1 /*

     2  * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 

    26 /*

    27  * This header file is used to hijack the include of "zlib.h" from libpng on

    28  * Macos. We do that to be able to build on macos 10.13 or later, but still

    29  * keep binary compatibility with older versions (as specified to configure).

    30  *

    31  * The problem is that in 10.13, Macos shipped with a newer version of zlib,

    32  * which exports the function inflateValidate. There is a call to this

    33  * function in pngrutil.c, guarded by a preprocessor check of ZLIB_VERNUM being

    34  * high enough. If we compile this call in and link to the newer version of

    35  * zlib, we will get link errors if the code is executed on an older Mac with

    36  * an older version of zlib.

    37  *

    38  * The zlib.h header in Macos has been annotated with Macos specific macros that

    39  * guard these kinds of version specific APIs, but libpng is not using those

    40  * checks in its conditionals, just ZLIB_VERNUM. To fix this, we check for the

    41  * MAC_OS_X_VERSION_MIN_REQUIRED macro here and adjust the ZLIB_VERNUM to the

    42  # known version bundled with that release. This solution is certainly a hack,

    43  * but it seems the affected versions of zlib.h are compatible enough for this

    44  * to work.

    45  */

    46 

    47 #include <zlib.h>

    48 #include <AvailabilityMacros.h>

    49 

    50 #if MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_12

    51 #  undef ZLIB_VERNUM

    52 #  define ZLIB_VERNUM 0x1250

    53 #elif MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_13

    54 #  undef ZLIB_VERNUM

    55 #  define ZLIB_VERNUM 0x1280

    56 #endif