Propagate receiver from initial call site to code generator.

src/fast-codegen.cc

 // Copyright 2010 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 32 matching lines @@
   } while (false)
 
 
 #define CHECK_BAILOUT                           \
   do {                                          \
     if (!has_supported_syntax_) return;         \
   } while (false)
 
 
 void FastCodeGenSyntaxChecker::Check(FunctionLiteral* fun) {
-  Scope* scope = fun->scope();
+  // We do not specialize if we do not have a receiver.
+  if (receiver().is_null()) BAILOUT("No receiver");
 
   // We do not support stack or heap slots (both of which require
   // allocation).
+  Scope* scope = fun->scope();
   if (scope->num_stack_slots() > 0) {
     BAILOUT("Function has stack-allocated locals");
   }
   if (scope->num_heap_slots() > 0) {
     BAILOUT("Function has context-allocated locals");
   }
 
   VisitDeclarations(scope->declarations());
   CHECK_BAILOUT;
 
@@ skipping 172 matching lines @@
   Property* prop = expr->target()->AsProperty();
   if (prop == NULL) BAILOUT("Non-property assignment");
   VariableProxy* proxy = prop->obj()->AsVariableProxy();
   if (proxy == NULL || !proxy->var()->is_this()) {
     BAILOUT("Non-this-property assignment");
   }
   if (!prop->key()->IsPropertyName()) {
     BAILOUT("Non-named-property assignment");
   }
 
+  // We will only specialize for fields on the object itself.
+  // Expression::IsPropertyName implies that the name is a literal
+  // symbol but we do not assume that.
+  Literal* key = prop->key()->AsLiteral();
+  if (key != NULL && key->handle()->IsString()) {
+    Handle<String> name = Handle<String>::cast(key->handle());
+    LookupResult lookup;
+    receiver()->Lookup(*name, &lookup);
+    if (lookup.holder() != *receiver()) BAILOUT("Non-own property assignment");
+    if (!lookup.type() == FIELD) BAILOUT("Non-field property assignment");
+  } else {
+    UNREACHABLE();
+    BAILOUT("Unexpected non-string-literal property key");
+  }
+
   Visit(expr->value());
 }
 
 
 void FastCodeGenSyntaxChecker::VisitThrow(Throw* expr) {
   BAILOUT("Throw");
 }
 
 
 void FastCodeGenSyntaxChecker::VisitProperty(Property* expr) {
@@ skipping 38 matching lines @@
 
 void FastCodeGenSyntaxChecker::VisitThisFunction(ThisFunction* expr) {
   BAILOUT("ThisFunction");
 }
 
 #undef BAILOUT
 #undef CHECK_BAILOUT
 
 
 } }  // namespace v8::internal