Allow closures to be optimized if outer contexts that call eval are all in strict mode.

src/scopes.cc

Index: src/scopes.cc
diff --git a/src/scopes.cc b/src/scopes.cc
index 7d9bce5c40da0d442d5084ebe4ee7a0b6dfa5e27..33f8c83bd852131bcb94da938a31b68da3a27e75 100644
--- a/src/scopes.cc
+++ b/src/scopes.cc
@@ -1,4 +1,4 @@
-// Copyright 2010 the V8 project authors. All rights reserved.
+// Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
@@ -199,6 +199,7 @@ void Scope::SetDefaults(Type type,
   // Inherit the strict mode from the parent scope.
   strict_mode_ = (outer_scope != NULL) && outer_scope->strict_mode_;
   outer_scope_calls_eval_ = false;
+  outer_scope_calls_non_strict_eval_ = false;
   inner_scope_calls_eval_ = false;
   outer_scope_is_eval_scope_ = false;
   force_eager_compilation_ = false;
@@ -483,8 +484,17 @@ void Scope::AllocateVariables(Handle<Context> context) {
   // and assume they may invoke eval themselves. Eventually we could capture
   // this information in the ScopeInfo and then use it here (by traversing
   // the call chain stack, at compile time).
+
   bool eval_scope = is_eval_scope();
-  PropagateScopeInfo(eval_scope, eval_scope);
+  bool outer_scope_calls_eval = false;
+  bool outer_scope_calls_non_strict_eval = false;
+  if (!is_global_scope()) {
+    context->ComputeEvalScopeInfo(&outer_scope_calls_eval,
+                                  &outer_scope_calls_non_strict_eval);
+  }
+  PropagateScopeInfo(outer_scope_calls_eval,
+                     outer_scope_calls_non_strict_eval,
+                     eval_scope);
 
   // 2) Resolve variables.
   Scope* global_scope = NULL;
@@ -616,10 +626,14 @@ void Scope::Print(int n) {
   if (HasTrivialOuterContext()) {
     Indent(n1, "// scope has trivial outer context\n");
   }
+  if (is_strict_mode()) Indent(n1, "// strict mode scope\n");
   if (scope_inside_with_) Indent(n1, "// scope inside 'with'\n");
   if (scope_contains_with_) Indent(n1, "// scope contains 'with'\n");
   if (scope_calls_eval_) Indent(n1, "// scope calls 'eval'\n");
   if (outer_scope_calls_eval_) Indent(n1, "// outer scope calls 'eval'\n");
+  if (outer_scope_calls_non_strict_eval_) {
+    Indent(n1, "// outer scope calls 'eval' in non-strict context\n");
+  }
   if (inner_scope_calls_eval_) Indent(n1, "// inner scope calls 'eval'\n");
   if (outer_scope_is_eval_scope_) {
     Indent(n1, "// outer scope is 'eval' scope\n");
@@ -846,20 +860,29 @@ void Scope::ResolveVariablesRecursively(Scope* global_scope,
 
 
 bool Scope::PropagateScopeInfo(bool outer_scope_calls_eval,
+                               bool outer_scope_calls_non_strict_eval,
                                bool outer_scope_is_eval_scope) {
   if (outer_scope_calls_eval) {
     outer_scope_calls_eval_ = true;
   }
 
+  if (outer_scope_calls_non_strict_eval) {
+    outer_scope_calls_non_strict_eval_ = true;
+  }
+
   if (outer_scope_is_eval_scope) {
     outer_scope_is_eval_scope_ = true;
   }
 
   bool calls_eval = scope_calls_eval_ || outer_scope_calls_eval_;
   bool is_eval = is_eval_scope() || outer_scope_is_eval_scope_;
+  bool calls_non_strict_eval =
+      (scope_calls_eval_ && !is_strict_mode()) || outer_scope_calls_non_strict_eval_;

[fschneider, 2011/05/11 10:35:11]

Long line.

[Mads Ager (chromium), 2011/05/11 11:24:11]

Done.

   for (int i = 0; i < inner_scopes_.length(); i++) {
     Scope* inner_scope = inner_scopes_[i];
-    if (inner_scope->PropagateScopeInfo(calls_eval, is_eval)) {
+    if (inner_scope->PropagateScopeInfo(calls_eval,
+                                        calls_non_strict_eval,
+                                        is_eval)) {
       inner_scope_calls_eval_ = true;
     }
     if (inner_scope->force_eager_compilation_) {