QScript: fix the way the js stack is advanced.

It is possible to call QScriptEngine::pushContext before we start any evaluation.
We need to change JSC so it doesn't always start at the beginning of the stack.

Also fix QScriptContext::pushContext not to waste space between callframes.

Reviewed-by: Kent Hansen

2 files changed, 10 insertions, 4 deletions

diff --git a/src/3rdparty/javascriptcore/JavaScriptCore/interpreter/Interpreter.cpp b/src/3rdparty/javascriptcore/JavaScriptCore/interpreter/Interpreter.cpp
index bfb0307..4200023 100644
--- a/src/3rdparty/javascriptcore/JavaScriptCore/interpreter/Interpreter.cpp
+++ b/src/3rdparty/javascriptcore/JavaScriptCore/interpreter/Interpreter.cpp
@@ -885,13 +885,21 @@ JSValue Interpreter::execute(EvalExecutable* eval, CallFrame* callFrame, JSObjec
     }
 
     Register* oldEnd = m_registerFile.end();
+#ifdef  QT_BUILD_SCRIPT_LIB //with QtScript, we do not necesserly start from scratch
+    Register* newEnd = oldEnd + globalRegisterOffset + codeBlock->m_numCalleeRegisters;
+#else
     Register* newEnd = m_registerFile.start() + globalRegisterOffset + codeBlock->m_numCalleeRegisters;
+#endif
     if (!m_registerFile.grow(newEnd)) {
         *exception = createStackOverflowError(callFrame);
         return jsNull();
     }
 
+#ifdef QT_BUILD_SCRIPT_LIB //with QtScript, we do not necesserly start from scratch
+    CallFrame* newCallFrame = CallFrame::create(oldEnd + globalRegisterOffset);
+#else
     CallFrame* newCallFrame = CallFrame::create(m_registerFile.start() + globalRegisterOffset);
+#endif
 
     // a 0 codeBlock indicates a built-in caller
     newCallFrame->r(codeBlock->thisRegister()) = JSValue(thisObj);
diff --git a/src/script/api/qscriptengine.cpp b/src/script/api/qscriptengine.cpp
index b27d1be..ee25239 100644
--- a/src/script/api/qscriptengine.cpp
+++ b/src/script/api/qscriptengine.cpp
@@ -2360,11 +2360,9 @@ JSC::CallFrame *QScriptEnginePrivate::pushContext(JSC::CallFrame *exec, JSC::JSV
         JSC::Register *oldEnd = interp->registerFile().end();
         int argc = args.size() + 1; //add "this"
         JSC::Register *newEnd = oldEnd + argc + JSC::RegisterFile::CallFrameHeaderSize;
-        //Without + argc + JSC::RegisterFile::CallFrameHeaderSize, it crashes.
-        //It seems that JSC is not consistant with the way the callframe is crated
-        if (!interp->registerFile().grow(newEnd + argc + JSC::RegisterFile::CallFrameHeaderSize))
+        if (!interp->registerFile().grow(newEnd))
             return 0; //### Stack overflow
-        newCallFrame = JSC::CallFrame::create(newEnd);
+        newCallFrame = JSC::CallFrame::create(oldEnd);
         newCallFrame[0] = thisObject;
         int dst = 0;
         JSC::ArgList::const_iterator it;