Add some scope-related DCHECKs.

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/bootstrapper.h"
@@ skipping 236 matching lines @@
       if (context->IsDebugEvaluateContext()) {
         with_scope->set_is_debug_evaluate_scope();
       }
       current_scope = with_scope;
       // All the inner scopes are inside a with.
       for (Scope* s = innermost_scope; s != nullptr; s = s->outer_scope()) {
         s->scope_inside_with_ = true;
       }
     } else if (context->IsScriptContext()) {
       Handle<ScopeInfo> scope_info(context->scope_info(), isolate);
+      DCHECK(scope_info->scope_type() == SCRIPT_SCOPE);

[Toon Verwaest, 2016/08/19 12:48:52]

DCHECK_EQ

       current_scope = new (zone)
           DeclarationScope(zone, current_scope, SCRIPT_SCOPE, scope_info);
     } else if (context->IsFunctionContext()) {
       Handle<ScopeInfo> scope_info(context->closure()->shared()->scope_info(),
                                    isolate);
+      // TODO(neis): For an eval scope, we currently create an ordinary function
+      // context.  This is wrong and needs to be fixed.
+      // https://bugs.chromium.org/p/v8/issues/detail?id=5295
+      DCHECK(scope_info->scope_type() == FUNCTION_SCOPE ||
+             scope_info->scope_type() == EVAL_SCOPE);
       current_scope = new (zone)
           DeclarationScope(zone, current_scope, FUNCTION_SCOPE, scope_info);
       if (scope_info->IsAsmFunction()) current_scope->asm_function_ = true;
       if (scope_info->IsAsmModule()) current_scope->asm_module_ = true;
     } else if (context->IsBlockContext()) {
       Handle<ScopeInfo> scope_info(context->scope_info(), isolate);
+      DCHECK(scope_info->scope_type() == BLOCK_SCOPE);

[Toon Verwaest, 2016/08/19 12:48:52]

DCHECK_EQ

       if (scope_info->is_declaration_scope()) {
         current_scope = new (zone)
             DeclarationScope(zone, current_scope, BLOCK_SCOPE, scope_info);
       } else {
         current_scope =
             new (zone) Scope(zone, current_scope, BLOCK_SCOPE, scope_info);
       }
     } else {
       DCHECK(context->IsCatchContext());
       String* name = context->catch_name();
@@ skipping 1500 matching lines @@
       function != nullptr && function->IsContextSlot();
   return num_heap_slots() - Context::MIN_CONTEXT_SLOTS - num_global_slots() -
          (is_function_var_in_context ? 1 : 0);
 }
 
 
 int Scope::ContextGlobalCount() const { return num_global_slots(); }
 
 }  // namespace internal
 }  // namespace v8