Move generateloader.cpp to QmlCompiler

We need to be able to generate the loader code from multiple places.

Change-Id: I9e04fd3583b535bc5f7d5fb293cb61309c1e199a
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>

4 files changed, 294 insertions, 0 deletions

diff --git a/src/qmlcompiler/CMakeLists.txt b/src/qmlcompiler/CMakeLists.txt
index f2180f35cd..82810165a9 100644
--- a/src/qmlcompiler/CMakeLists.txt
+++ b/src/qmlcompiler/CMakeLists.txt
@@ -11,6 +11,7 @@ qt_internal_add_module(QmlCompiler
         qdeferredpointer_p.h
         qqmljsimporter.cpp qqmljsimporter_p.h
         qqmljsimportvisitor.cpp qqmljsimportvisitor_p.h
+        qqmljsloadergenerator.cpp qqmljsloadergenerator_p.h
         qqmljsmetatypes_p.h
         qqmljsresourcefilemapper.cpp qqmljsresourcefilemapper_p.h
         qqmljsscope.cpp qqmljsscope_p.h
diff --git a/src/qmlcompiler/qmlcompiler.pro b/src/qmlcompiler/qmlcompiler.pro
index a8c81af081..1b2e617809 100644
--- a/src/qmlcompiler/qmlcompiler.pro
+++ b/src/qmlcompiler/qmlcompiler.pro
@@ -11,6 +11,7 @@ SOURCES = \
     qqmljsscope.cpp \
     qqmljstypedescriptionreader.cpp \
     qqmljsstreamwriter.cpp \
+    qqmljsloadergenerator.cpp \
     qresourcerelocater.cpp
 
 HEADERS = \
@@ -23,6 +24,7 @@ HEADERS = \
     qqmljsscope_p.h \
     qqmljstypedescriptionreader_p.h \
     qqmljsstreamwriter_p.h \
+    qqmljsloadergenerator_p.h \
     qresourcerelocater_p.h
 
 load(qt_module)
diff --git a/src/qmlcompiler/qqmljsloadergenerator.cpp b/src/qmlcompiler/qqmljsloadergenerator.cpp
new file mode 100644
index 0000000000..bd560e6266
--- /dev/null
+++ b/src/qmlcompiler/qqmljsloadergenerator.cpp
@@ -0,0 +1,238 @@
+/****************************************************************************
+**
+** 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.
+**
+** $QT_BEGIN_LICENSE:GPL-EXCEPT$
+** 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.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qqmljsloadergenerator_p.h"
+
+#include <QByteArray>
+#include <QRegularExpression>
+#include <QString>
+#include <QStringList>
+#include <QTextStream>
+#include <QVector>
+#include <QtEndian>
+#include <QStack>
+#include <QFileInfo>
+#include <QSaveFile>
+
+#include <algorithm>
+
+QT_BEGIN_NAMESPACE
+
+/*!
+ * \internal
+ * Mangles \a str to be a unique C++ identifier. Characters that are invalid for C++ identifiers
+ * are replaced by the pattern \c _0x<hex>_ where <hex> is the hexadecimal unicode
+ * representation of the character. As identifiers with leading underscores followed by either
+ * another underscore or a capital letter are reserved in C++, we also escape those, by escaping
+ * the first underscore, using the above method.
+ *
+ * \note
+ * Although C++11 allows for non-ascii (unicode) characters to be used in identifiers,
+ * many compilers forgot to read the spec and do not implement this. Some also do not
+ * implement C99 identifiers, because that is \e {at the implementation's discretion}. So,
+ * we are stuck with plain old boring identifiers.
+ */
+QString mangledIdentifier(const QString &str)
+{
+    Q_ASSERT(!str.isEmpty());
+
+    QString mangled;
+    mangled.reserve(str.size());
+
+    int i = 0;
+    if (str.startsWith(QLatin1Char('_')) && str.size() > 1) {
+        QChar ch = str.at(1);
+        if (ch == QLatin1Char('_')
+                || (ch >= QLatin1Char('A') && ch <= QLatin1Char('Z'))) {
+            mangled += QLatin1String("_0x5f_");
+            ++i;
+        }
+    }
+
+    for (int ei = str.length(); i != ei; ++i) {
+        auto c = str.at(i).unicode();
+        if ((c >= QLatin1Char('0') && c <= QLatin1Char('9'))
+            || (c >= QLatin1Char('a') && c <= QLatin1Char('z'))
+            || (c >= QLatin1Char('A') && c <= QLatin1Char('Z'))
+            || c == QLatin1Char('_')) {
+            mangled += QChar(c);
+        } else {
+            mangled += QLatin1String("_0x") + QString::number(c, 16) + QLatin1Char('_');
+        }
+    }
+
+    return mangled;
+}
+
+QString qQmlJSSymbolNamespaceForPath(const QString &relativePath)
+{
+    QFileInfo fi(relativePath);
+    QString symbol = fi.path();
+    if (symbol.length() == 1 && symbol.startsWith(QLatin1Char('.'))) {
+        symbol.clear();
+    } else {
+        symbol.replace(QLatin1Char('/'), QLatin1Char('_'));
+        symbol += QLatin1Char('_');
+    }
+    symbol += fi.baseName();
+    symbol += QLatin1Char('_');
+    symbol += fi.completeSuffix();
+    return mangledIdentifier(symbol);
+}
+
+static QString qtResourceNameForFile(const QString &fileName)
+{
+    QFileInfo fi(fileName);
+    QString name = fi.completeBaseName();
+    if (name.isEmpty())
+        name = fi.fileName();
+    name.replace(QRegularExpression(QLatin1String("[^a-zA-Z0-9_]")), QLatin1String("_"));
+    return name;
+}
+
+bool qQmlJSGenerateLoader(const QStringList &compiledFiles, const QString &outputFileName,
+                          const QStringList &resourceFileMappings, QString *errorString)
+{
+    QByteArray generatedLoaderCode;
+
+    {
+        QTextStream stream(&generatedLoaderCode);
+        stream << "#include <QtQml/qqmlprivate.h>\n";
+        stream << "#include <QtCore/qdir.h>\n";
+        stream << "#include <QtCore/qurl.h>\n";
+        stream << "\n";
+
+        stream << "namespace QmlCacheGeneratedCode {\n";
+        for (int i = 0; i < compiledFiles.count(); ++i) {
+            const QString compiledFile = compiledFiles.at(i);
+            const QString ns = qQmlJSSymbolNamespaceForPath(compiledFile);
+            stream << "namespace " << ns << " { \n";
+            stream << "    extern const unsigned char qmlData[];\n";
+            stream << "    const QQmlPrivate::CachedQmlUnit unit = {\n";
+            stream << "        reinterpret_cast<const QV4::CompiledData::Unit*>(&qmlData), nullptr, nullptr\n";
+            stream << "    };\n";
+            stream << "}\n";
+        }
+
+        stream << "\n}\n";
+        stream << "namespace {\n";
+
+        stream << "struct Registry {\n";
+        stream << "    Registry();\n";
+        stream << "    ~Registry();\n";
+        stream << "    QHash<QString, const QQmlPrivate::CachedQmlUnit*> resourcePathToCachedUnit;\n";
+        stream << "    static const QQmlPrivate::CachedQmlUnit *lookupCachedUnit(const QUrl &url);\n";
+        stream << "};\n\n";
+        stream << "Q_GLOBAL_STATIC(Registry, unitRegistry)\n";
+        stream << "\n\n";
+
+        stream << "Registry::Registry() {\n";
+
+        for (int i = 0; i < compiledFiles.count(); ++i) {
+            const QString qrcFile = compiledFiles.at(i);
+            const QString ns = qQmlJSSymbolNamespaceForPath(qrcFile);
+            stream << "        resourcePathToCachedUnit.insert(QStringLiteral(\"" << qrcFile << "\"), &QmlCacheGeneratedCode::" << ns << "::unit);\n";
+        }
+
+        stream << "    QQmlPrivate::RegisterQmlUnitCacheHook registration;\n";
+        stream << "    registration.structVersion = 0;\n";
+        stream << "    registration.lookupCachedQmlUnit = &lookupCachedUnit;\n";
+        stream << "    QQmlPrivate::qmlregister(QQmlPrivate::QmlUnitCacheHookRegistration, &registration);\n";
+
+        stream << "}\n\n";
+        stream << "Registry::~Registry() {\n";
+        stream << "    QQmlPrivate::qmlunregister(QQmlPrivate::QmlUnitCacheHookRegistration, quintptr(&lookupCachedUnit));\n";
+        stream << "}\n\n";
+
+        stream << "const QQmlPrivate::CachedQmlUnit *Registry::lookupCachedUnit(const QUrl &url) {\n";
+        stream << "    if (url.scheme() != QLatin1String(\"qrc\"))\n";
+        stream << "        return nullptr;\n";
+        stream << "    QString resourcePath = QDir::cleanPath(url.path());\n";
+        stream << "    if (resourcePath.isEmpty())\n";
+        stream << "        return nullptr;\n";
+        stream << "    if (!resourcePath.startsWith(QLatin1Char('/')))\n";
+        stream << "        resourcePath.prepend(QLatin1Char('/'));\n";
+        stream << "    return unitRegistry()->resourcePathToCachedUnit.value(resourcePath, nullptr);\n";
+        stream << "}\n";
+        stream << "}\n";
+
+        for (const QString &mapping: resourceFileMappings) {
+            QString originalResourceFile = mapping;
+            QString newResourceFile;
+            const int mappingSplit = originalResourceFile.indexOf(QLatin1Char('='));
+            if (mappingSplit != -1) {
+                newResourceFile = originalResourceFile.mid(mappingSplit + 1);
+                originalResourceFile.truncate(mappingSplit);
+            }
+
+            const QString suffix = qtResourceNameForFile(originalResourceFile);
+            const QString initFunction = QLatin1String("qInitResources_") + suffix;
+
+            stream << QStringLiteral("int QT_MANGLE_NAMESPACE(%1)() {\n").arg(initFunction);
+            stream << "    ::unitRegistry();\n";
+            if (!newResourceFile.isEmpty())
+                stream << "    Q_INIT_RESOURCE(" << qtResourceNameForFile(newResourceFile) << ");\n";
+            stream << "    return 1;\n";
+            stream << "}\n";
+            stream << "Q_CONSTRUCTOR_FUNCTION(QT_MANGLE_NAMESPACE(" << initFunction << "))\n";
+
+            const QString cleanupFunction = QLatin1String("qCleanupResources_") + suffix;
+            stream << QStringLiteral("int QT_MANGLE_NAMESPACE(%1)() {\n").arg(cleanupFunction);
+            if (!newResourceFile.isEmpty())
+                stream << "    Q_CLEANUP_RESOURCE(" << qtResourceNameForFile(newResourceFile) << ");\n";
+            stream << "    return 1;\n";
+            stream << "}\n";
+        }
+    }
+
+#if QT_CONFIG(temporaryfile)
+    QSaveFile f(outputFileName);
+#else
+    QFile f(outputFileName);
+#endif
+    if (!f.open(QIODevice::WriteOnly | QIODevice::Truncate)) {
+        *errorString = f.errorString();
+        return false;
+    }
+
+    if (f.write(generatedLoaderCode) != generatedLoaderCode.size()) {
+        *errorString = f.errorString();
+        return false;
+    }
+
+#if QT_CONFIG(temporaryfile)
+    if (!f.commit()) {
+        *errorString = f.errorString();
+        return false;
+    }
+#endif
+
+    return true;
+}
+
+QT_END_NAMESPACE
diff --git a/src/qmlcompiler/qqmljsloadergenerator_p.h b/src/qmlcompiler/qqmljsloadergenerator_p.h
new file mode 100644
index 0000000000..a8f00d30d0
--- /dev/null
+++ b/src/qmlcompiler/qqmljsloadergenerator_p.h
@@ -0,0 +1,53 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the tools applications of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:GPL-EXCEPT$
+** 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.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QQMLJSLOADERGENERATOR_P_H
+#define QQMLJSLOADERGENERATOR_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/qstring.h>
+#include <QtCore/qlist.h>
+
+QT_BEGIN_NAMESPACE
+
+bool qQmlJSGenerateLoader(const QStringList &compiledFiles, const QString &outputFileName,
+                          const QStringList &resourceFileMappings, QString *errorString);
+QString qQmlJSSymbolNamespaceForPath(const QString &relativePath);
+
+QT_END_NAMESPACE
+
+#endif // QQMLJSLOADERGENERATOR_P_H