PreParsing inner funcs: make scope analysis more complete.

src/ast/scopes.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/ast/scopes.h"
 
 #include <set>
 
 #include "src/accessors.h"
 #include "src/ast/ast.h"
@@ skipping 1014 matching lines @@
 }
 
 void Scope::DeclareVariableName(const AstRawString* name, VariableMode mode) {
   DCHECK(IsDeclaredVariableMode(mode));
   DCHECK(!already_resolved_);
   DCHECK(GetDeclarationScope()->is_being_lazily_parsed());
 
   if (mode == VAR && !is_declaration_scope()) {
     return GetDeclarationScope()->DeclareVariableName(name, mode);
   }
-  DCHECK(!is_catch_scope());
   DCHECK(!is_with_scope());
   DCHECK(!is_eval_scope());
-  DCHECK(is_declaration_scope() ||
-         (IsLexicalVariableMode(mode) && is_block_scope()));
+  // Unlike DeclareVariable, DeclareVariableName allows declaring variables in
+  // catch scopes: Parser::RewriteCatchPattern bypasses DeclareVariable by
+  // calling DeclareLocal directly, and it doesn't make sense to add a similar
+  // bypass mechanism for PreParser.
+  DCHECK(is_declaration_scope() || (IsLexicalVariableMode(mode) &&
+                                    (is_block_scope() || is_catch_scope())));
   DCHECK(scope_info_.is_null());
 
   // Declare the variable in the declaration scope.
   variables_.DeclareName(zone(), name);
 }
 
 VariableProxy* Scope::NewUnresolved(AstNodeFactory* factory,
                                     const AstRawString* name,
                                     int start_position, VariableKind kind) {
   // Note that we must not share the unresolved variables with
@@ skipping 1076 matching lines @@
   Variable* function =
       is_function_scope() ? AsDeclarationScope()->function_var() : nullptr;
   bool is_function_var_in_context =
       function != nullptr && function->IsContextSlot();
   return num_heap_slots() - Context::MIN_CONTEXT_SLOTS -
          (is_function_var_in_context ? 1 : 0);
 }
 
 }  // namespace internal
 }  // namespace v8