Changeset 68171 in webkit for trunk/JavaScriptCore/runtime/JSActivation.cpp

Timestamp:

Sep 23, 2010, 11:49:56 AM (15 years ago)

Author:

[email protected]

Message:

Only copy captured variables into activation
​https://bugs.webkit.org/show_bug.cgi?id=46330

Reviewed by Geoff Garen

We now track free variable information which means that
we no longer need to copy every variable defined in a
function. With this patch activations only retain those
variables needed for correctness. In order to interact
safely with the inspector this means that JSActivation
now provides its own lookup functions so it can avoid
trying to read or write to variables that have been
optimised out.

• bytecode/CodeBlock.h:
• bytecompiler/BytecodeGenerator.cpp:

(JSC::BytecodeGenerator::BytecodeGenerator):

• parser/Nodes.h:

(JSC::ScopeNode::capturedVariableCount):
(JSC::ScopeNode::captures):

• runtime/Arguments.h:

(JSC::JSActivation::copyRegisters):

• runtime/Executable.cpp:

(JSC::FunctionExecutable::FunctionExecutable):
(JSC::FunctionExecutable::compileForCallInternal):
(JSC::FunctionExecutable::compileForConstructInternal):

• runtime/Executable.h:

(JSC::FunctionExecutable::capturedVariableCount):

• runtime/JSActivation.cpp:

(JSC::JSActivation::markChildren):
(JSC::JSActivation::symbolTableGet):
(JSC::JSActivation::symbolTablePut):
(JSC::JSActivation::getOwnPropertyNames):
(JSC::JSActivation::symbolTablePutWithAttributes):

• runtime/JSActivation.h:

File:

• trunk/JavaScriptCore/runtime/JSActivation.cpp (modified) (1 diff)

trunk/JavaScriptCore/runtime/JSActivation.cpp

@@ -63 +63 @@
     markStack.appendValues(registerArray, count);
 
-    size_t numVars = d()->functionExecutable->variableCount();
+    size_t numVars = d()->functionExecutable->capturedVariableCount();
 
     // Skip the call frame, which sits between the parameters and vars.
     markStack.appendValues(registerArray + count + RegisterFile::CallFrameHeaderSize, numVars, MayContainNullValues);
+}
+
+inline bool JSActivation::symbolTableGet(const Identifier& propertyName, PropertySlot& slot)
+{
+    SymbolTableEntry entry = symbolTable().inlineGet(propertyName.impl());
+    if (!entry.isNull()) {
+        ASSERT(entry.getIndex() < static_cast<int>(d()->functionExecutable->capturedVariableCount()));
+        slot.setRegisterSlot(&registerAt(entry.getIndex()));
+        return true;
+    }
+    return false;
+}
+
+inline bool JSActivation::symbolTablePut(const Identifier& propertyName, JSValue value)
+{
+    ASSERT(!Heap::heap(value) || Heap::heap(value) == Heap::heap(this));
+    
+    SymbolTableEntry entry = symbolTable().inlineGet(propertyName.impl());
+    if (entry.isNull())
+        return false;
+    if (entry.isReadOnly())
+        return true;
+    ASSERT(entry.getIndex() < static_cast<int>(d()->functionExecutable->capturedVariableCount()));
+    registerAt(entry.getIndex()) = value;
+    return true;
+}
+
+void JSActivation::getOwnPropertyNames(ExecState* exec, PropertyNameArray& propertyNames, EnumerationMode mode)
+{
+    SymbolTable::const_iterator end = symbolTable().end();
+    for (SymbolTable::const_iterator it = symbolTable().begin(); it != end; ++it) {
+        ASSERT(it->second.getIndex() < static_cast<int>(d()->functionExecutable->capturedVariableCount()));
+        if (!(it->second.getAttributes() & DontEnum) || (mode == IncludeDontEnumProperties))
+            propertyNames.add(Identifier(exec, it->first.get()));
+    }
+    // Skip the JSVariableObject implementation of getOwnPropertyNames
+    JSObject::getOwnPropertyNames(exec, propertyNames, mode);
+}
+
+inline bool JSActivation::symbolTablePutWithAttributes(const Identifier& propertyName, JSValue value, unsigned attributes)
+{
+    ASSERT(!Heap::heap(value) || Heap::heap(value) == Heap::heap(this));
+    
+    SymbolTable::iterator iter = symbolTable().find(propertyName.impl());
+    if (iter == symbolTable().end())
+        return false;
+    SymbolTableEntry& entry = iter->second;
+    ASSERT(!entry.isNull());
+    if (entry.getIndex() >= static_cast<int>(d()->functionExecutable->capturedVariableCount()))
+        return false;
+    entry.setAttributes(attributes);
+    registerAt(entry.getIndex()) = value;
+    return true;
 }