PreParsing inner functions: Fix declaration-only variables, part 2.

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 980 matching lines @@
       current->set_next_unresolved(next->next_unresolved());
       var->set_next_unresolved(nullptr);
       return true;
     }
     current = next;
   }
   return false;
 }
 
 bool Scope::RemoveUnresolved(const AstRawString* name) {
-  if (unresolved_->raw_name() == name) {
+  if (unresolved_ != nullptr && unresolved_->raw_name() == name) {
     VariableProxy* removed = unresolved_;
     unresolved_ = unresolved_->next_unresolved();
     removed->set_next_unresolved(nullptr);
     return true;
   }
   VariableProxy* current = unresolved_;
   while (current != nullptr) {
     VariableProxy* next = current->next_unresolved();
-    if (next->raw_name() == name) {
+    if (next != nullptr && next->raw_name() == name) {

[adamk, 2016/10/07 18:35:55]

Why was this null check (and the one above) not needed before?

[marja, 2016/10/07 19:00:27]

- This function is only used by the PreParser
- PreParser shouldn't RemoveUnresolved(sth_that_doesnt_exist) even after this
CL, so it's strictly not needed
- However, this code is much more sensemaking w/ the nullptr check so it makes
sense to have it
- I'll add a DCHECK to PreParser to check the return value.

       current->set_next_unresolved(next->next_unresolved());
       next->set_next_unresolved(nullptr);
       return true;
     }
     current = next;
   }
   return false;
 }
 
 Variable* Scope::NewTemporary(const AstRawString* name) {
@@ skipping 902 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