/*
 * Copyright (C) 2006 Apple Inc.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1.  Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer. 
 * 2.  Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution. 
 * 3.  Neither the name of Apple Inc. ("Apple") nor the names of
 *     its contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission. 
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#import "WebKitVersionChecks.h"

#import <mach-o/dyld.h>
#import <mutex>

static int WebKitLinkTimeVersion(void);
static int overriddenWebKitLinkTimeVersion;

BOOL WebKitLinkedOnOrAfter(int version)
{
#if !PLATFORM(IOS_FAMILY)
    return (WebKitLinkTimeVersion() >= version);
#else
    int32_t linkTimeVersion = WebKitLinkTimeVersion();
    int32_t majorVersion = linkTimeVersion >> 16 & 0x0000FFFF;
    
    // The application was not linked against UIKit so assume most recent WebKit
    if (linkTimeVersion == -1)
        return YES;
    
    return (majorVersion >= version);
#endif
}

void setWebKitLinkTimeVersion(int version)
{
    overriddenWebKitLinkTimeVersion = version;
}

static int WebKitLinkTimeVersion(void)
{
    if (overriddenWebKitLinkTimeVersion)
        return overriddenWebKitLinkTimeVersion;

#if !PLATFORM(IOS_FAMILY)
    return NSVersionOfLinkTimeLibrary("WebKit");
#else
    // <rdar://problem/6627758> Need to implement WebKitLinkedOnOrAfter
    // Third party applications do not link against WebKit, but rather against UIKit.
    return NSVersionOfLinkTimeLibrary("UIKit");
#endif
}