Properly create variables to access outer arguments and function names.

Review URL: http://codereview.chromium.org/6266007

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6380 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/scopeinfo.cc

@@ -152,19 +152,18 @@ ScopeInfo<Allocator>::ScopeInfo(Scope* scope)
 //
 // - function name
 //
+// - calls eval boolean flag
+//
 // - number of variables in the context object (smi) (= function context
 //   slot index + 1)
 // - list of pairs (name, Var mode) of context-allocated variables (starting
 //   with context slot 0)
-// - NULL (sentinel)
 //
 // - number of parameters (smi)
 // - list of parameter names (starting with parameter 0 first)
-// - NULL (sentinel)
 //
 // - number of variables on the stack (smi)
 // - list of names of stack-allocated variables (starting with stack slot 0)
-// - NULL (sentinel)
 
 // The ScopeInfo representation could be simplified and the ScopeInfo
 // re-implemented (with almost the same interface). Here is a

src/scopes.cc

@@ -154,6 +154,24 @@ Scope::Scope(Scope* inner_scope, SerializedScopeInfo* scope_info)
   if (scope_info->HasHeapAllocatedLocals()) {
     num_heap_slots_ = scope_info_->NumberOfContextSlots();
   }
+
+  // This scope's arguments shadow (if present) is context-allocated if an inner
+  // scope accesses this one's parameters.  Allocate the arguments_shadow_
+  // variable if necessary.
+  Variable::Mode mode;
+  int arguments_shadow_index =
+      scope_info_->ContextSlotIndex(Heap::arguments_shadow_symbol(), &mode);
+  if (arguments_shadow_index >= 0) {
+    ASSERT(mode == Variable::INTERNAL);
+    arguments_shadow_ = new Variable(this,
+                                     Factory::arguments_shadow_symbol(),
+                                     Variable::INTERNAL,
+                                     true,
+                                     Variable::ARGUMENTS);
+    arguments_shadow_->set_rewrite(
+        new Slot(arguments_shadow_, Slot::CONTEXT, arguments_shadow_index));
+    arguments_shadow_->set_is_used(true);
+  }
 }
 
 
@@ -239,21 +257,49 @@ Variable* Scope::LocalLookup(Handle<String> name) {
   // If the scope is resolved, we can find a variable in serialized scope info.
 
   // We should never lookup 'arguments' in this scope
-  // as it is impllicitly present in any scope.
+  // as it is implicitly present in any scope.
   ASSERT(*name != *Factory::arguments_symbol());
 
+  // Assert that there is no local slot with the given name.
+  ASSERT(scope_info_->StackSlotIndex(*name) < 0);
+
   // Check context slot lookup.
   Variable::Mode mode;
   int index = scope_info_->ContextSlotIndex(*name, &mode);
-  if (index < 0) {
-    return NULL;
+  if (index >= 0) {
+    Variable* var =
+        variables_.Declare(this, name, mode, true, Variable::NORMAL);
+    var->set_rewrite(new Slot(var, Slot::CONTEXT, index));
+    return var;
   }
 
+  index = scope_info_->ParameterIndex(*name);
+  if (index >= 0) {
+    // ".arguments" must be present in context slots.
+    ASSERT(arguments_shadow_ != NULL);
+    Variable* var =
+        variables_.Declare(this, name, Variable::VAR, true, Variable::NORMAL);
+    Property* rewrite =
+        new Property(new VariableProxy(arguments_shadow_),
+                     new Literal(Handle<Object>(Smi::FromInt(index))),
+                     RelocInfo::kNoPosition,
+                     Property::SYNTHETIC);
+    rewrite->set_is_arguments_access(true);
+    var->set_rewrite(rewrite);
+    return var;
+  }
+
+  index = scope_info_->FunctionContextSlotIndex(*name);
+  if (index >= 0) {
     // Check that there is no local slot with the given name.
     ASSERT(scope_info_->StackSlotIndex(*name) < 0);
-  Variable* var = variables_.Declare(this, name, mode, true, Variable::NORMAL);
+    Variable* var =
+        variables_.Declare(this, name, Variable::VAR, true, Variable::NORMAL);
     var->set_rewrite(new Slot(var, Slot::CONTEXT, index));
     return var;
+  }
+
+  return NULL;
 }
 
 

test/mjsunit/compiler/regress-serialized-slots.js

+// 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
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// The test verifies that parameters of the outer function are correctly
+// accessible from the inner closure.
+
+function runner(f, expected) {
+  for (var i = 0; i < 10000; i++) {  // Loop to trigger optimization.
+    assertEquals(expected, f.call(this, 10));
+  }
+}
+
+Function.prototype.bind = function(thisObject)
+{
+    var func = this;
+    var args = Array.prototype.slice.call(arguments, 1);
+    function bound()
+    {
+      // Note outer function parameter access (|thisObject|).
+      return func.apply(
+          thisObject,
+          args.concat(Array.prototype.slice.call(arguments, 0)));
+    }
+    return bound;
+}
+
+function sum(x, y) {
+  return x + y;
+}
+
+function test(n) {
+  runner(sum.bind(this, n), n + 10);
+}
+
+test(1);
+test(42);
+test(239);