jpeg/ckconfig.c

   1 /*
   2  * ckconfig.c
   3  *
   4  * Copyright (C) 1991-1994, Thomas G. Lane.
   5  * This file is part of the Independent JPEG Group's software.
   6  * For conditions of distribution and use, see the accompanying README file.
   7  */
   8
   9 /*
  10  * This program is intended to help you determine how to configure the JPEG
  11  * software for installation on a particular system.  The idea is to try to
  12  * compile and execute this program.  If your compiler fails to compile the
  13  * program, make changes as indicated in the comments below.  Once you can
  14  * compile the program, run it, and it will produce a "jconfig.h" file for
  15  * your system.
  16  *
  17  * As a general rule, each time you try to compile this program,
  18  * pay attention only to the *first* error message you get from the compiler.
  19  * Many C compilers will issue lots of spurious error messages once they
  20  * have gotten confused.  Go to the line indicated in the first error message,
  21  * and read the comments preceding that line to see what to change.
  22  *
  23  * Almost all of the edits you may need to make to this program consist of
  24  * changing a line that reads "#define SOME_SYMBOL" to "#undef SOME_SYMBOL",
  25  * or vice versa.  This is called defining or undefining that symbol.
  26  */
  27
  28
  29 /* First we must see if your system has the include files we need.
  30  * We start out with the assumption that your system has all the ANSI-standard
  31  * include files.  If you get any error trying to include one of these files,
  32  * undefine the corresponding HAVE_xxx symbol.
  33  */
  34
  35 #define HAVE_STDDEF_H           /* replace 'define' by 'undef' if error here */
  36 #ifdef HAVE_STDDEF_H            /* next line will be skipped if you undef... */
  37 #include <stddef.h>
  38 #endif
  39
  40 #define HAVE_STDLIB_H           /* same thing for stdlib.h */
  41 #ifdef HAVE_STDLIB_H
  42 #include <stdlib.h>
  43 #endif
  44
  45 #include <stdio.h>              /* If you ain't got this, you ain't got C. */
  46
  47 /* We have to see if your string functions are defined by
  48  * strings.h (old BSD convention) or string.h (everybody else).
  49  * We try the non-BSD convention first; define NEED_BSD_STRINGS
  50  * if the compiler says it can't find string.h.
  51  */
  52
  53 #undef NEED_BSD_STRINGS
  54
  55 #ifdef NEED_BSD_STRINGS
  56 #include <strings.h>
  57 #else
  58 #include <string.h>
  59 #endif
  60
  61 /* On some systems (especially older Unix machines), type size_t is
  62  * defined only in the include file <sys/types.h>.  If you get a failure
  63  * on the size_t test below, try defining NEED_SYS_TYPES_H.
  64  */
  65
  66 #undef NEED_SYS_TYPES_H         /* start by assuming we don't need it */
  67 #ifdef NEED_SYS_TYPES_H
  68 #include <sys/types.h>
  69 #endif
  70
  71
  72 /* Usually type size_t is defined in one of the include files we've included
  73  * above.  If not, you'll get an error on the "typedef size_t my_size_t;" line.
  74  * In that case, first try defining NEED_SYS_TYPES_H just above.
  75  * If that doesn't work, you'll have to search through your system library
  76  * to figure out which include file defines "size_t".  Look for a line that
  77  * says "typedef something-or-other size_t;".  Then, change the line below
  78  * that says "#include <someincludefile.h>" to instead include the file
  79  * you found size_t in, and define NEED_SPECIAL_INCLUDE.  If you can't find
  80  * type size_t anywhere, try replacing "#include <someincludefile.h>" with
  81  * "typedef unsigned int size_t;".
  82  */
  83
  84 #undef NEED_SPECIAL_INCLUDE     /* assume we DON'T need it, for starters */
  85
  86 #ifdef NEED_SPECIAL_INCLUDE
  87 #include <someincludefile.h>
  88 #endif
  89
  90 typedef size_t my_size_t;       /* The payoff: do we have size_t now? */
  91
  92
  93 /* The next question is whether your compiler supports ANSI-style function
  94  * prototypes.  You need to know this in order to choose between using
  95  * makefile.ansi and using makefile.unix.
  96  * The #define line below is set to assume you have ANSI function prototypes.
  97  * If you get an error in this group of lines, undefine HAVE_PROTOTYPES.
  98  */
  99
 100 #define HAVE_PROTOTYPES
 101
 102 #ifdef HAVE_PROTOTYPES
 103 int testfunction (int arg1, int * arg2); /* check prototypes */
 104
 105 struct methods_struct {         /* check method-pointer declarations */
 106   int (*error_exit) (char *msgtext);
 107   int (*trace_message) (char *msgtext);
 108   int (*another_method) (void);
 109 };
 110
 111 int testfunction (int arg1, int * arg2) /* check definitions */
 112 {
 113   return arg2[arg1];
 114 }
 115
 116 int test2function (void)        /* check void arg list */
 117 {
 118   return 0;
 119 }
 120 #endif
 121
 122
 123 /* Now we want to find out if your compiler knows what "unsigned char" means.
 124  * If you get an error on the "unsigned char un_char;" line,
 125  * then undefine HAVE_UNSIGNED_CHAR.
 126  */
 127
 128 #define HAVE_UNSIGNED_CHAR
 129
 130 #ifdef HAVE_UNSIGNED_CHAR
 131 unsigned char un_char;
 132 #endif
 133
 134
 135 /* Now we want to find out if your compiler knows what "unsigned short" means.
 136  * If you get an error on the "unsigned short un_short;" line,
 137  * then undefine HAVE_UNSIGNED_SHORT.
 138  */
 139
 140 #define HAVE_UNSIGNED_SHORT
 141
 142 #ifdef HAVE_UNSIGNED_SHORT
 143 unsigned short un_short;
 144 #endif
 145
 146
 147 /* Now we want to find out if your compiler understands type "void".
 148  * If you get an error anywhere in here, undefine HAVE_VOID.
 149  */
 150
 151 #define HAVE_VOID
 152
 153 #ifdef HAVE_VOID
 154 /* Caution: a C++ compiler will insist on complete prototypes */
 155 typedef void * void_ptr;        /* check void * */
 156 #ifdef HAVE_PROTOTYPES          /* check ptr to function returning void */
 157 typedef void (*void_func) (int a, int b);
 158 #else
 159 typedef void (*void_func) ();
 160 #endif
 161
 162 #ifdef HAVE_PROTOTYPES          /* check void function result */
 163 void test3function (void_ptr arg1, void_func arg2)
 164 #else
 165 void test3function (arg1, arg2)
 166      void_ptr arg1;
 167      void_func arg2;
 168 #endif
 169 {
 170   char * locptr = (char *) arg1; /* check casting to and from void * */
 171   arg1 = (void *) locptr;
 172   (*arg2) (1, 2);               /* check call of fcn returning void */
 173 }
 174 #endif
 175
 176
 177 /* Now we want to find out if your compiler knows what "const" means.
 178  * If you get an error here, undefine HAVE_CONST.
 179  */
 180
 181 #define HAVE_CONST
 182
 183 #ifdef HAVE_CONST
 184 static const int carray[3] = {1, 2, 3};
 185
 186 #ifdef HAVE_PROTOTYPES
 187 int test4function (const int arg1)
 188 #else
 189 int test4function (arg1)
 190      const int arg1;
 191 #endif
 192 {
 193   return carray[arg1];
 194 }
 195 #endif
 196
 197
 198 /* If you get an error or warning about this structure definition,
 199  * define INCOMPLETE_TYPES_BROKEN.
 200  */
 201
 202 #undef INCOMPLETE_TYPES_BROKEN
 203
 204 #ifndef INCOMPLETE_TYPES_BROKEN
 205 typedef struct undefined_structure * undef_struct_ptr;
 206 #endif
 207
 208
 209 /* If you get an error about duplicate names,
 210  * define NEED_SHORT_EXTERNAL_NAMES.
 211  */
 212
 213 #undef NEED_SHORT_EXTERNAL_NAMES
 214
 215 #ifndef NEED_SHORT_EXTERNAL_NAMES
 216
 217 int possibly_duplicate_function ()
 218 {
 219   return 0;
 220 }
 221
 222 int possibly_dupli_function ()
 223 {
 224   return 1;
 225 }
 226
 227 #endif
 228
 229
 230
 231 /************************************************************************
 232  *  OK, that's it.  You should not have to change anything beyond this
 233  *  point in order to compile and execute this program.  (You might get
 234  *  some warnings, but you can ignore them.)
 235  *  When you run the program, it will make a couple more tests that it
 236  *  can do automatically, and then it will create jconfig.h and print out
 237  *  any additional suggestions it has.
 238  ************************************************************************
 239  */
 240
 241
 242 #ifdef HAVE_PROTOTYPES
 243 int is_char_signed (int arg)
 244 #else
 245 int is_char_signed (arg)
 246      int arg;
 247 #endif
 248 {
 249   if (arg == 189) {             /* expected result for unsigned char */
 250     return 0;                   /* type char is unsigned */
 251   }
 252   else if (arg != -67) {        /* expected result for signed char */
 253     printf("Hmm, it seems 'char' is not eight bits wide on your machine.\n");
 254     printf("I fear the JPEG software will not work at all.\n\n");
 255   }
 256   return 1;                     /* assume char is signed otherwise */
 257 }
 258
 259
 260 #ifdef HAVE_PROTOTYPES
 261 int is_shifting_signed (long arg)
 262 #else
 263 int is_shifting_signed (arg)
 264      long arg;
 265 #endif
 266 /* See whether right-shift on a long is signed or not. */
 267 {
 268   long res = arg >> 4;
 269
 270   if (res == -0x7F7E80CL) {     /* expected result for signed shift */
 271     return 1;                   /* right shift is signed */
 272   }
 273   /* see if unsigned-shift hack will fix it. */
 274   /* we can't just test exact value since it depends on width of long... */
 275   res |= (~0L) << (32-4);
 276   if (res == -0x7F7E80CL) {     /* expected result now? */
 277     return 0;                   /* right shift is unsigned */
 278   }
 279   printf("Right shift isn't acting as I expect it to.\n");
 280   printf("I fear the JPEG software will not work at all.\n\n");
 281   return 0;                     /* try it with unsigned anyway */
 282 }
 283
 284
 285 #ifdef HAVE_PROTOTYPES
 286 int main (int argc, char ** argv)
 287 #else
 288 int main (argc, argv)
 289      int argc;
 290      char ** argv;
 291 #endif
 292 {
 293   char signed_char_check = (char) (-67);
 294   FILE *outfile;
 295
 296   /* Attempt to write jconfig.h */
 297   if ((outfile = fopen("jconfig.h", "w")) == NULL) {
 298     printf("Failed to write jconfig.h\n");
 299     return 1;
 300   }
 301
 302   /* Write out all the info */
 303   fprintf(outfile, "/* jconfig.h --- generated by ckconfig.c */\n");
 304   fprintf(outfile, "/* see jconfig.doc for explanations */\n\n");
 305 #ifdef HAVE_PROTOTYPES
 306   fprintf(outfile, "#define HAVE_PROTOTYPES\n");
 307 #else
 308   fprintf(outfile, "#undef HAVE_PROTOTYPES\n");
 309 #endif
 310 #ifdef HAVE_UNSIGNED_CHAR
 311   fprintf(outfile, "#define HAVE_UNSIGNED_CHAR\n");
 312 #else
 313   fprintf(outfile, "#undef HAVE_UNSIGNED_CHAR\n");
 314 #endif
 315 #ifdef HAVE_UNSIGNED_SHORT
 316   fprintf(outfile, "#define HAVE_UNSIGNED_SHORT\n");
 317 #else
 318   fprintf(outfile, "#undef HAVE_UNSIGNED_SHORT\n");
 319 #endif
 320 #ifdef HAVE_VOID
 321   fprintf(outfile, "/* #define void char */\n");
 322 #else
 323   fprintf(outfile, "#define void char\n");
 324 #endif
 325 #ifdef HAVE_CONST
 326   fprintf(outfile, "/* #define const */\n");
 327 #else
 328   fprintf(outfile, "#define const\n");
 329 #endif
 330   if (is_char_signed((int) signed_char_check))
 331     fprintf(outfile, "#undef CHAR_IS_UNSIGNED\n");
 332   else
 333     fprintf(outfile, "#define CHAR_IS_UNSIGNED\n");
 334 #ifdef HAVE_STDDEF_H
 335   fprintf(outfile, "#define HAVE_STDDEF_H\n");
 336 #else
 337   fprintf(outfile, "#undef HAVE_STDDEF_H\n");
 338 #endif
 339 #ifdef HAVE_STDLIB_H
 340   fprintf(outfile, "#define HAVE_STDLIB_H\n");
 341 #else
 342   fprintf(outfile, "#undef HAVE_STDLIB_H\n");
 343 #endif
 344 #ifdef NEED_BSD_STRINGS
 345   fprintf(outfile, "#define NEED_BSD_STRINGS\n");
 346 #else
 347   fprintf(outfile, "#undef NEED_BSD_STRINGS\n");
 348 #endif
 349 #ifdef NEED_SYS_TYPES_H
 350   fprintf(outfile, "#define NEED_SYS_TYPES_H\n");
 351 #else
 352   fprintf(outfile, "#undef NEED_SYS_TYPES_H\n");
 353 #endif
 354   fprintf(outfile, "#undef NEED_FAR_POINTERS\n");
 355 #ifdef NEED_SHORT_EXTERNAL_NAMES
 356   fprintf(outfile, "#define NEED_SHORT_EXTERNAL_NAMES\n");
 357 #else
 358   fprintf(outfile, "#undef NEED_SHORT_EXTERNAL_NAMES\n");
 359 #endif
 360 #ifdef INCOMPLETE_TYPES_BROKEN
 361   fprintf(outfile, "#define INCOMPLETE_TYPES_BROKEN\n");
 362 #else
 363   fprintf(outfile, "#undef INCOMPLETE_TYPES_BROKEN\n");
 364 #endif
 365   fprintf(outfile, "\n#ifdef JPEG_INTERNALS\n\n");
 366   if (is_shifting_signed(-0x7F7E80B1L))
 367     fprintf(outfile, "#undef RIGHT_SHIFT_IS_UNSIGNED\n");
 368   else
 369     fprintf(outfile, "#define RIGHT_SHIFT_IS_UNSIGNED\n");
 370   fprintf(outfile, "\n#endif /* JPEG_INTERNALS */\n");
 371   fprintf(outfile, "\n#ifdef JPEG_CJPEG_DJPEG\n\n");
 372   fprintf(outfile, "#define BMP_SUPPORTED               /* BMP image file format */\n");
 373   fprintf(outfile, "#define GIF_SUPPORTED               /* GIF image file format */\n");
 374   fprintf(outfile, "#define PPM_SUPPORTED               /* PBMPLUS PPM/PGM image file format */\n");
 375   fprintf(outfile, "#undef RLE_SUPPORTED                /* Utah RLE image file format */\n");
 376   fprintf(outfile, "#define TARGA_SUPPORTED             /* Targa image file format */\n\n");
 377   fprintf(outfile, "#undef TWO_FILE_COMMANDLINE /* You may need this on non-Unix systems */\n");
 378   fprintf(outfile, "#undef NEED_SIGNAL_CATCHER  /* Define this if you use jmemname.c */\n");
 379   fprintf(outfile, "#undef DONT_USE_B_MODE\n");
 380   fprintf(outfile, "/* #define PROGRESS_REPORT */       /* optional */\n");
 381   fprintf(outfile, "\n#endif /* JPEG_CJPEG_DJPEG */\n");
 382
 383   /* Close the jconfig.h file */
 384   fclose(outfile);
 385
 386   /* User report */
 387   printf("Configuration check for Independent JPEG Group's software done.\n");
 388   printf("\nI have written the jconfig.h file for you.\n\n");
 389 #ifdef HAVE_PROTOTYPES
 390   printf("You should use makefile.ansi as the starting point for your Makefile.\n");
 391 #else
 392   printf("You should use makefile.unix as the starting point for your Makefile.\n");
 393 #endif
 394
 395 #ifdef NEED_SPECIAL_INCLUDE
 396   printf("\nYou'll need to change jconfig.h to include the system include file\n");
 397   printf("that you found type size_t in, or add a direct definition of type\n");
 398   printf("size_t if that's what you used.  Just add it to the end.\n");
 399 #endif
 400
 401   return 0;
 402 }