18b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project/* Copyright (c) 2008 The Android Open Source Project 28b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * 38b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * Permission is hereby granted, free of charge, to any person obtaining a copy 48b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * of this software and associated documentation files (the "Software"), to deal 58b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * in the Software without restriction, including without limitation the rights 68b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 78b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * copies of the Software, and to permit persons to whom the Software is 88b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * furnished to do so, subject to the following conditions: 98b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * 108b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * The above copyright notice and this permission notice shall be included in 118b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * all copies or substantial portions of the Software. 128b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * 138b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 148b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 158b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 168b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 178b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 188b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 198b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * THE SOFTWARE. 208b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project */ 218b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project 228b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project/* 238b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * Lazy Dynamic Linking Support 248b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * 258b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * This header file is meant to be included multiple times. 268b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * 278b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * It is used to define function pointers to symbols in external 288b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * shared objects (Unix dynamic libraries) which will be lazily resolved 298b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * at runtime, by calling a specific initialization function. 308b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * 318b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * You must define, before including this header, a DYNLINK_FUNCTIONS 328b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * macro which must contain a sequence of DYNLINK_FUNC(ret,name,sig) 338b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * statements. 348b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * 358b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * In each statement, 'ret' is a function return type, 'name' is 368b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * the function's name as provided by the library, and 'sig' is 378b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * the function signature, including enclosing parentheses. 388b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * 398b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * Here's an example: 408b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * 418b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * #define DYNLINK_FUNCTIONS \ 428b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * DYNLINK_FUNC(int,open,(const char*, int)) \ 438b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * DYNLINK_FUNC(int,read,(int,char*,int)) \ 448b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * DYNLINK_FUNC(int,close,(int)) \ 458b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * 468b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * 478b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * You must also define a DYNLINK_FUNCTIONS_INIT macro which contains the 488b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * name of a generated function used to initialize the function pointers. 498b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * (see below) 508b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project */ 518b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project 528b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project#ifndef DYNLINK_FUNCTIONS 538b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project#error DYNLINK_FUNCTIONS should be defined when including this file 548b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project#endif 558b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project 568b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project#ifndef DYNLINK_FUNCTIONS_INIT 578b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project#error DYNLINK_FUNCTIONS_INIT should be defined when including this file 588b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project#endif 598b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project 608b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project/* just in case */ 618b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project#undef DYNLINK_FUNC 628b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project 638b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project/* define pointers to dynamic library functions as static pointers. 648b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project */ 658b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project#define DYNLINK_FUNC(ret,name,sig) \ 668b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project static ret (*_dynlink_##name) sig ; 678b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project 688b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project#define DYNLINK_STR(name) DYNLINK_STR_(name) 698b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project#define DYNLINK_STR_(name) #name 708b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project 718b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source ProjectDYNLINK_FUNCTIONS 728b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project#undef DYNLINK_FUNC 738b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project 748b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project/* now define a function that tries to load all dynlink function 758b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * pointers. returns 0 on success, or -1 on error (i.e. if any of 768b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * the functions could not be loaded). 778b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * 788b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * 'library' must be the result of a succesful dlopen() call 798b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * 808b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * You must define DYNLINK_FUNCTIONS_INIT 818b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project */ 828b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Projectstatic int 838b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source ProjectDYNLINK_FUNCTIONS_INIT(void* library) 848b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project{ 858b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project#define DYNLINK_FUNC(ret,name,sig) \ 868b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project do { \ 878b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project _dynlink_##name = dlsym( library, DYNLINK_STR(name) ); \ 888b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project if (_dynlink_##name == NULL) goto Fail; \ 898b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project } while (0); 908b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project 918b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project DYNLINK_FUNCTIONS 928b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project#undef DYNLINK_FUNC 938b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project 948b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project return 0; 958b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source ProjectFail: 968b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project return -1; 978b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project} 988b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project 998b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project/* in user code, use FF(function_name) to invoke the 1008b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * corresponding dynamic function named 'function_name' 1018b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project * after initialization succeeded. 1028b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project */ 1038b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project#ifndef FF 1048b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project#define FF(name) (*_dynlink_##name) 1058b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project#endif 1068b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project 1078b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project/* clear macros */ 1088b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project#undef DYNLINK_FUNC 1098b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project#undef DYNLINK_FUNCTIONS 1108b23a6c7e1aee255004dd19098d4c2462b61b849The Android Open Source Project#undef DYNLINK_FUNCTIONS_INIT 111