V4: check for exceptions after convertThisToObject

The method_convertThisToObject method was invalidly tagged as not
needing exception checks. As a side-effect method_pushCatchScope and
method_popScope are now correctly tagged with a NoThrowEngine.

Change-Id: I11d987e62136216a29eadcbd641546311030058f
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

3 files changed, 6 insertions, 11 deletions

diff --git a/src/qml/jsruntime/qv4runtime.cpp b/src/qml/jsruntime/qv4runtime.cpp
index 0a71f0000a..2026ecdfde 100644
--- a/src/qml/jsruntime/qv4runtime.cpp
+++ b/src/qml/jsruntime/qv4runtime.cpp
@@ -1259,7 +1259,7 @@ ReturnedValue Runtime::method_unwindException(ExecutionEngine *engine)
  *
  * Instead the push/pop pair acts as a non local scope.
  */
-void Runtime::method_pushWithScope(const Value &o, ExecutionEngine *engine)
+void Runtime::method_pushWithScope(const Value &o, NoThrowEngine *engine)
 {
     engine->pushContext(engine->currentContext->newWithContext(o.toObject(engine)));
     Q_ASSERT(engine->jsStackTop == engine->currentContext + 2);
@@ -1272,7 +1272,7 @@ void Runtime::method_pushCatchScope(NoThrowEngine *engine, int exceptionVarNameI
     Q_ASSERT(engine->jsStackTop == engine->currentContext + 2);
 }
 
-void Runtime::method_popScope(ExecutionEngine *engine)
+void Runtime::method_popScope(NoThrowEngine *engine)
 {
     Q_ASSERT(engine->jsStackTop == engine->currentContext + 2);
     engine->popContext();
diff --git a/src/qml/jsruntime/qv4runtimeapi_p.h b/src/qml/jsruntime/qv4runtimeapi_p.h
index 040a545b83..e06a3f5ec2 100644
--- a/src/qml/jsruntime/qv4runtimeapi_p.h
+++ b/src/qml/jsruntime/qv4runtimeapi_p.h
@@ -63,11 +63,6 @@ template <typename T>
 struct ExceptionCheck {
     enum { NeedsCheck = 1 };
 };
-// push_catch and pop context methods shouldn't check for exceptions
-template <>
-struct ExceptionCheck<void (*)(QV4::ExecutionEngine *)> {
-    enum { NeedsCheck = 0 };
-};
 template <typename A>
 struct ExceptionCheck<void (*)(A, QV4::NoThrowEngine)> {
     enum { NeedsCheck = 0 };
@@ -244,9 +239,9 @@ struct Q_QML_PRIVATE_EXPORT Runtime {
     // exceptions & scopes
     RUNTIME_METHOD(void, throwException, (ExecutionEngine *engine, const Value &value));
     RUNTIME_METHOD(ReturnedValue, unwindException, (ExecutionEngine *engine));
-    RUNTIME_METHOD(void, pushWithScope, (const Value &o, ExecutionEngine *engine));
+    RUNTIME_METHOD(void, pushWithScope, (const Value &o, NoThrowEngine *engine));
     RUNTIME_METHOD(void, pushCatchScope, (NoThrowEngine *engine, int exceptionVarNameIndex));
-    RUNTIME_METHOD(void, popScope, (ExecutionEngine *engine));
+    RUNTIME_METHOD(void, popScope, (NoThrowEngine *engine));
 
     // closures
     RUNTIME_METHOD(ReturnedValue, closure, (ExecutionEngine *engine, int functionId));
diff --git a/src/qml/jsruntime/qv4vme_moth.cpp b/src/qml/jsruntime/qv4vme_moth.cpp
index 0f7f6b1f75..b19c36a5bd 100644
--- a/src/qml/jsruntime/qv4vme_moth.cpp
+++ b/src/qml/jsruntime/qv4vme_moth.cpp
@@ -662,13 +662,13 @@ QV4::ReturnedValue VME::run(ExecutionEngine *engine, const uchar *code
     MOTH_END_INSTR(CallBuiltinPushCatchScope)
 
     MOTH_BEGIN_INSTR(CallBuiltinPushScope)
-        engine->runtime.pushWithScope(VALUE(instr.arg), engine);
+        engine->runtime.pushWithScope(VALUE(instr.arg), static_cast<QV4::NoThrowEngine*>(engine));
         context = engine->currentContext;
         CHECK_EXCEPTION;
     MOTH_END_INSTR(CallBuiltinPushScope)
 
     MOTH_BEGIN_INSTR(CallBuiltinPopScope)
-        engine->runtime.popScope(engine);
+        engine->runtime.popScope(static_cast<QV4::NoThrowEngine*>(engine));
         context = engine->currentContext;
     MOTH_END_INSTR(CallBuiltinPopScope)