Force ctxt allocation in eval scopes.

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 1160 matching lines @@
 
 bool Scope::AllowsLazyParsingWithoutUnresolvedVariables(
     const Scope* outer) const {
   // If none of the outer scopes need to decide whether to context allocate
   // specific variables, we can preparse inner functions without unresolved
   // variables. Otherwise we need to find unresolved variables to force context
   // allocation of the matching declarations. We can stop at the outer scope for
   // the parse, since context allocation of those variables is already
   // guaranteed to be correct.
   for (const Scope* s = this; s != outer; s = s->outer_scope_) {
-    if (s->is_eval_scope()) return false;
+    // Eval forces context allocation on all outer scopes, so we don't need to
+    // look at those scopes. Sloppy eval makes top-level non-lexical variables
+    // dynamic, whereas strict-mode requires context allocation.
+    if (s->is_eval_scope()) return !is_strict(s->language_mode());

[adamk, 2017/01/03 19:49:05]

Nit:

!is_strict(...)

could be

is_sloppy(...)

[marja, 2017/01/03 19:55:50]

Done.

     // Catch scopes force context allocation of all variables.
     if (s->is_catch_scope()) continue;
     // With scopes do not introduce variables that need allocation.
     if (s->is_with_scope()) continue;
     // If everything is guaranteed to be context allocated we can ignore the
     // scope.
     if (s->has_forced_context_allocation()) continue;
     // Only block scopes and function scopes should disallow preparsing.
     DCHECK(s->is_block_scope() || s->is_function_scope());
     return false;
@@ skipping 689 matching lines @@
   // an eval() call or a runtime with lookup), it must be allocated in the
   // context.
   //
   // Exceptions: If the scope as a whole has forced context allocation, all
   // variables will have context allocation, even temporaries.  Otherwise
   // temporary variables are always stack-allocated.  Catch-bound variables are
   // always context-allocated.
   if (has_forced_context_allocation()) return true;
   if (var->mode() == TEMPORARY) return false;
   if (is_catch_scope()) return true;
-  if (is_script_scope() && IsLexicalVariableMode(var->mode())) return true;
+  if ((is_script_scope() || is_eval_scope()) &&
+      IsLexicalVariableMode(var->mode())) {
+    return true;
+  }
   return var->has_forced_context_allocation() || inner_scope_calls_eval_;
 }
 
 
 void Scope::AllocateStackSlot(Variable* var) {
   if (is_block_scope()) {
     outer_scope()->GetDeclarationScope()->AllocateStackSlot(var);
   } else {
     var->AllocateTo(VariableLocation::LOCAL, num_stack_slots_++);
   }
@@ skipping 220 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