00001 /******************************************************************************* 00002 * Copyright (C) 2004 Vintela, Inc. All rights reserved. 00003 * Copyright (C) 2005 Novell, Inc. All rights reserved. 00004 * 00005 * Redistribution and use in source and binary forms, with or without 00006 * modification, are permitted provided that the following conditions are met: 00007 * 00008 * - Redistributions of source code must retain the above copyright notice, 00009 * this list of conditions and the following disclaimer. 00010 * 00011 * - Redistributions in binary form must reproduce the above copyright notice, 00012 * this list of conditions and the following disclaimer in the documentation 00013 * and/or other materials provided with the distribution. 00014 * 00015 * - Neither the name of Vintela, Inc., Novell, Inc., nor the names of its 00016 * contributors may be used to endorse or promote products derived from this 00017 * software without specific prior written permission. 00018 * 00019 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' 00020 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 00021 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 00022 * ARE DISCLAIMED. IN NO EVENT SHALL Vintela, Inc., Novell, Inc., OR THE 00023 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 00024 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 00025 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 00026 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 00027 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 00028 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 00029 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 00030 *******************************************************************************/ 00031 00032 00037 #include "blocxx/BLOCXX_config.h" 00038 #if defined(BLOCXX_USE_DL) 00039 #include "blocxx/dlSharedLibraryLoader.hpp" 00040 #include "blocxx/dlSharedLibrary.hpp" 00041 #include "blocxx/Format.hpp" 00042 #include <dlfcn.h> 00043 00044 namespace BLOCXX_NAMESPACE 00045 { 00046 00048 SharedLibraryRef 00049 dlSharedLibraryLoader::loadSharedLibrary(const String& filename, 00050 const LoggerRef& logger) const 00051 { 00052 // There is a reason to use RTLD_NOW. If some symbols can't be resolved because 00053 // the shared library is built incorrectly or missing some symbols or something, 00054 // then using RTLD_NOW will cause dlopen() to fail, and then the error can be detected 00055 // and handled. If RTLD_LAZY is specified, dlopen() won't fail, but when code is 00056 // executed that tries to use an unresolvable symbol, that will cause a segfault. 00057 // RTLD_GLOBAL is necessary for proper exception and rtti support with gcc. 00058 // See http://gcc.gnu.org/faq.html#dso, so even though it may cause symbol conflicts, 00059 // we have to live with it. 00060 void* libhandle = dlopen(filename.c_str(), RTLD_NOW | RTLD_GLOBAL); 00061 00062 String first_error = dlerror(); 00063 String second_error; 00064 00065 #if defined(BLOCXX_USE_FAKE_LIBS) 00066 // This section, if it determines that a library is fake, will attempt 00067 // to load NULL (which, on most dlopen platforms should return a handle 00068 // to the main executable). This handle can be used just like any 00069 // other, assuming that the main executable was linked with the proper 00070 // export flags (--export-dynamic on linux, -bexpall on AIX, etc.). 00071 if ( !libhandle ) 00072 { 00073 if ( dlSharedLibrary::isFakeLibrary(filename) ) 00074 { 00075 libhandle = dlopen(NULL, RTLD_NOW | RTLD_GLOBAL); 00076 00077 if ( !libhandle ) 00078 { 00079 second_error = dlerror(); 00080 } 00081 } 00082 } 00083 #endif /* defined(BLOCXX_USE_FAKE_LIBS) */ 00084 if (libhandle) 00085 { 00086 return SharedLibraryRef( new dlSharedLibrary(libhandle, 00087 filename)); 00088 } 00089 else 00090 { 00091 BLOCXX_LOG_ERROR(logger, Format("dlSharedLibraryLoader::loadSharedLibrary " 00092 "dlopen returned NULL. Error is: %1", first_error)); 00093 if ( !second_error.empty() ) 00094 { 00095 BLOCXX_LOG_ERROR(logger, Format("dlSharedLibraryLoader::loadSharedLibrary (fakelib) " 00096 "dlopen returned NULL. Error is: %1", second_error)); 00097 } 00098 return SharedLibraryRef( 0 ); 00099 } 00100 } 00101 00103 SharedLibraryLoaderRef 00104 SharedLibraryLoader::createSharedLibraryLoader() 00105 { 00106 return SharedLibraryLoaderRef(new dlSharedLibraryLoader); 00107 } 00109 dlSharedLibraryLoader::~dlSharedLibraryLoader() 00110 { 00111 } 00112 00113 } // end namespace BLOCXX_NAMESPACE 00114 00115 #endif // BLOCXX_USE_DL