[WIP] Initial CallFunctionCallback builtin.

src/mips64/code-stubs-mips64.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_MIPS64
 
 #include "src/code-stubs.h"
 #include "src/api-arguments.h"
 #include "src/bootstrapper.h"
 #include "src/codegen.h"
@@ skipping 2779 matching lines @@
   }
 
   Label fast_elements_case;
   __ Branch(&fast_elements_case, eq, a3, Operand(FAST_ELEMENTS));
   GenerateCase(masm, FAST_HOLEY_ELEMENTS);
 
   __ bind(&fast_elements_case);
   GenerateCase(masm, FAST_ELEMENTS);
 }
 
-static int AddressOffset(ExternalReference ref0, ExternalReference ref1) {
-  int64_t offset = (ref0.address() - ref1.address());
-  DCHECK(static_cast<int>(offset) == offset);
-  return static_cast<int>(offset);
-}
-
-
 // Calls an API function.  Allocates HandleScope, extracts returned value
 // from handle and propagates exceptions.  Restores context.  stack_space
 // - space to be unwound on exit (includes the call JS arguments space and
 // the additional space allocated for the fast call).
 static void CallApiFunctionAndReturn(
     MacroAssembler* masm, Register function_address,
     ExternalReference thunk_ref, int stack_space, int32_t stack_space_offset,
     MemOperand return_value_operand, MemOperand* context_restore_operand) {
   Isolate* isolate = masm->isolate();
   ExternalReference next_address =
@@ skipping 90 matching lines @@
   }
   __ LeaveExitFrame(false, s0, !restore_context, NO_EMIT_RETURN,
                     stack_space_offset != kInvalidStackOffset);
 
   // Check if the function scheduled an exception.
   __ LoadRoot(a4, Heap::kTheHoleValueRootIndex);
   __ li(at, Operand(ExternalReference::scheduled_exception_address(isolate)));
   __ Ld(a5, MemOperand(at));
   __ Branch(&promote_scheduled_exception, ne, a4, Operand(a5));
 
+  // Check if the function returned a valid JavaScript value.
+  __ AssertApiCallResult(v0);
+
   __ Ret();
 
   // Re-throw by promoting a scheduled exception.
   __ bind(&promote_scheduled_exception);
   __ TailCallRuntime(Runtime::kPromoteScheduledException);
 
   // HandleScope limit has changed. Delete allocated extensions.
   __ bind(&delete_allocated_handles);
   __ Sd(s1, MemOperand(s3, kLimitOffset));
   __ mov(s0, v0);
@@ skipping 178 matching lines @@
                            kStackUnwindSpace, kInvalidStackOffset,
                            return_value_operand, NULL);
 }
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_MIPS64