Prevent dangling JS values

As opposed to QtScript, such values cannot be re-used in QuickJS. This
was overlooked in 087c22e17721f37490dd2048a567b6a58065d939.
I assume this is the culprit for seemingly random crashes and "not a
function" messages we have been seeing sometimes when building with Qt
Creator.

Change-Id: Ia4e7aed0cda97439ac75db5ecfbf08ff096a02b2
Reviewed-by: Ivan Komissarov <ABBAPOH@gmail.com>

1 files changed, 3 insertions, 5 deletions

diff --git a/src/lib/corelib/language/language.h b/src/lib/corelib/language/language.h
index d055aa132..a1115519d 100644
--- a/src/lib/corelib/language/language.h
+++ b/src/lib/corelib/language/language.h
@@ -70,15 +70,12 @@
 #include <mutex>
 #include <vector>
 
-QT_BEGIN_NAMESPACE
-class QScriptEngine;
-QT_END_NAMESPACE
-
 namespace qbs {
 namespace Internal {
 class BuildGraphLocker;
 class BuildGraphLoader;
 class BuildGraphVisitor;
+class ScriptEngine;
 
 class FileTagger
 {
@@ -335,8 +332,8 @@ class PrivateScriptFunction
     friend bool operator==(const PrivateScriptFunction &a, const PrivateScriptFunction &b);
 public:
     void initialize(const ScriptFunctionPtr &sharedData) { m_sharedData = sharedData; }
-    mutable JSValue scriptFunction = JS_UNDEFINED; // not stored
 
+    JSValue getFunction(ScriptEngine *engine, const QString &errorMessage) const;
     QString &sourceCode() const { return m_sharedData->sourceCode; }
     CodeLocation &location()  const { return m_sharedData->location; }
     ResolvedFileContextConstPtr &fileContext() const { return m_sharedData->fileContext; }
@@ -349,6 +346,7 @@ public:
 
 private:
     ScriptFunctionPtr m_sharedData;
+    mutable JSValue scriptFunction = JS_UNDEFINED; // not stored
 };
 
 bool operator==(const PrivateScriptFunction &a, const PrivateScriptFunction &b);