VM: Clean up generated code for NoSuchMethod invocation of closures.

runtime/vm/stub_code_x64.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/assembler.h"
 #include "vm/compiler.h"
 #include "vm/dart_entry.h"
@@ skipping 1155 matching lines @@
   __ ret();
 }
 
 
 // Called for invoking "dynamic noSuchMethod(Invocation invocation)" function
 // from the entry code of a dart function after an error in passed argument
 // name or number is detected.
 // Input parameters:
 //   RSP : points to return address.
 //   RSP + 8 : address of last argument.
-//   RBX : ic-data.
 //   R10 : arguments descriptor array.
 void StubCode::GenerateCallNoSuchMethodFunctionStub(Assembler* assembler) {
   __ EnterStubFrame();
 
   // Load the receiver.
   __ movq(R13, FieldAddress(R10, ArgumentsDescriptor::count_offset()));
   __ movq(RAX, Address(RBP, R13, TIMES_4, kParamEndSlotFromFp * kWordSize));
 
   __ LoadObject(R12, Object::null_object(), PP);
   __ pushq(R12);  // Setup space on stack for result from noSuchMethod.
   __ pushq(RAX);  // Receiver.
-  __ pushq(RBX);  // IC data array.
   __ pushq(R10);  // Arguments descriptor array.
 
   __ movq(R10, R13);  // Smi-tagged arguments array length.
   PushArgumentsArray(assembler);
 
-  __ CallRuntime(kInvokeNoSuchMethodFunctionRuntimeEntry, 4);
+  const intptr_t kNumArgs = 3;
+  __ CallRuntime(kInvokeNoSuchMethodFunctionRuntimeEntry, kNumArgs);
 

[Vyacheslav Egorov (Google), 2014/09/02 22:28:04]

I think all the code after CallRuntime is dead because
kInvokeNoSuchMethodFunctionRuntimeEntry always throws. Just kill it on all
platforms?

[Florian Schneider, 2014/09/03 09:05:00]

Only Object::noSuchMethod throws, otherwise it can do whatever the user decides
to do.

[Florian Schneider, 2014/09/03 12:17:28]

You're right that in the case of closures, it always throws.

   // Remove arguments.
-  __ Drop(4);
+  __ Drop(kNumArgs);
   __ popq(RAX);  // Get result into RAX.
 
   // Remove the stub frame as we are about to return.
   __ LeaveStubFrame();
   __ ret();
 }
 
 
 // Cannot use function object from ICData as it may be the inlined
 // function and not the top-scope function.
@@ skipping 808 matching lines @@
 
   __ movq(left, Address(RSP, 2 * kWordSize));
   __ movq(right, Address(RSP, 1 * kWordSize));
   GenerateIdenticalWithNumberCheckStub(assembler, left, right);
   __ ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64