Changeset 189819 in webkit for trunk/Source/JavaScriptCore/parser/Nodes.h

Timestamp:

Sep 15, 2015, 12:26:45 PM (10 years ago)

Author:

[email protected]

Message:

functions that use try/catch will allocate a top level JSLexicalEnvironment even when it is not necessary
​https://bugs.webkit.org/show_bug.cgi?id=148169

Patch by Saam barati <​[email protected]> on 2015-09-15
Reviewed by Geoffrey Garen.

We used to do this before we had proper lexical scoping
in the bytecode generator. There is absolutely no reason
why need to allocate a top-level "var" activation when a
function/program uses a "catch" block.

• parser/ASTBuilder.h:

(JSC::ASTBuilder::createTryStatement):
(JSC::ASTBuilder::incConstants):
(JSC::ASTBuilder::usesThis):
(JSC::ASTBuilder::usesArguments):
(JSC::ASTBuilder::usesWith):
(JSC::ASTBuilder::usesEval):
(JSC::ASTBuilder::usesCatch): Deleted.

• parser/Nodes.h:

(JSC::ScopeNode::isStrictMode):
(JSC::ScopeNode::setUsesArguments):
(JSC::ScopeNode::usesThis):
(JSC::ScopeNode::needsActivation):
(JSC::ScopeNode::hasCapturedVariables):
(JSC::ScopeNode::captures):
(JSC::ScopeNode::needsActivationForMoreThanVariables): Deleted.

• parser/ParserModes.h:
• runtime/Executable.h:

(JSC::ScriptExecutable::usesEval):
(JSC::ScriptExecutable::usesArguments):
(JSC::ScriptExecutable::needsActivation):
(JSC::ScriptExecutable::isStrictMode):
(JSC::ScriptExecutable::ecmaMode):

File:

• trunk/Source/JavaScriptCore/parser/Nodes.h (modified) (1 diff)

trunk/Source/JavaScriptCore/parser/Nodes.h

@@ -1555 +1555 @@
         void setUsesArguments() { m_features |= ArgumentsFeature; }
         bool usesThis() const { return m_features & ThisFeature; }
-        bool needsActivationForMoreThanVariables() const { return m_features & (EvalFeature | WithFeature | CatchFeature); }
-        bool needsActivation() const { return (hasCapturedVariables()) || (m_features & (EvalFeature | WithFeature | CatchFeature)); }
+        bool needsActivation() const { return (hasCapturedVariables()) || (m_features & (EvalFeature | WithFeature)); }
         bool hasCapturedVariables() const { return m_varDeclarations.hasCapturedVariables(); }
         bool captures(UniquedStringImpl* uid) { return m_varDeclarations.captures(uid); }