Use Object::null_object() instead of Object::ZoneHandle() when a null object

runtime/vm/intermediate_language_mips.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"  // Needed here to get TARGET_ARCH_MIPS.
 #if defined(TARGET_ARCH_MIPS)
 
 #include "vm/intermediate_language.h"
 
 #include "vm/dart_entry.h"
@@ skipping 850 matching lines @@
 
 
 void NativeCallInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   __ TraceSimMsg("NativeCallInstr");
   ASSERT(locs()->temp(0).reg() == A1);
   ASSERT(locs()->temp(1).reg() == A2);
   ASSERT(locs()->temp(2).reg() == T5);
   Register result = locs()->out(0).reg();
 
   // Push the result place holder initialized to NULL.
-  __ PushObject(Object::ZoneHandle());
+  __ PushObject(Object::null_object());
   // Pass a pointer to the first argument in A2.
   if (!function().HasOptionalParameters()) {
     __ AddImmediate(A2, FP, (kParamEndSlotFromFp +
                              function().NumParameters()) * kWordSize);
   } else {
     __ AddImmediate(A2, FP, kFirstLocalSlotFromFp * kWordSize);
   }
   // Compute the effective address. When running under the simulator,
   // this is a redirection address that forces the simulator to call
   // into the runtime system.
@@ skipping 1206 matching lines @@
   ASSERT(locs()->in(1).reg() == kLengthReg);
 
   Label slow_path, done;
   if (num_elements()->BindsToConstant() &&
       num_elements()->BoundConstant().IsSmi()) {
     const intptr_t length = Smi::Cast(num_elements()->BoundConstant()).Value();
     if ((length >= 0) && (length <= Array::kMaxElements)) {
       Label slow_path, done;
       InlineArrayAllocation(compiler, length, &slow_path, &done);
       __ Bind(&slow_path);
-      __ PushObject(Object::ZoneHandle());  // Make room for the result.
+      __ PushObject(Object::null_object());  // Make room for the result.
       __ Push(kLengthReg);  // length.
       __ Push(kElemTypeReg);
       compiler->GenerateRuntimeCall(token_pos(),
                                     deopt_id(),
                                     kAllocateArrayRuntimeEntry,
                                     2,
                                     locs());
       __ Drop(2);
       __ Pop(kResultReg);
       __ Bind(&done);
@@ skipping 156 matching lines @@
 
 
 void InstantiateTypeInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   __ TraceSimMsg("InstantiateTypeInstr");
   Register instantiator_reg = locs()->in(0).reg();
   Register result_reg = locs()->out(0).reg();
 
   // 'instantiator_reg' is the instantiator TypeArguments object (or null).
   // A runtime call to instantiate the type is required.
   __ addiu(SP, SP, Immediate(-3 * kWordSize));
-  __ LoadObject(TMP, Object::ZoneHandle());
+  __ LoadObject(TMP, Object::null_object());
   __ sw(TMP, Address(SP, 2 * kWordSize));  // Make room for the result.
   __ LoadObject(TMP, type());
   __ sw(TMP, Address(SP, 1 * kWordSize));
   // Push instantiator type arguments.
   __ sw(instantiator_reg, Address(SP, 0 * kWordSize));
 
   compiler->GenerateRuntimeCall(token_pos(),
                                 deopt_id(),
                                 kInstantiateTypeRuntimeEntry,
                                 2,
@@ skipping 53 matching lines @@
   __ delay_slot()->addiu(T2, T2, Immediate(2 * kWordSize));
   __ b(&slow_case);
   __ Bind(&found);
   __ lw(T0, Address(T2, 1 * kWordSize));  // Cached instantiated args.
   __ b(&type_arguments_instantiated);
 
   __ Bind(&slow_case);
   // Instantiate non-null type arguments.
   // A runtime call to instantiate the type arguments is required.
   __ addiu(SP, SP, Immediate(-3 * kWordSize));
-  __ LoadObject(TMP, Object::ZoneHandle());
+  __ LoadObject(TMP, Object::null_object());
   __ sw(TMP, Address(SP, 2 * kWordSize));  // Make room for the result.
   __ LoadObject(TMP, type_arguments());
   __ sw(TMP, Address(SP, 1 * kWordSize));
   // Push instantiator type arguments.
   __ sw(instantiator_reg, Address(SP, 0 * kWordSize));
 
   compiler->GenerateRuntimeCall(token_pos(),
                                 deopt_id(),
                                 kInstantiateTypeArgumentsRuntimeEntry,
                                 2,
@@ skipping 45 matching lines @@
 }
 
 
 void CloneContextInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   Register context_value = locs()->in(0).reg();
   Register result = locs()->out(0).reg();
 
   __ TraceSimMsg("CloneContextInstr");
 
   __ addiu(SP, SP, Immediate(-2 * kWordSize));
-  __ LoadObject(TMP, Object::ZoneHandle());  // Make room for the result.
+  __ LoadObject(TMP, Object::null_object());  // Make room for the result.
   __ sw(TMP, Address(SP, 1 * kWordSize));
   __ sw(context_value, Address(SP, 0 * kWordSize));
 
   compiler->GenerateRuntimeCall(token_pos(),
                                 deopt_id(),
                                 kCloneContextRuntimeEntry,
                                 1,
                                 locs());
   __ lw(result, Address(SP, 1 * kWordSize));  // Get result (cloned context).
   __ addiu(SP, SP, Immediate(2 * kWordSize));
@@ skipping 2271 matching lines @@
   compiler->GenerateCall(token_pos(), &label, stub_kind_, locs());
 #if defined(DEBUG)
   __ LoadImmediate(S4, kInvalidObjectPointer);
   __ LoadImmediate(S5, kInvalidObjectPointer);
 #endif
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_MIPS