Add option to retain sources when generating QML cache

By default any .qrc files are filtered and QML and JS sources dropped
when generating the cache. The new QTQUICK_COMPILER_RETAINED_RESOURCES
option allows the specification of .qrc files to be kept as they are.
The source fils specified in them will be available to the application.

Change-Id: If45bcd95c29fe4b91f5817573964ff55b1db8a00
Fixes: QTBUG-72430
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

3 files changed, 41 insertions, 11 deletions

diff --git a/tools/qmlcachegen/generateloader.cpp b/tools/qmlcachegen/generateloader.cpp
index de79576d67..0027d53d00 100644
--- a/tools/qmlcachegen/generateloader.cpp
+++ b/tools/qmlcachegen/generateloader.cpp
@@ -36,6 +36,8 @@
 #include <QFileInfo>
 #include <QSaveFile>
 
+#include <algorithm>
+
 /*!
  * \internal
  * Mangles \a str to be a unique C++ identifier. Characters that are invalid for C++ identifiers
@@ -261,7 +263,8 @@ private:
     }
 };
 
-static QByteArray generateResourceDirectoryTree(QTextStream &code, const QStringList &qrcFiles)
+static QByteArray generateResourceDirectoryTree(QTextStream &code, const QStringList &qrcFiles,
+                                                const QStringList &sortedRetainedFiles)
 {
     QByteArray call;
     if (qrcFiles.isEmpty())
@@ -277,7 +280,8 @@ static QByteArray generateResourceDirectoryTree(QTextStream &code, const QString
 
         for (int i = 0; i < segments.count() - 1; ++i)
             dirEntry = dirEntry->append(segments.at(i));
-        dirEntry->appendEmptyFile(segments.last());
+        if (!std::binary_search(sortedRetainedFiles.begin(), sortedRetainedFiles.end(), entry))
+            dirEntry->appendEmptyFile(segments.last());
     }
 
     if (resourceDirs.isEmpty())
@@ -328,7 +332,9 @@ static QString qtResourceNameForFile(const QString &fileName)
     return name;
 }
 
-bool generateLoader(const QStringList &compiledFiles, const QString &outputFileName, const QStringList &resourceFileMappings, QString *errorString)
+bool generateLoader(const QStringList &compiledFiles, const QStringList &sortedRetainedFiles,
+                    const QString &outputFileName, const QStringList &resourceFileMappings,
+                    QString *errorString)
 {
     QByteArray generatedLoaderCode;
 
@@ -339,7 +345,8 @@ bool generateLoader(const QStringList &compiledFiles, const QString &outputFileN
         stream << "#include <QtCore/qurl.h>\n";
         stream << "\n";
 
-        QByteArray resourceRegisterCall = generateResourceDirectoryTree(stream, compiledFiles);
+        QByteArray resourceRegisterCall = generateResourceDirectoryTree(stream, compiledFiles,
+                                                                        sortedRetainedFiles);
 
         stream << "namespace QmlCacheGeneratedCode {\n";
         for (int i = 0; i < compiledFiles.count(); ++i) {
diff --git a/tools/qmlcachegen/qmlcachegen.cpp b/tools/qmlcachegen/qmlcachegen.cpp
index 1805dde5d2..b3c55e85e0 100644
--- a/tools/qmlcachegen/qmlcachegen.cpp
+++ b/tools/qmlcachegen/qmlcachegen.cpp
@@ -43,8 +43,12 @@
 
 #include "resourcefilemapper.h"
 
+#include <algorithm>
+
 int filterResourceFile(const QString &input, const QString &output);
-bool generateLoader(const QStringList &compiledFiles, const QString &output, const QStringList &resourceFileMappings, QString *errorString);
+bool generateLoader(const QStringList &compiledFiles, const QStringList &retainedFiles,
+                    const QString &output, const QStringList &resourceFileMappings,
+                    QString *errorString);
 QString symbolNamespaceForPath(const QString &relativePath);
 
 QSet<QString> illegalNames;
@@ -438,6 +442,8 @@ int main(int argc, char **argv)
     parser.addOption(resourceFileMappingOption);
     QCommandLineOption resourceOption(QStringLiteral("resource"), QCoreApplication::translate("main", "Qt resource file that might later contain one of the compiled files"), QCoreApplication::translate("main", "resource-file-name"));
     parser.addOption(resourceOption);
+    QCommandLineOption retainOption(QStringLiteral("retain"), QCoreApplication::translate("main", "Qt resource file the contents of which should not be replaced by empty stubs"), QCoreApplication::translate("main", "resource-file-name"));
+    parser.addOption(retainOption);
     QCommandLineOption resourcePathOption(QStringLiteral("resource-path"), QCoreApplication::translate("main", "Qt resource file path corresponding to the file being compiled"), QCoreApplication::translate("main", "resource-path"));
     parser.addOption(resourcePathOption);
 
@@ -485,9 +491,13 @@ int main(int argc, char **argv)
 
     if (target == GenerateLoader) {
         ResourceFileMapper mapper(sources);
+        ResourceFileMapper retain(parser.values(retainOption));
 
         Error error;
-        if (!generateLoader(mapper.qmlCompilerFiles(), outputFileName, parser.values(resourceFileMappingOption), &error.message)) {
+        QStringList retainedFiles = retain.qmlCompilerFiles();
+        std::sort(retainedFiles.begin(), retainedFiles.end());
+        if (!generateLoader(mapper.qmlCompilerFiles(), retainedFiles, outputFileName,
+                            parser.values(resourceFileMappingOption), &error.message)) {
             error.augment(QLatin1String("Error generating loader stub: ")).print();
             return EXIT_FAILURE;
         }
diff --git a/tools/qmlcachegen/qtquickcompiler.prf b/tools/qmlcachegen/qtquickcompiler.prf
index 608b5c9143..c7899c5100 100644
--- a/tools/qmlcachegen/qtquickcompiler.prf
+++ b/tools/qmlcachegen/qtquickcompiler.prf
@@ -15,6 +15,13 @@ defineReplace(qmlCacheResourceFileOutputName) {
     return($${name})
 }
 
+defineTest(qtQuickRetainSources) {
+    for(retainedRes, QTQUICK_COMPILER_RETAINED_RESOURCES) {
+        equals(1, $$retainedRes): return(true)
+    }
+    return(false)
+}
+
 defineTest(qtQuickSkippedResourceFile) {
     for(skippedRes, QTQUICK_COMPILER_SKIPPED_RESOURCES) {
         equals(1, $$skippedRes): return(true)
@@ -39,12 +46,18 @@ for(res, RESOURCES) {
     contains(rccContents,.*\\.js$)|contains(rccContents,.*\\.qml$)|contains(rccContents,.*\\.mjs$) {
         new_resource = $$qmlCacheResourceFileOutputName($$res)
         mkpath($$dirname(new_resource))
-        remaining_files = $$system($$QML_CACHEGEN_FILTER -filter-resource-file -o $$system_quote($$new_resource) $$system_quote($$absRes),lines)
-        !isEmpty(remaining_files) {
-            NEWRESOURCES += $$new_resource
-            QMLCACHE_LOADER_FLAGS += --resource-file-mapping=$$shell_quote($$absRes=$$new_resource)
+        qtQuickRetainSources($$res) {
+            NEWRESOURCES += $$res
+            QMLCACHE_LOADER_FLAGS += --retain=$$shell_quote($$absRes)
         } else {
-            QMLCACHE_LOADER_FLAGS += --resource-file-mapping=$$shell_quote($$absRes)
+            remaining_files = $$system($$QML_CACHEGEN_FILTER -filter-resource-file \
+                    -o $$system_quote($$new_resource) $$system_quote($$absRes),lines)
+            !isEmpty(remaining_files) {
+                NEWRESOURCES += $$new_resource
+                QMLCACHE_LOADER_FLAGS += --resource-file-mapping=$$shell_quote($$absRes=$$new_resource)
+            } else {
+                QMLCACHE_LOADER_FLAGS += --resource-file-mapping=$$shell_quote($$absRes)
+            }
         }
 
         QMLCACHE_RESOURCE_FILES += $$absRes