QmlJS: Fix issues with getting modulePaths

This patch

- improves performance by removing the usage of QRegularExpression for
trivial string operations (this is called 3000 times after configuring
Qt Creator)

- fixes handling of version number like "2.-1" which are the result of
imports with only a major version number like "import QtQuick 2"

Task-number: QTCREATORBUG-25899
Fixes: QTCREATORBUG-26178
Fixes: QTCREATORBUG-26216
Change-Id: Ic792909513f4fe25ac72043645f297ee41890375
Reviewed-by: Fawzi Mohamed <fawzi.mohamed@qt.io>
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>

src/libs/qmljs/qmljsutils.cpp

@@ -213,6 +213,29 @@ bool QmlJS::maybeModuleVersion(const QString &version) {
     return version.isEmpty() || version == undefinedVersion || re.match(version).hasMatch();
 }
 
+const QStringList QmlJS::splitVersion(const QString &version)
+{
+    // Successively removing minor and major version numbers.
+    QStringList result;
+    int versionEnd = version.length();
+    while (versionEnd > 0) {
+        result.append(version.left(versionEnd));
+        // remove numbers and then potential . at the end
+        const int oldVersionEnd = versionEnd;
+        while (versionEnd > 0 && version.at(versionEnd - 1).isDigit())
+            --versionEnd;
+        // handle e.g. -1, because an import "QtQuick 2" results in version "2.-1"
+        if (versionEnd > 0 && version.at(versionEnd - 1) == '-')
+            --versionEnd;
+        if (versionEnd > 0 && version.at(versionEnd - 1) == '.')
+            --versionEnd;
+        // bail out if we didn't proceed because version string contains invalid characters
+        if (versionEnd == oldVersionEnd)
+            break;
+    }
+    return result;
+}
+
 /*!
  * \brief Get the path of a module
  * \param name
@@ -242,24 +265,19 @@ QStringList QmlJS::modulePaths(const QString &name, const QString &version,
 
     const QString sanitizedVersion = version == undefinedVersion ? QString() : version;
     const QStringList parts = name.split('.', Qt::SkipEmptyParts);
-    auto mkpath = [] (const QStringList &xs) -> QString { return xs.join(QLatin1Char('/')); };
-
-    // Regular expression for building candidates by successively removing minor and major
-    // version numbers.  It does not match the undefined version, so it has to be applied to the
-    // sanitized version.
-    const QRegularExpression re("\\.?\\d+$");
+    auto mkpath = [](const QStringList &xs) -> QString { return xs.join(QLatin1Char('/')); };
 
     QStringList result;
     QString candidate;
 
-    for (QString ver = sanitizedVersion; !ver.isEmpty(); ver.remove(re)) {
-        for (const QString &path: importPaths) {
+    for (const QString &versionPart : splitVersion(sanitizedVersion)) {
+        for (const QString &path : importPaths) {
             for (int i = parts.count() - 1; i >= 0; --i) {
-                candidate = QDir::cleanPath(
-                            QString::fromLatin1("%1/%2.%3/%4").arg(path,
-                                                                   mkpath(parts.mid(0, i + 1)),
-                                                                   ver,
-                                                                   mkpath(parts.mid(i + 1))));
+                candidate = QDir::cleanPath(QString::fromLatin1("%1/%2.%3/%4")
+                                                .arg(path,
+                                                     mkpath(parts.mid(0, i + 1)),
+                                                     versionPart,
+                                                     mkpath(parts.mid(i + 1))));
                 if (QDir(candidate).exists())
                     result << candidate;
             }

src/libs/qmljs/qmljsutils.h

@@ -57,6 +57,7 @@ QMLJS_EXPORT DiagnosticMessage errorMessage(const SourceLocation &loc,
 
 QMLJS_EXPORT bool maybeModuleVersion(const QString &version);
 
+QMLJS_EXPORT const QStringList splitVersion(const QString &version);
 QMLJS_EXPORT QStringList modulePaths(const QString &moduleImportName, const QString &version,
                                      const QStringList &importPaths);
 

tests/auto/qml/CMakeLists.txt

@@ -7,6 +7,7 @@ add_subdirectory(persistenttrie)
 add_subdirectory(qmldesigner)
 add_subdirectory(qmleditor)
 add_subdirectory(qmljssimplereader)
+add_subdirectory(qmljsutils)
 add_subdirectory(qmlprojectmanager)
 add_subdirectory(qrcparser)
 add_subdirectory(reformatter)

tests/auto/qml/qmljsutils/CMakeLists.txt

@@ -0,0 +1,5 @@
+add_qtc_test(tst_qmljstools
+  DEPENDS QmlJS
+  DEFINES
+  SOURCES tst_qmljsutils.cpp
+)

tests/auto/qml/qmljsutils/tst_qmljsutils.cpp

@@ -0,0 +1,62 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt Creator.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+****************************************************************************/
+
+#include <QtTest>
+#include <QDebug>
+
+#include <qmljs/qmljsutils.h>
+
+class tst_QmlJSUtils: public QObject
+{
+    Q_OBJECT
+
+private slots:
+    void moduleVersionNumbers_data();
+    void moduleVersionNumbers();
+};
+
+void tst_QmlJSUtils::moduleVersionNumbers_data()
+{
+    QTest::addColumn<QString>("version");
+    QTest::addColumn<QStringList>("result");
+
+    QTest::newRow("empty") << "" << QStringList();
+    QTest::newRow("full") << "2.15" << QStringList{"2.15", "2"};
+    QTest::newRow("single") << "2" << QStringList{"2"};
+    // result if "import QtQuick 2":
+    QTest::newRow("major") << "2.-1" << QStringList{"2.-1", "2"};
+    QTest::newRow("broken") << "2.+3" << QStringList{"2.+3", "2.+"};
+}
+
+void tst_QmlJSUtils::moduleVersionNumbers()
+{
+    QFETCH(QString, version);
+    QFETCH(QStringList, result);
+    QCOMPARE(QmlJS::splitVersion(version), result);
+}
+
+QTEST_GUILESS_MAIN(tst_QmlJSUtils)
+
+#include "tst_qmljsutils.moc"