Changeset 68288 in webkit for trunk/JavaScriptCore/parser/JSParser.cpp

Timestamp:

Sep 24, 2010, 1:54:48 PM (15 years ago)

Author:

[email protected]

Message:

2010-09-24 Oliver Hunt <​[email protected]>

Reviewed by Geoffrey Garen.

Variable declarations inside a catch scope don't get propogated to the parent scope
​https://bugs.webkit.org/show_bug.cgi?id=46501

Add logic to make variable declaration look for a scope for the
new variable. This allows us to create a scope (eg. for catch)
and then seal it, so that additional variable declarations
contained are propogated to the correct target. Strangely this
comes out as a performance win, but I think it's mostly cache
effects.

• parser/JSParser.cpp: (JSC::JSParser::Scope::Scope): (JSC::JSParser::Scope::preventNewDecls): (JSC::JSParser::Scope::allowsNewDecls): (JSC::JSParser::declareVariable): (JSC::JSParser::parseVarDeclarationList): (JSC::JSParser::parseConstDeclarationList): (JSC::JSParser::parseTryStatement): (JSC::JSParser::parseFormalParameters): (JSC::JSParser::parseFunctionDeclaration):

File:

• trunk/JavaScriptCore/parser/JSParser.cpp (modified) (10 diffs)

trunk/JavaScriptCore/parser/JSParser.cpp

@@ -205 +205 @@
             : m_usesEval(false)
             , m_needsFullActivation(false)
+            , m_allowsNewDecls(true)
         {
         }
@@ -213 +214 @@
         }
         
+        void preventNewDecls() { m_allowsNewDecls = false; }
+        bool allowsNewDecls() const { return m_allowsNewDecls; }
+
         void useVariable(const Identifier* ident, bool isEval)
         {
@@ -250 +254 @@
         bool m_usesEval;
         bool m_needsFullActivation;
+        bool m_allowsNewDecls;
         IdentifierSet m_declaredVariables;
         IdentifierSet m_usedVariables;
@@ -287 +292 @@
         m_scopeStack[m_scopeStack.size() - 2].collectFreeVariables(&m_scopeStack.last(), shouldTrackClosedVariables);
         m_scopeStack.removeLast();
+    }
+    
+    void declareVariable(const Identifier* ident)
+    {
+        unsigned i = m_scopeStack.size() - 1;
+        ASSERT(i < m_scopeStack.size());
+        while (!m_scopeStack[i].allowsNewDecls()) {
+            i--;
+            ASSERT(i < m_scopeStack.size());
+        }
+        m_scopeStack[i].declareVariable(ident);
     }
 
@@ -426 +442 @@
         next();
         bool hasInitializer = match(EQUAL);
-        currentScope()->declareVariable(name);
+        declareVariable(name);
         context.addVar(name, (hasInitializer || (!m_allowsIn && match(INTOKEN))) ? DeclarationStacks::HasInitializer : 0);
         if (hasInitializer) {
@@ -458 +474 @@
         next();
         bool hasInitializer = match(EQUAL);
-        currentScope()->declareVariable(name);
+        declareVariable(name);
         context.addVar(name, DeclarationStacks::IsConstant | (hasInitializer ? DeclarationStacks::HasInitializer : 0));
         TreeExpression initializer = 0;
@@ -760 +776 @@
         ScopeRef catchScope = pushScope();
         catchScope->declareVariable(ident);
+        catchScope->preventNewDecls();
         consumeOrFail(CLOSEPAREN);
         matchOrFail(OPENBRACE);
@@ -863 +880 @@
     matchOrFail(IDENT);
     usesArguments = m_globalData->propertyNames->arguments == *m_token.m_data.ident;
-    currentScope()->declareVariable(m_token.m_data.ident);
+    declareVariable(m_token.m_data.ident);
     TreeFormalParameterList list = context.createFormalParameterList(*m_token.m_data.ident);
     TreeFormalParameterList tail = list;
@@ -871 +888 @@
         matchOrFail(IDENT);
         const Identifier* ident = m_token.m_data.ident;
-        currentScope()->declareVariable(ident);
+        declareVariable(ident);
         next();
         usesArguments = usesArguments || m_globalData->propertyNames->arguments == *ident;
@@ -934 +951 @@
     failIfFalse((parseFunctionInfo<FunctionNeedsName, true>(context, name, parameters, body, openBracePos, closeBracePos, bodyStartLine)));
     failIfFalse(name);
-    currentScope()->declareVariable(name);
+    declareVariable(name);
     return context.createFuncDeclStatement(name, body, parameters, openBracePos, closeBracePos, bodyStartLine, m_lastLine);
 }