124bool QLibraryPrivate::load_sys()
125{
126    qDebug()<<__FILE__<<"  "<<__LINE__<<"=============================================";
127    QMutexLocker locker(&mutex);
128    QString attempt;
129    QFileSystemEntry fsEntry(fileName);
130
131    QString path = fsEntry.path();
132    QString name = fsEntry.fileName();
133    if (path == QLatin1String(".") && !fileName.startsWith(path))
134        path.clear();
135    else
136        path += QLatin1Char('/');
137
138    QStringList suffixes;
139    QStringList prefixes;
140    if (pluginState != IsAPlugin) {
141        prefixes = prefixes_sys();
142        suffixes = suffixes_sys(fullVersion);
143    }
144    int dlFlags = 0;
145    qDebug()<<__FILE__<<"  "<<__LINE__<<"=== dlFlags = "<<dlFlags;
146    int loadHints = this->loadHints();
147    if (loadHints & QLibrary::ResolveAllSymbolsHint) {
148        dlFlags |= RTLD_NOW;
149        qDebug()<<__FILE__<<"  "<<__LINE__<<"=== dlFlags = "<<dlFlags;
150    } else {
151        dlFlags |= RTLD_LAZY;
152        qDebug()<<__FILE__<<"  "<<__LINE__<<"=== dlFlags = "<<dlFlags;
153    }
154    if (loadHints & QLibrary::ExportExternalSymbolsHint) {
155        dlFlags |= RTLD_GLOBAL;
156        qDebug()<<__FILE__<<"  "<<__LINE__<<"=== dlFlags = "<<dlFlags;
157    }
158#if !defined(Q_OS_CYGWIN)
159    else {
160        dlFlags |= RTLD_LOCAL;
161        qDebug()<<__FILE__<<"  "<<__LINE__<<"=== dlFlags = "<<dlFlags;
162    }
163#endif
164#if defined(RTLD_DEEPBIND)
165    if (loadHints & QLibrary::DeepBindHint)
166        dlFlags |= RTLD_DEEPBIND;
167        qDebug()<<__FILE__<<"  "<<__LINE__<<"=== dlFlags = "<<dlFlags;
168#endif
169
170    // Provide access to RTLD_NODELETE flag on Unix
171    // From GNU documentation on RTLD_NODELETE:
172    // Do not unload the library during dlclose(). Consequently, the
173    // library's specific static variables are not reinitialized if the
174    // library is reloaded with dlopen() at a later time.
175#if defined(RTLD_NODELETE)
176    if (loadHints & QLibrary::PreventUnloadHint) {
177#   ifdef Q_OS_ANDROID // RTLD_NODELETE flag is supported by Android 23+
178        if (QtAndroidPrivate::androidSdkVersion() > 22)
179#   endif
180            dlFlags |= RTLD_NODELETE;
181            qDebug()<<__FILE__<<"  "<<__LINE__<<"=== use RTLD_NODELETE dlFlags = "<<dlFlags;
182    }
183#endif
184
185#if defined(Q_OS_AIX)   // Not sure if any other platform actually support this thing.
186    if (loadHints & QLibrary::LoadArchiveMemberHint) {
187        dlFlags |= RTLD_MEMBER;
188        qDebug()<<__FILE__<<"  "<<__LINE__<<"=== dlFlags = "<<dlFlags;
189    }
190#endif
191
192    // If the filename is an absolute path then we want to try that first as it is most likely
193    // what the callee wants. If we have been given a non-absolute path then lets try the
194    // native library name first to avoid unnecessary calls to dlopen().
195    if (fsEntry.isAbsolute()) {
196        suffixes.prepend(QString());
197        prefixes.prepend(QString());
198    } else {
199        suffixes.append(QString());
200        prefixes.append(QString());
201    }
202
203#if defined(Q_PROCESSOR_X86) && !defined(Q_OS_DARWIN)
204    qDebug()<<__FILE__<<"  "<<__LINE__<<"===";
205    if (qCpuHasFeature(ArchHaswell)) {
206        auto transform = [](QStringList &list, void (*f)(QString *)) {
207            QStringList tmp;
208            qSwap(tmp, list);
209            list.reserve(tmp.size() * 2);
210            for (const QString &s : qAsConst(tmp)) {
211                QString modifiedPath = s;
212                f(&modifiedPath);
213                list.append(modifiedPath);
214                list.append(s);
215            }
216        };
217        if (pluginState == IsAPlugin) {
218            // add ".avx2" to each suffix in the list
219            transform(suffixes, [](QString *s) { s->append(QLatin1String(".avx2")); });
220        } else {
221            // prepend "haswell/" to each prefix in the list
222            transform(prefixes, [](QString *s) { s->prepend(QLatin1String("haswell/")); });
223        }
224    }
225#endif
226
227    locker.unlock();
228    bool retry = true;
229    Handle hnd = nullptr;
230    for (int prefix = 0; retry && !hnd && prefix < prefixes.size(); prefix++) {
231        for (int suffix = 0; retry && !hnd && suffix < suffixes.size(); suffix++) {
232            if (!prefixes.at(prefix).isEmpty() && name.startsWith(prefixes.at(prefix)))
233                continue;
234            if (path.isEmpty() && prefixes.at(prefix).contains(QLatin1Char('/')))
235                continue;
236            if (!suffixes.at(suffix).isEmpty() && name.endsWith(suffixes.at(suffix)))
237                continue;
238            if (loadHints & QLibrary::LoadArchiveMemberHint) {
239                attempt = name;
240                int lparen = attempt.indexOf(QLatin1Char('('));
241                if (lparen == -1)
242                    lparen = attempt.count();
243                attempt = path + prefixes.at(prefix) + attempt.insert(lparen, suffixes.at(suffix));
244            } else {
245                attempt = path + prefixes.at(prefix) + name + suffixes.at(suffix);
246            }
247
248            qDebug()<<__FILE__<<"  "<<__LINE__<<"===attempt = "<<attempt<<"  dlFlags = "<<dlFlags;
249            hnd = dlopen(QFile::encodeName(attempt), dlFlags);
250#ifdef Q_OS_ANDROID
251            if (!hnd) {
252                auto attemptFromBundle = attempt;
253                hnd = dlopen(QFile::encodeName(attemptFromBundle.replace(QLatin1Char('/'), QLatin1Char('_'))), dlFlags);
254            }
255            if (hnd) {
256                using JniOnLoadPtr = jint (*)(JavaVM *vm, void *reserved);
257                JniOnLoadPtr jniOnLoad = reinterpret_cast<JniOnLoadPtr>(dlsym(hnd, "JNI_OnLoad"));
258                if (jniOnLoad && jniOnLoad(QtAndroidPrivate::javaVM(), nullptr) == JNI_ERR) {
259                    dlclose(hnd);
260                    hnd = nullptr;
261                }
262            }
263#endif
264
265            if (!hnd && fileName.startsWith(QLatin1Char('/')) && QFile::exists(attempt)) {
266                qDebug()<<__FILE__<<"  "<<__LINE__<<"===";
267                // We only want to continue if dlopen failed due to that the shared library did not exist.
268                // However, we are only able to apply this check for absolute filenames (since they are
269                // not influenced by the content of LD_LIBRARY_PATH, /etc/ld.so.cache, DT_RPATH etc...)
270                // This is all because dlerror is flawed and cannot tell us the reason why it failed.
271                retry = false;
272            }
273        }
274    }
275
276#ifdef Q_OS_MAC
277    if (!hnd) {
278        QByteArray utf8Bundle = fileName.toUtf8();
279        QCFType<CFURLRef> bundleUrl = CFURLCreateFromFileSystemRepresentation(NULL, reinterpret_cast<const UInt8*>(utf8Bundle.data()), utf8Bundle.length(), true);
280        QCFType<CFBundleRef> bundle = CFBundleCreate(NULL, bundleUrl);
281        if(bundle) {
282            QCFType<CFURLRef> url = CFBundleCopyExecutableURL(bundle);
283            char executableFile[FILENAME_MAX];
284            CFURLGetFileSystemRepresentation(url, true, reinterpret_cast<UInt8*>(executableFile), FILENAME_MAX);
285            attempt = QString::fromUtf8(executableFile);
286            hnd = dlopen(QFile::encodeName(attempt), dlFlags);
287        }
288    }
289#endif
290
291    locker.relock();
292    if (!hnd) {
293        errorString = QLibrary::tr("Cannot load library %1: %2").arg(fileName, qdlerror());
294        qDebug()<<__FILE__<<"  "<<__LINE__<<"===errorString = "<<errorString;
295    }
296    if (hnd) {
297        qualifiedFileName = attempt;
298        errorString.clear();
299    }
300    pHnd.storeRelaxed(hnd);
301    qDebug()<<__FILE__<<"  "<<__LINE__<<"=============================================";
302    return (hnd != nullptr);
303}