acinclude.m4

MPEG2的编码的加密和解码的C源程序

dnl AC_C_RESTRICT
dnl Do nothing if the compiler accepts the restrict keyword.
dnl Otherwise define restrict to __restrict__ or __restrict if one of
dnl those work, otherwise define restrict to be empty.
AC_DEFUN([AC_C_RESTRICT],
    [AC_MSG_CHECKING([for restrict])
    ac_cv_c_restrict=no
    for ac_kw in restrict __restrict__ __restrict; do
	AC_TRY_COMPILE([],[char * $ac_kw p;],[ac_cv_c_restrict=$ac_kw; break])
    done
    AC_MSG_RESULT([$ac_cv_c_restrict])
    case $ac_cv_c_restrict in
	restrict) ;;
	no)	AC_DEFINE([restrict],,
		    [Define as `__restrict' if that's what the C compiler calls
		    it, or to nothing if it is not supported.]) ;;
	*)	AC_DEFINE_UNQUOTED([restrict],$ac_cv_c_restrict) ;;
    esac])

dnl AC_C_BUILTIN_EXPECT
dnl Check whether compiler understands __builtin_expect.
AC_DEFUN([AC_C_BUILTIN_EXPECT],
    [AC_CACHE_CHECK([for __builtin_expect],[ac_cv_builtin_expect],
	[cat > conftest.c <<EOF
#line __oline__ "configure"
int foo (int a)
{
    a = __builtin_expect (a, 10);
    return a == 10 ? 0 : 1;
}
EOF
	if AC_TRY_COMMAND([${CC-cc} $CFLAGS -nostdlib -nostartfiles
            -o conftest conftest.c -lgcc >&AC_FD_CC]); then
	    ac_cv_builtin_expect=yes
	else
	    ac_cv_builtin_expect=no
	fi
	rm -f conftest*])
    if test x"$ac_cv_builtin_expect" = x"yes"; then
	AC_DEFINE(HAVE_BUILTIN_EXPECT,,
	    [Define if you have the `__builtin_expect' function.])
    fi])

dnl AC_C_ALWAYS_INLINE
dnl Define inline to something appropriate, including the new always_inline
dnl attribute from gcc 3.1
AC_DEFUN([AC_C_ALWAYS_INLINE],
    [AC_C_INLINE
    if test x"$GCC" = x"yes" -a x"$ac_cv_c_inline" = x"inline"; then
	AC_MSG_CHECKING([for always_inline])
	SAVE_CFLAGS="$CFLAGS"
	CFLAGS="$CFLAGS -Wall -Werror"
	AC_TRY_COMPILE([],
	    [__attribute__ ((__always_inline__)) void f (void);
	    #ifdef __cplusplus
	    42 = 42;	// obviously illegal - we want c++ to fail here
	    #endif],
	    [ac_cv_always_inline=yes],[ac_cv_always_inline=no])
	CFLAGS="$SAVE_CFLAGS"
	AC_MSG_RESULT([$ac_cv_always_inline])
	if test x"$ac_cv_always_inline" = x"yes"; then
	    AC_DEFINE_UNQUOTED([inline],[__attribute__ ((__always_inline__))])
	fi
    fi])

dnl AC_C_ATTRIBUTE_ALIGNED
dnl define ATTRIBUTE_ALIGNED_MAX to the maximum alignment if this is supported
AC_DEFUN([AC_C_ATTRIBUTE_ALIGNED],
    [SAV_CFLAGS=$CFLAGS;
    if test x"$GCC" = xyes; then CFLAGS="$CFLAGS -Werror"; fi
    AC_CACHE_CHECK([__attribute__ ((aligned ())) support],
	[ac_cv_c_attribute_aligned],
	[ac_cv_c_attribute_aligned=0
	for ac_cv_c_attr_align_try in 2 4 8 16 32 64; do
	    AC_TRY_COMPILE([],
		[static struct s {
		    char a;
		    char b __attribute__ ((aligned($ac_cv_c_attr_align_try)));
		} S = {0, 0};
		switch (1) {
		    case 0:
		    case (int)(&((struct s *)0)->b) == $ac_cv_c_attr_align_try:
			return 0;
		}
		return (long)&S;],
		[ac_cv_c_attribute_aligned=$ac_cv_c_attr_align_try])
	done])
    if test x"$ac_cv_c_attribute_aligned" != x"0"; then
	AC_DEFINE_UNQUOTED([ATTRIBUTE_ALIGNED_MAX],
	    [$ac_cv_c_attribute_aligned],[maximum supported data alignment])
    fi
    CFLAGS=$SAV_CFLAGS])

dnl AC_TRY_CFLAGS (CFLAGS, [ACTION-IF-WORKS], [ACTION-IF-FAILS])
dnl check if $CC supports a given set of cflags
AC_DEFUN([AC_TRY_CFLAGS],
    [AC_MSG_CHECKING([if $CC supports $1 flags])
    SAVE_CFLAGS="$CFLAGS"
    CFLAGS="$1"
    AC_TRY_COMPILE([],[],[ac_cv_try_cflags_ok=yes],[ac_cv_try_cflags_ok=no])
    CFLAGS="$SAVE_CFLAGS"
    AC_MSG_RESULT([$ac_cv_try_cflags_ok])
    if test x"$ac_cv_try_cflags_ok" = x"yes"; then
	ifelse([$2],[],[:],[$2])
    else
	ifelse([$3],[],[:],[$3])
    fi])

dnl AC_LIBTOOL_NON_PIC ([ACTION-IF-WORKS], [ACTION-IF-FAILS])
dnl check for nonbuggy libtool -prefer-non-pic
AC_DEFUN([AC_LIBTOOL_NON_PIC],
    [AC_MSG_CHECKING([if libtool supports -prefer-non-pic flag])
    mkdir ac_test_libtool; cd ac_test_libtool; ac_cv_libtool_non_pic=no
    echo "int g (int i); static int h (int i) {return g (i);} int f (int i) {return h (i);}" >f.c
    echo "int (* hook) (int) = 0; int g (int i) {if (hook) i = hook (i); return i + 1;}" >g.c
    ../libtool --mode=compile $CC $CFLAGS -prefer-non-pic \
		-c f.c >/dev/null 2>&1 && \
	../libtool --mode=compile $CC $CFLAGS -prefer-non-pic \
		-c g.c >/dev/null 2>&1 && \
	../libtool --mode=link $CC $CFLAGS -prefer-non-pic -o libfoo.la \
		-rpath / f.lo g.lo >/dev/null 2>&1 &&
	ac_cv_libtool_non_pic=yes
    cd ..; rm -fr ac_test_libtool; AC_MSG_RESULT([$ac_cv_libtool_non_pic])
    if test x"$ac_cv_libtool_non_pic" = x"yes"; then
	ifelse([$1],[],[:],[$1])
    else
	ifelse([$2],[],[:],[$2])
    fi])

dnl AC_CHECK_GENERATE_INTTYPES_H (INCLUDE-DIRECTORY)
dnl generate a default inttypes.h if the header file does not exist already
AC_DEFUN([AC_CHECK_GENERATE_INTTYPES],
    [rm -f $1/inttypes.h
    AC_CHECK_HEADER([inttypes.h],[],[AX_CREATE_STDINT_H([$1/inttypes.h])])])

dnl from http://ac-archive.sourceforge.net/guidod/ax_create_stdint_h.html
dnl modified: s/AC_COMPILE_CHECK_SIZEOF/AC_CHECK_SIZEOF/g

dnl @synopsis AX_CREATE_STDINT_H [( HEADER-TO-GENERATE [, HEDERS-TO-CHECK])]
dnl
dnl the "ISO C9X: 7.18 Integer types <stdint.h>" section requires the
dnl existence of an include file <stdint.h> that defines a set of 
dnl typedefs, especially uint8_t,int32_t,uintptr_t.
dnl Many older installations will not provide this file, but some will
dnl have the very same definitions in <inttypes.h>. In other enviroments
dnl we can use the inet-types in <sys/types.h> which would define the
dnl typedefs int8_t and u_int8_t respectivly.
dnl
dnl This macros will create a local "_stdint.h" or the headerfile given as 
dnl an argument. In many cases that file will just "#include <stdint.h>" 
dnl or "#include <inttypes.h>", while in other environments it will provide 
dnl the set of basic 'stdint's definitions/typedefs: 
dnl   int8_t,uint8_t,int16_t,uint16_t,int32_t,uint32_t,intptr_t,uintptr_t
dnl   int_least32_t.. int_fast32_t.. intmax_t
dnl which may or may not rely on the definitions of other files,
dnl or using the AC_CHECK_SIZEOF macro to determine the actual
dnl sizeof each type.
dnl
dnl if your header files require the stdint-types you will want to create an
dnl installable file mylib-int.h that all your other installable header
dnl may include. So if you have a library package named "mylib", just use
dnl      AX_CREATE_STDINT_H(mylib-int.h) 
dnl in configure.ac and go to install that very header file in Makefile.am
dnl along with the other headers (mylib.h) - and the mylib-specific headers
dnl can simply use "#include <mylib-int.h>" to obtain the stdint-types.
dnl
dnl Remember, if the system already had a valid <stdint.h>, the generated
dnl file will include it directly. No need for fuzzy HAVE_STDINT_H things...
dnl
dnl @, (status: used on new platforms) (see http://ac-archive.sf.net/gstdint/)
dnl @version $Id: acinclude.m4,v 1.16.2.1 2006/02/14 14:22:16 sammy Exp $
dnl @author  Guido Draheim <[e-mail]> 

AC_DEFUN([AX_CREATE_STDINT_H],
[# ------ AX CREATE STDINT H -------------------------------------
AC_MSG_CHECKING([for stdint types])
ac_stdint_h=`echo ifelse($1, , _stdint.h, $1)`
# try to shortcircuit - if the default include path of the compiler
# can find a "stdint.h" header then we assume that all compilers can.
AC_CACHE_VAL([ac_cv_header_stdint_t],[
old_CXXFLAGS="$CXXFLAGS" ; CXXFLAGS=""
old_CPPFLAGS="$CPPFLAGS" ; CPPFLAGS=""
old_CFLAGS="$CFLAGS"     ; CFLAGS=""
AC_TRY_COMPILE([#include <stdint.h>],[int_least32_t v = 0;],
[ac_cv_stdint_result="(assuming C99 compatible system)"
 ac_cv_header_stdint_t="stdint.h"; ],
[ac_cv_header_stdint_t=""])
CXXFLAGS="$old_CXXFLAGS"
CPPFLAGS="$old_CPPFLAGS"
CFLAGS="$old_CFLAGS" ])

v="... $ac_cv_header_stdint_h"
if test "$ac_stdint_h" = "stdint.h" ; then
 AC_MSG_RESULT([(are you sure you want them in ./stdint.h?)])
elif test "$ac_stdint_h" = "inttypes.h" ; then
 AC_MSG_RESULT([(are you sure you want them in ./inttypes.h?)])
elif test "_$ac_cv_header_stdint_t" = "_" ; then
 AC_MSG_RESULT([(putting them into $ac_stdint_h)$v])
else
 ac_cv_header_stdint="$ac_cv_header_stdint_t"
 AC_MSG_RESULT([$ac_cv_header_stdint (shortcircuit)])
fi

if test "_$ac_cv_header_stdint_t" = "_" ; then # can not shortcircuit..

dnl .....intro message done, now do a few system checks.....
dnl btw, all CHECK_TYPE macros do automatically "DEFINE" a type, therefore
dnl we use the autoconf implementation detail _AC CHECK_TYPE_NEW instead

inttype_headers=`echo $2 | sed -e 's/,/ /g'`

ac_cv_stdint_result="(no helpful system typedefs seen)"
AC_CACHE_CHECK([for stdint uintptr_t], [ac_cv_header_stdint_x],[
 ac_cv_header_stdint_x="" # the 1997 typedefs (inttypes.h)
  AC_MSG_RESULT([(..)])
  for i in stdint.h inttypes.h sys/inttypes.h $inttype_headers ; do
   unset ac_cv_type_uintptr_t 
   unset ac_cv_type_uint64_t
   _AC_CHECK_TYPE_NEW(uintptr_t,[ac_cv_header_stdint_x=$i],dnl
     continue,[#include <$i>])
   AC_CHECK_TYPE(uint64_t,[and64="/uint64_t"],[and64=""],[#include<$i>])
   ac_cv_stdint_result="(seen uintptr_t$and64 in $i)"
   break;
  done
  AC_MSG_CHECKING([for stdint uintptr_t])
 ])

if test "_$ac_cv_header_stdint_x" = "_" ; then
AC_CACHE_CHECK([for stdint uint32_t], [ac_cv_header_stdint_o],[
 ac_cv_header_stdint_o="" # the 1995 typedefs (sys/inttypes.h)
  AC_MSG_RESULT([(..)])
  for i in inttypes.h sys/inttypes.h stdint.h $inttype_headers ; do
   unset ac_cv_type_uint32_t
   unset ac_cv_type_uint64_t
   AC_CHECK_TYPE(uint32_t,[ac_cv_header_stdint_o=$i],dnl
     continue,[#include <$i>])
   AC_CHECK_TYPE(uint64_t,[and64="/uint64_t"],[and64=""],[#include<$i>])
   ac_cv_stdint_result="(seen uint32_t$and64 in $i)"
   break;
  done
  AC_MSG_CHECKING([for stdint uint32_t])
 ])
fi

if test "_$ac_cv_header_stdint_x" = "_" ; then
if test "_$ac_cv_header_stdint_o" = "_" ; then
AC_CACHE_CHECK([for stdint u_int32_t], [ac_cv_header_stdint_u],[
 ac_cv_header_stdint_u="" # the BSD typedefs (sys/types.h)
  AC_MSG_RESULT([(..)])
  for i in sys/types.h inttypes.h sys/inttypes.h $inttype_headers ; do
   unset ac_cv_type_u_int32_t
   unset ac_cv_type_u_int64_t
   AC_CHECK_TYPE(u_int32_t,[ac_cv_header_stdint_u=$i],dnl
     continue,[#include <$i>])
   AC_CHECK_TYPE(u_int64_t,[and64="/u_int64_t"],[and64=""],[#include<$i>])
   ac_cv_stdint_result="(seen u_int32_t$and64 in $i)"
   break;
  done
  AC_MSG_CHECKING([for stdint u_int32_t])
 ])
fi fi

dnl if there was no good C99 header file, do some typedef checks...
if test "_$ac_cv_header_stdint_x" = "_" ; then
   AC_MSG_CHECKING([for stdint datatype model])
   AC_MSG_RESULT([(..)])
   AC_CHECK_SIZEOF(char)
   AC_CHECK_SIZEOF(short)
   AC_CHECK_SIZEOF(int)
   AC_CHECK_SIZEOF(long)
   AC_CHECK_SIZEOF(void*)
   ac_cv_stdint_char_model=""
   ac_cv_stdint_char_model="$ac_cv_stdint_char_model$ac_cv_sizeof_char"
   ac_cv_stdint_char_model="$ac_cv_stdint_char_model$ac_cv_sizeof_short"
   ac_cv_stdint_char_model="$ac_cv_stdint_char_model$ac_cv_sizeof_int"
   ac_cv_stdint_long_model=""
   ac_cv_stdint_long_model="$ac_cv_stdint_long_model$ac_cv_sizeof_int"
   ac_cv_stdint_long_model="$ac_cv_stdint_long_model$ac_cv_sizeof_long"
   ac_cv_stdint_long_model="$ac_cv_stdint_long_model$ac_cv_sizeof_voidp"
   name="$ac_cv_stdint_long_model"
   case "$ac_cv_stdint_char_model/$ac_cv_stdint_long_model" in
    122/242)     name="$name,  IP16 (standard 16bit machine)" ;;
    122/244)     name="$name,  LP32 (standard 32bit mac/win)" ;;
    122/*)       name="$name        (unusual int16 model)" ;; 
    124/444)     name="$name, ILP32 (standard 32bit unixish)" ;;
    124/488)     name="$name,  LP64 (standard 64bit unixish)" ;;
    124/448)     name="$name, LLP64 (unusual  64bit unixish)" ;;
    124/*)       name="$name        (unusual int32 model)" ;; 
    128/888)     name="$name, ILP64 (unusual  64bit numeric)" ;;
    128/*)       name="$name        (unusual int64 model)" ;; 
    222/*|444/*) name="$name        (unusual dsptype)" ;;
     *)          name="$name        (very unusal model)" ;;
   esac
   AC_MSG_RESULT([combined for stdint datatype model...  $name])
fi

if test "_$ac_cv_header_stdint_x" != "_" ; then
   ac_cv_header_stdint="$ac_cv_header_stdint_x"
elif  test "_$ac_cv_header_stdint_o" != "_" ; then
   ac_cv_header_stdint="$ac_cv_header_stdint_o"
elif  test "_$ac_cv_header_stdint_u" != "_" ; then
   ac_cv_header_stdint="$ac_cv_header_stdint_u"
else
   ac_cv_header_stdint="stddef.h"
fi

AC_MSG_CHECKING([for extra inttypes in chosen header])
AC_MSG_RESULT([($ac_cv_header_stdint)])
dnl see if int_least and int_fast types are present in _this_ header.
unset ac_cv_type_int_least32_t
unset ac_cv_type_int_fast32_t
AC_CHECK_TYPE(int_least32_t,,,[#include <$ac_cv_header_stdint>])
AC_CHECK_TYPE(int_fast32_t,,,[#include<$ac_cv_header_stdint>])
AC_CHECK_TYPE(intmax_t,,,[#include <$ac_cv_header_stdint>])

fi # shortcircut to system "stdint.h"
# ------------------ PREPARE VARIABLES ------------------------------
if test "$GCC" = "yes" ; then
ac_cv_stdint_message="using gnu compiler "`$CC --version | head -1` 
else
ac_cv_stdint_message="using $CC"
fi

AC_MSG_RESULT([make use of $ac_cv_header_stdint in $ac_stdint_h dnl
$ac_cv_stdint_result])

# ----------------- DONE inttypes.h checks START header -------------
AC_CONFIG_COMMANDS([$ac_stdint_h],[
AC_MSG_NOTICE(creating $ac_stdint_h : $_ac_stdint_h)
ac_stdint=$tmp/_stdint.h

echo "#ifndef" $_ac_stdint_h >$ac_stdint
echo "#define" $_ac_stdint_h "1" >>$ac_stdint
echo "#ifndef" _GENERATED_STDINT_H >>$ac_stdint
echo "#define" _GENERATED_STDINT_H '"'$PACKAGE $VERSION'"' >>$ac_stdint
echo "/* generated $ac_cv_stdint_message */" >>$ac_stdint
if test "_$ac_cv_header_stdint_t" != "_" ; then 
echo "#define _STDINT_HAVE_STDINT_H" "1" >>$ac_stdint
fi

cat >>$ac_stdint <<STDINT_EOF

/* ................... shortcircuit part ........................... */

#if defined HAVE_STDINT_H || defined _STDINT_HAVE_STDINT_H
#include <stdint.h>
#else
#include <stddef.h>

/* .................... configured part ............................ */

STDINT_EOF

echo "/* whether we have a C99 compatible stdint header file */" >>$ac_stdint