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

runtime/vm/stub_code_arm.cc

Index: runtime/vm/stub_code_arm.cc
===================================================================
--- runtime/vm/stub_code_arm.cc	(revision 39693)
+++ runtime/vm/stub_code_arm.cc	(working copy)
@@ -1155,7 +1155,6 @@
 // Input parameters:
 //  LR : return address.
 //  SP : address of last argument.
-//  R5: inline cache data object.
 //  R4: arguments descriptor array.
 void StubCode::GenerateCallNoSuchMethodFunctionStub(Assembler* assembler) {
   __ EnterStubFrame();
@@ -1170,14 +1169,15 @@
   // Push IC data object.

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

comment is obsolete, update

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

Done.

   // Push arguments descriptor array.
   __ LoadImmediate(IP, reinterpret_cast<intptr_t>(Object::null()));
-  __ PushList((1 << R4) | (1 << R5) | (1 << R6) | (1 << IP));
+  __ PushList((1 << R4) | (1 << R6) | (1 << IP));
 
   // R2: Smi-tagged arguments array length.
   PushArgumentsArray(assembler);
 
-  __ CallRuntime(kInvokeNoSuchMethodFunctionRuntimeEntry, 4);
+  const intptr_t kNumArgs = 3;

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

this 3 is related to the number of bits set in the list above. I wonder if this
can be unified somehow.

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

It's a little tricky to generate the push-list - maybe some macro-magic could
help out, but I'd rather do this in a separate CL. IP (=null) contains the slot
for the result

+  __ CallRuntime(kInvokeNoSuchMethodFunctionRuntimeEntry, kNumArgs);
   // Remove arguments.
-  __ Drop(4);
+  __ Drop(kNumArgs);
   __ Pop(R0);  // Get result into R0.
   __ LeaveStubFrame();

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

something is off here: three things were pushed and you dropped three things.
where does the result come from?

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

I'm sure PushArgumentsArray is the missing piece here.

   __ Ret();