/* 
 * 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 ck_main (int argc, char ** argv) 
#else 
int ck_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; 
} 
