/*

 * ckconfig.c

 *

 * Copyright (C) 1991-1994, Thomas G. Lane.

 * This file is part of the Independent JPEG Group's software.

 * For conditions of distribution and use, see the accompanying README file.

 */



/*

 * This program is intended to help you determine how to configure the JPEG

 * software for installation on a particular system.  The idea is to try to

 * compile and execute this program.  If your compiler fails to compile the

 * program, make changes as indicated in the comments below.  Once you can

 * compile the program, run it, and it will produce a "jconfig.h" file for

 * your system.

 *

 * As a general rule, each time you try to compile this program,

 * pay attention only to the *first* error message you get from the compiler.

 * Many C compilers will issue lots of spurious error messages once they

 * have gotten confused.  Go to the line indicated in the first error message,

 * and read the comments preceding that line to see what to change.

 *

 * Almost all of the edits you may need to make to this program consist of

 * changing a line that reads "#define SOME_SYMBOL" to "#undef SOME_SYMBOL",

 * or vice versa.  This is called defining or undefining that symbol.

 */





/* First we must see if your system has the include files we need.

 * We start out with the assumption that your system has all the ANSI-standard

 * include files.  If you get any error trying to include one of these files,

 * undefine the corresponding HAVE_xxx symbol.

 */



#define HAVE_STDDEF_H		/* replace 'define' by 'undef' if error here */

#ifdef HAVE_STDDEF_H		/* next line will be skipped if you undef... */

#include <stddef.h>

#endif



#define HAVE_STDLIB_H		/* same thing for stdlib.h */

#ifdef HAVE_STDLIB_H

#include <stdlib.h>

#endif



#include <stdio.h>		/* If you ain't got this, you ain't got C. */



/* We have to see if your string functions are defined by

 * strings.h (old BSD convention) or string.h (everybody else).

 * We try the non-BSD convention first; define NEED_BSD_STRINGS

 * if the compiler says it can't find string.h.

 */



#undef NEED_BSD_STRINGS



#ifdef NEED_BSD_STRINGS

#include <strings.h>

#else

#include <string.h>

#endif



/* On some systems (especially older Unix machines), type size_t is

 * defined only in the include file <sys/types.h>.  If you get a failure

 * on the size_t test below, try defining NEED_SYS_TYPES_H.

 */



#undef NEED_SYS_TYPES_H		/* start by assuming we don't need it */

#ifdef NEED_SYS_TYPES_H

#include <sys/types.h>

#endif





/* Usually type size_t is defined in one of the include files we've included

 * above.  If not, you'll get an error on the "typedef size_t my_size_t;" line.

 * In that case, first try defining NEED_SYS_TYPES_H just above.

 * If that doesn't work, you'll have to search through your system library

 * to figure out which include file defines "size_t".  Look for a line that

 * says "typedef something-or-other size_t;".  Then, change the line below

 * that says "#include <someincludefile.h>" to instead include the file

 * you found size_t in, and define NEED_SPECIAL_INCLUDE.  If you can't find

 * type size_t anywhere, try replacing "#include <someincludefile.h>" with

 * "typedef unsigned int size_t;".

 */



#undef NEED_SPECIAL_INCLUDE	/* assume we DON'T need it, for starters */



#ifdef NEED_SPECIAL_INCLUDE

#include <someincludefile.h>

#endif



typedef size_t my_size_t;	/* The payoff: do we have size_t now? */





/* The next question is whether your compiler supports ANSI-style function

 * prototypes.  You need to know this in order to choose between using

 * makefile.ansi and using makefile.unix.

 * The #define line below is set to assume you have ANSI function prototypes.

 * If you get an error in this group of lines, undefine HAVE_PROTOTYPES.

 */



#define HAVE_PROTOTYPES



#ifdef HAVE_PROTOTYPES

int testfunction (int arg1, int * arg2); /* check prototypes */



struct methods_struct {		/* check method-pointer declarations */

  int (*error_exit) (char *msgtext);

  int (*trace_message) (char *msgtext);

  int (*another_method) (void);

};



int testfunction (int arg1, int * arg2) /* check definitions */

{

  return arg2[arg1];

}



int test2function (void)	/* check void arg list */

{

  return 0;

}

#endif





/* Now we want to find out if your compiler knows what "unsigned char" means.

 * If you get an error on the "unsigned char un_char;" line,

 * then undefine HAVE_UNSIGNED_CHAR.

 */



#define HAVE_UNSIGNED_CHAR



#ifdef HAVE_UNSIGNED_CHAR

unsigned char un_char;

#endif





/* Now we want to find out if your compiler knows what "unsigned short" means.

 * If you get an error on the "unsigned short un_short;" line,

 * then undefine HAVE_UNSIGNED_SHORT.

 */



#define HAVE_UNSIGNED_SHORT



#ifdef HAVE_UNSIGNED_SHORT

unsigned short un_short;

#endif





/* Now we want to find out if your compiler understands type "void".

 * If you get an error anywhere in here, undefine HAVE_VOID.

 */



#define HAVE_VOID



#ifdef HAVE_VOID

/* Caution: a C++ compiler will insist on complete prototypes */

typedef void * void_ptr;	/* check void * */

#ifdef HAVE_PROTOTYPES		/* check ptr to function returning void */

typedef void (*void_func) (int a, int b);

#else

typedef void (*void_func) ();

#endif



#ifdef HAVE_PROTOTYPES		/* check void function result */

void test3function (void_ptr arg1, void_func arg2)

#else

void test3function (arg1, arg2)

     void_ptr arg1;

     void_func arg2;

#endif

{

  char * locptr = (char *) arg1; /* check casting to and from void * */

  arg1 = (void *) locptr;

  (*arg2) (1, 2);		/* check call of fcn returning void */

}

#endif





/* Now we want to find out if your compiler knows what "const" means.

 * If you get an error here, undefine HAVE_CONST.

 */



#define HAVE_CONST



#ifdef HAVE_CONST

static const int carray[3] = {1, 2, 3};



#ifdef HAVE_PROTOTYPES

int test4function (const int arg1)

#else

int test4function (arg1)

     const int arg1;

#endif

{

  return carray[arg1];

}

#endif





/* If you get an error or warning about this structure definition,

 * define INCOMPLETE_TYPES_BROKEN.

 */



#undef INCOMPLETE_TYPES_BROKEN



#ifndef INCOMPLETE_TYPES_BROKEN

typedef struct undefined_structure * undef_struct_ptr;

#endif





/* If you get an error about duplicate names,

 * define NEED_SHORT_EXTERNAL_NAMES.

 */



#undef NEED_SHORT_EXTERNAL_NAMES



#ifndef NEED_SHORT_EXTERNAL_NAMES



int possibly_duplicate_function ()

{

  return 0;

}



int possibly_dupli_function ()

{

  return 1;

}



#endif







/************************************************************************

 *  OK, that's it.  You should not have to change anything beyond this

 *  point in order to compile and execute this program.  (You might get

 *  some warnings, but you can ignore them.)

 *  When you run the program, it will make a couple more tests that it

 *  can do automatically, and then it will create jconfig.h and print out

 *  any additional suggestions it has.

 ************************************************************************

 */





#ifdef HAVE_PROTOTYPES

int is_char_signed (int arg)

#else

int is_char_signed (arg)

     int arg;

#endif

{

  if (arg == 189) {		/* expected result for unsigned char */

    return 0;			/* type char is unsigned */

  }

  else if (arg != -67) {	/* expected result for signed char */

    printf("Hmm, it seems 'char' is not eight bits wide on your machine.\n");

    printf("I fear the JPEG software will not work at all.\n\n");

  }

  return 1;			/* assume char is signed otherwise */

}





#ifdef HAVE_PROTOTYPES

int is_shifting_signed (long arg)

#else

int is_shifting_signed (arg)

     long arg;

#endif

/* See whether right-shift on a long is signed or not. */

{

  long res = arg >> 4;



  if (res == -0x7F7E80CL) {	/* expected result for signed shift */

    return 1;			/* right shift is signed */

  }

  /* see if unsigned-shift hack will fix it. */

  /* we can't just test exact value since it depends on width of long... */

  res |= (~0L) << (32-4);

  if (res == -0x7F7E80CL) {	/* expected result now? */

    return 0;			/* right shift is unsigned */

  }

  printf("Right shift isn't acting as I expect it to.\n");

  printf("I fear the JPEG software will not work at all.\n\n");

  return 0;			/* try it with unsigned anyway */

}





#ifdef HAVE_PROTOTYPES

int main (int argc, char ** argv)

#else

int main (argc, argv)

     int argc;

     char ** argv;

#endif

{

  char signed_char_check = (char) (-67);

  FILE *outfile;



  /* Attempt to write jconfig.h */

  if ((outfile = fopen("jconfig.h", "w")) == NULL) {

    printf("Failed to write jconfig.h\n");

    return 1;

  }



  /* Write out all the info */

  fprintf(outfile, "/* jconfig.h --- generated by ckconfig.c */\n");

  fprintf(outfile, "/* see jconfig.doc for explanations */\n\n");

#ifdef HAVE_PROTOTYPES

  fprintf(outfile, "#define HAVE_PROTOTYPES\n");

#else

  fprintf(outfile, "#undef HAVE_PROTOTYPES\n");

#endif

#ifdef HAVE_UNSIGNED_CHAR

  fprintf(outfile, "#define HAVE_UNSIGNED_CHAR\n");

#else

  fprintf(outfile, "#undef HAVE_UNSIGNED_CHAR\n");

#endif

#ifdef HAVE_UNSIGNED_SHORT

  fprintf(outfile, "#define HAVE_UNSIGNED_SHORT\n");

#else

  fprintf(outfile, "#undef HAVE_UNSIGNED_SHORT\n");

#endif

#ifdef HAVE_VOID

  fprintf(outfile, "/* #define void char */\n");

#else

  fprintf(outfile, "#define void char\n");

#endif

#ifdef HAVE_CONST

  fprintf(outfile, "/* #define const */\n");

#else

  fprintf(outfile, "#define const\n");

#endif

  if (is_char_signed((int) signed_char_check))

    fprintf(outfile, "#undef CHAR_IS_UNSIGNED\n");

  else

    fprintf(outfile, "#define CHAR_IS_UNSIGNED\n");

#ifdef HAVE_STDDEF_H

  fprintf(outfile, "#define HAVE_STDDEF_H\n");

#else

  fprintf(outfile, "#undef HAVE_STDDEF_H\n");

#endif

#ifdef HAVE_STDLIB_H

  fprintf(outfile, "#define HAVE_STDLIB_H\n");

#else

  fprintf(outfile, "#undef HAVE_STDLIB_H\n");

#endif

#ifdef NEED_BSD_STRINGS

  fprintf(outfile, "#define NEED_BSD_STRINGS\n");

#else

  fprintf(outfile, "#undef NEED_BSD_STRINGS\n");

#endif

#ifdef NEED_SYS_TYPES_H

  fprintf(outfile, "#define NEED_SYS_TYPES_H\n");

#else

  fprintf(outfile, "#undef NEED_SYS_TYPES_H\n");

#endif

  fprintf(outfile, "#undef NEED_FAR_POINTERS\n");

#ifdef NEED_SHORT_EXTERNAL_NAMES

  fprintf(outfile, "#define NEED_SHORT_EXTERNAL_NAMES\n");

#else

  fprintf(outfile, "#undef NEED_SHORT_EXTERNAL_NAMES\n");

#endif

#ifdef INCOMPLETE_TYPES_BROKEN

  fprintf(outfile, "#define INCOMPLETE_TYPES_BROKEN\n");

#else

  fprintf(outfile, "#undef INCOMPLETE_TYPES_BROKEN\n");

#endif

  fprintf(outfile, "\n#ifdef JPEG_INTERNALS\n\n");

  if (is_shifting_signed(-0x7F7E80B1L))

    fprintf(outfile, "#undef RIGHT_SHIFT_IS_UNSIGNED\n");

  else

    fprintf(outfile, "#define RIGHT_SHIFT_IS_UNSIGNED\n");

  fprintf(outfile, "\n#endif /* JPEG_INTERNALS */\n");

  fprintf(outfile, "\n#ifdef JPEG_CJPEG_DJPEG\n\n");

  fprintf(outfile, "#define BMP_SUPPORTED		/* BMP image file format */\n");

  fprintf(outfile, "#define GIF_SUPPORTED		/* GIF image file format */\n");

  fprintf(outfile, "#define PPM_SUPPORTED		/* PBMPLUS PPM/PGM image file format */\n");

  fprintf(outfile, "#undef RLE_SUPPORTED		/* Utah RLE image file format */\n");

  fprintf(outfile, "#define TARGA_SUPPORTED		/* Targa image file format */\n\n");

  fprintf(outfile, "#undef TWO_FILE_COMMANDLINE	/* You may need this on non-Unix systems */\n");

  fprintf(outfile, "#undef NEED_SIGNAL_CATCHER	/* Define this if you use jmemname.c */\n");

  fprintf(outfile, "#undef DONT_USE_B_MODE\n");

  fprintf(outfile, "/* #define PROGRESS_REPORT */	/* optional */\n");

  fprintf(outfile, "\n#endif /* JPEG_CJPEG_DJPEG */\n");



  /* Close the jconfig.h file */

  fclose(outfile);



  /* User report */

  printf("Configuration check for Independent JPEG Group's software done.\n");

  printf("\nI have written the jconfig.h file for you.\n\n");

#ifdef HAVE_PROTOTYPES

  printf("You should use makefile.ansi as the starting point for your Makefile.\n");

#else

  printf("You should use makefile.unix as the starting point for your Makefile.\n");

#endif



#ifdef NEED_SPECIAL_INCLUDE

  printf("\nYou'll need to change jconfig.h to include the system include file\n");

  printf("that you found type size_t in, or add a direct definition of type\n");

  printf("size_t if that's what you used.  Just add it to the end.\n");

#endif



  return 0;

}

