1 /* 2 * libjingle 3 * Copyright 2004--2010, Google Inc. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright notice, 9 * this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright notice, 11 * this list of conditions and the following disclaimer in the documentation 12 * and/or other materials provided with the distribution. 13 * 3. The name of the author may not be used to endorse or promote products 14 * derived from this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 17 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 18 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO 19 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #include "talk/base/latebindingsymboltable.h" 29 30 #ifdef LINUX 31 #include <dlfcn.h> 32 #endif 33 34 #include "talk/base/logging.h" 35 36 namespace talk_base { 37 38 inline static const char *GetDllError() { 39 #ifdef LINUX 40 char *err = dlerror(); 41 if (err) { 42 return err; 43 } else { 44 return "No error"; 45 } 46 #else 47 #error Not implemented 48 #endif 49 } 50 51 DllHandle InternalLoadDll(const char dll_name[]) { 52 #ifdef LINUX 53 DllHandle handle = dlopen(dll_name, RTLD_NOW); 54 #else 55 #error Not implemented 56 #endif 57 if (handle == kInvalidDllHandle) { 58 LOG(LS_WARNING) << "Can't load " << dll_name << ": " << GetDllError(); 59 } 60 return handle; 61 } 62 63 void InternalUnloadDll(DllHandle handle) { 64 #ifdef LINUX 65 if (dlclose(handle) != 0) { 66 LOG(LS_ERROR) << GetDllError(); 67 } 68 #else 69 #error Not implemented 70 #endif 71 } 72 73 static bool LoadSymbol(DllHandle handle, 74 const char *symbol_name, 75 void **symbol) { 76 #ifdef LINUX 77 *symbol = dlsym(handle, symbol_name); 78 char *err = dlerror(); 79 if (err) { 80 LOG(LS_ERROR) << "Error loading symbol " << symbol_name << ": " << err; 81 return false; 82 } else if (!*symbol) { 83 LOG(LS_ERROR) << "Symbol " << symbol_name << " is NULL"; 84 return false; 85 } 86 return true; 87 #else 88 #error Not implemented 89 #endif 90 } 91 92 // This routine MUST assign SOME value for every symbol, even if that value is 93 // NULL, or else some symbols may be left with uninitialized data that the 94 // caller may later interpret as a valid address. 95 bool InternalLoadSymbols(DllHandle handle, 96 int num_symbols, 97 const char *const symbol_names[], 98 void *symbols[]) { 99 #ifdef LINUX 100 // Clear any old errors. 101 dlerror(); 102 #endif 103 for (int i = 0; i < num_symbols; ++i) { 104 if (!LoadSymbol(handle, symbol_names[i], &symbols[i])) { 105 return false; 106 } 107 } 108 return true; 109 } 110 111 } // namespace talk_base 112