[runtime] [proxy] Implementing [[Call]]

src/x64/builtins-x64.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.
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/code-factory.h"
 #include "src/codegen.h"
 #include "src/deoptimizer.h"
 #include "src/full-codegen/full-codegen.h"
@@ skipping 1727 matching lines @@
 
   Label non_callable, non_function, non_smi;
   __ JumpIfSmi(rdi, &non_callable);
   __ bind(&non_smi);
   __ CmpObjectType(rdi, JS_FUNCTION_TYPE, rcx);
   __ j(equal, masm->isolate()->builtins()->CallFunction(mode),
        RelocInfo::CODE_TARGET);
   __ CmpInstanceType(rcx, JS_PROXY_TYPE);
   __ j(not_equal, &non_function);
 
-  // 1. Call to function proxy.
-  // TODO(neis): Implement [[Call]] on proxies.
+  // 1. Runtime fallback for Proxy [[Call]].
+  __ PopReturnAddressTo(kScratchRegister);
+  __ Push(rdi);
+  __ PushReturnAddressFrom(kScratchRegister);
+  // Increase the arguments size to include the pushed function and the
+  // existing receiver on the stack.
+  __ addp(rax, Immediate(2));
+  // Tail-call to the runtime.
+  __ JumpToExternalReference(
+      ExternalReference(Runtime::kJSProxyCall, masm->isolate()), 1);
 
   // 2. Call to something else, which might have a [[Call]] internal method (if
   // not we raise an exception).
   __ bind(&non_function);
   // Check if target has a [[Call]] internal method.
   __ testb(FieldOperand(rcx, Map::kBitFieldOffset),
            Immediate(1 << Map::kIsCallable));
   __ j(zero, &non_callable, Label::kNear);
   // Overwrite the original receiver with the (original) target.
   __ movp(args.GetReceiverOperand(), rdi);
@@ skipping 274 matching lines @@
   __ ret(0);
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64