/* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*- 
 *
 * Copyright (c) 2009-2012 Apple Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */

#include <stdlib.h>
#include <stdio.h>
#include <Availability.h>


#include "dsc_iterator.h"
#define NO_ULEB
#include "DyldSharedCache.h"
#include "MachOAnalyzer.h"


static void forEachDylibInCache(const void* shared_cache_file, void (^handler)(const dyld_cache_image_info* cachedDylibInfo, bool isAlias))
{
    const dyld_cache_header*        header      = (dyld_cache_header*)shared_cache_file;
    const dyld_cache_mapping_info*  mappings    = (dyld_cache_mapping_info*)((char*)shared_cache_file + header->mappingOffset);
    dyld_cache_image_info*          images      = (dyld_cache_image_info*)((char*)shared_cache_file + header->imagesOffsetOld);
    uint32_t                        imagesCount = header->imagesCountOld;
    if ( header->mappingOffset >= __offsetof(dyld_cache_header, imagesCount) ) {
        images = (dyld_cache_image_info*)((char*)shared_cache_file + header->imagesOffset);
        imagesCount = header->imagesCount;
    }

    if ( mappings[0].fileOffset != 0 )
        return;
    uint64_t firstImageOffset = 0;
    uint64_t firstRegionAddress = mappings[0].address;
    for (uint32_t i=0; i < imagesCount; ++i) {
        uint64_t offset = images[i].address - firstRegionAddress;
        if ( firstImageOffset == 0 )
            firstImageOffset = offset;
        // skip over aliases.  This is no longer valid in newer caches
        //bool isAlias = false;//(dylibs[i].pathFileOffset < firstImageOffset);
        handler(&images[i], false);
    }
}


extern int dyld_shared_cache_iterate(const void* shared_cache_file, uint32_t shared_cache_size,
                                         void (^callback)(const dyld_shared_cache_dylib_info* dylibInfo, const dyld_shared_cache_segment_info* segInfo)) {
    const dyld_cache_header*       header             = (dyld_cache_header*)shared_cache_file;
    const dyld_cache_mapping_info* mappings           = (dyld_cache_mapping_info*)((char*)shared_cache_file + header->mappingOffset);
    const uint64_t                 unslideLoadAddress = mappings[0].address;

    __block uint32_t index = 0;
    __block int      result = 0;
    forEachDylibInCache(shared_cache_file, ^(const dyld_cache_image_info* cachedDylibInfo, bool isAlias) {
        uint64_t                    imageCacheOffset = cachedDylibInfo->address - unslideLoadAddress;
        const dyld3::MachOAnalyzer* ma               = (dyld3::MachOAnalyzer*)((uint8_t*)shared_cache_file + imageCacheOffset);
        const char*                 dylibPath        = (char*)shared_cache_file + cachedDylibInfo->pathFileOffset;

        dyld_shared_cache_dylib_info dylibInfo;
        uuid_t                       uuid;
        dylibInfo.version    = 2;
        dylibInfo.machHeader = ma;
        dylibInfo.path       = dylibPath;
        dylibInfo.modTime    = cachedDylibInfo->modTime;
        dylibInfo.inode      = cachedDylibInfo->inode;
        dylibInfo.isAlias    = isAlias;
        ma->getUuid(uuid);
        dylibInfo.uuid       = &uuid;
        ma->forEachSegment(^(const dyld3::MachOAnalyzer::SegmentInfo& info, bool& stop) {
            if ( info.fileSize > info.vmSize ) {
                stop = true;
                return;
            }
            dyld_shared_cache_segment_info segInfo;
            segInfo.version       = 2;
            segInfo.name          = info.segName;
            segInfo.fileOffset    = info.fileOffset;
            segInfo.fileSize      = info.vmSize;
            segInfo.address       = info.vmAddr;
            segInfo.addressOffset = info.vmAddr - unslideLoadAddress;
            callback(&dylibInfo, &segInfo);
        });
        index++;
    });
    return result;
}