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  * Declaration of the Abstract Syntax data structure components

    27  */

    28 

    29 /*

    30  * ABSYNTAX.H

    31  *

    32  * This generates the parse tree structure used to bind the components

    33  * identified by Bison in the correct syntax order. At the end of the

    34  * Bison analysis the tree is walked in a sequential fashion generating

    35  * the relavent code.

    36  */

    37 

    38 #ifndef _ABSYNTAX_HH

    39 #define _ABSYNTAX_HH

    40 

    41 

    42 #include <stdio.h> // required for NULL

    43 

    44 /* Forward declaration of the visitor interface

    45  * dclared in the visitor.hh file

    46  * We cannot include the visitor.hh file, as it will

    47  * include this same file first, as it too requires references

    48  * to the abstract syntax classes defined here.

    49  */

    50 class visitor_c; // forward declaration

    51 

    52 

    53 class symbol_c; // forward declaration

    54 //extern symbol_c *tree_root;

    55 

    56 

    57 

    58 /* The base class of all symbols */

    59 class symbol_c {

    60 

    61   public:

    62     /*

    63      * Line number for the purposes of error checking

    64      */

    65     long lineno;

    66 

    67   public:

    68     /* default constructor */

    69     symbol_c(void);

    70     symbol_c(long lineno);

    71 

    72     /* default destructor */

    73     /* must be virtual so compiler does not complain... */ 

    74     virtual ~symbol_c(void) {return;};

    75 

    76     virtual void *accept(visitor_c &visitor) {return NULL;};

    77 };

    78 

    79 

    80 class token_c: public symbol_c {

    81   public:

    82     /* the value of the symbol. */

    83     const char *value;

    84 

    85   public:

    86     token_c(const char *value);

    87 };

    88 

    89 

    90  /* a list of symbols... */

    91 class list_c: public symbol_c {

    92   public:

    93     int n;

    94     symbol_c **elements;

    95 

    96   public:

    97     list_c(void);

    98     list_c(symbol_c *elem);

    99      /* insert a new element */

   100     virtual void add_element(symbol_c *elem);

   101 };

   102 

   103 

   104 

   105 

   106 #define SYM_LIST(class_name_c)			\

   107 class class_name_c:	public list_c {		\

   108   public:					\

   109     virtual void *accept(visitor_c &visitor);	\

   110 };

   111 

   112 

   113 #define SYM_TOKEN(class_name_c)			\

   114 class class_name_c: 	public token_c {	\

   115   public:					\

   116     class_name_c(const char *value);			\

   117     virtual void *accept(visitor_c &visitor);	\

   118 };

   119 

   120 

   121 #define SYM_REF0(class_name_c)			\

   122 class class_name_c: public symbol_c {		\

   123   public:					\

   124     virtual void *accept(visitor_c &visitor);	\

   125 };

   126 

   127 

   128 #define SYM_REF2(class_name_c, ref1, ref2)	\

   129 class class_name_c: public symbol_c {		\

   130   public:					\

   131     symbol_c *ref1;				\

   132     symbol_c *ref2;				\

   133   public:					\

   134     class_name_c(symbol_c *ref1,		\

   135 		 symbol_c *ref2 = NULL);	\

   136     virtual void *accept(visitor_c &visitor);	\

   137 };

   138 

   139 

   140 #define SYM_REF4(class_name_c, ref1, ref2, ref3, ref4)	\

   141 class class_name_c: public symbol_c {			\

   142   public:						\

   143     symbol_c *ref1;					\

   144     symbol_c *ref2;					\

   145     symbol_c *ref3;					\

   146     symbol_c *ref4;					\

   147   public:						\

   148     class_name_c(symbol_c *ref1,			\

   149 		 symbol_c *ref2,			\

   150 		 symbol_c *ref3,			\

   151 		 symbol_c *ref4 = NULL);		\

   152     virtual void *accept(visitor_c &visitor);		\

   153 };

   154 

   155 

   156 #define SYM_REF6(class_name_c, ref1, ref2, ref3, ref4, ref5, ref6)	\

   157 class class_name_c: public symbol_c {					\

   158   public:								\

   159     symbol_c *ref1;							\

   160     symbol_c *ref2;							\

   161     symbol_c *ref3;							\

   162     symbol_c *ref4;							\

   163     symbol_c *ref5;							\

   164     symbol_c *ref6;							\

   165   public:								\

   166     class_name_c(symbol_c *ref1,					\

   167 		 symbol_c *ref2,					\

   168 		 symbol_c *ref3,					\

   169 		 symbol_c *ref4,					\

   170 		 symbol_c *ref5,					\

   171 		 symbol_c *ref6 = NULL);		\

   172     virtual void *accept(visitor_c &visitor);				\

   173 };

   174 

   175 

   176 #include "absyntax.def"

   177 

   178 

   179 

   180 #undef SYM_LIST

   181 #undef SYM_TOKEN

   182 #undef SYM_REF0

   183 #undef SYM_REF2

   184 #undef SYM_REF4

   185 #undef SYM_REF6

   186 

   187 

   188 

   189 #endif /*  _ABSYNTAX_HH */