commands/ifdef/ifdef.c

   1 /* ifdef - remove #ifdefs               Author: Warren Toomey */
   2
   3 /* Copyright 1989 by Warren Toomey      wkt@cs.adfa.oz.au[@uunet.uu.net]
   4  *
   5  * You may freely copy or distribute this code as long as this notice
   6  * remains intact.
   7  *
   8  * You may modify this code, as long as this notice remains intact, and
   9  * you add another notice indicating that the code has been modified.
  10  *
  11  * You may NOT sell this code or in any way profit from this code without
  12  * prior agreement from the author.
  13  */
  14
  15 #include <sys/types.h>
  16 #include <string.h>
  17 #include <stdlib.h>
  18 #include <stdio.h>
  19 #include <unistd.h>
  20
  21 /* Definition of structures and constants used in ifdef.c  */
  22
  23 /* Types of symbols */
  24 #define DEF       1             /* Symbol is defined    */
  25 #define UNDEF     2             /* Symbol isn't defined */
  26 #define IGN       3             /* Ignore this symbol unless defined */
  27
  28 /* Redef mode values */
  29 #define MUTABLE   1             /* Symbol can change defined <-> undefined */
  30 #define IMMUTABLE 2             /* Symbol can't change as above            */
  31
  32 /* Processing modes */
  33 #define NO      0               /* Don't process */
  34 #define YES     1               /* Process */
  35
  36 /* Ignore (IGN), ignore but process */
  37 struct DEFINE {
  38   char *symbol;                 /* SLL of defined symbols. The redef  */
  39   char type;                    /* field indicates if this symbol can */
  40   char redef;                   /* change from defined <-> undefined. */
  41   struct DEFINE *next;          /* Type is DEF or UNDEF.              */
  42 };
  43
  44 /* Global variables & structures */
  45 FILE *zin;                      /* Input file for processing  */
  46 struct DEFINE *defptr;          /* Defined symbols SLL        */
  47 struct DEFINE *defend;          /* Ptr to last node in defptr */
  48 struct DEFINE *deftemp;         /* Ptr to last found node     */
  49 int line = 1;                   /* Current line number        */
  50 int table = 0;                  /* Don't normally want a table */
  51
  52 extern int optind;
  53 extern char *optarg;
  54
  55 /* Prototypes. */
  56 int main(int argc, char **argv);
  57 char fgetarg(FILE *stream, char *cbuf);
  58 int find(char *symd);
  59 void defit(char *sym, int redef, int typed);
  60 void stop(void);
  61 void gotoeoln(void);
  62 void prteoln(void);
  63 void printtable(void);
  64 char getendif(void);
  65 void gettable(void);
  66 void parse(void);
  67 void usage(void);
  68
  69 #ifdef __STDC__
  70 char fgetarg ( FILE *stream , char *cbuf )
  71 #else
  72 char fgetarg(stream, cbuf)      /* Get next arg from file into cbuf, */
  73 FILE *stream;                   /* returning the character that      */
  74 char *cbuf;                     /* terminated it. Cbuf returns 0     */
  75 #endif
  76 {                               /* if no arg. EOF is returned if no  */
  77   int ch;                       /* args left in file.                */
  78   int i;
  79
  80   i = 0;
  81   cbuf[i] = 0;
  82
  83   while (((ch = fgetc(stream)) == ' ') || (ch == '\t') || (ch == '\n'))
  84         if (ch == '\n') return(ch);     /* Bypass leading */
  85                                         /* Whitespace     */
  86   if (feof(stream)) return(EOF);
  87
  88   cbuf[i++] = ch;
  89
  90   while (((ch = fgetc(stream)) != ' ') && (ch != '\t') && (ch != '\n'))
  91         cbuf[i++] = ch;                 /* Get the argument */
  92
  93   cbuf[i] = 0;
  94   return(ch);
  95 }
  96
  97
  98 #ifdef __STDC__
  99 int find ( char *sym )
 100 #else
 101 int find(sym)
 102 char *sym;
 103 #endif
 104 {                               /* Return DEF if defined else UNDEF */
 105
 106   deftemp = defptr;
 107   while (deftemp) {                     /* Search for the symbol */
 108         if (!strcmp(deftemp->symbol, sym))
 109                 return(deftemp->type);  /* Setting up the type */
 110         deftemp = deftemp->next;
 111   }
 112   return(0);
 113 }
 114
 115
 116
 117 #define Define(x,y)     defit(x,y,DEF)
 118 #define Undefine(x,y)   defit(x,y,UNDEF)
 119 #define Ignore(x,y)     defit(x,y,IGN)
 120
 121 #ifdef __STDC__
 122 void defit ( char *sym , int redef , int type )
 123 #else
 124 void defit(sym, redef, type)    /* Add symbol to the define list */
 125 char *sym;
 126 char redef;                     /* Mode: MUTABLE etc      */
 127 char type;                      /* Type: DEF, UNDEF, IGN  */
 128 #endif
 129 {
 130   struct DEFINE *temp;
 131   char c;
 132
 133   c = find(sym);                /* First try finding the symbol */
 134   if (type == c) return;        /* Return if already declared */
 135   if (c) {                      /* We have to move if from DEF <-> UNDEF */
 136         if (deftemp->redef == IMMUTABLE)
 137                 return;
 138         else {
 139                 deftemp->type = type;
 140                 deftemp->redef = redef;
 141         }
 142   } else {                      /* We must create a struct & add it */
 143                                 /* Malloc room for the struct */
 144         if ((temp = (struct DEFINE *)malloc(sizeof(struct DEFINE))) == NULL) {
 145                 (void)fprintf(stderr, "ifdef: could not malloc\n");
 146                 exit(1);
 147         }
 148
 149                                         /* Malloc room for symbol */
 150         if ((temp->symbol = (char *)malloc(strlen(sym) + 1)) == NULL) {
 151                 (void)fprintf(stderr, "ifdef: could not malloc\n");
 152                 exit(1);
 153         }
 154         (void)strcpy(temp->symbol, sym); /* Copy symbol into struct      */
 155         temp->redef = redef;            /* and set its redef mode too   */
 156         temp->type = type;              /* as well as making it defined */
 157
 158
 159                                         /* Now add to the SLL */
 160         if (defptr == NULL)             /* If first node set  */
 161                 defptr = temp;          /* the pointers to it */
 162         else
 163                 defend->next = temp;    /* else add it to the */
 164         defend = temp;                  /* end of the list.   */
 165   }
 166 }
 167
 168
 169
 170 #ifdef __STDC__
 171 void stop ( void )
 172 #else
 173 void stop()
 174 #endif
 175 {                               /* Stop: Tidy up at EOF */
 176   if (table) printtable();
 177   (void)fclose(zin);
 178   exit(0);
 179 }
 180
 181 #define Goto    { line++; if (ch!='\n') gotoeoln(); }
 182 #define Print   { line++; if (ch!='\n') prteoln();  }
 183
 184 #ifdef __STDC__
 185 void gotoeoln ( void )
 186 #else
 187 void gotoeoln()                 /* Go to the end of the line */
 188 #endif
 189 {
 190   int ch;
 191   while ((ch = fgetc(zin)) != '\n')
 192         if (ch == EOF) stop();
 193 }
 194
 195
 196 #ifdef __STDC__
 197 void prteoln ( void )
 198 #else
 199 void prteoln()                  /* Print to the end of the line */
 200 #endif
 201 {
 202   int ch;
 203   while ((ch = fgetc(zin)) != '\n')
 204         if (ch == EOF)
 205                 stop();
 206         else
 207                 (void)putchar(ch);
 208   (void)putchar('\n');
 209 }
 210
 211
 212 #ifdef __STDC__
 213 void printtable ( void )
 214 #else
 215 void printtable()               /* Print the defines in the SLL */
 216 #endif
 217 {
 218   struct DEFINE *temp;
 219
 220   (void)printf("Defined\n\n");
 221
 222   temp = defptr;
 223   while (temp) {
 224         if (temp->type == DEF) (void)printf("%s\n", temp->symbol);
 225         temp = temp->next;
 226   }
 227
 228   (void)printf("\n\nUndefined\n\n");
 229
 230   temp = defptr;
 231   while (temp) {
 232         if (temp->type == UNDEF) (void)printf("%s\n", temp->symbol);
 233         temp = temp->next;
 234   }
 235 }
 236
 237 #ifdef __STDC__
 238 char getendif ( void )
 239 #else
 240 char getendif()
 241 #endif
 242 {                               /* Find matching endif when ignoring */
 243   char word[80];                /* Buffer for symbols */
 244   int ch;
 245   int skip;                     /* Number of skipped #ifdefs */
 246
 247   skip = 1;
 248
 249   while (1) {
 250                         /* Scan through the file looking for starting lines */
 251         if ((ch = fgetc(zin)) == EOF)
 252                 stop();         /* Get first char on the line */
 253         if (ch != '#') {        /* If not a # ignore line     */
 254                 (void)putchar(ch);
 255                 Print;
 256                 continue;
 257         }
 258         ch = fgetarg(zin, word);        /* Get the word after the # */
 259
 260         if (!strcmp(word, "ifdef") || !strcmp(word, "ifndef")) skip++;
 261                                                 /* Keep track of ifdefs & */
 262         if (!strcmp(word, "endif")) skip--;     /* endifs                 */
 263
 264         (void)printf("#%s%c", word, ch);        /* Print the line out     */
 265         Print;
 266         if (!skip) return('\n');        /* If matching endif, return */
 267   }
 268 }
 269
 270
 271 #ifdef __STDC__
 272 void gettable ( void )
 273 #else
 274 void gettable()                 /* Get & print a table of defines etc.  */
 275 #endif
 276 {
 277
 278   char word[80];                /* Buffer for symbols */
 279   int ch;
 280
 281   while (1) {
 282                         /* Scan through the file looking for starting lines */
 283         if ((ch = fgetc(zin)) == EOF)
 284                 stop();         /* Get first char on the line */
 285         if (ch != '#') {        /* If not a # ignore line     */
 286                 Goto;
 287                 continue;
 288         }
 289         ch = fgetarg(zin, word);        /* Get the word after the # */
 290
 291         if (!strcmp(word, "define")) {          /* Define: Define the */
 292                 ch = fgetarg(zin, word);        /* symbol, and goto   */
 293                 Define(word, MUTABLE);          /* the end of line    */
 294                 Goto;
 295                 continue;
 296         }
 297         if (!strcmp(word, "undef")) {           /* Undef: Undefine the */
 298                 ch = fgetarg(zin, word);        /* symbol, and goto    */
 299                 Undefine(word, MUTABLE);        /* the end of line     */
 300                 Goto;
 301                 continue;
 302         }                                       /* Ifdef:            */
 303         if (!strcmp(word, "ifdef") || !strcmp(word, "ifndef")) {
 304                 ch = fgetarg(zin, word);        /* Get the symbol */
 305                 if (find(word) != DEF)
 306                         Undefine(word, MUTABLE);        /* undefine it */
 307                 Goto;
 308                 continue;
 309         }
 310         Goto;                           /* else ignore the line */
 311   }
 312 }
 313
 314
 315
 316 #ifdef __STDC__
 317 void parse ( void )
 318 #else
 319 void parse()
 320 #endif
 321 {                               /* Parse & remove ifdefs from C source */
 322   char word[80];                /* Buffer for symbols */
 323   int ch;
 324   int proc;                     /* Should we be processing this bit?    */
 325   int skip;                     /* Number of skipped #ifdefs             */
 326
 327   proc = 1;
 328   skip = 0;
 329
 330   while (1) {
 331                         /* Scan through the file looking for starting lines */
 332         if ((ch = fgetc(zin)) == EOF)
 333                 stop();         /* Get first char on the line */
 334         if (ch != '#')
 335                 if (proc) {     /* If not # and  we're processing */
 336                         (void)putchar(ch); /* then print the line */
 337                         Print;
 338                         continue;
 339                 } else {
 340                         Goto;   /* else just skip the line  */
 341                         continue;
 342                 }
 343
 344         ch = fgetarg(zin, word);        /* Get the word after the # */
 345
 346         if (!strcmp(word, "define") && proc) {  /* Define: Define the */
 347                 ch = fgetarg(zin, word);        /* symbol, and goto   */
 348                 Define(word, MUTABLE);          /* the end of line    */
 349                 (void)printf("#define %s%c", word, ch);
 350                 Print;
 351                 continue;
 352         }
 353         if (!strcmp(word, "undef") && proc) {   /* Undef: Undefine the */
 354                 ch = fgetarg(zin, word);        /* symbol, and goto    */
 355                 Undefine(word, MUTABLE);        /* the end of line     */
 356                 (void)printf("#undef %s%c", word, ch);
 357                 Print;
 358                 continue;
 359         }
 360         if (!strcmp(word, "if")) {      /* If: we cannot handle these */
 361                 if (!proc)              /* at the moment, so just */
 362                         skip++;         /* treat them as an ignored */
 363                 else {                  /* definition */
 364                         (void)printf("#%s%c",word,ch);
 365                         Print;
 366                         ch = getendif();        /* Get matching endif */
 367                         continue;
 368                         }
 369         }
 370         if (!strcmp(word, "ifdef")) {   /* Ifdef:            */
 371                 if (!proc)              /* If not processing */
 372                         skip++;         /* skip it           */
 373                 else {
 374                         ch = fgetarg(zin, word); /* Get the symbol */
 375                         switch (find(word)) {
 376                             case DEF:
 377                                 break;
 378                             case IGN:
 379                                 (void)printf("#ifdef %s%c", word, ch);
 380                                 Print;
 381                                 ch = getendif(); /* Get matching endif */
 382                                 break;
 383                                                 /* If symbol undefined */
 384                             default:
 385                                 Undefine(word, MUTABLE); /* undefine it */
 386                                 proc = 0;       /* & stop processing */
 387                         }
 388                 }
 389                 Goto;
 390                 continue;
 391         }
 392         if (!strcmp(word, "ifndef")) {
 393                 /* Ifndef: */
 394                 if (!proc)      /* If not processing */
 395                         skip++; /* skip the line     */
 396                 else {
 397                         ch = fgetarg(zin, word); /* Get the symbol */
 398                         switch (find(word)) {   /* If defined, stop */
 399                             case DEF:
 400                                 proc = 0;       /* processing       */
 401                                 break;
 402                             case IGN:
 403                                 (void)printf("#ifdef %s%c", word, ch);
 404                                 Print;
 405                                 ch = getendif(); /* Get matching endif */
 406                                 break;
 407                         }
 408                 }
 409                 Goto;
 410                 continue;
 411         }
 412         if (!strcmp(word, "else") && !skip) {   /* Else: Flip processing */
 413                 proc = !proc;
 414                 Goto;
 415                 continue;
 416         }
 417         if (!strcmp(word, "endif")) {   /* Endif: If no skipped   */
 418                                         /* ifdefs turn processing */
 419                 if (!skip)              /* on, else decrement the */
 420                         proc = 1;       /* number of skips        */
 421                 else
 422                         skip--;
 423                 Goto;
 424                 continue;
 425         }
 426                 /* The word fails all of the above tests, so if we're */
 427                 /* processing, print the line. */
 428         if (proc) {
 429                 (void)printf("#%s%c", word, ch);
 430                 Print;
 431         } else
 432                 Goto;
 433   }
 434 }
 435
 436
 437 #ifdef __STDC__
 438 void usage ( void )
 439 #else
 440 void usage()
 441 #endif
 442 {
 443   (void)fprintf(stderr, "Usage: ifdef [-t] [-Dsymbol] [-dsymbol] [-Usymbol] [-Isymbol] <file>\n");
 444   exit(0);
 445 }
 446
 447
 448 #ifdef __STDC__
 449 int main(int argc , char *argv [])
 450 #else
 451 int main(argc, argv)
 452 int argc;
 453 char *argv[];
 454 #endif
 455 {
 456   char sym[80];                 /* Temp symbol storage */
 457   int c;
 458
 459   if (argc == 1) usage();       /* Catch the curious user        */
 460   while ((c = getopt(argc, argv, "tD:d:U:I:")) != EOF) {
 461         switch (c) {
 462             case 't':
 463                 table = 1;      /* Get the various options */
 464                 break;
 465
 466             case 'd':
 467                 (void)strcpy(sym, optarg);
 468                 Define(sym, MUTABLE);
 469                 break;
 470
 471             case 'D':
 472                 (void)strcpy(sym, optarg);
 473                 Define(sym, IMMUTABLE);
 474                 break;
 475
 476             case 'U':
 477                 (void)strcpy(sym, optarg);
 478                 Undefine(sym, IMMUTABLE);
 479                 break;
 480
 481             case 'I':
 482                 (void)strcpy(sym, optarg);
 483                 Ignore(sym, IMMUTABLE);
 484                 break;
 485
 486             default:    usage();
 487         }
 488   }
 489
 490   zin = stdin;          /* If a C file is named */
 491                         /* Open stdin with it */
 492   if (*argv[argc - 1] != '-') {
 493         (void)fclose(zin);
 494         if ((zin = fopen(argv[argc - 1], "r")) == NULL) {
 495                 perror("ifdef");
 496                 exit(1);
 497         }
 498   }
 499   if (table)
 500         gettable();             /* Either generate a table or    */
 501   else
 502         parse();                /* parse & replace with the file */
 503   return(0);
 504 }