Add support for proper lexical scoping

This is still to some extend work in progress as
lexically scoped for loops won't yet do the right
thing.

let and const variables are still accessible before
they are declared, and the global scope doesn't yet
have a proper context for lexically declared variables.

Change-Id: Ie39f74a8fccdaead437fbf07f9fc228a444c26ed
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

1 files changed, 28 insertions, 0 deletions

diff --git a/src/qml/jsruntime/qv4context.cpp b/src/qml/jsruntime/qv4context.cpp
index 020e519e74..39fdcf0227 100644
--- a/src/qml/jsruntime/qv4context.cpp
+++ b/src/qml/jsruntime/qv4context.cpp
@@ -55,6 +55,29 @@ DEFINE_MANAGED_VTABLE(ExecutionContext);
 DEFINE_MANAGED_VTABLE(CallContext);
 DEFINE_MANAGED_VTABLE(CatchContext);
 
+Heap::CallContext *ExecutionContext::newBlockContext(CppStackFrame *frame, int blockIndex)
+{
+    Function *function = frame->v4Function;
+    Heap::ExecutionContext *outer = static_cast<Heap::ExecutionContext *>(frame->context()->m());
+
+    Heap::InternalClass *ic = function->compilationUnit->runtimeBlocks.at(blockIndex);
+    int nLocals = ic->size;
+    size_t requiredMemory = sizeof(CallContext::Data) - sizeof(Value) + sizeof(Value) * nLocals;
+
+    ExecutionEngine *v4 = outer->internalClass->engine;
+    Heap::CallContext *c = v4->memoryManager->allocManaged<CallContext>(requiredMemory, ic);
+    c->init();
+    c->type = Heap::ExecutionContext::Type_BlockContext;
+
+    c->outer.set(v4, outer);
+    c->function.set(v4, static_cast<Heap::FunctionObject *>(frame->jsFrame->function.m()));
+
+    c->locals.size = nLocals;
+    c->locals.alloc = nLocals;
+
+    return c;
+}
+
 Heap::CallContext *ExecutionContext::newCallContext(CppStackFrame *frame)
 {
     Function *function = frame->v4Function;
@@ -112,6 +135,7 @@ void ExecutionContext::createMutableBinding(String *name, bool deletable)
     ScopedContext ctx(scope, this);
     while (ctx) {
         switch (ctx->d()->type) {
+        case Heap::ExecutionContext::Type_BlockContext:
         case Heap::ExecutionContext::Type_CallContext:
             if (!activation) {
                 Heap::CallContext *c = static_cast<Heap::CallContext *>(ctx->d());
@@ -170,6 +194,7 @@ bool ExecutionContext::deleteProperty(String *name)
                 return false;
             break;
         }
+        case Heap::ExecutionContext::Type_BlockContext:
         case Heap::ExecutionContext::Type_CallContext: {
             Heap::CallContext *c = static_cast<Heap::CallContext *>(ctx);
             uint index = c->internalClass->find(id);
@@ -225,6 +250,7 @@ ExecutionContext::Error ExecutionContext::setProperty(String *name, const Value
             }
             break;
         }
+        case Heap::ExecutionContext::Type_BlockContext:
         case Heap::ExecutionContext::Type_CallContext: {
             Heap::CallContext *c = static_cast<Heap::CallContext *>(ctx);
             uint index = c->internalClass->find(id);
@@ -273,6 +299,7 @@ ReturnedValue ExecutionContext::getProperty(String *name)
                 return c->exceptionValue.asReturnedValue();
             break;
         }
+        case Heap::ExecutionContext::Type_BlockContext:
         case Heap::ExecutionContext::Type_CallContext: {
             Heap::CallContext *c = static_cast<Heap::CallContext *>(ctx);
             Identifier *id = name->identifier();
@@ -314,6 +341,7 @@ ReturnedValue ExecutionContext::getPropertyAndBase(String *name, Value *base)
                 return c->exceptionValue.asReturnedValue();
             break;
         }
+        case Heap::ExecutionContext::Type_BlockContext:
         case Heap::ExecutionContext::Type_CallContext: {
             Heap::CallContext *c = static_cast<Heap::CallContext *>(ctx);
             name->makeIdentifier();