Revert of change most cases of variable redeclaration from TypeError to...

Revert of change most cases of variable redeclaration from TypeError to SyntaxError (patchset #8 id:140001 of https://codereview.chromium.org/2048703002/ )

Reason for revert:
This is going to break the LayoutTest inspector-protocol/console/console-let-const-with-api.html as seen in https://build.chromium.org/p/tryserver.v8/builders/v8_linux_blink_rel/builds/2247 . Please run this test manually, using instructions at https://www.chromium.org/developers/testing/webkit-layout-tests , and fix on the Chrome side if needed before resubmitting this patch.

Original issue's description:
> change most cases of variable redeclaration from TypeError to SyntaxError.
>
> Code like `let a; eval("var a;");` should throw a SyntaxError, not a TypeError
> (this caused a test262 failure.). However, the code `eval("function NaN() {}");`
> should actually throw a TypeError. This patch changes most cases of
> redeclaration errors from TypeError to SyntaxError. See the test
> mjsunit/regress/redeclaration-error-types for a thorough analysis with spec
> references.
>
> The relevant sections of the spec are ES#sec-globaldeclarationinstantiation and
> ES#sec-evaldeclarationinstantiation
>
> BUG=v8:4955
> LOG=y
>
> Committed: https://crrev.com/2b787561763d0f7e8dab698652715a742cf78291
> Cr-Commit-Position: refs/heads/master@{#36940}

TBR=adamk@chromium.org,jwolfe@igalia.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4955

Review-Url: https://codereview.chromium.org/2064793002
Cr-Commit-Position: refs/heads/master@{#36941}

src/runtime/runtime-scopes.cc

@@ -16,18 +16,10 @@
 namespace v8 {
 namespace internal {
 
-enum class RedeclarationType { kSyntaxError = 0, kTypeError = 1 };
-
-static Object* ThrowRedeclarationError(Isolate* isolate, Handle<String> name,
-                                       RedeclarationType redeclaration_type) {
+static Object* ThrowRedeclarationError(Isolate* isolate, Handle<String> name) {
   HandleScope scope(isolate);
-  if (redeclaration_type == RedeclarationType::kSyntaxError) {
-    THROW_NEW_ERROR_RETURN_FAILURE(
-        isolate, NewSyntaxError(MessageTemplate::kVarRedeclaration, name));
-  } else {
-    THROW_NEW_ERROR_RETURN_FAILURE(
-        isolate, NewTypeError(MessageTemplate::kVarRedeclaration, name));
-  }
+  THROW_NEW_ERROR_RETURN_FAILURE(
+      isolate, NewTypeError(MessageTemplate::kVarRedeclaration, name));
 }
 
 
@@ -42,18 +34,13 @@ RUNTIME_FUNCTION(Runtime_ThrowConstAssignError) {
 static Object* DeclareGlobals(Isolate* isolate, Handle<JSGlobalObject> global,
                               Handle<String> name, Handle<Object> value,
                               PropertyAttributes attr, bool is_var,
-                              bool is_function,
-                              RedeclarationType redeclaration_type) {
+                              bool is_function) {
   Handle<ScriptContextTable> script_contexts(
       global->native_context()->script_context_table());
   ScriptContextTable::LookupResult lookup;
   if (ScriptContextTable::Lookup(script_contexts, name, &lookup) &&
       IsLexicalVariableMode(lookup.mode)) {
-    // ES#sec-globaldeclarationinstantiation 6.a:
-    // If envRec.HasLexicalDeclaration(name) is true, throw a SyntaxError
-    // exception.
-    return ThrowRedeclarationError(isolate, name,
-                                   RedeclarationType::kSyntaxError);
+    return ThrowRedeclarationError(isolate, name);
   }
 
   // Do the lookup own properties only, see ES5 erratum.
@@ -80,11 +67,7 @@ static Object* DeclareGlobals(Isolate* isolate, Handle<JSGlobalObject> global,
       if (old_details.IsReadOnly() || old_details.IsDontEnum() ||
           (it.state() == LookupIterator::ACCESSOR &&
            it.GetAccessors()->IsAccessorPair())) {
-        // ES#sec-globaldeclarationinstantiation 5.d:
-        // If hasRestrictedGlobal is true, throw a SyntaxError exception.
-        // ES#sec-evaldeclarationinstantiation 8.a.iv.1.b:
-        // If fnDefinable is false, throw a TypeError exception.
-        return ThrowRedeclarationError(isolate, name, redeclaration_type);
+        return ThrowRedeclarationError(isolate, name);
       }
       // If the existing property is not configurable, keep its attributes. Do
       attr = old_attributes;
@@ -147,11 +130,9 @@ RUNTIME_FUNCTION(Runtime_DeclareGlobals) {
     if (is_function && is_native) attr |= READ_ONLY;
     if (!is_eval) attr |= DONT_DELETE;
 
-    // ES#sec-globaldeclarationinstantiation 5.d:
-    // If hasRestrictedGlobal is true, throw a SyntaxError exception.
-    Object* result = DeclareGlobals(
-        isolate, global, name, value, static_cast<PropertyAttributes>(attr),
-        is_var, is_function, RedeclarationType::kSyntaxError);
+    Object* result = DeclareGlobals(isolate, global, name, value,
+                                    static_cast<PropertyAttributes>(attr),
+                                    is_var, is_function);
     if (isolate->has_pending_exception()) return result;
   });
 
@@ -234,13 +215,7 @@ Object* DeclareLookupSlot(Isolate* isolate, Handle<String> name,
     context_arg->Lookup(name, LEXICAL_TEST, &index, &attributes,
                         &binding_flags);
     if (attributes != ABSENT && binding_flags == BINDING_CHECK_INITIALIZED) {
-      // ES#sec-evaldeclarationinstantiation 5.a.i.1:
-      // If varEnvRec.HasLexicalDeclaration(name) is true, throw a SyntaxError
-      // exception.
-      // ES#sec-evaldeclarationinstantiation 5.d.ii.2.a.i:
-      // Throw a SyntaxError exception.
-      return ThrowRedeclarationError(isolate, name,
-                                     RedeclarationType::kSyntaxError);
+      return ThrowRedeclarationError(isolate, name);
     }
     attr = static_cast<PropertyAttributes>(attr & ~EVAL_DECLARED);
   }
@@ -260,30 +235,26 @@ Object* DeclareLookupSlot(Isolate* isolate, Handle<String> name,
   // TODO(verwaest): This case should probably not be covered by this function,
   // but by DeclareGlobals instead.
   if (attributes != ABSENT && holder->IsJSGlobalObject()) {
-    // ES#sec-evaldeclarationinstantiation 8.a.iv.1.b:
-    // If fnDefinable is false, throw a TypeError exception.
     return DeclareGlobals(isolate, Handle<JSGlobalObject>::cast(holder), name,
-                          value, attr, is_var, is_function,
-                          RedeclarationType::kTypeError);
+                          value, attr, is_var, is_function);
   }
   if (context_arg->extension()->IsJSGlobalObject()) {
     Handle<JSGlobalObject> global(
         JSGlobalObject::cast(context_arg->extension()), isolate);
     return DeclareGlobals(isolate, global, name, value, attr, is_var,
-                          is_function, RedeclarationType::kTypeError);
+                          is_function);
   } else if (context->IsScriptContext()) {
     DCHECK(context->global_object()->IsJSGlobalObject());
     Handle<JSGlobalObject> global(
         JSGlobalObject::cast(context->global_object()), isolate);
     return DeclareGlobals(isolate, global, name, value, attr, is_var,
-                          is_function, RedeclarationType::kTypeError);
+                          is_function);
   }
 
   if (attributes != ABSENT) {
     // The name was declared before; check for conflicting re-declarations.
     if ((attributes & READ_ONLY) != 0) {
-      return ThrowRedeclarationError(isolate, name,
-                                     RedeclarationType::kSyntaxError);
+      return ThrowRedeclarationError(isolate, name);
     }
 
     // Skip var re-declarations.
@@ -622,11 +593,7 @@ static Object* FindNameClash(Handle<ScopeInfo> scope_info,
     ScriptContextTable::LookupResult lookup;
     if (ScriptContextTable::Lookup(script_context, name, &lookup)) {
       if (IsLexicalVariableMode(mode) || IsLexicalVariableMode(lookup.mode)) {
-        // ES#sec-globaldeclarationinstantiation 5.b:
-        // If envRec.HasLexicalDeclaration(name) is true, throw a SyntaxError
-        // exception.
-        return ThrowRedeclarationError(isolate, name,
-                                       RedeclarationType::kSyntaxError);
+        return ThrowRedeclarationError(isolate, name);
       }
     }
 
@@ -636,13 +603,7 @@ static Object* FindNameClash(Handle<ScopeInfo> scope_info,
       Maybe<PropertyAttributes> maybe = JSReceiver::GetPropertyAttributes(&it);
       if (!maybe.IsJust()) return isolate->heap()->exception();
       if ((maybe.FromJust() & DONT_DELETE) != 0) {
-        // ES#sec-globaldeclarationinstantiation 5.a:
-        // If envRec.HasVarDeclaration(name) is true, throw a SyntaxError
-        // exception.
-        // ES#sec-globaldeclarationinstantiation 5.d:
-        // If hasRestrictedGlobal is true, throw a SyntaxError exception.
-        return ThrowRedeclarationError(isolate, name,
-                                       RedeclarationType::kSyntaxError);
+        return ThrowRedeclarationError(isolate, name);
       }
 
       JSGlobalObject::InvalidatePropertyCell(global_object, name);

test/mjsunit/es6/block-eval-var-over-let.js

@@ -8,13 +8,13 @@
 assertThrows(function() {
   let x = 1;
   eval('var x');
-}, SyntaxError);
+}, TypeError);
 
 // If the eval is in its own block scope, throws
 assertThrows(function() {
   let y = 1;
   { eval('var y'); }
-}, SyntaxError);
+}, TypeError);
 
 // If the let is in its own block scope, with the eval, throws
 assertThrows(function() {
@@ -22,7 +22,7 @@ assertThrows(function() {
     let x = 1;
     eval('var x');
   }
-}, SyntaxError);
+}, TypeError);
 
 // Legal if the let is no longer visible
 assertDoesNotThrow(function() {
@@ -37,13 +37,13 @@ assertDoesNotThrow(function() {
 assertThrows(function() {
   const x = 1;
   eval('var x');
-}, SyntaxError);
+}, TypeError);
 
 // If the eval is in its own block scope, throws
 assertThrows(function() {
   const y = 1;
   { eval('var y'); }
-}, SyntaxError);
+}, TypeError);
 
 // If the const is in its own block scope, with the eval, throws
 assertThrows(function() {
@@ -51,7 +51,7 @@ assertThrows(function() {
     const x = 1;
     eval('var x');
   }
-}, SyntaxError);
+}, TypeError);
 
 // Legal if the const is no longer visible
 assertDoesNotThrow(function() {

test/mjsunit/regress/redeclaration-error-types.js

-// Copyright 2016 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-
-function doTest(scripts, expectedError) {
-  var realm = Realm.create();
-
-  for (var i = 0; i < scripts.length - 1; i++) {
-    Realm.eval(realm, scripts[i]);
-  }
-  assertThrows(function() {
-    Realm.eval(realm, scripts[scripts.length - 1]);
-  }, Realm.eval(realm, expectedError));
-
-  Realm.dispose(realm);
-}
-
-var tests = [
-  {
-    // ES#sec-globaldeclarationinstantiation 5.a:
-    // If envRec.HasVarDeclaration(name) is true, throw a SyntaxError
-    // exception.
-    scripts: [
-      "var a;",
-      "let a;",
-    ],
-    expectedError: "SyntaxError",
-  },
-  {
-    // ES#sec-globaldeclarationinstantiation 6.a:
-    // If envRec.HasLexicalDeclaration(name) is true, throw a SyntaxError
-    // exception.
-    scripts: [
-      "let a;",
-      "var a;",
-    ],
-    expectedError: "SyntaxError",
-  },
-  {
-    // ES#sec-globaldeclarationinstantiation 5.b:
-    // If envRec.HasLexicalDeclaration(name) is true, throw a SyntaxError
-    // exception.
-    scripts: [
-      "let a;",
-      "let a;",
-    ],
-    expectedError: "SyntaxError",
-  },
-  {
-    // ES#sec-evaldeclarationinstantiation 5.a.i.1:
-    // If varEnvRec.HasLexicalDeclaration(name) is true, throw a SyntaxError
-    // exception.
-    scripts: [
-      'let a; eval("var a;");',
-    ],
-    expectedError: "SyntaxError",
-  },
-  {
-    // ES#sec-evaldeclarationinstantiation 5.a.i.1:
-    // If varEnvRec.HasLexicalDeclaration(name) is true, throw a SyntaxError
-    // exception.
-    scripts: [
-      'let a; eval("function a() {}");',
-    ],
-    expectedError: "SyntaxError",
-  },
-  {
-    // ES#sec-evaldeclarationinstantiation 5.d.ii.2.a.i:
-    // Throw a SyntaxError exception.
-    scripts: [
-      '(function() { let a; eval("var a;"); })();',
-    ],
-    expectedError: "SyntaxError",
-  },
-  {
-    // ES#sec-evaldeclarationinstantiation 5.d.ii.2.a.i:
-    // Throw a SyntaxError exception.
-    scripts: [
-      '(function() { let a; eval("function a() {}"); })();',
-    ],
-    expectedError: "SyntaxError",
-  },
-  {
-    // ES#sec-globaldeclarationinstantiation 5.d:
-    // If hasRestrictedGlobal is true, throw a SyntaxError exception.
-    scripts: [
-      'let NaN;',
-    ],
-    expectedError: "SyntaxError",
-  },
-  {
-    // ES#sec-globaldeclarationinstantiation 5.d:
-    // If hasRestrictedGlobal is true, throw a SyntaxError exception.
-    scripts: [
-      'function NaN() {}',
-    ],
-    expectedError: "SyntaxError",
-  },
-
-  {
-    // ES#sec-evaldeclarationinstantiation 8.a.iv.1.b:
-    // If fnDefinable is false, throw a TypeError exception.
-    scripts: [
-      'eval("function NaN() {}");',
-    ],
-    expectedError: "TypeError",
-  },
-  {
-    // ES#sec-evaldeclarationinstantiation 8.a.iv.1.b:
-    // If fnDefinable is false, throw a TypeError exception.
-    scripts: [
-      `
-        let a;
-        try {
-          eval("function a() {}");
-        } catch (e) {}
-        eval("function NaN() {}");
-      `,
-    ],
-    expectedError: "TypeError",
-  },
-  {
-    // ES#sec-evaldeclarationinstantiation 8.a.iv.1.b:
-    // If fnDefinable is false, throw a TypeError exception.
-    scripts: [
-      `
-        eval("
-          function f() {
-            function b() {
-              (0, eval)('function NaN() {}');
-            }
-            b();
-          }
-          f();
-        ");
-      `.replace(/"/g, '`'),
-    ],
-    expectedError: "TypeError",
-  },
-];
-
-tests.forEach(function(test) {
-  doTest(test.scripts, test.expectedError);
-});

test/test262/test262.status

@@ -263,6 +263,11 @@
   'language/eval-code/indirect/non-definable-function-with-function': [FAIL],
   'language/eval-code/indirect/non-definable-function-with-variable': [FAIL],
 
+  # https://bugs.chromium.org/p/v8/issues/detail?id=4955
+  'language/eval-code/direct/var-env-global-lex-non-strict': [FAIL],
+  'language/eval-code/direct/var-env-lower-lex-non-strict': [FAIL],
+  'language/eval-code/indirect/var-env-global-lex-non-strict': [FAIL],
+
   # https://bugs.chromium.org/p/v8/issues/detail?id=4124
   'built-ins/Simd/*': [SKIP],