path: root/src/corelib/plugin/qlibrary.cpp

// Copyright (C) 2020 The Qt Company Ltd.// Copyright (C) 2021 Intel Corporation.// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only#include"qlibrary.h"#include"qlibrary_p.h"#include <q20algorithm.h>#include <qbytearraymatcher.h>#include <qdebug.h>#include <qendian.h>#include <qfile.h>#include <qfileinfo.h>#include <qjsondocument.h>#include <qmutex.h>#include <qoperatingsystemversion.h>#include <qstringlist.h>#ifdef Q_OS_DARWIN# include <private/qcore_mac_p.h>#endif#include <private/qcoreapplication_p.h>#include <private/qloggingregistry_p.h>#include <private/qsystemerror_p.h>#include"qcoffpeparser_p.h"#include"qelfparser_p.h"#include"qfactoryloader_p.h"#include"qmachparser_p.h"#include <qtcore_tracepoints_p.h>#include <QtCore/q20map.h> QT_BEGIN_NAMESPACE using namespaceQt::StringLiterals;Q_TRACE_POINT(qtcore, QLibraryPrivate_load_entry,const QString &fileName);Q_TRACE_POINT(qtcore, QLibraryPrivate_load_exit,bool success);// On Unix systema and on Windows with MinGW, we can mix and match debug and// release plugins without problems. (unless compiled in debug-and-release mode// - why?)staticconstexprbool PluginMustMatchQtDebug =QOperatingSystemVersion::currentType() ==QOperatingSystemVersion::Windows #if defined(Q_CC_MINGW)&&QT_CONFIG(debug_and_release)#endif;#ifdef QT_NO_DEBUGstaticconstexprbool QtBuildIsDebug =false;#elsestaticconstexprbool QtBuildIsDebug =true;#endifQ_LOGGING_CATEGORY_WITH_ENV_OVERRIDE(qt_lcDebugPlugins,"QT_DEBUG_PLUGINS","qt.core.plugin.loader")Q_STATIC_LOGGING_CATEGORY_WITH_ENV_OVERRIDE(lcDebugLibrary,"QT_DEBUG_PLUGINS","qt.core.library")/*! \class QLibrary \inmodule QtCore \reentrant \brief The QLibrary class loads shared libraries at runtime. \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 name is an absolute path then an attempt is made to load this path first. If the file cannot be found, QLibrary tries the name with different platform-specific file prefixes, like "lib" on Unix and Mac, and suffixes, like ".so" on Unix, ".dylib" on the Mac, or ".dll" on Windows. If the file path is not absolute then QLibrary modifies the search order to try the system-specific prefixes and suffixes first, followed by the file path specified. 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 yet still minimise the number of attempts to find the library. 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 \nullptr and won't be called. \snippet 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 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. \value PreventUnloadHint Prevents the library from being unloaded from the address space if close() is called. The library's static variables are not reinitialized if open() is called at a later time. \value DeepBindHint Instructs the linker to prefer definitions in the loaded library over exported definitions in the loading application when resolving external symbols in the loaded library. This option is only supported on Linux. \sa loadHints*/static QLibraryScanResult qt_find_pattern(const char*s, qsizetype s_len, QString *errMsg){/* We used to search from the end of the file so we'd skip the code and find the read-only data that usually follows. Unfortunately, in debug builds, the debug sections come after and are usually much bigger than everything else, making this process slower than necessary with debug plugins. More importantly, the pattern string may exist in the debug information due to it being used in the plugin in the first place. */#if defined(Q_OF_ELF)returnQElfParser::parse({s, s_len}, errMsg);#elif defined(Q_OF_MACH_O)returnQMachOParser::parse(s, s_len, errMsg);#elif defined(Q_OS_WIN) || defined(Q_OS_CYGWIN)returnQCoffPeParser::parse({s, s_len}, errMsg);#else# warning"Qt does not know how to efficiently parse your platform's binary format; using slow fall-back."#endifstaticconstexpr auto matcher = [] {// QPluginMetaData::MagicString is not NUL-terminated, but// qMakeStaticByteArrayMatcher requires its argument to be, so// duplicate here, but statically check we didn't mess up:constexpr auto&pattern ="QTMETADATA !";constexpr auto magic =std::string_view(QPluginMetaData::MagicString,sizeof(QPluginMetaData::MagicString));static_assert(pattern == magic);returnqMakeStaticByteArrayMatcher(pattern);}(); qsizetype i = matcher.indexIn({s, s_len});if(i <0) {*errMsg =QLibrary::tr("'%1' is not a Qt plugin").arg(*errMsg);return QLibraryScanResult{};} i +=sizeof(QPluginMetaData::MagicString);return{ i, s_len - i };}/* 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 \c false if version information is not present, or if the information could not be read. Returns true if version information is present and successfully read.*/static QLibraryScanResult findPatternUnloaded(const QString &library, QLibraryPrivate *lib){ QFile file(library);if(!file.open(QIODevice::ReadOnly)) {if(lib) lib->errorString = file.errorString();qCWarning(qt_lcDebugPlugins,"%ls: cannot open: %ls",qUtf16Printable(library),qUtf16Printable(file.errorString()));return{};}// Files can be bigger than the virtual memory size on 32-bit systems, so// we limit to 512 MB there. For 64-bit, we allow up to 2^40 bytes.constexpr qint64 MaxMemoryMapSize =Q_INT64_C(1) << (sizeof(qsizetype) >4?40:29); qsizetype fdlen =qMin(file.size(), MaxMemoryMapSize);const char*filedata =reinterpret_cast<char*>(file.map(0, fdlen));#ifdef Q_OS_UNIXif(filedata ==nullptr) {// If we can't mmap(), then the dynamic loader won't be able to either.// This can't be used as a plugin.qCWarning(qt_lcDebugPlugins,"%ls: failed to map to memory: %ls",qUtf16Printable(library),qUtf16Printable(file.errorString()));return{};}#else QByteArray data;if(filedata ==nullptr) {// It's unknown at this point whether Windows supports LoadLibrary() on// files that fail to CreateFileMapping / MapViewOfFile, so we err on// the side of doing a regular read into memory (up to 64 MB). data = file.read(64*1024*1024); filedata = data.constData(); fdlen = data.size();}#endif QString errMsg = library; QLibraryScanResult r =qt_find_pattern(filedata, fdlen, &errMsg);if(r.length) {#if defined(Q_OF_MACH_O)if(r.isEncrypted)return r;#endifif(!lib->metaData.parse(QByteArrayView(filedata + r.pos, r.length))) { errMsg = lib->metaData.errorString();qCDebug(qt_lcDebugPlugins,"Found invalid metadata in lib %ls: %ls",qUtf16Printable(library),qUtf16Printable(errMsg));}else{qCDebug(qt_lcDebugPlugins,"Found metadata in lib %ls, metadata=\n%s\n",qUtf16Printable(library),QJsonDocument(lib->metaData.toJson()).toJson().constData());return r;}}else{qCDebug(qt_lcDebugPlugins,"Failed to find metadata in lib %ls: %ls",qUtf16Printable(library),qUtf16Printable(errMsg));} lib->errorString =QLibrary::tr("Failed to extract plugin meta data from '%1': %2").arg(library, errMsg);return{};}static voidinstallCoverageTool(QLibraryPrivate *libPrivate){#ifdef __COVERAGESCANNER__/* __COVERAGESCANNER__ is defined when Qt has been instrumented for code coverage by TestCocoon. CoverageScanner is the name of the tool that generates the code instrumentation. This code is required here when code coverage analysis with TestCocoon is enabled in order to allow the loading application to register the plugin and then store its execution report. The execution report gathers information about each part of the plugin's code that has been used when the plugin was loaded by the launching application. The execution report for the plugin will go to the same execution report as the one defined for the application loading it. */int ret =__coveragescanner_register_library(libPrivate->fileName.toLocal8Bit());if(ret >=0) {qDebug("coverage data for %ls registered",qUtf16Printable(libPrivate->fileName));}else{qWarning("could not register %ls: error %d; coverage data may be incomplete",qUtf16Printable(libPrivate->fileName), ret);}}#elseQ_UNUSED(libPrivate);#endif}class QLibraryStore {public:inline~QLibraryStore();staticinline QLibraryPrivate *findOrCreate(const QString &fileName,const QString &version,QLibrary::LoadHints loadHints);staticinlinevoidreleaseLibrary(QLibraryPrivate *lib);staticinlinevoidcleanup();private:staticinline QLibraryStore *instance();// all members and instance() are protected by qt_library_mutextypedef std::map<QString, QLibraryPrivate *> LibraryMap; LibraryMap libraryMap;}; Q_CONSTINIT static QBasicMutex qt_library_mutex; Q_CONSTINIT static QLibraryStore *qt_library_data =nullptr; Q_CONSTINIT static bool qt_library_data_once;QLibraryStore::~QLibraryStore(){ qt_library_data =nullptr;}inlinevoidQLibraryStore::cleanup(){ QLibraryStore *data = qt_library_data;if(!data)return;// find any libraries that are still loaded but have a no one attached to themfor(auto&[_, lib] : data->libraryMap) {if(lib->libraryRefCount.loadRelaxed() ==1) {if(lib->libraryUnloadCount.loadRelaxed() >0) {Q_ASSERT(lib->pHnd.loadRelaxed()); lib->libraryUnloadCount.storeRelaxed(1);#if defined(Q_OS_DARWIN)// We cannot fully unload libraries, as we don't know if there are// lingering references (in system threads e.g.) to Objective-C classes// defined in the library. lib->unload(QLibraryPrivate::NoUnloadSys);#else lib->unload();#endif}deletestd::exchange(lib,nullptr);}}// dump all objects that remainif(lcDebugLibrary().isDebugEnabled()) {for(auto&[_, lib] : data->libraryMap) {if(lib)qCDebug(lcDebugLibrary)<<"On QtCore unload,"<< lib->fileName <<"was leaked, with"<< lib->libraryRefCount.loadRelaxed() <<"users";}}delete data;}static voidqlibraryCleanup(){QLibraryStore::cleanup();}Q_DESTRUCTOR_FUNCTION(qlibraryCleanup)// must be called with a locked mutex QLibraryStore *QLibraryStore::instance(){if(Q_UNLIKELY(!qt_library_data_once && !qt_library_data)) {// only create once per process lifetime qt_library_data =new QLibraryStore; qt_library_data_once =true;}return qt_library_data;}inline QLibraryPrivate *QLibraryStore::findOrCreate(const QString &fileName,const QString &version,QLibrary::LoadHints loadHints){auto lazyNewLib = [&] {auto result =newQLibraryPrivate(fileName, version, loadHints); result->libraryRefCount.ref();return result;};if(fileName.isEmpty())// request for empty d-pointer in QLibrary::setLoadHints();returnlazyNewLib();// must return an independent (new) object QMutexLocker locker(&qt_library_mutex); QLibraryStore *data =instance();if(Q_UNLIKELY(!data)) { locker.unlock();returnlazyNewLib();} QString mapName = version.isEmpty() ? fileName : fileName + u'\0'+ version; QLibraryPrivate *&lib = data->libraryMap[std::move(mapName)];if(lib) {// already loaded lib->libraryRefCount.ref(); lib->mergeLoadHints(loadHints);}else{ lib =lazyNewLib();}return lib;}inlinevoidQLibraryStore::releaseLibrary(QLibraryPrivate *lib){ QMutexLocker locker(&qt_library_mutex); QLibraryStore *data =instance();if(lib->libraryRefCount.deref()) {// still in usereturn;}// no one else is usingQ_ASSERT(lib->libraryUnloadCount.loadRelaxed() ==0);if(Q_LIKELY(data) && !lib->fileName.isEmpty()) {usingq20::erase_if;constauto n =erase_if(data->libraryMap, [lib](constauto&e) {return e.second == lib;});Q_ASSERT_X(n,"~QLibrary","Did not find this library in the library map");Q_UNUSED(n);}delete lib;}QLibraryPrivate::QLibraryPrivate(const QString &canonicalFileName,const QString &version,QLibrary::LoadHints loadHints):fileName(canonicalFileName),fullVersion(version),pluginState(MightBeAPlugin){ loadHintsInt.storeRelaxed(loadHints.toInt());if(canonicalFileName.isEmpty()) errorString =QLibrary::tr("The shared library was not found.");} QLibraryPrivate *QLibraryPrivate::findOrCreate(const QString &fileName,const QString &version,QLibrary::LoadHints loadHints){returnQLibraryStore::findOrCreate(fileName, version, loadHints);}QLibraryPrivate::~QLibraryPrivate(){}voidQLibraryPrivate::mergeLoadHints(QLibrary::LoadHints lh){// if the library is already loaded, we can't change the load hintsif(pHnd.loadRelaxed())return; loadHintsInt.fetchAndOrRelaxed(lh.toInt());} QFunctionPointer QLibraryPrivate::resolve(const char*symbol){if(!pHnd.loadRelaxed())returnnullptr;returnresolve_sys(symbol);}voidQLibraryPrivate::setLoadHints(QLibrary::LoadHints lh){// Set the load hints directly for a dummy if this object is not associated// with a file. Such object is not shared between multiple instances.if(fileName.isEmpty()) { loadHintsInt.storeRelaxed(lh.toInt());return;}// this locks a global mutex QMutexLocker lock(&qt_library_mutex);mergeLoadHints(lh);} QObject *QLibraryPrivate::pluginInstance(){// first, check if the instance is cached and hasn't been deleted QObject *obj = [&](){ QMutexLocker locker(&mutex);return inst.data(); }();if(obj)return obj;// We need to call the plugin's factory function. Is that cached?// skip increasing the reference count (why? -Thiago) QtPluginInstanceFunction factory = instanceFactory.loadAcquire();if(!factory) factory =loadPlugin();if(!factory)returnnullptr; obj =factory();// cache again QMutexLocker locker(&mutex);if(inst) obj = inst;else inst = obj;return obj;}boolQLibraryPrivate::load(){if(pHnd.loadRelaxed()) { libraryUnloadCount.ref();return true;}if(fileName.isEmpty())return false;Q_TRACE(QLibraryPrivate_load_entry, fileName);bool ret =load_sys();qCDebug(lcDebugLibrary)<< fileName << (ret ?"loaded library":qUtf8Printable(u"cannot load: "+ errorString));if(ret) {//when loading a library we add a reference to it so that the QLibraryPrivate won't get deleted//this allows to unload the library at a later time libraryUnloadCount.ref(); libraryRefCount.ref();installCoverageTool(this);}Q_TRACE(QLibraryPrivate_load_exit, ret);return ret;}boolQLibraryPrivate::unload(UnloadFlag flag){if(!pHnd.loadRelaxed())return false;if(libraryUnloadCount.loadRelaxed() >0&& !libraryUnloadCount.deref()) {// only unload if ALL QLibrary instance wanted to QMutexLocker locker(&mutex);delete inst.data();if(flag == NoUnloadSys ||unload_sys()) {qCDebug(lcDebugLibrary) << fileName <<"unloaded library"<< (flag == NoUnloadSys ?"(faked)":"");// when the library is unloaded, we release the reference on it so that 'this'// can get deleted libraryRefCount.deref(); pHnd.storeRelaxed(nullptr); instanceFactory.storeRelaxed(nullptr);return true;}}return false;}voidQLibraryPrivate::release(){QLibraryStore::releaseLibrary(this);} QtPluginInstanceFunction QLibraryPrivate::loadPlugin(){if(auto ptr = instanceFactory.loadAcquire()) { libraryUnloadCount.ref();return ptr;}if(pluginState == IsNotAPlugin)returnnullptr;if(load()) {auto ptr =reinterpret_cast<QtPluginInstanceFunction>(resolve("qt_plugin_instance")); instanceFactory.storeRelease(ptr);// two threads may store the same valueif(Q_LIKELY(ptr))return ptr; errorString =QLibrary::tr("Could not resolve 'qt_plugin_instance' function");}qCDebug(qt_lcDebugPlugins) <<"QLibraryPrivate::loadPlugin failed on"<< fileName <<":"<< errorString; pluginState = IsNotAPlugin;returnnullptr;}/*! Returns \c true if \a fileName has a valid suffix for a loadable library; otherwise returns \c false. \table \header \li Platform \li Valid suffixes \row \li Windows \li \c .dll, \c .DLL \row \li Unix/Linux \li \c .so \row \li AIX \li \c .a \row \li HP-UX \li \c .sl, \c .so (HP-UXi) \row \li \macos and iOS \li \c .dylib, \c .bundle, \c .so \endtable Trailing versioning numbers on Unix are ignored. */boolQLibrary::isLibrary(const QString &fileName){#if defined(Q_OS_WIN) || defined(Q_OS_CYGWIN)return fileName.endsWith(".dll"_L1,Qt::CaseInsensitive);#else// Generic Unix# if defined(Q_OS_DARWIN)// On Apple platforms, dylib look like libmylib.1.0.0.dylibif(fileName.endsWith(".dylib"_L1))return true;# endif QString completeSuffix =QFileInfo(fileName).completeSuffix();if(completeSuffix.isEmpty())return false;// if this throws an empty-array error, you need to fix the #ifdef's:const QLatin1StringView candidates[] = {# 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."*/"sl"_L1,# if defined __ia64"so"_L1,# endif# elif defined(Q_OS_AIX)"a"_L1,"so"_L1,# elif defined(Q_OS_DARWIN)"so"_L1,"bundle"_L1,# elif defined(Q_OS_UNIX)"so"_L1,# endif};// candidatesauto isValidSuffix = [&candidates](QStringView s) {returnstd::find(std::begin(candidates),std::end(candidates), s) !=std::end(candidates);};// Examples of valid library names:// libfoo.so// libfoo.so.0// libfoo.so.0.3// libfoo-0.3.so// libfoo-0.3.so.0.3.0auto suffixes =qTokenize(completeSuffix, u'.');auto it = suffixes.begin();constauto end = suffixes.end();auto isNumeric = [](QStringView s) {bool ok; (void)s.toInt(&ok);return ok; };while(it != end) {if(isValidSuffix(*it++))returnq20::ranges::all_of(it, end, isNumeric);}return false;// no valid suffix found#endif}static boolqt_get_metadata(QLibraryPrivate *priv, QString *errMsg){auto error = [=](QString &&explanation) {*errMsg =QLibrary::tr("'%1' is not a Qt plugin (%2)").arg(priv->fileName,std::move(explanation));return false;}; QPluginMetaData metaData; QFunctionPointer pfn = priv->resolve("qt_plugin_query_metadata_v2");if(pfn) { metaData =reinterpret_cast<QPluginMetaData(*)()>(pfn)();#if QT_VERSION <= QT_VERSION_CHECK(7, 0, 0)}else if((pfn = priv->resolve("qt_plugin_query_metadata"))) { metaData =reinterpret_cast<QPluginMetaData(*)()>(pfn)();if(metaData.size <sizeof(QPluginMetaData::MagicHeader))returnerror(QLibrary::tr("metadata too small"));// adjust the meta data to point to the headerauto data =reinterpret_cast<const char*>(metaData.data); data +=sizeof(QPluginMetaData::MagicString); metaData.data = data; metaData.size -=sizeof(QPluginMetaData::MagicString);#endif}else{returnerror(QLibrary::tr("entrypoint to query the plugin meta data not found"));}if(metaData.size <sizeof(QPluginMetaData::Header))returnerror(QLibrary::tr("metadata too small"));if(priv->metaData.parse(metaData))return true;*errMsg = priv->metaData.errorString();return false;}boolQLibraryPrivate::isPlugin(){if(pluginState == MightBeAPlugin)updatePluginState();return pluginState == IsAPlugin;}voidQLibraryPrivate::updatePluginState(){ QMutexLocker locker(&mutex); errorString.clear();if(pluginState != MightBeAPlugin)return;bool success =false;#if defined(Q_OS_UNIX) && !defined(Q_OS_DARWIN)if(fileName.endsWith(".debug"_L1)) {// refuse to load a file that ends in .debug// these are the debug symbols from the libraries// the problem is that they are valid shared library files// and dlopen is known to crash while opening them// pretend we didn't see the file errorString =QLibrary::tr("The shared library was not found."); pluginState = IsNotAPlugin;return;}#endifif(!pHnd.loadRelaxed()) {// scan for the plugin metadata without loading QLibraryScanResult result =findPatternUnloaded(fileName,this);#if defined(Q_OF_MACH_O)if(result.length && result.isEncrypted) {// We found the .qtmetadata section, but since the library is encrypted// we need to dlopen() it before we can parse the metadata for further// validation.qCDebug(qt_lcDebugPlugins,"Library is encrypted. Doing prospective load before parsing metadata"); locker.unlock();load(); locker.relock(); success =qt_get_metadata(this, &errorString);}else#endif{ success = result.length !=0;}}else{// library is already loaded (probably via QLibrary)// simply get the target function and call it. success =qt_get_metadata(this, &errorString);}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);} pluginState = IsNotAPlugin;return;} pluginState = IsNotAPlugin;// be pessimistic uint qt_version =uint(metaData.value(QtPluginMetaDataKeys::QtVersion).toInteger());bool debug = metaData.value(QtPluginMetaDataKeys::IsDebug).toBool();if((qt_version &0x00ff00) > (QT_VERSION &0x00ff00) || (qt_version &0xff0000) != (QT_VERSION &0xff0000)) {qCDebug(qt_lcDebugPlugins,"In %s:\n"" Plugin uses incompatible Qt library (%d.%d.%d) [%s]",QFile::encodeName(fileName).constData(),(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,QString::number((qt_version &0xff0000) >>16),QString::number((qt_version &0xff00) >>8),QString::number(qt_version &0xff), debug ?"debug"_L1 :"release"_L1);}else if(PluginMustMatchQtDebug && debug != QtBuildIsDebug) {//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);}else{ pluginState = IsAPlugin;}}/*! Loads the library and returns \c true if the library was loaded successfully; otherwise returns \c 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()*/boolQLibrary::load(){if(!d)return false;if(d.tag() == Loaded)return d->pHnd.loadRelaxed();if(d->load()) { d.setTag(Loaded);return true;}return false;}/*! Unloads the library and returns \c true if the library could be unloaded; otherwise returns \c 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 \macos, dynamic libraries cannot be unloaded. QLibrary::unload() will return \c true, but the library will remain loaded into the process. \sa resolve(), load()*/boolQLibrary::unload(){if(d.tag() == Loaded) { d.setTag(NotLoaded);return d->unload();}return false;}/*! Returns \c true if load() succeeded; otherwise returns \c false. \note Prior to Qt 6.6, this function would return \c true even without a call to load() if another QLibrary object on the same library had caused it to be loaded. \sa load() */boolQLibrary::isLoaded()const{return d.tag() == Loaded;}/*! Constructs a library with the given \a parent. */QLibrary::QLibrary(QObject *parent) :QObject(parent){}/*! 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 \macos and iOS, and ".dll" on Windows. (See \l{fileName}.) */QLibrary::QLibrary(const QString &fileName, QObject *parent) :QObject(parent){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 \macos and iOS, and ".dll" on Windows. (See \l{fileName}.)*/QLibrary::QLibrary(const QString &fileName,int verNum, QObject *parent) :QObject(parent){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 \macos and iOS, and ".dll" on Windows. (See \l{fileName}.) */QLibrary::QLibrary(const QString &fileName,const QString &version, QObject *parent):QObject(parent){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 (for example, \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".*/voidQLibrary::setFileName(const QString &fileName){setFileNameAndVersion(fileName,QString());} QString QLibrary::fileName()const{if(d) { QMutexLocker locker(&d->mutex);return d->qualifiedFileName.isEmpty() ? d->fileName : d->qualifiedFileName;}returnQString();}/*! \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()*/voidQLibrary::setFileNameAndVersion(const QString &fileName,int verNum){setFileNameAndVersion(fileName, verNum >=0?QString::number(verNum) :QString());}/*! \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()*/voidQLibrary::setFileNameAndVersion(const QString &fileName,const QString &version){QLibrary::LoadHints lh;if(d) { lh = d->loadHints(); d->release();} QLibraryPrivate *dd =QLibraryPrivate::findOrCreate(fileName, version, lh); d =QTaggedPointer(dd, NotLoaded);// we haven't load()ed}/*! Returns the address of the exported symbol \a symbol. The library is loaded if necessary. The function returns \nullptr if the symbol could not be resolved or if the library could not be loaded. Example: \snippet 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 code/src_corelib_plugin_qlibrary.cpp 3 with \c MY_EXPORT defined as \snippet code/src_corelib_plugin_qlibrary.cpp 4*/ QFunctionPointer QLibrary::resolve(const char*symbol){if(!isLoaded() && !load())returnnullptr;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 \nullptr if the symbol could not be resolved or if the library could not be loaded. \sa resolve()*/ QFunctionPointer 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 \nullptr if the symbol could not be resolved or if the library could not be loaded. \sa resolve()*/ QFunctionPointer 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 \nullptr if the symbol could not be resolved or if the library could not be loaded. \sa resolve()*/ QFunctionPointer QLibrary::resolve(const QString &fileName,const QString &version,const char*symbol){ QLibrary library(fileName, version);return library.resolve(symbol);}/*! \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{ QString str;if(d) { QMutexLocker locker(&d->mutex); str = d->errorString;}return str.isEmpty() ?tr("Unknown error") : str;}/*! \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 loadHints 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. \note Hints can only be cleared when this object is not associated with a file. Hints can only be added once the file name is set (\a hints will be or'ed with the old hints). \note Setting this property after the library has been loaded has no effect and loadHints() will not reflect those changes. \note This property is shared among all QLibrary instances that refer to the same library.*/voidQLibrary::setLoadHints(LoadHints hints){if(!d) { d =QLibraryPrivate::findOrCreate(QString());// ugly, but we need a d-ptr d->errorString.clear();} d->setLoadHints(hints);}QLibrary::LoadHints QLibrary::loadHints()const{return d ? d->loadHints() :QLibrary::LoadHints();}/* Internal, for debugging */boolqt_debug_component(){static int debug_env =QT_PREPEND_NAMESPACE(qEnvironmentVariableIntValue)("QT_DEBUG_PLUGINS");return debug_env !=0;} QT_END_NAMESPACE #include"moc_qlibrary.cpp"