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 } 403
