base_t::const_iterator const_iterator;

    76   typedef typename base_t::reverse_iterator reverse_iterator;

    77   typedef typename base_t::const_reverse_iterator const_reverse_iterator;

    78 

    79   private:

    80       /* pointer to symbol table of the next inner scope */

    81     symtable_c *inner_scope;

    82     void reset(void); /* clear all entries... */

    83 

    84   public:

    85     symtable_c(void);

    86 

    87     void push(void); /* create new inner scope */

    88     int  pop(void);  /* clear most inner scope */

    89 

    90     void set(const char *identifier_str, value_t value);

    91     void set(const symbol_c *symbol, value_t value);

    92     void insert(const char *identifier_str, value_t value);

    93     void insert(const symbol_c *symbol, value_t value);

    94 

    95     /* Search for an entry. Will return end_value() if not found */

    96     value_t end_value(void) {return null_value;}

    97     value_t find_value(const char *identifier_str);

    98     value_t find_value(const symbol_c *symbol);

    99 

   100     iterator find(const char *identifier_str) {return _base.find(identifier_str);}

   101 

   102   /* iterators pointing to beg/end of map... */

   103     iterator begin() 			{return _base.begin();}

   104     const_iterator begin() const	{return _base.begin();}

   105     iterator end()			{return _base.end();}

   106     const_iterator end() const 		{return _base.end();}

   107     reverse_iterator rbegin()		{return _base.rbegin();}

   108     const_reverse_iterator rbegin() const {return _base.rbegin();}

   109     reverse_iterator rend() 		{return _base.rend();}

   110     const_reverse_iterator rend() const	{return _base.rend();}

   111 

   112     /* debuging function... */

   113     void print(void);

   114 };

   115 

   116 

   117 

   118 /* Templates must include the source into the code! */

   119 #include "symtable.cc"

   120 

   121 #endif /*  _SYMTABLE_HH */