src/I.h

   1 /*
   2  * I.h -  support for invariants (assertions) using C code.
   3  *
   4  * Copyright (c) 1997 Phil Maker
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  *
  28  * Id: I.h,v 1.1.1.1 1997/11/23 11:45:50 pjm Exp
  29  */
  30
  31
  32 #ifndef _I_h_
  33 #define _I_h_ 1
  34
  35 #ifdef __cplusplus
  36 extern "C" {
  37 #endif
  38
  39 #ifndef WITHOUT_NANA
  40
  41 /*
  42  * nana-config.h - the system wide configuration file; we put the ifndef
  43  *   around it to avoid the file 5 million times during a compile.
  44  */
  45
  46 #ifndef _nana_config_h_
  47 #include <nana-config.h>
  48 #endif
  49
  50 /*
  51  * I_LEVEL sets the level of invariant analogously to NDEBUG in assert.h
  52  *
  53  *   I_LEVEL == 2: invariants are always evaluated.
  54  *   I_LEVEL == 1: evaluate invariants iff they have a true GUARD.
  55  *   I_LEVEL == 0: invariants are never evaluated.
  56  */
  57
  58 #ifndef I_LEVEL /* define DEFAULT for I_LEVEL */
  59 #define I_LEVEL 1
  60 #endif
  61
  62
  63 /*
  64  * I_DEFAULT_GUARD - the default guard expression; an invariant is checked
  65  *     iff the guard is true. By default its always true.
  66  */
  67
  68 #ifndef I_DEFAULT_GUARD
  69 #define I_DEFAULT_GUARD (1)
  70 #endif
  71
  72 /*
  73  * I_DEFAULT_PARAMS - the default value to be passed as the second argument
  74  *       to the handler macro when an invariant fails.
  75  */
  76
  77
  78 #ifndef I_DEFAULT_PARAMS
  79 #define I_DEFAULT_PARAMS /* nothing */
  80 #endif
  81
  82 /*
  83  * I_DEFAULT_HANDLER(expr,file,line,param) - called when an error is detected.
  84  */
  85
  86 #ifndef I_DEFAULT_HANDLER /* define default handler */
  87 void _I_default_handler(char *expr, char *file, int line);
  88
  89 #define I_DEFAULT_HANDLER(expr,file,line,param) \
  90   _I_default_handler(expr,__FILE__,__LINE__)
  91
  92 #endif /* I_DEFAULT_HANDLER */
  93
  94 /*
  95  * _IGHPS(e,g,h,p,s) - implements the general case for invariant handling.
  96  *
  97  * e - expression to check
  98  * g - guard, check only if this is true (subject to I_DEFAULT_LEVEL)
  99  * h - handler, called when a failure is detected
 100  * p - parameter to pass off to the handler
 101  * s - string representation of the expression (e.g. "I(x>=i)")
 102  *
 103  * _ISD(e) - generates a data declaration for use in postconditions
 104  * _ISG(e,g) - generates a guarded assignment to a data declaration
 105  *     for use in postconditions
 106  *
 107  *     N.B. The two types are necessary since we cannot guard a C declaration
 108  *     with an if statement.
 109  */
 110
 111 #if I_LEVEL == 2 /* always check the assertion */
 112 #define _IGHPS(e,g,h,p,s) \
 113         do { \
 114                 if(!(e)) { \
 115                         h (s, __FILE__, __LINE__, p); \
 116                 } \
 117         } while(0)
 118
 119 #define _ID(e) e
 120 #define _ISG(e,g) e
 121 #elif I_LEVEL == 1 /* check it iff g is true */
 122 #define _IGHPS(e,g,h,p,s) \
 123         do { \
 124                 if(g) { \
 125                         if(!(e)) { \
 126                                 h (s, __FILE__, __LINE__, p); \
 127                         } \
 128                 } \
 129         } while(0)
 130 #define _ID(e) e
 131 #define _ISG(e,g) \
 132         do { \
 133                 if(g) { \
 134                         e; \
 135                 } \
 136         } while(0)
 137 #elif I_LEVEL == 0 /* no assertions so just remove them */
 138 #define _IGHPS(e,g,h,p,s) /* nothing */
 139 #define _ID(e) /* nothing */
 140 #define _ISG(e,g) /* nothing */
 141 #endif /* I_LEVEL */
 142
 143 /*
 144  * And all the user macros; these are used to put in the default arguments.
 145  * The name is used to determine the arguments; e.g. IGH takes an expression
 146  * to check; a guard and a handler as parameters. The letters in the names
 147  * are in ascending order (i.e. IGH(...) not IHG(...)).
 148  *
 149  * I[G][H][P] - it must be true (e) with an optional guard, handler and
 150  *    parameter for the handler.
 151  * N[G][H][P] - as for I... except that (e) must never ever be true.
 152  */
 153
 154 #define I(e) \
 155   _IGHPS(e,I_DEFAULT_GUARD,I_DEFAULT_HANDLER,I_DEFAULT_PARAMS,"I("#e")")
 156 #define IG(e,g) \
 157   _IGHPS(e,g,I_DEFAULT_HANDLER,I_DEFAULT_PARAMS,"I("#e")")
 158 #define IH(e,h) \
 159   _IGHPS(e,I_DEFAULT_GUARD,h,I_DEFAULT_PARAMS,"I("#e")")
 160 #define IP(e,p) \
 161   _IGHPS(e,I_DEFAULT_GUARD,I_DEFAULT_HANDLER,p,"I("#e")")
 162 #define IGH(e,g,h) \
 163   _IGHPS(e,g,h,I_DEFAULT_PARAMS,"I("#e")")
 164 #define IGP(e,g,p) \
 165   _IGHPS(e,g,I_DEFAULT_HANDLER,p,"I("#e")")
 166 #define IHP(e,h,p) \
 167   _IGHPS(e,I_DEFAULT_GUARD,h,p,"I("#e")")
 168 #define IGHP(e,g,h,p) \
 169   _IGHPS(e,g,h,p,"I("#e")")
 170
 171 #define N(e) \
 172   _IGHPS((!(e)),I_DEFAULT_GUARD,I_DEFAULT_HANDLER,I_DEFAULT_PARAMS,"N("#e")")
 173 #define NG(e,g) \
 174   _IGHPS((!(e)),g,I_DEFAULT_HANDLER,I_DEFAULT_PARAMS,"N("#e")")
 175 #define NH(e,h) \
 176   _IGHPS((!(e)),I_DEFAULT_GUARD,h,I_DEFAULT_PARAMS,"N("#e")")
 177 #define NP(e,p) \
 178   _IGHPS((!(e)),I_DEFAULT_GUARD,I_DEFAULT_HANDLER,p,"N("#e")")
 179 #define NGH(e,g,h) \
 180   _IGHPS((!(e)),g,h,I_DEFAULT_PARAMS,"N("#e")")
 181 #define NGP(e,g,p) \
 182   _IGHPS((!(e)),g,I_DEFAULT_HANDLER,p,"N("#e")")
 183 #define NHP(e,h,p) \
 184   _IGHPS((!(e)),I_DEFAULT_GUARD,h,p,"N("#e")")
 185 #define NGHP(e,g,h,p) \
 186   _IGHPS((!(e)),g,h,p,"N("#e")")
 187
 188 /*
 189  * ID(e) - declares a variable to be used to store values for a postcondition.
 190  *        This can include an initialiser.
 191  *        Note this declaration is not disabled by I_DEFAULT_GUARD
 192  * IS(e) - an assignment to a variable. This statement is enabled by
 193  *        I_DEFAULT_GUARD
 194  * ISG(e,g) - the guarded version of IS
 195  */
 196
 197 #define ID(e) _ID(e)
 198 #define IS(e) _ISG(e,I_DEFAULT_GUARD)
 199 #define ISG(e,g) _ISG(e,g)
 200
 201 #else /* defined(WITHOUT_NANA) */
 202
 203 #define I(e) /* empty */
 204 #define IG(e,g) /* empty */
 205 #define IH(e,h) /* empty */
 206 #define IP(e,p) /* empty */
 207 #define IGH(e,g,h) /* empty */
 208 #define IGP(e,g,p) /* empty */
 209 #define IHP(e,h,p) /* empty */
 210 #define IGHP(e,g,h,p) /* empty */
 211
 212 #define N(e) /* empty */
 213 #define NG(e,g) /* empty */
 214 #define NH(e,h) /* empty */
 215 #define NP(e,p) /* empty */
 216 #define NGH(e,g,h) /* empty */
 217 #define NGP(e,g,p) /* empty */
 218 #define NHP(e,h,p) /* empty */
 219 #define NGHP(e,g,h,p) /* empty */
 220
 221 #define ID(e) /* empty */
 222 #define IS(e) /* empty */
 223 #define ISG(e,g) /* empty */
 224
 225 #endif /* !defined(WITHOUT_NANA) */
 226
 227 #ifdef __cplusplus
 228 }
 229 #endif
 230
 231 #endif /* _I_h_ */
 232
 233
 234