Handle function as default arguments in toplevel functions

Top level functions, that is, those directly defined in a QML component
as opposed to those defined inside another function or class, are not
visited directly by the ScanFunction visitor. Instead, they are manually
considered in generateJSCodeForFunctionsAndBindings, and the visitor is
then run on their body.
This worked mostly fine, with one notable exception: In case there is a
function expression used as the default value of a function parameter,
that function would have never been visited. This would lead to
subsequent asserts/crashes in the codegen, as the function was not
properly set up.
We fix this by manually visiting the function's formals in addition to
the body.

Pick-to: 6.2 5.15
Fixes: QTBUG-98032
Change-Id: I5cb4caae39ab45f01a0dfa1555099d7d4b796a19
Reviewed-by: Andrei Golubev <andrei.golubev@qt.io>
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>

1 files changed, 7 insertions, 0 deletions

diff --git a/src/qml/compiler/qv4compilerscanfunctions_p.h b/src/qml/compiler/qv4compilerscanfunctions_p.h
index 073ee5c2a4..d2868fc428 100644
--- a/src/qml/compiler/qv4compilerscanfunctions_p.h
+++ b/src/qml/compiler/qv4compilerscanfunctions_p.h
@@ -83,6 +83,13 @@ public:
     ScanFunctions(Codegen *cg, const QString &sourceCode, ContextType defaultProgramType);
     void operator()(QQmlJS::AST::Node *node);
 
+    // see comment at its call site in generateJSCodeForFunctionsAndBindings
+    // for why this function is necessary
+    void handleTopLevelFunctionFormals(QQmlJS::AST::FunctionExpression *node) {
+        if (node && node->formals)
+            node->formals->accept(this);
+    }
+
     void enterGlobalEnvironment(ContextType compilationMode);
     void enterEnvironment(QQmlJS::AST::Node *node, ContextType compilationMode,
                           const QString &name);