Prevent objects from being collected while in their constructor

While objects are being constructed, we don't have a reference to them
on the JS stack yet. So the constructor needs to protect itself against
being collected by putting the this object onto the JS stack.

Added an environment switch MM_EXACT_GC to test exact garbage
collection.

Change-Id: Ie37665a954de800359c272ffbebbe1488e7a8ace
Reviewed-by: Gunnar Sletta <gunnar.sletta@digia.com>
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>

1 files changed, 2 insertions, 4 deletions

diff --git a/tools/v4/main.cpp b/tools/v4/main.cpp
index ad91b88cda..8e9a880ccd 100644
--- a/tools/v4/main.cpp
+++ b/tools/v4/main.cpp
@@ -72,9 +72,8 @@ using namespace QV4;
 
 struct Print: FunctionObject
 {
-    Print(ExecutionContext *scope): FunctionObject(scope) {
+    Print(ExecutionContext *scope): FunctionObject(scope, QStringLiteral("print")) {
         vtbl = &static_vtbl;
-        name = scope->engine->newString("print");
     }
 
     static ReturnedValue call(Managed *, CallData *callData)
@@ -97,10 +96,9 @@ DEFINE_MANAGED_VTABLE(Print);
 struct GC: public FunctionObject
 {
     GC(ExecutionContext* scope)
-        : FunctionObject(scope)
+        : FunctionObject(scope, QStringLiteral("gc"))
     {
         vtbl = &static_vtbl;
-        name = scope->engine->newString("gc");
     }
     static ReturnedValue call(Managed *m, CallData *)
     {