/* * Copyright (c) 2000,2008-2012 Apple Inc. All rights reserved. * * @APPLE_OSREFERENCE_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. The rights granted to you under the License * may not be used to create, or enable the creation or redistribution of, * unlawful or unlicensed copies of an Apple operating system, or to * circumvent, violate, or enable the circumvention or violation of, any * terms of an Apple operating system software license agreement. * * 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_OSREFERENCE_LICENSE_HEADER_END@ */ /* * Subtle combination of files and libraries make up the C++ runtime system for kernel modules. We are dependant on the KernelModule kmod.make and CreateKModInfo.perl scripts to be exactly instep with both this library module and the libkmod module as well. * * If you do any maintenance on any of the following files make sure great care is taken to keep them in Sync. * KernelModule.bproj/kmod.make * KernelModule.bproj/CreateKModInfo.perl * KernelModule.bproj/kmodc++/pure.c * KernelModule.bproj/kmodc++/cplus_start.c * KernelModule.bproj/kmodc++/cplus_start.c * KernelModule.bproj/kmodc/c_start.c * KernelModule.bproj/kmodc/c_stop.c * * The trick is that the linkline links all of the developers modules. If any static constructors are used .constructors_used will be left as an undefined symbol. This symbol is exported by the cplus_start.c routine which automatically brings in the appropriate C++ _start routine. However the actual _start symbol is only required by the kmod_info structure that is created and initialized by the CreateKModInfo.perl script. If no C++ was used the _start will be an undefined symbol that is finally satisfied by the c_start module in the kmod library. * * The linkline must look like this. *.o -lkmodc++ kmod_info.o -lkmod */