libvips/m4/zlib.m4
Felix Bünemann 5ab0001ec6 Add configure check for zlib with inflateInit2
and replace old unused and poorly named FIND_ZIP. The new code prefers
pkgconfig and only falls back to manual detection if needed.

This also prioritizes detected zlib flags and includes to be preferred
over the ones that are added by pkgconfig for libpng, tifflib etc. which
would otherwise have caused the system default zlib to be used.
2016-06-27 03:03:45 +02:00

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dnl From FIND_MOTIF and ACX_PTHREAD, without much understanding
dnl
dnl FIND_ZLIB[ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]]
dnl ------------------------------------------------
dnl
dnl Find zlib libraries and headers ... useful for platforms which are missing
dnl the zlib .pc file
dnl
dnl Put compile stuff in ZLIB_INCLUDES
dnl Put link stuff in ZLIB_LIBS
dnl Define HAVE_ZLIB if found
dnl
AC_DEFUN([FIND_ZLIB], [
AC_REQUIRE([AC_PATH_XTRA])
ZLIB_INCLUDES=""
ZLIB_LIBS=""
AC_ARG_WITH(zlib,
AS_HELP_STRING([--without-zlib], [build without zlib (default: test)]))
# Treat --without-zlib like --without-zlib-includes --without-zlib-libraries.
if test "$with_zlib" = "no"; then
ZLIB_INCLUDES=no
ZLIB_LIBS=no
fi
AC_ARG_WITH(zlib-includes,
AS_HELP_STRING([--with-zlib-includes=DIR], [libz includes are in DIR]),
ZLIB_INCLUDES="-I$withval")
AC_ARG_WITH(zlib-libraries,
AS_HELP_STRING([--with-zlib-libraries=DIR], [libz libraries are in DIR]),
ZLIB_LIBS="-L$withval -lz")
AC_MSG_CHECKING(for ZLIB)
# Look for zlib.h
if test "$ZLIB_INCLUDES" = ""; then
# Check the standard search path
AC_TRY_COMPILE([#include <stdio.h>
#include <zlib.h>],[int a;],[
ZLIB_INCLUDES=""
], [
# zlib.h is not in the standard search path, try
# $prefix
zlib_save_INCLUDES="$INCLUDES"
INCLUDES="-I${prefix}/include $INCLUDES"
AC_TRY_COMPILE([#include <stdio.h>
#include <zlib.h>],[int a;],[
ZLIB_INCLUDES="-I${prefix}/include"
], [
ZLIB_INCLUDES="no"
])
INCLUDES=$zlib_save_INCLUDES
])
fi
# Now for the libraries
if test "$ZLIB_LIBS" = ""; then
zlib_save_LIBS="$LIBS"
zlib_save_INCLUDES="$INCLUDES"
LIBS="-lz $LIBS"
INCLUDES="$ZLIB_INCLUDES $INCLUDES"
# Try the standard search path first
AC_TRY_LINK([#include <stdio.h>
#include <zlib.h>
],[z_stream zs;inflateInit2(&zs, 15 | 32)], [
ZLIB_LIBS="-lz"
], [
# libz is not in the standard search path, try $prefix
LIBS="-L${prefix}/lib $LIBS"
AC_TRY_LINK([#include <stdio.h>
#include <zlib.h>
],[z_stream zs;inflateInit2(&zs, 15 | 32)], [
ZLIB_LIBS="-L${prefix}/lib -lz"
], [
ZLIB_LIBS=no
])
])
LIBS="$zlib_save_LIBS"
INCLUDES="$zlib_save_INCLUDES"
fi
AC_SUBST(ZLIB_LIBS)
AC_SUBST(ZLIB_INCLUDES)
# Print a helpful message
zlib_libraries_result="$ZLIB_LIBS"
zlib_includes_result="$ZLIB_INCLUDES"
if test x"$zlib_libraries_result" = x""; then
zlib_libraries_result="in default path"
fi
if test x"$zlib_includes_result" = x""; then
zlib_includes_result="in default path"
fi
if test "$zlib_libraries_result" = "no"; then
zlib_libraries_result="(none)"
fi
if test "$zlib_includes_result" = "no"; then
zlib_includes_result="(none)"
fi
AC_MSG_RESULT([libraries $zlib_libraries_result, headers $zlib_includes_result])
# Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND:
if test "$ZLIB_INCLUDES" != "no" && test "$ZLIB_LIBS" != "no"; then
AC_DEFINE(HAVE_ZLIB,1,[Define if you have zlib libraries and header files.])
$1
else
ZLIB_INCLUDES=""
ZLIB_LIBS=""
$2
fi
])dnl