/**************************************************************************** ** ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). ** Contact: Nokia Corporation (qt-info@nokia.com) ** ** This file is part of the QtCore module of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:LGPL$ ** No Commercial Usage ** This file contains pre-release code and may not be distributed. ** You may use this file in accordance with the terms and conditions ** contained in the either Technology Preview License Agreement or the ** Beta Release License Agreement. ** ** GNU Lesser General Public License Usage ** Alternatively, this file may be used under the terms of the GNU Lesser ** General Public License version 2.1 as published by the Free Software ** Foundation and appearing in the file LICENSE.LGPL included in the ** packaging of this file. Please review the following information to ** ensure the GNU Lesser General Public License version 2.1 requirements ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. ** ** In addition, as a special exception, Nokia gives you certain ** additional rights. These rights are described in the Nokia Qt LGPL ** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this ** package. ** ** GNU General Public License Usage ** Alternatively, this file may be used under the terms of the GNU ** General Public License version 3.0 as published by the Free Software ** Foundation and appearing in the file LICENSE.GPL included in the ** packaging of this file. Please review the following information to ** ensure the GNU General Public License version 3.0 requirements will be ** met: http://www.gnu.org/copyleft/gpl.html. ** ** If you are unsure which license is appropriate for your use, please ** contact the sales department at http://www.qtsoftware.com/contact. ** $QT_END_LICENSE$ ** ****************************************************************************/ #include "qplatformdefs.h" #include "qlibrary.h" #ifndef QT_NO_LIBRARY #include "qlibrary_p.h" #include #include #include #include #include #include #include #ifdef Q_OS_MAC # include #endif #ifndef NO_ERRNO_H #include #endif // NO_ERROR_H #include #include #include QT_BEGIN_NAMESPACE //#define QT_DEBUG_COMPONENT #ifdef QT_NO_DEBUG # define QLIBRARY_AS_DEBUG false #else # define QLIBRARY_AS_DEBUG true #endif #if defined(Q_OS_UNIX) && !defined(Q_OS_MAC) // We don't use separate debug and release libs on UNIX, so we want // to allow loading plugins, regardless of how they were built. # define QT_NO_DEBUG_PLUGIN_CHECK #endif Q_GLOBAL_STATIC(QMutex, qt_library_mutex) /*! \class QLibrary \reentrant \brief The QLibrary class loads shared libraries at runtime. \mainclass \ingroup plugins An instance of a QLibrary object operates on a single shared object file (which we call a "library", but is also known as a "DLL"). A QLibrary provides access to the functionality in the library in a platform independent way. You can either pass a file name in the constructor, or set it explicitly with setFileName(). When loading the library, QLibrary searches in all the system-specific library locations (e.g. \c LD_LIBRARY_PATH on Unix), unless the file name has an absolute path. If the file cannot be found, QLibrary tries the name with different platform-specific file suffixes, like ".so" on Unix, ".dylib" on the Mac, or ".dll" on Windows. This makes it possible to specify shared libraries that are only identified by their basename (i.e. without their suffix), so the same code will work on different operating systems. The most important functions are load() to dynamically load the library file, isLoaded() to check whether loading was successful, and resolve() to resolve a symbol in the library. The resolve() function implicitly tries to load the library if it has not been loaded yet. Multiple instances of QLibrary can be used to access the same physical library. Once loaded, libraries remain in memory until the application terminates. You can attempt to unload a library using unload(), but if other instances of QLibrary are using the same library, the call will fail, and unloading will only happen when every instance has called unload(). A typical use of QLibrary is to resolve an exported symbol in a library, and to call the C function that this symbol represents. This is called "explicit linking" in contrast to "implicit linking", which is done by the link step in the build process when linking an executable against a library. The following code snippet loads a library, resolves the symbol "mysymbol", and calls the function if everything succeeded. If something goes wrong, e.g. the library file does not exist or the symbol is not defined, the function pointer will be 0 and won't be called. \snippet doc/src/snippets/code/src_corelib_plugin_qlibrary.cpp 0 The symbol must be exported as a C function from the library for resolve() to work. This means that the function must be wrapped in an \c{extern "C"} block if the library is compiled with a C++ compiler. On Windows, this also requires the use of a \c dllexport macro; see resolve() for the details of how this is done. For convenience, there is a static resolve() function which you can use if you just want to call a function in a library without explicitly loading the library first: \snippet doc/src/snippets/code/src_corelib_plugin_qlibrary.cpp 1 \sa QPluginLoader */ /*! \enum QLibrary::LoadHint This enum describes the possible hints that can be used to change the way libraries are handled when they are loaded. These values indicate how symbols are resolved when libraries are loaded, and are specified using the setLoadHints() function. \value ResolveAllSymbolsHint Causes all symbols in a library to be resolved when it is loaded, not simply when resolve() is called. \value ExportExternalSymbolsHint Exports unresolved and external symbols in the library so that they can be resolved in other dynamically-loaded libraries loaded later. \value LoadArchiveMemberHint Allows the file name of the library to specify a particular object file within an archive file. If this hint is given, the filename of the library consists of a path, which is a reference to an archive file, followed by a reference to the archive member. \sa loadHints */ #ifndef QT_NO_PLUGIN_CHECK struct qt_token_info { qt_token_info(const char *f, const ulong fc) : fields(f), field_count(fc), results(fc), lengths(fc) { results.fill(0); lengths.fill(0); } const char *fields; const ulong field_count; QVector results; QVector lengths; }; /* return values: 1 parse ok 0 eos -1 parse error */ static int qt_tokenize(const char *s, ulong s_len, ulong *advance, qt_token_info &token_info) { ulong pos = 0, field = 0, fieldlen = 0; char current; int ret = -1; *advance = 0; for (;;) { current = s[pos]; // next char ++pos; ++fieldlen; ++*advance; if (! current || pos == s_len + 1) { // save result token_info.results[(int)field] = s; token_info.lengths[(int)field] = fieldlen - 1; // end of string ret = 0; break; } if (current == token_info.fields[field]) { // save result token_info.results[(int)field] = s; token_info.lengths[(int)field] = fieldlen - 1; // end of field fieldlen = 0; ++field; if (field == token_info.field_count - 1) { // parse ok ret = 1; } if (field == token_info.field_count) { // done parsing break; } // reset string and its length s = s + pos; s_len -= pos; pos = 0; } } return ret; } /* returns true if the string s was correctly parsed, false otherwise. */ static bool qt_parse_pattern(const char *s, uint *version, bool *debug, QByteArray *key) { bool ret = true; qt_token_info pinfo("=\n", 2); int parse; ulong at = 0, advance, parselen = qstrlen(s); do { parse = qt_tokenize(s + at, parselen, &advance, pinfo); if (parse == -1) { ret = false; break; } at += advance; parselen -= advance; if (qstrncmp("version", pinfo.results[0], pinfo.lengths[0]) == 0) { // parse version string qt_token_info pinfo2("..-", 3); if (qt_tokenize(pinfo.results[1], pinfo.lengths[1], &advance, pinfo2) != -1) { QByteArray m(pinfo2.results[0], pinfo2.lengths[0]); QByteArray n(pinfo2.results[1], pinfo2.lengths[1]); QByteArray p(pinfo2.results[2], pinfo2.lengths[2]); *version = (m.toUInt() << 16) | (n.toUInt() << 8) | p.toUInt(); } else { ret = false; break; } } else if (qstrncmp("debug", pinfo.results[0], pinfo.lengths[0]) == 0) { *debug = qstrncmp("true", pinfo.results[1], pinfo.lengths[1]) == 0; } else if (qstrncmp("buildkey", pinfo.results[0], pinfo.lengths[0]) == 0){ // save buildkey *key = QByteArray(pinfo.results[1], pinfo.lengths[1]); } } while (parse == 1 && parselen > 0); return ret; } #endif // QT_NO_PLUGIN_CHECK #if defined(Q_OS_UNIX) && !defined(Q_OS_MAC) && !defined(QT_NO_PLUGIN_CHECK) #if defined(Q_OS_FREEBSD) || defined(Q_OS_LINUX) # define USE_MMAP QT_BEGIN_INCLUDE_NAMESPACE # include # include QT_END_INCLUDE_NAMESPACE #endif // Q_OS_FREEBSD || Q_OS_LINUX static long qt_find_pattern(const char *s, ulong s_len, const char *pattern, ulong p_len) { /* we search from the end of the file because on the supported systems, the read-only data/text segments are placed at the end of the file. HOWEVER, when building with debugging enabled, all the debug symbols are placed AFTER the data/text segments. what does this mean? when building in release mode, the search is fast because the data we are looking for is at the end of the file... when building in debug mode, the search is slower because we have to skip over all the debugging symbols first */ if (! s || ! pattern || p_len > s_len) return -1; ulong i, hs = 0, hp = 0, delta = s_len - p_len; for (i = 0; i < p_len; ++i) { hs += s[delta + i]; hp += pattern[i]; } i = delta; for (;;) { if (hs == hp && qstrncmp(s + i, pattern, p_len) == 0) return i; if (i == 0) break; --i; hs -= s[i + p_len]; hs += s[i]; } return -1; } /* This opens the specified library, mmaps it into memory, and searches for the QT_PLUGIN_VERIFICATION_DATA. The advantage of this approach is that we can get the verification data without have to actually load the library. This lets us detect mismatches more safely. Returns false if version/key information is not present, or if the information could not be read. Returns true if version/key information is present and successfully read. */ static bool qt_unix_query(const QString &library, uint *version, bool *debug, QByteArray *key, QLibraryPrivate *lib = 0) { QFile file(library); if (!file.open(QIODevice::ReadOnly)) { if (lib) lib->errorString = file.errorString(); if (qt_debug_component()) { qWarning("%s: %s", (const char*) QFile::encodeName(library), qPrintable(qt_error_string(errno))); } return false; } QByteArray data; char *filedata = 0; ulong fdlen = 0; #ifdef USE_MMAP char *mapaddr = 0; size_t maplen = file.size(); mapaddr = (char *) mmap(mapaddr, maplen, PROT_READ, MAP_PRIVATE, file.handle(), 0); if (mapaddr != MAP_FAILED) { // mmap succeeded filedata = mapaddr; fdlen = maplen; } else { // mmap failed if (qt_debug_component()) { qWarning("mmap: %s", qPrintable(qt_error_string(errno))); } if (lib) lib->errorString = QLibrary::tr("Could not mmap '%1': %2") .arg(library) .arg(qt_error_string()); #endif // USE_MMAP // try reading the data into memory instead data = file.readAll(); filedata = data.data(); fdlen = data.size(); #ifdef USE_MMAP } #endif // USE_MMAP // verify that the pattern is present in the plugin const char pattern[] = "pattern=QT_PLUGIN_VERIFICATION_DATA"; const ulong plen = qstrlen(pattern); long pos = qt_find_pattern(filedata, fdlen, pattern, plen); bool ret = false; if (pos >= 0) ret = qt_parse_pattern(filedata + pos, version, debug, key); if (!ret && lib) lib->errorString = QLibrary::tr("Plugin verification data mismatch in '%1'").arg(library); #ifdef USE_MMAP if (mapaddr != MAP_FAILED && munmap(mapaddr, maplen) != 0) { if (qt_debug_component()) qWarning("munmap: %s", qPrintable(qt_error_string(errno))); if (lib) lib->errorString = QLibrary::tr("Could not unmap '%1': %2") .arg(library) .arg( qt_error_string() ); } #endif // USE_MMAP file.close(); return ret; } #endif // Q_OS_UNIX && !Q_OS_MAC && !defined(QT_NO_PLUGIN_CHECK) typedef QMap LibraryMap; Q_GLOBAL_STATIC(LibraryMap, libraryMap) QLibraryPrivate::QLibraryPrivate(const QString &canonicalFileName, const QString &version) :pHnd(0), fileName(canonicalFileName), fullVersion(version), instance(0), qt_version(0), libraryRefCount(1), libraryUnloadCount(0), pluginState(MightBeAPlugin) { libraryMap()->insert(canonicalFileName, this); } QLibraryPrivate *QLibraryPrivate::findOrCreate(const QString &fileName, const QString &version) { QMutexLocker locker(qt_library_mutex()); if (QLibraryPrivate *lib = libraryMap()->value(fileName)) { lib->libraryRefCount.ref(); return lib; } return new QLibraryPrivate(fileName, version); } QLibraryPrivate::~QLibraryPrivate() { LibraryMap * const map = libraryMap(); if (map) { QLibraryPrivate *that = map->take(fileName); Q_ASSERT(this == that); Q_UNUSED(that); } } void *QLibraryPrivate::resolve(const char *symbol) { if (!pHnd) return 0; return resolve_sys(symbol); } bool QLibraryPrivate::load() { libraryUnloadCount.ref(); if (pHnd) return true; if (fileName.isEmpty()) return false; return load_sys(); } bool QLibraryPrivate::unload() { if (!pHnd) return false; if (!libraryUnloadCount.deref()) { // only unload if ALL QLibrary instance wanted to if (instance) delete instance(); if (unload_sys()) { instance = 0; pHnd = 0; } } return (pHnd == 0); } void QLibraryPrivate::release() { QMutexLocker locker(qt_library_mutex()); if (!libraryRefCount.deref()) delete this; } bool QLibraryPrivate::loadPlugin() { if (instance) { libraryUnloadCount.ref(); return true; } if (load()) { instance = (QtPluginInstanceFunction)resolve("qt_plugin_instance"); return instance; } return false; } /*! Returns true if \a fileName has a valid suffix for a loadable library; otherwise returns false. \table \header \i Platform \i Valid suffixes \row \i Windows \i \c .dll \row \i Unix/Linux \i \c .so \row \i AIX \i \c .a \row \i HP-UX \i \c .sl, \c .so (HP-UXi) \row \i Mac OS X \i \c .dylib, \c .bundle, \c .so \endtable Trailing versioning numbers on Unix are ignored. */ bool QLibrary::isLibrary(const QString &fileName) { #if defined(Q_OS_WIN32) || defined(Q_OS_WINCE) return fileName.endsWith(QLatin1String(".dll")); #else QString completeSuffix = QFileInfo(fileName).completeSuffix(); if (completeSuffix.isEmpty()) return false; QStringList suffixes = completeSuffix.split(QLatin1Char('.')); # if defined(Q_OS_DARWIN) // On Mac, libs look like libmylib.1.0.0.dylib const QString lastSuffix = suffixes.at(suffixes.count() - 1); const QString firstSuffix = suffixes.at(0); bool valid = (lastSuffix == QLatin1String("dylib") || firstSuffix == QLatin1String("so") || firstSuffix == QLatin1String("bundle")); return valid; # else // Generic Unix QStringList validSuffixList; # if defined(Q_OS_HPUX) /* See "HP-UX Linker and Libraries User's Guide", section "Link-time Differences between PA-RISC and IPF": "In PA-RISC (PA-32 and PA-64) shared libraries are suffixed with .sl. In IPF (32-bit and 64-bit), the shared libraries are suffixed with .so. For compatibility, the IPF linker also supports the .sl suffix." */ validSuffixList << QLatin1String("sl"); # if defined __ia64 validSuffixList << QLatin1String("so"); # endif # elif defined(Q_OS_AIX) validSuffixList << QLatin1String("a") << QLatin1String("so"); # elif defined(Q_OS_UNIX) validSuffixList << QLatin1String("so"); # endif // Examples of valid library names: // libfoo.so // libfoo.so.0 // libfoo.so.0.3 // libfoo-0.3.so // libfoo-0.3.so.0.3.0 int suffix; int suffixPos = -1; for (suffix = 0; suffix < validSuffixList.count() && suffixPos == -1; ++suffix) suffixPos = suffixes.indexOf(validSuffixList.at(suffix)); bool valid = suffixPos != -1; for (int i = suffixPos + 1; i < suffixes.count() && valid; ++i) if (i != suffixPos) suffixes.at(i).toInt(&valid); return valid; # endif #endif } bool QLibraryPrivate::isPlugin(QSettings *settings) { errorString.clear(); if (pluginState != MightBeAPlugin) return pluginState == IsAPlugin; #ifndef QT_NO_PLUGIN_CHECK bool debug = !QLIBRARY_AS_DEBUG; QByteArray key; bool success = false; QFileInfo fileinfo(fileName); #ifndef QT_NO_DATESTRING lastModified = fileinfo.lastModified().toString(Qt::ISODate); #endif QString regkey = QString::fromLatin1("Qt Plugin Cache %1.%2.%3/%4") .arg((QT_VERSION & 0xff0000) >> 16) .arg((QT_VERSION & 0xff00) >> 8) .arg(QLIBRARY_AS_DEBUG ? QLatin1String("debug") : QLatin1String("false")) .arg(fileName); QStringList reg; #ifndef QT_NO_SETTINGS bool madeSettings = false; if (!settings) { settings = new QSettings(QSettings::UserScope, QLatin1String("Trolltech")); madeSettings = true; } reg = settings->value(regkey).toStringList(); #endif if (reg.count() == 4 && lastModified == reg.at(3)) { qt_version = reg.at(0).toUInt(0, 16); debug = bool(reg.at(1).toInt()); key = reg.at(2).toLatin1(); success = qt_version != 0; } else { #if defined(Q_OS_UNIX) && !defined(Q_OS_MAC) if (!pHnd) { // use unix shortcut to avoid loading the library success = qt_unix_query(fileName, &qt_version, &debug, &key, this); } else #endif { bool temporary_load = false; #ifdef Q_OS_WIN HMODULE hTempModule = 0; #endif if (!pHnd) { #ifdef Q_OS_WIN QT_WA({ hTempModule = ::LoadLibraryExW((wchar_t*)QDir::toNativeSeparators(fileName).utf16(), 0, DONT_RESOLVE_DLL_REFERENCES); } , { temporary_load = load_sys(); }); #else temporary_load = load_sys(); #endif } # ifdef Q_CC_BOR typedef const char * __stdcall (*QtPluginQueryVerificationDataFunction)(); # else typedef const char * (*QtPluginQueryVerificationDataFunction)(); # endif #ifdef Q_OS_WIN QtPluginQueryVerificationDataFunction qtPluginQueryVerificationDataFunction = hTempModule ? (QtPluginQueryVerificationDataFunction) #ifdef Q_OS_WINCE ::GetProcAddressW(hTempModule, L"qt_plugin_query_verification_data") #else ::GetProcAddress(hTempModule, "qt_plugin_query_verification_data") #endif : (QtPluginQueryVerificationDataFunction) resolve("qt_plugin_query_verification_data"); #else QtPluginQueryVerificationDataFunction qtPluginQueryVerificationDataFunction = (QtPluginQueryVerificationDataFunction) resolve("qt_plugin_query_verification_data"); #endif if (!qtPluginQueryVerificationDataFunction || !qt_parse_pattern(qtPluginQueryVerificationDataFunction(), &qt_version, &debug, &key)) { qt_version = 0; key = "unknown"; if (temporary_load) unload_sys(); } else { success = true; } #ifdef Q_OS_WIN if (hTempModule) { BOOL ok = ::FreeLibrary(hTempModule); if (ok) { hTempModule = 0; } } #endif } QStringList queried; queried << QString::number(qt_version,16) << QString::number((int)debug) << QLatin1String(key) << lastModified; #ifndef QT_NO_SETTINGS settings->setValue(regkey, queried); #endif } #ifndef QT_NO_SETTINGS if (madeSettings) delete settings; #endif if (!success) { if (errorString.isEmpty()){ if (fileName.isEmpty()) errorString = QLibrary::tr("The shared library was not found."); else errorString = QLibrary::tr("The file '%1' is not a valid Qt plugin.").arg(fileName); } return false; } pluginState = IsNotAPlugin; // be pessimistic if ((qt_version > QT_VERSION) || ((QT_VERSION & 0xff0000) > (qt_version & 0xff0000))) { if (qt_debug_component()) { qWarning("In %s:\n" " Plugin uses incompatible Qt library (%d.%d.%d) [%s]", (const char*) QFile::encodeName(fileName), (qt_version&0xff0000) >> 16, (qt_version&0xff00) >> 8, qt_version&0xff, debug ? "debug" : "release"); } errorString = QLibrary::tr("The plugin '%1' uses incompatible Qt library. (%2.%3.%4) [%5]") .arg(fileName) .arg((qt_version&0xff0000) >> 16) .arg((qt_version&0xff00) >> 8) .arg(qt_version&0xff) .arg(debug ? QLatin1String("debug") : QLatin1String("release")); } else if (key != QT_BUILD_KEY #ifdef QT_BUILD_KEY_COMPAT // be sure to load plugins using an older but compatible build key && key != QT_BUILD_KEY_COMPAT #endif ) { if (qt_debug_component()) { qWarning("In %s:\n" " Plugin uses incompatible Qt library\n" " expected build key \"%s\", got \"%s\"", (const char*) QFile::encodeName(fileName), QT_BUILD_KEY, key.isEmpty() ? "" : (const char *) key); } errorString = QLibrary::tr("The plugin '%1' uses incompatible Qt library." " Expected build key \"%2\", got \"%3\"") .arg(fileName) .arg(QLatin1String(QT_BUILD_KEY)) .arg(key.isEmpty() ? QLatin1String("") : QLatin1String((const char *) key)); #ifndef QT_NO_DEBUG_PLUGIN_CHECK } else if(debug != QLIBRARY_AS_DEBUG) { //don't issue a qWarning since we will hopefully find a non-debug? --Sam errorString = QLibrary::tr("The plugin '%1' uses incompatible Qt library." " (Cannot mix debug and release libraries.)").arg(fileName); #endif } else { pluginState = IsAPlugin; } return pluginState == IsAPlugin; #else Q_UNUSED(settings); return pluginState == MightBeAPlugin; #endif } /*! Loads the library and returns true if the library was loaded successfully; otherwise returns false. Since resolve() always calls this function before resolving any symbols it is not necessary to call it explicitly. In some situations you might want the library loaded in advance, in which case you would use this function. \sa unload() */ bool QLibrary::load() { if (!d) return false; if (did_load) return d->pHnd; did_load = true; return d->load(); } /*! Unloads the library and returns true if the library could be unloaded; otherwise returns false. This happens automatically on application termination, so you shouldn't normally need to call this function. If other instances of QLibrary are using the same library, the call will fail, and unloading will only happen when every instance has called unload(). Note that on Mac OS X 10.3 (Panther), dynamic libraries cannot be unloaded. \sa resolve(), load() */ bool QLibrary::unload() { if (did_load) { did_load = false; return d->unload(); } return false; } /*! Returns true if the library is loaded; otherwise returns false. \sa load() */ bool QLibrary::isLoaded() const { return d && d->pHnd; } /*! Constructs a library with the given \a parent. */ QLibrary::QLibrary(QObject *parent) :QObject(parent), d(0), did_load(false) { } /*! Constructs a library object with the given \a parent that will load the library specified by \a fileName. We recommend omitting the file's suffix in \a fileName, since QLibrary will automatically look for the file with the appropriate suffix in accordance with the platform, e.g. ".so" on Unix, ".dylib" on Mac OS X, and ".dll" on Windows. (See \l{fileName}.) */ QLibrary::QLibrary(const QString& fileName, QObject *parent) :QObject(parent), d(0), did_load(false) { setFileName(fileName); } /*! Constructs a library object with the given \a parent that will load the library specified by \a fileName and major version number \a verNum. Currently, the version number is ignored on Windows. We recommend omitting the file's suffix in \a fileName, since QLibrary will automatically look for the file with the appropriate suffix in accordance with the platform, e.g. ".so" on Unix, ".dylib" on Mac OS X, and ".dll" on Windows. (See \l{fileName}.) */ QLibrary::QLibrary(const QString& fileName, int verNum, QObject *parent) :QObject(parent), d(0), did_load(false) { setFileNameAndVersion(fileName, verNum); } /*! Constructs a library object with the given \a parent that will load the library specified by \a fileName and full version number \a version. Currently, the version number is ignored on Windows. We recommend omitting the file's suffix in \a fileName, since QLibrary will automatically look for the file with the appropriate suffix in accordance with the platform, e.g. ".so" on Unix, ".dylib" on Mac OS X, and ".dll" on Windows. (See \l{fileName}.) */ QLibrary::QLibrary(const QString& fileName, const QString &version, QObject *parent) :QObject(parent), d(0), did_load(false) { setFileNameAndVersion(fileName, version); } /*! Destroys the QLibrary object. Unless unload() was called explicitly, the library stays in memory until the application terminates. \sa isLoaded(), unload() */ QLibrary::~QLibrary() { if (d) d->release(); } /*! \property QLibrary::fileName \brief the file name of the library We recommend omitting the file's suffix in the file name, since QLibrary will automatically look for the file with the appropriate suffix (see isLibrary()). When loading the library, QLibrary searches in all system-specific library locations (e.g. \c LD_LIBRARY_PATH on Unix), unless the file name has an absolute path. After loading the library successfully, fileName() returns the fully-qualified file name of the library, including the full path to the library if one was given in the constructor or passed to setFileName(). For example, after successfully loading the "GL" library on Unix platforms, fileName() will return "libGL.so". If the file name was originally passed as "/usr/lib/libGL", fileName() will return "/usr/lib/libGL.so". */ void QLibrary::setFileName(const QString &fileName) { QLibrary::LoadHints lh; if (d) { lh = d->loadHints; d->release(); d = 0; did_load = false; } d = QLibraryPrivate::findOrCreate(fileName); d->loadHints = lh; } QString QLibrary::fileName() const { if (d) return d->qualifiedFileName.isEmpty() ? d->fileName : d->qualifiedFileName; return QString(); } /*! \fn void QLibrary::setFileNameAndVersion(const QString &fileName, int versionNumber) Sets the fileName property and major version number to \a fileName and \a versionNumber respectively. The \a versionNumber is ignored on Windows. \sa setFileName() */ void QLibrary::setFileNameAndVersion(const QString &fileName, int verNum) { QLibrary::LoadHints lh; if (d) { lh = d->loadHints; d->release(); d = 0; did_load = false; } d = QLibraryPrivate::findOrCreate(fileName, verNum >= 0 ? QString::number(verNum) : QString()); d->loadHints = lh; } /*! \since 4.4 Sets the fileName property and full version number to \a fileName and \a version respectively. The \a version parameter is ignored on Windows. \sa setFileName() */ void QLibrary::setFileNameAndVersion(const QString &fileName, const QString &version) { QLibrary::LoadHints lh; if (d) { lh = d->loadHints; d->release(); d = 0; did_load = false; } d = QLibraryPrivate::findOrCreate(fileName, version); d->loadHints = lh; } /*! Returns the address of the exported symbol \a symbol. The library is loaded if necessary. The function returns 0 if the symbol could not be resolved or if the library could not be loaded. Example: \snippet doc/src/snippets/code/src_corelib_plugin_qlibrary.cpp 2 The symbol must be exported as a C function from the library. This means that the function must be wrapped in an \c{extern "C"} if the library is compiled with a C++ compiler. On Windows you must also explicitly export the function from the DLL using the \c{__declspec(dllexport)} compiler directive, for example: \snippet doc/src/snippets/code/src_corelib_plugin_qlibrary.cpp 3 with \c MY_EXPORT defined as \snippet doc/src/snippets/code/src_corelib_plugin_qlibrary.cpp 4 */ void *QLibrary::resolve(const char *symbol) { if (!load()) return 0; return d->resolve(symbol); } /*! \overload Loads the library \a fileName and returns the address of the exported symbol \a symbol. Note that \a fileName should not include the platform-specific file suffix; (see \l{fileName}). The library remains loaded until the application exits. The function returns 0 if the symbol could not be resolved or if the library could not be loaded. \sa resolve() */ void *QLibrary::resolve(const QString &fileName, const char *symbol) { QLibrary library(fileName); return library.resolve(symbol); } /*! \overload Loads the library \a fileName with major version number \a verNum and returns the address of the exported symbol \a symbol. Note that \a fileName should not include the platform-specific file suffix; (see \l{fileName}). The library remains loaded until the application exits. \a verNum is ignored on Windows. The function returns 0 if the symbol could not be resolved or if the library could not be loaded. \sa resolve() */ void *QLibrary::resolve(const QString &fileName, int verNum, const char *symbol) { QLibrary library(fileName, verNum); return library.resolve(symbol); } /*! \overload \since 4.4 Loads the library \a fileName with full version number \a version and returns the address of the exported symbol \a symbol. Note that \a fileName should not include the platform-specific file suffix; (see \l{fileName}). The library remains loaded until the application exits. \a version is ignored on Windows. The function returns 0 if the symbol could not be resolved or if the library could not be loaded. \sa resolve() */ void *QLibrary::resolve(const QString &fileName, const QString &version, const char *symbol) { QLibrary library(fileName, version); return library.resolve(symbol); } /*! \fn QString QLibrary::library() const Use fileName() instead. */ /*! \fn void QLibrary::setAutoUnload( bool b ) Use load(), isLoaded(), and unload() as necessary instead. */ /*! \since 4.2 Returns a text string with the description of the last error that occurred. Currently, errorString will only be set if load(), unload() or resolve() for some reason fails. */ QString QLibrary::errorString() const { return (!d || d->errorString.isEmpty()) ? tr("Unknown error") : d->errorString; } /*! \property QLibrary::loadHints \brief Give the load() function some hints on how it should behave. You can give some hints on how the symbols are resolved. Usually, the symbols are not resolved at load time, but resolved lazily, (that is, when resolve() is called). If you set the loadHint to ResolveAllSymbolsHint, then all symbols will be resolved at load time if the platform supports it. Setting ExportExternalSymbolsHint will make the external symbols in the library available for resolution in subsequent loaded libraries. If LoadArchiveMemberHint is set, the file name is composed of two components: A path which is a reference to an archive file followed by the second component which is the reference to the archive member. For instance, the fileName \c libGL.a(shr_64.o) will refer to the library \c shr_64.o in the archive file named \c libGL.a. This is only supported on the AIX platform. The interpretation of the load hints is platform dependent, and if you use it you are probably making some assumptions on which platform you are compiling for, so use them only if you understand the consequences of them. By default, none of these flags are set, so libraries will be loaded with lazy symbol resolution, and will not export external symbols for resolution in other dynamically-loaded libraries. */ void QLibrary::setLoadHints(LoadHints hints) { if (!d) { d = QLibraryPrivate::findOrCreate(QString()); // ugly, but we need a d-ptr d->errorString.clear(); } d->loadHints = hints; } QLibrary::LoadHints QLibrary::loadHints() const { return d ? d->loadHints : (QLibrary::LoadHints)0; } /* Internal, for debugging */ bool qt_debug_component() { #if defined(QT_DEBUG_COMPONENT) return true; //compatibility? #else static int debug_env = -1; if (debug_env == -1) debug_env = QT_PREPEND_NAMESPACE(qgetenv)("QT_DEBUG_PLUGINS").toInt(); return debug_env != 0; #endif } QT_END_NAMESPACE #endif // QT_NO_LIBRARY