Do all parsing for try/catch destructuring inside the appropriate scopes

src/parsing/parser.cc

 // Copyright 2012 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.
 
 #include "src/parsing/parser.h"
 
 #include "src/api.h"
 #include "src/ast/ast.h"
 #include "src/ast/ast-expression-rewriter.h"
 #include "src/ast/ast-expression-visitor.h"
@@ skipping 2981 matching lines @@
   Variable* catch_variable = NULL;
   Block* catch_block = NULL;
   TailCallExpressionList tail_call_expressions_in_catch_block(zone());
   if (tok == Token::CATCH) {
     Consume(Token::CATCH);
 
     Expect(Token::LPAREN, CHECK_OK);
     catch_scope = NewScope(scope_, CATCH_SCOPE);
     catch_scope->set_start_position(scanner()->location().beg_pos);
 
-    ExpressionClassifier pattern_classifier(this);
-    Expression* pattern = ParsePrimaryExpression(&pattern_classifier, CHECK_OK);
-    ValidateBindingPattern(&pattern_classifier, CHECK_OK);
-
-    const AstRawString* name = ast_value_factory()->dot_catch_string();
-    bool is_simple = pattern->IsVariableProxy();
-    if (is_simple) {
-      auto proxy = pattern->AsVariableProxy();
-      scope_->RemoveUnresolved(proxy);
-      name = proxy->raw_name();
-    }
-
-    catch_variable = catch_scope->DeclareLocal(name, VAR, kCreatedInitialized,
-                                               Variable::NORMAL);
-
-    Expect(Token::RPAREN, CHECK_OK);
-
     {
       CollectExpressionsInTailPositionToListScope
           collect_tail_call_expressions_scope(
               function_state_, &tail_call_expressions_in_catch_block);
       BlockState block_state(&scope_, catch_scope);
 
-      // TODO(adamk): Make a version of ParseBlock that takes a scope and
-      // a block.
       catch_block =
           factory()->NewBlock(nullptr, 16, false, RelocInfo::kNoPosition);
+
+      // Create a block scope to hold any lexical declarations created
+      // as part of destructuring the catch parameter.
       Scope* block_scope = NewScope(scope_, BLOCK_SCOPE);
-
       block_scope->set_start_position(scanner()->location().beg_pos);
       {
         BlockState block_state(&scope_, block_scope);
         Target target(&this->target_stack_, catch_block);
 
+        ExpressionClassifier pattern_classifier(this);
+        Expression* pattern =
+            ParsePrimaryExpression(&pattern_classifier, CHECK_OK);
+        ValidateBindingPattern(&pattern_classifier, CHECK_OK);
+
+        const AstRawString* name = ast_value_factory()->dot_catch_string();
+        bool is_simple = pattern->IsVariableProxy();
+        if (is_simple) {
+          auto proxy = pattern->AsVariableProxy();
+          scope_->RemoveUnresolved(proxy);
+          name = proxy->raw_name();
+        }
+        catch_variable = catch_scope->DeclareLocal(
+            name, VAR, kCreatedInitialized, Variable::NORMAL);
+
+        Expect(Token::RPAREN, CHECK_OK);
+
         if (!is_simple) {
           DeclarationDescriptor descriptor;
           descriptor.declaration_kind = DeclarationDescriptor::NORMAL;
           descriptor.parser = this;
           descriptor.scope = scope_;
           descriptor.hoist_scope = nullptr;
           descriptor.mode = LET;
           descriptor.declaration_pos = pattern->position();
           descriptor.initialization_pos = pattern->position();
 
           DeclarationParsingResult::Declaration decl(
               pattern, pattern->position(),
               factory()->NewVariableProxy(catch_variable));
 
           Block* init_block =
               factory()->NewBlock(nullptr, 8, true, RelocInfo::kNoPosition);
           PatternRewriter::DeclareAndInitializeVariables(
               init_block, &descriptor, &decl, nullptr, CHECK_OK);
           catch_block->statements()->Add(init_block, zone());
         }
 
+        // TODO(adamk): This should call ParseBlock in order to properly
+        // add an additional block scope for the catch body.

[neis, 2016/06/30 06:47:05]

Is this related to the remaining test262 failure?

[adamk, 2016/06/30 16:02:10]

Yes, Kevin will fix this in his patch which fixes more conformance issues with
declarations in catch blocks.

         Expect(Token::LBRACE, CHECK_OK);
         while (peek() != Token::RBRACE) {
           Statement* stat = ParseStatementListItem(CHECK_OK);
           if (stat && !stat->IsEmpty()) {
             catch_block->statements()->Add(stat, zone());
           }
         }
         Consume(Token::RBRACE);
       }
       block_scope->set_end_position(scanner()->location().end_pos);
@@ skipping 3976 matching lines @@
                         try_block, target);
     final_loop = target;
   }
 
   return final_loop;
 }
 
 
 }  // namespace internal
 }  // namespace v8