Changeset 174606 in webkit for trunk/Source/JavaScriptCore/parser/Parser.cpp

Timestamp:

Oct 10, 2014, 12:03:20 PM (11 years ago)

Author:

[email protected]

Message:

Various arguments optimisations in codegen fail to account for arguments being in lexical record
​https://bugs.webkit.org/show_bug.cgi?id=137617

Reviewed by Michael Saboff.

Rework the way we track |arguments| references so that we don't try
to use the |arguments| reference on the stack if it's not safe.

To do this without nuking performance it was necessary to update
the parser to track modification of the |arguments| reference
itself.

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

(JSC::BytecodeGenerator::BytecodeGenerator):
(JSC::BytecodeGenerator::willResolveToArguments):
(JSC::BytecodeGenerator::uncheckedLocalArgumentsRegister):
(JSC::BytecodeGenerator::emitCall):
(JSC::BytecodeGenerator::emitConstruct):
(JSC::BytecodeGenerator::emitEnumeration):
(JSC::BytecodeGenerator::uncheckedRegisterForArguments): Deleted.

• bytecompiler/BytecodeGenerator.h:

(JSC::BytecodeGenerator::hasSafeLocalArgumentsRegister):

• bytecompiler/NodesCodegen.cpp:

(JSC::BracketAccessorNode::emitBytecode):
(JSC::DotAccessorNode::emitBytecode):
(JSC::getArgumentByVal):
(JSC::CallFunctionCallDotNode::emitBytecode):
(JSC::ApplyFunctionCallDotNode::emitBytecode):
(JSC::ArrayPatternNode::emitDirectBinding):

• interpreter/StackVisitor.cpp:

(JSC::StackVisitor::Frame::existingArguments):

• parser/Nodes.h:

(JSC::ScopeNode::modifiesArguments):

• parser/Parser.cpp:

(JSC::Parser<LexerType>::parseInner):

• parser/Parser.h:

(JSC::Scope::getCapturedVariables):

• parser/ParserModes.h:

File:

• trunk/Source/JavaScriptCore/parser/Parser.cpp (modified) (3 diffs)

trunk/Source/JavaScriptCore/parser/Parser.cpp

@@ -272 +272 @@
     IdentifierSet capturedVariables;
     bool modifiedParameter = false;
-    scope->getCapturedVariables(capturedVariables, modifiedParameter);
+    bool modifiedArguments = false;
+    scope->getCapturedVariables(capturedVariables, modifiedParameter, modifiedArguments);
     
     CodeFeatures features = context.features();
@@ -281 +282 @@
     if (modifiedParameter)
         features |= ModifiedParameterFeature;
-    
+    if (modifiedArguments)
+        features |= ModifiedArgumentsFeature;
     Vector<RefPtr<StringImpl>> closedVariables;
     if (m_parsingBuiltin) {
@@ -293 +295 @@
             if (scope->hasDeclaredParameter(Identifier(m_vm, variable.get())))
                 continue;
+
+            if (variable == m_vm->propertyNames->arguments.impl())
+                continue;
+
             closedVariables.append(variable);
         }