projects / apple / xnu.git / blame
| Commit | Line | Data |
|---|---|---|
| 1c79356b | 1 | /* |
| 39236c6e | 2 | * Copyright (c) 2000,2008-2012 Apple Inc. All rights reserved. |
| 1c79356b | 3 | * |
| 2d21ac55 | 4 | * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ |
| 1c79356b | 5 | * |
| 2d21ac55 A |
6 | * This file contains Original Code and/or Modifications of Original Code |
| 7 | * as defined in and that are subject to the Apple Public Source License | |
| 8 | * Version 2.0 (the 'License'). You may not use this file except in | |
| 9 | * compliance with the License. The rights granted to you under the License | |
| 10 | * may not be used to create, or enable the creation or redistribution of, | |
| 11 | * unlawful or unlicensed copies of an Apple operating system, or to | |
| 12 | * circumvent, violate, or enable the circumvention or violation of, any | |
| 13 | * terms of an Apple operating system software license agreement. | |
| 8f6c56a5 | 14 | * |
| 2d21ac55 A |
15 | * Please obtain a copy of the License at |
| 16 | * http://www.opensource.apple.com/apsl/ and read it before using this file. | |
| 17 | * | |
| 18 | * The Original Code and all software distributed under the License are | |
| 19 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER | |
| 8f6c56a5 A |
20 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, |
| 21 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, | |
| 2d21ac55 A |
22 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. |
| 23 | * Please see the License for the specific language governing rights and | |
| 24 | * limitations under the License. | |
| 8f6c56a5 | 25 | * |
| 2d21ac55 | 26 | * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ |
| 1c79356b A |
27 | */ |
| 28 | /* | |
| 29 | 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. | |
| 30 | ||
| 31 | If you do any maintenance on any of the following files make sure great care is taken to keep them in Sync. | |
| 32 | KernelModule.bproj/kmod.make | |
| 33 | KernelModule.bproj/CreateKModInfo.perl | |
| 34 | KernelModule.bproj/kmodc++/pure.c | |
| 35 | KernelModule.bproj/kmodc++/cplus_start.c | |
| 36 | KernelModule.bproj/kmodc++/cplus_start.c | |
| 37 | KernelModule.bproj/kmodc/c_start.c | |
| 38 | KernelModule.bproj/kmodc/c_stop.c | |
| 39 | ||
| 40 | 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. | |
| 41 | ||
| 42 | The linkline must look like this. | |
| 43 | *.o -lkmodc++ kmod_info.o -lkmod | |
| 44 | */ |