3 files changed, 53 insertions, 1 deletions
diff --git a/src/qmlcompiler/qqmljsimporter_p.h b/src/qmlcompiler/qqmljsimporter_p.h
index 45e527b967..6aec963586 100644
--- a/src/qmlcompiler/qqmljsimporter_p.h
+++ b/src/qmlcompiler/qqmljsimporter_p.h
@@ -34,9 +34,12 @@ public:
     QQmlJSImporter(const QStringList &importPaths, QQmlJSResourceFileMapper *mapper,
                    bool useOptionalImports = false);
 
-    QQmlJSResourceFileMapper *resourceFileMapper() { return m_mapper; }
+    QQmlJSResourceFileMapper *resourceFileMapper() const { return m_mapper; }
     void setResourceFileMapper(QQmlJSResourceFileMapper *mapper) { m_mapper = mapper; }
 
+    QQmlJSResourceFileMapper *metaDataMapper() const { return m_metaDataMapper; }
+    void setMetaDataMapper(QQmlJSResourceFileMapper *mapper) { m_metaDataMapper = mapper; }
+
     ImportedTypes importBuiltins();
     void importQmldirs(const QStringList &qmltypesFiles);
 
@@ -143,6 +146,7 @@ private:
     QList<QQmlJS::DiagnosticMessage> m_warnings;
     AvailableTypes m_builtins;
     QQmlJSResourceFileMapper *m_mapper = nullptr;
+    QQmlJSResourceFileMapper *m_metaDataMapper = nullptr;
     bool m_useOptionalImports;
 
     ImportVisitorCreator m_createImportVisitor = nullptr;
diff --git a/src/qmlcompiler/qqmljsutils.cpp b/src/qmlcompiler/qqmljsutils.cpp
index c07c0b6845..548c86eb67 100644
--- a/src/qmlcompiler/qqmljsutils.cpp
+++ b/src/qmlcompiler/qqmljsutils.cpp
@@ -146,3 +146,47 @@ std::optional<FixSuggestion> QQmlJSUtils::didYouMean(const QString &userInput,
         return {};
     }
 }
+
+/*! \internal
+
+    Returns a corresponding source directory path for \a buildDirectoryPath
+    Returns empty string on error
+*/
+std::variant<QString, QQmlJS::DiagnosticMessage>
+QQmlJSUtils::sourceDirectoryPath(const QQmlJSImporter *importer, const QString &buildDirectoryPath)
+{
+    const auto makeError = [](const QString &msg) {
+        return QQmlJS::DiagnosticMessage { msg, QtWarningMsg, QQmlJS::SourceLocation() };
+    };
+
+    if (!importer->metaDataMapper())
+        return makeError(u"QQmlJSImporter::metaDataMapper() is nullptr"_s);
+
+    // for now, meta data contains just a single entry
+    QQmlJSResourceFileMapper::Filter matchAll { QString(), QStringList(),
+                                                QQmlJSResourceFileMapper::Directory
+                                                        | QQmlJSResourceFileMapper::Recurse };
+    QQmlJSResourceFileMapper::Entry entry = importer->metaDataMapper()->entry(matchAll);
+    if (!entry.isValid())
+        return makeError(u"Failed to find meta data entry in QQmlJSImporter::metaDataMapper()"_s);
+    if (!buildDirectoryPath.startsWith(entry.filePath)) // assume source directory path already
+        return makeError(u"The module output directory does not match the build directory path"_s);
+
+    QString qrcPath = buildDirectoryPath;
+    qrcPath.remove(0, entry.filePath.size());
+    qrcPath.prepend(entry.resourcePath);
+    qrcPath.remove(0, 1); // remove extra "/"
+
+    const QStringList sourceDirPaths = importer->resourceFileMapper()->filePaths(
+            QQmlJSResourceFileMapper::resourceFileFilter(qrcPath));
+    if (sourceDirPaths.size() != 1) {
+        const QString matchedPaths =
+                sourceDirPaths.isEmpty() ? u"<none>"_s : sourceDirPaths.join(u", ");
+        return makeError(
+                QStringLiteral("QRC path %1 (deduced from %2) has unexpected number of mappings "
+                               "(%3). File paths that matched:\n%4")
+                        .arg(qrcPath, buildDirectoryPath, QString::number(sourceDirPaths.size()),
+                             matchedPaths));
+    }
+    return sourceDirPaths[0];
+}
diff --git a/src/qmlcompiler/qqmljsutils_p.h b/src/qmlcompiler/qqmljsutils_p.h
index 3698d3861b..ab3dbd9745 100644
--- a/src/qmlcompiler/qqmljsutils_p.h
+++ b/src/qmlcompiler/qqmljsutils_p.h
@@ -29,6 +29,7 @@
 #include <optional>
 #include <functional>
 #include <type_traits>
+#include <variant>
 
 QT_BEGIN_NAMESPACE
 
@@ -333,6 +334,9 @@ struct Q_QMLCOMPILER_PRIVATE_EXPORT QQmlJSUtils
     static std::optional<FixSuggestion> didYouMean(const QString &userInput,
                                                    QStringList candidates,
                                                    QQmlJS::SourceLocation location);
+
+    static std::variant<QString, QQmlJS::DiagnosticMessage>
+    sourceDirectoryPath(const QQmlJSImporter *importer, const QString &buildDirectoryPath);
 };
 
 QT_END_NAMESPACE