Deduplicate the import resolution algorithm

We will need it in various other places, too.

Change-Id: I61c55f88b66ab85448ae8fff125fe34108532fc4
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>

9 files changed, 216 insertions, 138 deletions

diff --git a/src/qml/.prev_CMakeLists.txt b/src/qml/.prev_CMakeLists.txt
index a76dc2b0fb..49d707034d 100644
--- a/src/qml/.prev_CMakeLists.txt
+++ b/src/qml/.prev_CMakeLists.txt
@@ -272,6 +272,7 @@ qt_add_module(Qml
         qml/v8/qv4domerrors.cpp qml/v8/qv4domerrors_p.h
         qml/v8/qv4sqlerrors.cpp qml/v8/qv4sqlerrors_p.h
         qmldirparser/qqmldirparser.cpp qmldirparser/qqmldirparser_p.h
+        qmldirparser/qqmlimportresolver.cpp qmldirparser/qqmlimportresolver_p.h
         qtqmlcompilerglobal.h qtqmlcompilerglobal_p.h
         qtqmlglobal.h qtqmlglobal_p.h
         types/qqmlbind.cpp types/qqmlbind_p.h
diff --git a/src/qml/CMakeLists.txt b/src/qml/CMakeLists.txt
index 9729702290..0195d9f571 100644
--- a/src/qml/CMakeLists.txt
+++ b/src/qml/CMakeLists.txt
@@ -272,6 +272,7 @@ qt_add_module(Qml
         qml/v8/qv4domerrors.cpp qml/v8/qv4domerrors_p.h
         qml/v8/qv4sqlerrors.cpp qml/v8/qv4sqlerrors_p.h
         qmldirparser/qqmldirparser.cpp qmldirparser/qqmldirparser_p.h
+        qmldirparser/qqmlimportresolver.cpp qmldirparser/qqmlimportresolver_p.h
         qtqmlcompilerglobal.h qtqmlcompilerglobal_p.h
         qtqmlglobal.h qtqmlglobal_p.h
         types/qqmlbind.cpp types/qqmlbind_p.h
diff --git a/src/qml/qml/qqmlimport.cpp b/src/qml/qml/qqmlimport.cpp
index fec42827b6..a6a230090e 100644
--- a/src/qml/qml/qqmlimport.cpp
+++ b/src/qml/qml/qqmlimport.cpp
@@ -59,6 +59,7 @@
 #include <QtCore/qjsonobject.h>
 #include <QtCore/qjsonarray.h>
 #include <QtQml/private/qqmltype_p_p.h>
+#include <QtQml/private/qqmlimportresolver_p.h>
 
 #include <algorithm>
 #include <functional>
@@ -536,17 +537,6 @@ QList<QQmlImports::ScriptReference> QQmlImports::resolvedScripts() const
     return scripts;
 }
 
-static QString joinStringRefs(const QVector<QStringRef> &refs, const QChar &sep)
-{
-    QString str;
-    for (auto it = refs.cbegin(); it != refs.cend(); ++it) {
-        if (it != refs.cbegin())
-            str += sep;
-        str += *it;
-    }
-    return str;
-}
-
 /*!
     Forms complete paths to a qmldir file, from a base URL, a module URI and version specification.
 
@@ -560,48 +550,10 @@ static QString joinStringRefs(const QVector<QStringRef> &refs, const QChar &sep)
 QStringList QQmlImports::completeQmldirPaths(const QString &uri, const QStringList &basePaths,
                                              QTypeRevision version)
 {
-    const QVector<QStringRef> parts = uri.splitRef(Dot, Qt::SkipEmptyParts);
-
-    QStringList qmlDirPathsPaths;
-    // fully & partially versioned parts + 1 unversioned for each base path
-    qmlDirPathsPaths.reserve(basePaths.count() * (2 * parts.count() + 1));
-
-    for (int versionMode = FullyVersioned; versionMode <= Unversioned; ++versionMode) {
-        switch (versionMode) {
-        case FullyVersioned:
-            if (!version.hasMinorVersion())
-                continue;
-            break;
-        case PartiallyVersioned:
-            if (!version.hasMajorVersion())
-                continue;
-            break;
-        default:
-            break;
-        }
-
-        const QString ver = versionString(version, QQmlImports::ImportVersion(versionMode));
-
-        for (const QString &path : basePaths) {
-            QString dir = path;
-            if (!dir.endsWith(Slash) && !dir.endsWith(Backslash))
-                dir += Slash;
-
-            // append to the end
-            qmlDirPathsPaths += dir + joinStringRefs(parts, Slash) + ver + Slash_qmldir;
-
-            if (versionMode != Unversioned) {
-                // insert in the middle
-                for (int index = parts.count() - 2; index >= 0; --index) {
-                    qmlDirPathsPaths += dir + joinStringRefs(parts.mid(0, index + 1), Slash)
-                                            + ver + Slash
-                                            + joinStringRefs(parts.mid(index + 1), Slash) + Slash_qmldir;
-                }
-            }
-        }
-    }
-
-    return qmlDirPathsPaths;
+    QStringList paths = qQmlResolveImportPaths(uri, basePaths, version);
+    for (QString &path : paths)
+        path += Slash_qmldir;
+    return paths;
 }
 
 QString QQmlImports::versionString(QTypeRevision version, ImportVersion versionMode)
diff --git a/src/qml/qmldirparser/qmldirparser.pri b/src/qml/qmldirparser/qmldirparser.pri
index fefe2e75be..3923208e4a 100644
--- a/src/qml/qmldirparser/qmldirparser.pri
+++ b/src/qml/qmldirparser/qmldirparser.pri
@@ -2,7 +2,9 @@ INCLUDEPATH += $$PWD
 INCLUDEPATH += $$OUT_PWD
 
 HEADERS += \
-    $$PWD/qqmldirparser_p.h
+    $$PWD/qqmldirparser_p.h \
+    $$PWD/qqmlimportresolver_p.h
 
 SOURCES += \
-    $$PWD/qqmldirparser.cpp
+    $$PWD/qqmldirparser.cpp \
+    $$PWD/qqmlimportresolver.cpp
diff --git a/src/qml/qmldirparser/qqmlimportresolver.cpp b/src/qml/qmldirparser/qqmlimportresolver.cpp
new file mode 100644
index 0000000000..d427706140
--- /dev/null
+++ b/src/qml/qmldirparser/qqmlimportresolver.cpp
@@ -0,0 +1,122 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** 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 Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** 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-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qqmlimportresolver_p.h"
+
+QT_BEGIN_NAMESPACE
+
+enum ImportVersion { FullyVersioned, PartiallyVersioned, Unversioned };
+
+/*!
+    Forms complete paths to a module, from a list of base paths,
+    a module URI and version specification.
+
+    For example, QtQml.Models 2.0:
+    - base/QtQml/Models.2.0
+    - base/QtQml.2.0/Models
+    - base/QtQml/Models.2
+    - base/QtQml.2/Models
+    - base/QtQml/Models
+*/
+QStringList qQmlResolveImportPaths(const QString &uri, const QStringList &basePaths,
+                                   QTypeRevision version)
+{
+    static const QLatin1Char Slash('/');
+    static const QLatin1Char Backslash('\\');
+
+    const QVector<QStringRef> parts = uri.splitRef(QLatin1Char('.'), Qt::SkipEmptyParts);
+
+    QStringList importPaths;
+    // fully & partially versioned parts + 1 unversioned for each base path
+    importPaths.reserve(2 * parts.count() + 1);
+
+    auto versionString = [](QTypeRevision version, ImportVersion mode)
+    {
+        if (mode == FullyVersioned) {
+            // extension with fully encoded version number (eg. MyModule.3.2)
+            return QString::fromLatin1(".%1.%2").arg(version.majorVersion())
+                    .arg(version.minorVersion());
+        }
+        if (mode == PartiallyVersioned) {
+            // extension with encoded version major (eg. MyModule.3)
+            return QString::fromLatin1(".%1").arg(version.majorVersion());
+        }
+        // else extension without version number (eg. MyModule)
+        return QString();
+    };
+
+    auto joinStringRefs = [](const QVector<QStringRef> &refs, const QChar &sep) {
+        QString str;
+        for (auto it = refs.cbegin(); it != refs.cend(); ++it) {
+            if (it != refs.cbegin())
+                str += sep;
+            str += *it;
+        }
+        return str;
+    };
+
+    const ImportVersion initial = (version.hasMinorVersion())
+            ? FullyVersioned
+            : (version.hasMajorVersion() ? PartiallyVersioned : Unversioned);
+    for (int mode = initial; mode <= Unversioned; ++mode) {
+        const QString ver = versionString(version, ImportVersion(mode));
+
+        for (const QString &path : basePaths) {
+            QString dir = path;
+            if (!dir.endsWith(Slash) && !dir.endsWith(Backslash))
+                dir += Slash;
+
+            // append to the end
+            importPaths += dir + joinStringRefs(parts, Slash) + ver;
+
+            if (mode != Unversioned) {
+                // insert in the middle
+                for (int index = parts.count() - 2; index >= 0; --index) {
+                    importPaths += dir + joinStringRefs(parts.mid(0, index + 1), Slash)
+                            + ver + Slash
+                            + joinStringRefs(parts.mid(index + 1), Slash);
+                }
+            }
+        }
+    }
+
+    return importPaths;
+}
+
+QT_END_NAMESPACE
diff --git a/src/qml/qmldirparser/qqmlimportresolver_p.h b/src/qml/qmldirparser/qqmlimportresolver_p.h
new file mode 100644
index 0000000000..bfc0592bf8
--- /dev/null
+++ b/src/qml/qmldirparser/qqmlimportresolver_p.h
@@ -0,0 +1,65 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** 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 Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** 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-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QQMLIMPORTRESOLVER_P_H
+#define QQMLIMPORTRESOLVER_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <QtCore/qglobal.h>
+#include <QtCore/qstring.h>
+#include <QtCore/qversionnumber.h>
+
+QT_BEGIN_NAMESPACE
+
+QStringList qQmlResolveImportPaths(const QString &uri, const QStringList &basePaths,
+                                   QTypeRevision version);
+
+QT_END_NAMESPACE
+
+#endif // QQMLIMPORTRESOLVER_P_H
diff --git a/src/qmldevtools/.prev_CMakeLists.txt b/src/qmldevtools/.prev_CMakeLists.txt
index a1f121d6d0..5a26da799d 100644
--- a/src/qmldevtools/.prev_CMakeLists.txt
+++ b/src/qmldevtools/.prev_CMakeLists.txt
@@ -38,6 +38,7 @@ qt_add_module(QmlDevTools
         ../qml/parser/qqmljskeywords_p.h
         ../qml/parser/qqmljslexer.cpp ../qml/parser/qqmljslexer_p.h
         ../qml/qmldirparser/qqmldirparser.cpp ../qml/qmldirparser/qqmldirparser_p.h
+        ../qml/qmldirparser/qqmlimportresolver.cpp ../qml/qmldirparser/qqmlimportresolver_p.h
     INCLUDE_DIRECTORIES
         ${CMAKE_CURRENT_BINARY_DIR}/../qml
         ${CMAKE_CURRENT_BINARY_DIR}/../qml/compiler
diff --git a/src/qmldevtools/CMakeLists.txt b/src/qmldevtools/CMakeLists.txt
index 4648c6854c..9bd5563a5f 100644
--- a/src/qmldevtools/CMakeLists.txt
+++ b/src/qmldevtools/CMakeLists.txt
@@ -38,6 +38,7 @@ qt_add_module(QmlDevTools
         ../qml/parser/qqmljskeywords_p.h
         ../qml/parser/qqmljslexer.cpp ../qml/parser/qqmljslexer_p.h
         ../qml/qmldirparser/qqmldirparser.cpp ../qml/qmldirparser/qqmldirparser_p.h
+        ../qml/qmldirparser/qqmlimportresolver.cpp ../qml/qmldirparser/qqmlimportresolver_p.h
     INCLUDE_DIRECTORIES
         ${CMAKE_CURRENT_BINARY_DIR}/../qml
         ${CMAKE_CURRENT_BINARY_DIR}/../qml/compiler
diff --git a/tools/qmllint/findwarnings.cpp b/tools/qmllint/findwarnings.cpp
index 797b312d92..59b2fc90dc 100644
--- a/tools/qmllint/findwarnings.cpp
+++ b/tools/qmllint/findwarnings.cpp
@@ -37,6 +37,7 @@
 #include <QtQml/private/qqmljsparser_p.h>
 #include <QtQml/private/qv4codegen_p.h>
 #include <QtQml/private/qqmldirparser_p.h>
+#include <QtQml/private/qqmlimportresolver_p.h>
 
 #include <QtCore/qfile.h>
 #include <QtCore/qdiriterator.h>
@@ -108,72 +109,6 @@ ScopeTree::Ptr FindWarningVisitor::parseProgram(QQmlJS::AST::Program *program,
     return result;
 }
 
-enum ImportVersion { FullyVersioned, PartiallyVersioned, Unversioned, BasePath };
-
-QStringList completeImportPaths(const QString &uri, const QString &basePath, QTypeRevision version)
-{
-    static const QLatin1Char Slash('/');
-    static const QLatin1Char Backslash('\\');
-
-    const QVector<QStringRef> parts = uri.splitRef(QLatin1Char('.'), Qt::SkipEmptyParts);
-
-    QStringList qmlDirPathsPaths;
-    // fully & partially versioned parts + 1 unversioned for each base path
-    qmlDirPathsPaths.reserve(2 * parts.count() + 1);
-
-    auto versionString = [](QTypeRevision version, ImportVersion mode)
-    {
-        if (mode == FullyVersioned) {
-            // extension with fully encoded version number (eg. MyModule.3.2)
-            return QString::fromLatin1(".%1.%2").arg(version.majorVersion())
-                    .arg(version.minorVersion());
-        }
-        if (mode == PartiallyVersioned) {
-            // extension with encoded version major (eg. MyModule.3)
-            return QString::fromLatin1(".%1").arg(version.majorVersion());
-        }
-        // else extension without version number (eg. MyModule)
-        return QString();
-    };
-    auto joinStringRefs = [](const QVector<QStringRef> &refs, const QChar &sep) {
-        QString str;
-        for (auto it = refs.cbegin(); it != refs.cend(); ++it) {
-            if (it != refs.cbegin())
-                str += sep;
-            str += *it;
-        }
-        return str;
-    };
-
-    const ImportVersion initial = (version.hasMinorVersion())
-            ? FullyVersioned
-            : (version.hasMajorVersion() ? PartiallyVersioned : Unversioned);
-    for (int mode = initial; mode <= BasePath; ++mode) {
-        const QString ver = versionString(version, ImportVersion(mode));
-
-        QString dir = basePath;
-        if (!dir.endsWith(Slash) && !dir.endsWith(Backslash))
-            dir += Slash;
-
-        if (mode == BasePath) {
-            qmlDirPathsPaths += dir;
-        } else {
-            // append to the end
-            qmlDirPathsPaths += dir + joinStringRefs(parts, Slash) + ver;
-        }
-
-        if (mode < Unversioned) {
-            // insert in the middle
-            for (int index = parts.count() - 2; index >= 0; --index) {
-                qmlDirPathsPaths += dir + joinStringRefs(parts.mid(0, index + 1), Slash)
-                        + ver + Slash
-                        + joinStringRefs(parts.mid(index + 1), Slash);
-            }
-        }
-    }
-    return qmlDirPathsPaths;
-}
-
 static const QLatin1String SlashQmldir             = QLatin1String("/qmldir");
 static const QLatin1String SlashPluginsDotQmltypes = QLatin1String("/plugins.qmltypes");
 
@@ -280,30 +215,28 @@ void FindWarningVisitor::importHelper(const QString &module, const QString &pref
         return;
     m_alreadySeenImports.insert(importId);
 
-    for (const QString &qmltypeDir : m_qmltypeDirs) {
-        auto qmltypesPaths = completeImportPaths(id, qmltypeDir, version);
+    auto qmltypesPaths = qQmlResolveImportPaths(id, m_qmltypeDirs, version) + m_qmltypeDirs;
 
-        for (auto const &qmltypesPath : qmltypesPaths) {
-            if (QFile::exists(qmltypesPath + SlashQmldir)) {
-                processImport(prefix, readQmldir(qmltypesPath));
+    for (auto const &qmltypesPath : qmltypesPaths) {
+        if (QFile::exists(qmltypesPath + SlashQmldir)) {
+            processImport(prefix, readQmldir(qmltypesPath));
 
-                // break so that we don't import unversioned qml components
-                // in addition to versioned ones
-                break;
-            }
+            // break so that we don't import unversioned qml components
+            // in addition to versioned ones
+            break;
+        }
 
-            if (!m_qmltypeFiles.isEmpty())
-                continue;
+        if (!m_qmltypeFiles.isEmpty())
+            continue;
 
-            Import result;
+        Import result;
 
-            QDirIterator it { qmltypesPath, QStringList() << QLatin1String("*.qmltypes"), QDir::Files };
+        QDirIterator it { qmltypesPath, QStringList() << QLatin1String("*.qmltypes"), QDir::Files };
 
-            while (it.hasNext())
-                readQmltypes(it.next(), &result.objects, &result.dependencies);
+        while (it.hasNext())
+            readQmltypes(it.next(), &result.objects, &result.dependencies);
 
-            processImport(prefix, result);
-        }
+        processImport(prefix, result);
     }
 
     if (!m_qmltypeFiles.isEmpty())