Changeset 190188 in webkit for trunk/Source/JavaScriptCore/parser/Parser.cpp

Timestamp:

Sep 23, 2015, 3:37:36 PM (10 years ago)

Author:

[email protected]

Message:

JSC allows invalid var declarations when the declared name is the same as a let/const variable
​https://bugs.webkit.org/show_bug.cgi?id=147600

Reviewed by Yusuke Suzuki.

Source/JavaScriptCore:

We had an ordering bug where if you first declared a "let"
variable then a "var" variable with the same name, you wouldn't
get a syntax error. But, if you did it in the reverse order,
you would. This patch fixes this syntax error to be order independent.

• parser/Parser.cpp:

(JSC::Parser<LexerType>::parseVariableDeclarationList):
(JSC::Parser<LexerType>::createBindingPattern):
(JSC::Parser<LexerType>::parseFunctionDeclaration):

• parser/Parser.h:

(JSC::Scope::declareVariable):

LayoutTests:

• js/let-syntax-expected.txt:
• js/script-tests/let-syntax.js:

(hasSyntaxError):

File:

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

trunk/Source/JavaScriptCore/parser/Parser.cpp

@@ -605 +605 @@
                     if (declarationType == DeclarationType::ConstDeclaration)
                         internalFailWithMessage(false, "Cannot declare a const variable twice: '", name->impl(), "'");
-                    RELEASE_ASSERT_NOT_REACHED();
+                    ASSERT(declarationType == DeclarationType::VarDeclaration);
+                    internalFailWithMessage(false, "Cannot declare a var variable that shadows a let/const/class variable: '", name->impl(), "'");
                 }
             }
@@ -668 +669 @@
     ASSERT(name.impl()->isAtomic() || name.impl()->isSymbol());
 
-    if (kind == DestructureToVariables)
-        failIfTrueIfStrict(declareVariable(&name) & DeclarationResult::InvalidStrictMode, "Cannot declare a variable named '", name.impl(), "' in strict mode");
-    else if (kind == DestructureToLet || kind == DestructureToConst) {
+    if (kind == DestructureToVariables) {
+        DeclarationResultMask declarationResult = declareVariable(&name);
+        failIfTrueIfStrict(declarationResult & DeclarationResult::InvalidStrictMode, "Cannot declare a variable named '", name.impl(), "' in strict mode");
+        if (declarationResult & DeclarationResult::InvalidDuplicateDeclaration)
+            internalFailWithMessage(false, "Cannot declare a var variable that shadows a let/const/class variable: '", name.impl(), "'");
+    } else if (kind == DestructureToLet || kind == DestructureToConst) {
         DeclarationResultMask declarationResult = declareVariable(&name, kind == DestructureToLet ? DeclarationType::LetDeclaration : DeclarationType::ConstDeclaration);
         if (declarationResult != DeclarationResult::Valid) {
@@ -1874 +1878 @@
         functionKeywordStart, functionInfo, StandardFunctionParseType)), "Cannot parse this function");
     failIfFalse(functionInfo.name, "Function statements must have a name");
-    failIfTrueIfStrict(declareVariable(functionInfo.name) & DeclarationResult::InvalidStrictMode, "Cannot declare a function named '", functionInfo.name->impl(), "' in strict mode");
+    DeclarationResultMask declarationResult = declareVariable(functionInfo.name);
+    failIfTrueIfStrict(declarationResult & DeclarationResult::InvalidStrictMode, "Cannot declare a function named '", functionInfo.name->impl(), "' in strict mode");
+    if (declarationResult & DeclarationResult::InvalidDuplicateDeclaration)
+        internalFailWithMessage(false, "Cannot declare a function that shadows a let/const/class variable '", functionInfo.name->impl(), "' in strict mode");
     if (exportType == ExportType::Exported) {
         semanticFailIfFalse(exportName(*functionInfo.name), "Cannot export a duplicate function name: '", functionInfo.name->impl(), "'");