dnl IJG auto-configuration source file.
dnl Process this file with autoconf to produce a configure script.
AC_INIT(jcmaster.c)
AC_CONFIG_HEADER(jconfig.h:jconfig.cfg)
dnl
dnl do these first since other macros rely on them
AC_PROG_CC
AC_PROG_CPP
dnl
dnl See if compiler supports prototypes.
AC_MSG_CHECKING(for function prototypes)
AC_CACHE_VAL(ijg_cv_have_prototypes,
[AC_TRY_COMPILE([
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; }
], [ ], ijg_cv_have_prototypes=yes, ijg_cv_have_prototypes=no)])
AC_MSG_RESULT($ijg_cv_have_prototypes)
if test $ijg_cv_have_prototypes = yes; then
  AC_DEFINE(HAVE_PROTOTYPES,1)
else
  echo Your compiler does not seem to know about function prototypes.
  echo Perhaps it needs a special switch to enable ANSI C mode.
  echo If so, we recommend running configure like this:
  echo "   ./configure  CC='cc -switch'"
  echo where -switch is the proper switch.
fi
dnl
dnl check header files
AC_CHECK_HEADER(stddef.h, AC_DEFINE(HAVE_STDDEF_H,1))
AC_CHECK_HEADER(stdlib.h, AC_DEFINE(HAVE_STDLIB_H,1))
AC_CHECK_HEADER(string.h,, AC_DEFINE(NEED_BSD_STRINGS,1))
dnl See whether type size_t is defined in any ANSI-standard places;
dnl if not, perhaps it is defined in <sys/types.h>.
AC_MSG_CHECKING(for size_t)
AC_TRY_COMPILE([
#ifdef HAVE_STDDEF_H
#include <stddef.h>
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#include <stdio.h>
#ifdef NEED_BSD_STRINGS
#include <strings.h>
#else
#include <string.h>
#endif
typedef size_t my_size_t;
], [ my_size_t foovar; ], ijg_size_t_ok=yes,
[ijg_size_t_ok="not ANSI, perhaps it is in sys/types.h"])
AC_MSG_RESULT($ijg_size_t_ok)
if test "$ijg_size_t_ok" != yes; then
AC_CHECK_HEADER(sys/types.h, [AC_DEFINE(NEED_SYS_TYPES_H,1)
AC_EGREP_CPP(size_t, [#include <sys/types.h>],
[ijg_size_t_ok="size_t is in sys/types.h"], ijg_size_t_ok=no)],
ijg_size_t_ok=no)
AC_MSG_RESULT($ijg_size_t_ok)
if test "$ijg_size_t_ok" = no; then
  echo Type size_t is not defined in any of the usual places.
  echo Try putting '"typedef unsigned int size_t;"' in jconfig.h.
fi
fi
dnl
dnl check compiler characteristics
AC_MSG_CHECKING(for type unsigned char)
AC_TRY_COMPILE(, [ unsigned char un_char; ],
[AC_MSG_RESULT(yes)
AC_DEFINE(HAVE_UNSIGNED_CHAR,1)], AC_MSG_RESULT(no))
AC_MSG_CHECKING(for type unsigned short)
AC_TRY_COMPILE(, [ unsigned short un_short; ],
[AC_MSG_RESULT(yes)
AC_DEFINE(HAVE_UNSIGNED_SHORT,1)], AC_MSG_RESULT(no))
AC_MSG_CHECKING(for type void)
AC_TRY_COMPILE([
/* Caution: a C++ compiler will insist on valid 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 */
}
], [ ], AC_MSG_RESULT(yes), [AC_MSG_RESULT(no)
AC_DEFINE(void,char)])

AC_C_CONST
dnl check for non-broken inline under various spellings
AC_MSG_CHECKING(for inline)
ijg_cv_inline=""
AC_TRY_COMPILE(, [} __inline__ int foo() { return 0; }
int bar() { return foo();], ijg_cv_inline="__inline__",
AC_TRY_COMPILE(, [} __inline int foo() { return 0; }
int bar() { return foo();], ijg_cv_inline="__inline",
AC_TRY_COMPILE(, [} inline int foo() { return 0; }
int bar() { return foo();], ijg_cv_inline="inline")))
AC_MSG_RESULT($ijg_cv_inline)
AC_DEFINE_UNQUOTED(INLINE,$ijg_cv_inline)
dnl we cannot check for bogus warnings, but at least we can check for errors
AC_MSG_CHECKING(for broken incomplete types)
AC_TRY_COMPILE([ typedef struct undefined_structure * undef_struct_ptr; ], ,
AC_MSG_RESULT(ok),
[AC_MSG_RESULT(broken)
AC_DEFINE(INCOMPLETE_TYPES_BROKEN,1)])
dnl test whether global names are unique to at least 15 chars
AC_MSG_CHECKING(for short external names)
AC_TRY_LINK([
int possibly_duplicate_function () { return 0; }
int possibly_dupli_function () { return 1; }
], [ ], AC_MSG_RESULT(ok), [AC_MSG_RESULT(short)
AC_DEFINE(NEED_SHORT_EXTERNAL_NAMES,1)])
dnl
dnl run-time checks
AC_MSG_CHECKING(to see if char is signed)
AC_TRY_RUN([
#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 */
}
char signed_char_check = (char) (-67);
int main() {
  exit(is_char_signed((int) signed_char_check));
}], [AC_MSG_RESULT(no)
AC_DEFINE(CHAR_IS_UNSIGNED,1)], AC_MSG_RESULT(yes),
[echo Assuming that char is signed on target machine.
echo If it is unsigned, this will be a little bit inefficient.
])
dnl
AC_MSG_CHECKING(to see if right shift is signed)
AC_TRY_RUN([
#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 */
}
int main() {
  exit(is_shifting_signed(-0x7F7E80B1L));
}], [AC_MSG_RESULT(no)
AC_DEFINE(RIGHT_SHIFT_IS_UNSIGNED,1)], AC_MSG_RESULT(yes),
AC_MSG_RESULT(Assuming that right shift is signed on target machine.))
dnl
AC_MSG_CHECKING(to see if fopen accepts b spec)
AC_TRY_RUN([
#include <stdio.h>
int main() {
  if (fopen("conftestdata", "wb") != NULL)
    exit(0);
  exit(1);
}], AC_MSG_RESULT(yes), [AC_MSG_RESULT(no)
AC_DEFINE(DONT_USE_B_MODE,1)],
AC_MSG_RESULT(Assuming that it does.))
dnl
dnl system services
AC_PROG_INSTALL
AC_PROG_RANLIB

# Decide whether to use libtool,
# and if so whether to build shared, static, or both flavors of library.
AC_DISABLE_SHARED
AC_DISABLE_STATIC
if test "x$enable_shared" != xno  -o  "x$enable_static" != xno; then
  USELIBTOOL="yes"

  # Configure libtool.
  AC_PROG_LIBTOOL

  LIBTOOL="./libtool"
  O="lo"
  A="la"
  LN='$(LIBTOOL) --mode=link $(CC)'
  INSTALL_LIB='$(LIBTOOL) --mode=install ${INSTALL}'
  INSTALL_PROGRAM="\$(LIBTOOL) --mode=install $INSTALL_PROGRAM"
else
  USELIBTOOL="no"
  LIBTOOL=""
  O="o"
  A="a"
  LN='$(CC)'
  INSTALL_LIB="$INSTALL_DATA"
fi
AC_SUBST(LIBTOOL)
AC_SUBST(O)
AC_SUBST(A)
AC_SUBST(LN)
AC_SUBST(INSTALL_LIB)

# Select memory manager depending on user input.
# If no "-enable-maxmem", use jmemnobs
MEMORYMGR='jmemnobs.$(O)'
MAXMEM="no"
AC_ARG_ENABLE(maxmem,
[  --enable-maxmem[=N]     enable use of temp files, set max mem usage to N MB],
MAXMEM="$enableval")
dnl [# support --with-maxmem for backwards compatibility with IJG V5.]
dnl AC_ARG_WITH(maxmem, , MAXMEM="$withval")
if test "x$MAXMEM" = xyes; then
  MAXMEM=1
fi
if test "x$MAXMEM" != xno; then
changequote(, )dnl
  if test -n "`echo $MAXMEM | sed 's/[0-9]//g'`"; then
changequote([, ])dnl
    AC_MSG_ERROR(non-numeric argument to --enable-maxmem)
  fi
  DEFAULTMAXMEM=`expr $MAXMEM \* 1048576`
AC_DEFINE_UNQUOTED(DEFAULT_MAX_MEM, ${DEFAULTMAXMEM})
AC_MSG_CHECKING([for 'tmpfile()'])
AC_TRY_LINK([#include <stdio.h>], [ FILE * tfile = tmpfile(); ],
[AC_MSG_RESULT(yes)
MEMORYMGR='jmemansi.$(O)'],
[AC_MSG_RESULT(no)
dnl if tmpfile is not present, must use jmemname.
MEMORYMGR='jmemname.$(O)'
AC_DEFINE(NEED_SIGNAL_CATCHER,1)
AC_MSG_CHECKING([for 'mktemp()'])
AC_TRY_LINK(, [ char fname[80]; mktemp(fname); ], AC_MSG_RESULT(yes),
[AC_MSG_RESULT(no)
AC_DEFINE(NO_MKTEMP,1)])])
fi
AC_SUBST(MEMORYMGR)

# Include PNG support in cjpeg/djpeg if appropriate.
AC_ARG_WITH(png,
[  --with-png              enable PNG support in cjpeg/djpeg],
[#], [with_png="maybe"])

# try to detect whether libpng is present
if test "x$with_png" = xmaybe ; then
  AC_CHECK_HEADER(png.h, [: ok so far], [with_png="no"])
fi
if test "x$with_png" = xmaybe ; then
  AC_CHECK_HEADER(zlib.h, [: ok so far], [with_png="no"])
fi
if test "x$with_png" = xmaybe ; then
  AC_CHECK_LIB(z, deflate, [: ok so far], [with_png="no"])
fi
if test "x$with_png" = xmaybe ; then
  AC_CHECK_LIB(png, png_create_info_struct,
	[with_png="yes"], [with_png="no"], [-lz -lm])
fi

if test "x$with_png" = xyes ; then
  AC_DEFINE(PNG_SUPPORTED,1)
  LIBS="-lpng -lz -lm $LIBS"
fi

# Extract the library version ID from jpeglib.h.
AC_MSG_CHECKING([libjpeg version number])
[JPEG_LIB_VERSION=`sed -e '/^#define JPEG_LIB_VERSION/!d' -e 's/^[^0-9]*\([0-9][0-9]*\).*$/\1/' $srcdir/jpeglib.h`]
AC_MSG_RESULT($JPEG_LIB_VERSION)
AC_SUBST(JPEG_LIB_VERSION)

# Prepare to massage makefile.cfg correctly.
if test $ijg_cv_have_prototypes = yes; then
  A2K_DEPS=""
  COM_A2K="# "
else
  A2K_DEPS="ansi2knr"
  COM_A2K=""
fi
AC_SUBST(A2K_DEPS)
AC_SUBST(COM_A2K)
# ansi2knr needs -DBSD if string.h is missing
if test $ac_cv_header_string_h = no; then
  ANSI2KNRFLAGS="-DBSD"
else
  ANSI2KNRFLAGS=""
fi
AC_SUBST(ANSI2KNRFLAGS)
dnl
# Substitutions to enable or disable libtool-related stuff
if test $USELIBTOOL = yes -a $ijg_cv_have_prototypes = yes; then
  COM_LT=""
else
  COM_LT="# "
fi
AC_SUBST(COM_LT)
if test "x$enable_shared" != xno; then
  FORCE_INSTALL_LIB="install-lib"
else
  FORCE_INSTALL_LIB=""
fi
AC_SUBST(FORCE_INSTALL_LIB)
dnl
# Set up -I directives
if test "x$srcdir" = x.; then
  INCLUDEFLAGS='-I$(srcdir)'
else
  if test "x$GCC" = xyes; then
    INCLUDEFLAGS='-I- -I. -I$(srcdir)'
  else
    INCLUDEFLAGS='-I. -I$(srcdir)'
  fi
fi
AC_SUBST(INCLUDEFLAGS)
dnl
AC_OUTPUT(Makefile:makefile.cfg)