Introduce with scope and rework variable resolution.

src/scopes.cc

 // 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:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 138 matching lines @@
              Type type,
              Handle<SerializedScopeInfo> scope_info)
     : isolate_(Isolate::Current()),
       inner_scopes_(4),
       variables_(),
       temps_(4),
       params_(4),
       unresolved_(16),
       decls_(4),
       already_resolved_(true) {
-  ASSERT(!scope_info.is_null());
   SetDefaults(type, NULL, scope_info);
-  if (scope_info->HasHeapAllocatedLocals()) {
+  if (!scope_info.is_null() && scope_info->HasHeapAllocatedLocals()) {
     num_heap_slots_ = scope_info_->NumberOfContextSlots();
   }
   AddInnerScope(inner_scope);
 }
 
 
 Scope::Scope(Scope* inner_scope, Handle<String> catch_variable_name)
     : isolate_(Isolate::Current()),
       inner_scopes_(1),
       variables_(),
@@ skipping 23 matching lines @@
   dynamics_ = NULL;
   receiver_ = NULL;
   function_ = NULL;
   arguments_ = NULL;
   illegal_redecl_ = NULL;
   scope_inside_with_ = false;
   scope_contains_with_ = false;
   scope_calls_eval_ = false;
   // 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;
   num_var_or_const_ = 0;
   num_stack_slots_ = 0;
   num_heap_slots_ = 0;
   scope_info_ = scope_info;
 }
 
 
 Scope* Scope::DeserializeScopeChain(CompilationInfo* info,
                                     Scope* global_scope) {
   // Reconstruct the outer scope chain from a closure's context chain.
   ASSERT(!info->closure().is_null());
   Context* context = info->closure()->context();
   Scope* current_scope = NULL;
   Scope* innermost_scope = NULL;
   bool contains_with = false;
   while (!context->IsGlobalContext()) {
     if (context->IsWithContext()) {
+      Scope* with_scope = new Scope(current_scope, WITH_SCOPE,
+                                    Handle<SerializedScopeInfo>::null());
+      current_scope = with_scope;
       // All the inner scopes are inside a with.
       contains_with = true;
       for (Scope* s = innermost_scope; s != NULL; s = s->outer_scope()) {
         s->scope_inside_with_ = true;
       }
+    } else if (context->IsFunctionContext()) {
+      SerializedScopeInfo* scope_info =
+          context->closure()->shared()->scope_info();
+      current_scope = new Scope(current_scope, FUNCTION_SCOPE,
+                                Handle<SerializedScopeInfo>(scope_info));
+    } else if (context->IsBlockContext()) {
+      SerializedScopeInfo* scope_info =
+          SerializedScopeInfo::cast(context->extension());
+      current_scope = new Scope(current_scope, BLOCK_SCOPE,
+                                Handle<SerializedScopeInfo>(scope_info));
     } else {
-      if (context->IsFunctionContext()) {
-        SerializedScopeInfo* scope_info =
-            context->closure()->shared()->scope_info();
-        current_scope = new Scope(current_scope, FUNCTION_SCOPE,
-            Handle<SerializedScopeInfo>(scope_info));
-      } else if (context->IsBlockContext()) {
-        SerializedScopeInfo* scope_info =
-            SerializedScopeInfo::cast(context->extension());
-        current_scope = new Scope(current_scope, BLOCK_SCOPE,
-            Handle<SerializedScopeInfo>(scope_info));
-      } else {
-        ASSERT(context->IsCatchContext());
-        String* name = String::cast(context->extension());
-        current_scope = new Scope(current_scope, Handle<String>(name));
-      }
-      if (contains_with) current_scope->RecordWithStatement();
-      if (innermost_scope == NULL) innermost_scope = current_scope;
+      ASSERT(context->IsCatchContext());
+      String* name = String::cast(context->extension());
+      current_scope = new Scope(current_scope, Handle<String>(name));
     }
+    if (contains_with) current_scope->RecordWithStatement();
+    if (innermost_scope == NULL) innermost_scope = current_scope;
 
     // Forget about a with when we move to a context for a different function.
     if (context->previous()->closure() != context->closure()) {
       contains_with = false;
     }
     context = context->previous();
   }
 
   global_scope->AddInnerScope(current_scope);
   return (innermost_scope == NULL) ? global_scope : innermost_scope;
@@ skipping 13 matching lines @@
           : FLAG_print_scopes) {
     info->function()->scope()->Print();
   }
 #endif
 
   info->SetScope(info->function()->scope());
   return true;  // Can not fail.
 }
 
 
-void Scope::Initialize(bool inside_with) {
+void Scope::Initialize() {
   ASSERT(!already_resolved());
 
   // Add this scope as a new inner scope of the outer scope.
   if (outer_scope_ != NULL) {
     outer_scope_->inner_scopes_.Add(this);
-    scope_inside_with_ = outer_scope_->scope_inside_with_ || inside_with;
+    scope_inside_with_ = outer_scope_->scope_inside_with_ || is_with_scope();
   } else {
-    scope_inside_with_ = inside_with;
+    scope_inside_with_ = is_with_scope();
   }
 
   // Declare convenience variables.
   // Declare and allocate receiver (even for the global scope, and even
   // if naccesses_ == 0).
   // NOTE: When loading parameters in the global scope, we must take
   // care not to access them as properties of the global object, but
   // instead load them directly from the stack. Currently, the only
   // such parameter is 'this' which is passed on the stack when
   // invoking scripts
-  if (is_catch_scope() || is_block_scope()) {
-    ASSERT(outer_scope() != NULL);
-    receiver_ = outer_scope()->receiver();
-  } else {
+  if (is_declaration_scope()) {
     ASSERT(is_function_scope() ||

[Kevin Millikin (Chromium), 2011/09/16 12:58:19]

I don't think this ASSERT is necessary any more.

[Steven, 2011/09/16 18:29:52]

Done.

            is_global_scope() ||
            is_eval_scope());
     Variable* var =
         variables_.Declare(this,
                            isolate_->factory()->this_symbol(),
                            Variable::VAR,
                            false,
                            Variable::THIS);
     var->AllocateTo(Variable::PARAMETER, -1);
     receiver_ = var;
+  } else {
+    ASSERT(outer_scope() != NULL);
+    receiver_ = outer_scope()->receiver();
   }
 
   if (is_function_scope()) {
     // Declare 'arguments' variable which exists in all functions.
     // Note that it might never be accessed, in which case it won't be
     // allocated during variable allocation.
     variables_.Declare(this,
                        isolate_->factory()->arguments_symbol(),
                        Variable::VAR,
                        true,
@@ skipping 108 matching lines @@
 
 
 Variable* Scope::DeclareGlobal(Handle<String> name) {
   ASSERT(is_global_scope());
   return variables_.Declare(this, name, Variable::DYNAMIC_GLOBAL,
                             true,
                             Variable::NORMAL);
 }
 
 
-VariableProxy* Scope::NewUnresolved(Handle<String> name,
-                                    bool inside_with,
-                                    int position) {
+VariableProxy* Scope::NewUnresolved(Handle<String> name, int position) {
   // Note that we must not share the unresolved variables with
   // the same name because they may be removed selectively via
   // RemoveUnresolved().
   ASSERT(!already_resolved());
   VariableProxy* proxy = new(isolate_->zone()) VariableProxy(
-      isolate_, name, false, inside_with, position);
+      isolate_, name, false, position);
   unresolved_.Add(proxy);
   return proxy;
 }
 
 
 void Scope::RemoveUnresolved(VariableProxy* var) {
   // Most likely (always?) any variable we want to remove
   // was just added before, so we search backwards.
   for (int i = unresolved_.length(); i-- > 0;) {
     if (unresolved_[i] == var) {
@@ skipping 35 matching lines @@
   illegal_redecl_->Accept(visitor);
 }
 
 
 Declaration* Scope::CheckConflictingVarDeclarations() {
   int length = decls_.length();
   for (int i = 0; i < length; i++) {
     Declaration* decl = decls_[i];
     if (decl->mode() != Variable::VAR) continue;
     Handle<String> name = decl->proxy()->name();
-    bool cond = true;
-    for (Scope* scope = decl->scope(); cond ; scope = scope->outer_scope_) {
+
+    // Iterate through all scopes until and including the declaration scope.
+    Scope* previous = NULL;
+    Scope* current = decl->scope();
+    do {
       // There is a conflict if there exists a non-VAR binding.
-      Variable* other_var = scope->variables_.Lookup(name);
+      Variable* other_var = current->variables_.Lookup(name);
       if (other_var != NULL && other_var->mode() != Variable::VAR) {
         return decl;
       }
-
-      // Include declaration scope in the iteration but stop after.
-      if (!scope->is_block_scope() && !scope->is_catch_scope()) cond = false;
-    }
+      previous = current;
+      current = current->outer_scope_;
+    } while (!previous->is_declaration_scope());
   }
   return NULL;
 }
 
 
 template<class Allocator>
 void Scope::CollectUsedVariables(List<Variable*, Allocator>* locals) {
   // Collect variables in this scope.
   // Note that the function_ variable - if present - is not
   // collected here but handled separately in ScopeInfo
@@ skipping 27 matching lines @@
 void Scope::AllocateVariables(Handle<Context> context) {
   ASSERT(outer_scope_ == NULL);  // eval or global scopes only
 
   // 1) Propagate scope information.
   // If we are in an eval scope, we may have other outer scopes about
   // which we don't know anything at this point. Thus we must be conservative
   // 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();
-  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);
+    context->ComputeEvalScopeInfo(&outer_scope_calls_non_strict_eval);
   }
-  PropagateScopeInfo(outer_scope_calls_eval,
-                     outer_scope_calls_non_strict_eval,
-                     eval_scope);
+  PropagateScopeInfo(outer_scope_calls_non_strict_eval);
 
   // 2) Resolve variables.
   Scope* global_scope = NULL;
   if (is_global_scope()) global_scope = this;
   ResolveVariablesRecursively(global_scope, context);
 
   // 3) Allocate variables.
   AllocateVariablesRecursively();
 }
 
@@ skipping 32 matching lines @@
   for (Scope* s = this; s != scope; s = s->outer_scope_) {
     ASSERT(s != NULL);  // scope must be in the scope chain
     if (s->num_heap_slots() > 0) n++;
   }
   return n;
 }
 
 
 Scope* Scope::DeclarationScope() {
   Scope* scope = this;
-  while (scope->is_catch_scope() ||
-         scope->is_block_scope()) {
+  while (!scope->is_declaration_scope()) {
     scope = scope->outer_scope();
   }
   return scope;
 }
 
 
 Handle<SerializedScopeInfo> Scope::GetSerializedScopeInfo() {
   if (scope_info_.is_null()) {
     scope_info_ = SerializedScopeInfo::Create(this);
   }
   return scope_info_;
 }
 
 
 #ifdef DEBUG
 static const char* Header(Scope::Type type) {
   switch (type) {
     case Scope::EVAL_SCOPE: return "eval";
     case Scope::FUNCTION_SCOPE: return "function";
     case Scope::GLOBAL_SCOPE: return "global";
     case Scope::CATCH_SCOPE: return "catch";
     case Scope::BLOCK_SCOPE: return "block";
+    case Scope::WITH_SCOPE: return "with";
   }
   UNREACHABLE();
   return NULL;
 }
 
 
 static void Indent(int n, const char* str) {
   PrintF("%*s%s", n, "", str);
 }
 
@@ skipping 79 matching lines @@
   }
 
   // Scope info.
   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");
-  }
   if (num_stack_slots_ > 0) { Indent(n1, "// ");
   PrintF("%d stack slots\n", num_stack_slots_); }
   if (num_heap_slots_ > 0) { Indent(n1, "// ");
   PrintF("%d heap slots\n", num_heap_slots_); }
 
   // Print locals.
   Indent(n1, "// function var\n");
   if (function_ != NULL) {
     PrintVar(n1, function_->var());
   }
@@ skipping 33 matching lines @@
   if (var == NULL) {
     // Declare a new non-local.
     var = map->Declare(NULL, name, mode, true, Variable::NORMAL);
     // Allocate it by giving it a dynamic lookup.
     var->AllocateTo(Variable::LOOKUP, -1);
   }
   return var;
 }
 
 
-// Lookup a variable starting with this scope. The result is either
-// the statically resolved variable belonging to an outer scope, or
-// NULL. It may be NULL because a) we couldn't find a variable, or b)
-// because the variable is just a guess (and may be shadowed by
-// another variable that is introduced dynamically via an 'eval' call
-// or a 'with' statement).
-Variable* Scope::LookupRecursive(Handle<String> name,
-                                 bool from_inner_scope,
-                                 Variable** invalidated_local) {
-  // If we find a variable, but the current scope calls 'eval', the found
-  // variable may not be the correct one (the 'eval' may introduce a
-  // property with the same name). In that case, remember that the variable
-  // found is just a guess.
-  bool guess = scope_calls_eval_;
+Scope::LookupResult Scope::LookupRecursive(Handle<String> name,
+                                           Handle<Context> context,
+                                           Variable** var) {
+  // Try to find the variable in this scope.
+  *var = LocalLookup(name);

[Kevin Millikin (Chromium), 2011/09/16 12:58:19]

For some reason I prefer returning the variable and having the lookup kind be
the output parameter.  Just saying.

[Steven, 2011/09/16 18:29:52]

Yeah, after all me too.
On 2011/09/16 12:58:19, Kevin Millikin wrote:

 
-  // Try to find the variable in this scope.
-  Variable* var = LocalLookup(name);
+  // We found a variable and we are done. (Even if there is an 'eval' in
+  // this scope which introduces the same variable again, the resulting
+  // variable remains the same.)
+  if (*var != NULL) return BOUND;
 
-  if (var != NULL) {
-    // We found a variable. If this is not an inner lookup, we are done.
-    // (Even if there is an 'eval' in this scope which introduces the
-    // same variable again, the resulting variable remains the same.
-    // Note that enclosing 'with' statements are handled at the call site.)
-    if (!from_inner_scope)
-      return var;
-
-  } else {
-    // We did not find a variable locally. Check against the function variable,
-    // if any. We can do this for all scopes, since the function variable is
-    // only present - if at all - for function scopes.
-    //
-    // This lookup corresponds to a lookup in the "intermediate" scope sitting
-    // between this scope and the outer scope. (ECMA-262, 3rd., requires that
-    // the name of named function literal is kept in an intermediate scope
-    // in between this scope and the next outer scope.)
-    if (function_ != NULL && function_->name().is_identical_to(name)) {
-      var = function_->var();
-
-    } else if (outer_scope_ != NULL) {
-      var = outer_scope_->LookupRecursive(name, true, invalidated_local);
-      // We may have found a variable in an outer scope. However, if
-      // the current scope is inside a 'with', the actual variable may
-      // be a property introduced via the 'with' statement. Then, the
-      // variable we may have found is just a guess.
-      if (scope_inside_with_)
-        guess = true;
-    }
-
-    // If we did not find a variable, we are done.
-    if (var == NULL)
-      return NULL;
+  // We did not find a variable locally. Check against the function variable,
+  // if any. We can do this for all scopes, since the function variable is
+  // only present - if at all - for function scopes.
+  //
+  // This lookup corresponds to a lookup in the "intermediate" scope sitting
+  // between this scope and the outer scope. (ECMA-262, 3rd., requires that
+  // the name of named function literal is kept in an intermediate scope
+  // in between this scope and the next outer scope.)
+  LookupResult result = UNBOUND;
+  if (function_ != NULL && function_->name().is_identical_to(name)) {

[Kevin Millikin (Chromium), 2011/09/16 12:58:19]

I wonder if we could make Scope::LocalLookup check the function name after
checking the variable map, and get rid of this here.

It seems like it Scope::LocalLookup already does that for scopes backed by a
ScopeInfo.  That seems fishy, even if it's not an actual bug.

[Steven, 2011/09/16 18:29:52]

Unfortunately we can't. The function name is still in an 'implicit' outer scope
and might be shadowed by eval introduced variables, i.e. something like
function y( eval("var y = 1;"); return y; )
Thus the lookup for the y reference should produce BOUND_EVAL_SHADOWED. But if
we let LocalLookup do this check it will be BOUND.

Yes it is fishy that the function name of the SerializedScopeInfo is checked.
Removing it does not break any tests, but I left it in there for another cleanup
CL. It is for example used in another fishy function Scope::Lookup which in turn
is used in the parser to detect direct 'eval' calls.
On 2011/09/16 12:58:19, Kevin Millikin wrote:

+    *var = function_->var();
+    result = BOUND;
+  } else if (outer_scope_ != NULL) {
+    result = outer_scope_->LookupRecursive(name, context, var);
+    if (result == BOUND) (*var)->MarkAsAccessedFromInnerScope();
   }
 
-  ASSERT(var != NULL);
-
-  // If this is a lookup from an inner scope, mark the variable.
-  if (from_inner_scope) {
-    var->MarkAsAccessedFromInnerScope();
+  if (is_with_scope()) {
+    // The current scope is a with scope, so the variable binding can not be
+    // statically resolved. However, note that it was necessary to do a lookup
+    // in the outer scope anyway, because if a binding exists in an outer scope,
+    // the associated variable has to be marked as potentially being accessed
+    // from inside of an inner with scope (the property may not be in the 'with'
+    // object).
+    return DYNAMIC_LOOKUP;

[Kevin Millikin (Chromium), 2011/09/16 12:58:19]

And I'd prefer setting var to NULL (or returning NULL if you take the suggestion
above) in the cases where it's meaningless/should not be used/will not be used.

[Steven, 2011/09/16 18:29:52]

Done.

+  } else if (is_eval_scope()) {
+    // No local binding was found, no 'with' statements have been encountered
+    // and the code is executed as part of a call to 'eval'. The calling context
+    // contains scope information that we can use to determine if the variable
+    // is global, i.e. the calling context chain does not contain a binding and
+    // no 'with' contexts.
+    ASSERT(result == UNBOUND);
+    return context->GlobalIfNotShadowedByEval(name)
+        ? UNBOUND_EVAL_SHADOWED : DYNAMIC_LOOKUP;
+  } else if (calls_non_strict_eval()) {
+    // A variable binding may have been found in an outer scope, but the current
+    // scope makes a non-strict 'eval' call, so the found variable may not be
+    // the correct one (the 'eval' may introduce a binding with the same name).
+    // In that case, change the lookup result to reflect this situation.
+    if (result == BOUND) return BOUND_EVAL_SHADOWED;
+    if (result == UNBOUND) return UNBOUND_EVAL_SHADOWED;
   }
-
-  // If the variable we have found is just a guess, invalidate the
-  // result. If the found variable is local, record that fact so we
-  // can generate fast code to get it if it is not shadowed by eval.
-  if (guess) {
-    if (!var->is_global()) *invalidated_local = var;
-    var = NULL;
-  }
-
-  return var;
+  return result;
 }
 
 
 void Scope::ResolveVariable(Scope* global_scope,
                             Handle<Context> context,
                             VariableProxy* proxy) {
   ASSERT(global_scope == NULL || global_scope->is_global_scope());
 
   // If the proxy is already resolved there's nothing to do
   // (functions and consts may be resolved by the parser).
   if (proxy->var() != NULL) return;
 
   // Otherwise, try to resolve the variable.
-  Variable* invalidated_local = NULL;
-  Variable* var = LookupRecursive(proxy->name(), false, &invalidated_local);
+  Variable* var = NULL;
+  switch (LookupRecursive(proxy->name(), context, &var)) {
+    case BOUND:
+      // We found a variable binding.
+      break;
 
-  if (proxy->inside_with()) {
-    // If we are inside a local 'with' statement, all bets are off
-    // and we cannot resolve the proxy to a local variable even if
-    // we found an outer matching variable.
-    // Note that we must do a lookup anyway, because if we find one,
-    // we must mark that variable as potentially accessed from this
-    // inner scope (the property may not be in the 'with' object).
-    var = NonLocal(proxy->name(), Variable::DYNAMIC);
+    case BOUND_EVAL_SHADOWED:
+      // We found a variable variable binding that might be shadowed
+      // by 'eval' introduced variable bindings.
+      if (var->is_global()) {
+        var = NonLocal(proxy->name(), Variable::DYNAMIC_GLOBAL);
+      } else {
+        Variable* invalidated = var;
+        var = NonLocal(proxy->name(), Variable::DYNAMIC_LOCAL);
+        var->set_local_if_not_shadowed(invalidated);
+      }
+      break;
 
-  } else {
-    // We are not inside a local 'with' statement.
+    case UNBOUND:
+      // No binding has been found. Declare a variable in global scope.
+      ASSERT(global_scope != NULL);
+      var = global_scope->DeclareGlobal(proxy->name());
+      break;
 
-    if (var == NULL) {
-      // We did not find the variable. We have a global variable
-      // if we are in the global scope (we know already that we
-      // are outside a 'with' statement) or if there is no way
-      // that the variable might be introduced dynamically (through
-      // a local or outer eval() call, or an outer 'with' statement),
-      // or we don't know about the outer scope (because we are
-      // in an eval scope).
-      if (is_global_scope() ||
-          !(scope_inside_with_ || outer_scope_is_eval_scope_ ||
-            scope_calls_eval_ || outer_scope_calls_eval_)) {
-        // We must have a global variable.
-        ASSERT(global_scope != NULL);
-        var = global_scope->DeclareGlobal(proxy->name());
+    case UNBOUND_EVAL_SHADOWED:
+      // No binding has been found. But some scope makes a
+      // non-strict 'eval' call.
+      var = NonLocal(proxy->name(), Variable::DYNAMIC_GLOBAL);
+      break;
 
-      } else if (scope_inside_with_) {
-        // If we are inside a with statement we give up and look up
-        // the variable at runtime.
-        var = NonLocal(proxy->name(), Variable::DYNAMIC);
-
-      } else if (invalidated_local != NULL) {
-        // No with statements are involved and we found a local
-        // variable that might be shadowed by eval introduced
-        // variables.
-        var = NonLocal(proxy->name(), Variable::DYNAMIC_LOCAL);
-        var->set_local_if_not_shadowed(invalidated_local);
-
-      } else if (outer_scope_is_eval_scope_) {
-        // No with statements and we did not find a local and the code
-        // is executed with a call to eval.  The context contains
-        // scope information that we can use to determine if the
-        // variable is global if it is not shadowed by eval-introduced
-        // variables.
-        if (context->GlobalIfNotShadowedByEval(proxy->name())) {
-          var = NonLocal(proxy->name(), Variable::DYNAMIC_GLOBAL);
-
-        } else {
-          var = NonLocal(proxy->name(), Variable::DYNAMIC);
-        }
-
-      } else {
-        // No with statements and we did not find a local and the code
-        // is not executed with a call to eval.  We know that this
-        // variable is global unless it is shadowed by eval-introduced
-        // variables.
-        var = NonLocal(proxy->name(), Variable::DYNAMIC_GLOBAL);
-      }
-    }
+    case DYNAMIC_LOOKUP:
+      // The variable could not be resolved statically.
+      var = NonLocal(proxy->name(), Variable::DYNAMIC);
+      break;
   }
 
+  ASSERT(var != NULL);
   proxy->BindTo(var);
 }
 
 
 void Scope::ResolveVariablesRecursively(Scope* global_scope,
                                         Handle<Context> context) {
   ASSERT(global_scope == NULL || global_scope->is_global_scope());
 
   // Resolve unresolved variables for this scope.
   for (int i = 0; i < unresolved_.length(); i++) {
     ResolveVariable(global_scope, context, unresolved_[i]);
   }
 
   // Resolve unresolved variables for inner scopes.
   for (int i = 0; i < inner_scopes_.length(); i++) {
     inner_scopes_[i]->ResolveVariablesRecursively(global_scope, context);
   }
 }
 
 
-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;
-  }
-
+bool Scope::PropagateScopeInfo(bool outer_scope_calls_non_strict_eval ) {
   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_;
   for (int i = 0; i < inner_scopes_.length(); i++) {
     Scope* inner_scope = inner_scopes_[i];
-    if (inner_scope->PropagateScopeInfo(calls_eval,
-                                        calls_non_strict_eval,
-                                        is_eval)) {
+    if (inner_scope->PropagateScopeInfo(calls_non_strict_eval)) {
       inner_scope_calls_eval_ = true;
     }
     if (inner_scope->force_eager_compilation_) {
       force_eager_compilation_ = true;
     }
   }
 
   return scope_calls_eval_ || inner_scope_calls_eval_;
 }
 
@@ skipping 183 matching lines @@
   if (num_heap_slots_ == Context::MIN_CONTEXT_SLOTS &&
       !must_have_local_context) {
     num_heap_slots_ = 0;
   }
 
   // Allocation done.
   ASSERT(num_heap_slots_ == 0 || num_heap_slots_ >= Context::MIN_CONTEXT_SLOTS);
 }
 
 } }  // namespace v8::internal