qmljs: simple tracking of used modules

Change-Id: Idc977a8c5a6c6caa3749599cb6f4a236046f53d7
Reviewed-by: Fawzi Mohamed <fawzi.mohamed@digia.com>

src/libs/qmljs/qmljsinterpreter.cpp

@@ -2181,7 +2181,12 @@ UiImport *ImportInfo::ast() const
 }
 
 Import::Import()
-    : object(0)
+    : object(0), valid(false), used(false)
+{}
+
+Import::Import(const Import &other)
+    : object(other.object), info(other.info), libraryPath(other.libraryPath),
+      valid(other.valid), used(false)
 { }
 
 TypeScope::TypeScope(const Imports *imports, ValueOwner *valueOwner)
@@ -2208,6 +2213,7 @@ const Value *TypeScope::lookupMember(const QString &name, const Context *context
             if (info.as() == name) {
                 if (foundInObject)
                     *foundInObject = this;
+                i.used = true;
                 return import;
             }
             continue;
@@ -2264,6 +2270,7 @@ const Value *JSImportScope::lookupMember(const QString &name, const Context *,
         if (info.as() == name) {
             if (foundInObject)
                 *foundInObject = this;
+            i.used = true;
             return import;
         }
     }

src/libs/qmljs/qmljsinterpreter.h

@@ -40,6 +40,7 @@
 #include <QHash>
 #include <QSet>
 #include <QMutex>
+#include <QSharedPointer>
 
 namespace QmlJS {
 
@@ -906,6 +907,7 @@ private:
 class QMLJS_EXPORT Import {
 public:
     Import();
+    Import(const Import &other);
 
     // const!
     ObjectValue *object;
@@ -914,6 +916,7 @@ public:
     QString libraryPath;
     // whether the import succeeded
     bool valid;
+    mutable bool used;
 };
 
 class Imports;