In background compilation make a copy of Field in order to freeze its state

runtime/vm/assembler_arm64.cc

 // Copyright (c) 2014, 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"  // NOLINT
 #if defined(TARGET_ARCH_ARM64)
 
 #include "vm/assembler.h"
 #include "vm/cpu.h"
 #include "vm/longjump.h"
@@ skipping 350 matching lines @@
 }
 
 
 intptr_t Assembler::FindImmediate(int64_t imm) {
   return object_pool_wrapper_.FindImmediate(imm);
 }
 
 
 bool Assembler::CanLoadFromObjectPool(const Object& object) const {
   ASSERT(!object.IsICData() || ICData::Cast(object).IsOriginal());
+  ASSERT(!object.IsField() || Field::Cast(object).IsOriginal());
   ASSERT(!Thread::CanLoadFromThread(object));
   if (!constant_pool_allowed()) {
     return false;
   }
 
   // TODO(zra, kmillikin): Also load other large immediates from the object
   // pool
   if (object.IsSmi()) {
     // If the raw smi does not fit into a 32-bit signed int, then we'll keep
     // the raw value in the object pool.
@@ skipping 15 matching lines @@
 
 void Assembler::LoadIsolate(Register dst) {
   ldr(dst, Address(THR, Thread::isolate_offset()));
 }
 
 
 void Assembler::LoadObjectHelper(Register dst,
                                  const Object& object,
                                  bool is_unique) {
   ASSERT(!object.IsICData() || ICData::Cast(object).IsOriginal());
+  ASSERT(!object.IsField() || Field::Cast(object).IsOriginal());
   if (Thread::CanLoadFromThread(object)) {
     ldr(dst, Address(THR, Thread::OffsetFromThread(object)));
   } else if (CanLoadFromObjectPool(object)) {
     const int32_t offset = ObjectPool::element_offset(
         is_unique ? object_pool_wrapper_.AddObject(object)
                   : object_pool_wrapper_.FindObject(object));
     LoadWordFromPoolOffset(dst, offset);
   } else {
     ASSERT(object.IsSmi() || object.InVMHeap());
     ASSERT(object.IsSmi() || FLAG_allow_absolute_addresses);
@@ skipping 19 matching lines @@
 }
 
 
 void Assembler::LoadUniqueObject(Register dst, const Object& object) {
   LoadObjectHelper(dst, object, true);
 }
 
 
 void Assembler::CompareObject(Register reg, const Object& object) {
   ASSERT(!object.IsICData() || ICData::Cast(object).IsOriginal());
+  ASSERT(!object.IsField() || Field::Cast(object).IsOriginal());
   if (Thread::CanLoadFromThread(object)) {
     ldr(TMP, Address(THR, Thread::OffsetFromThread(object)));
     CompareRegisters(reg, TMP);
   } else if (CanLoadFromObjectPool(object)) {
     LoadObject(TMP, object);
     CompareRegisters(reg, TMP);
   } else {
     ASSERT(object.IsSmi() || FLAG_allow_absolute_addresses);
     CompareImmediate(reg, reinterpret_cast<int64_t>(object.raw()));
   }
@@ skipping 486 matching lines @@
     AddImmediate(TMP, object, offset - kHeapObjectTag);
     StoreIntoObjectNoBarrier(object, Address(TMP), value);
   }
 }
 
 
 void Assembler::StoreIntoObjectNoBarrier(Register object,
                                          const Address& dest,
                                          const Object& value) {
   ASSERT(!value.IsICData() || ICData::Cast(value).IsOriginal());
+  ASSERT(!value.IsField() || Field::Cast(value).IsOriginal());
   ASSERT(value.IsSmi() || value.InVMHeap() ||
          (value.IsOld() && value.IsNotTemporaryScopedHandle()));
   // No store buffer update.
   LoadObject(TMP2, value);
   str(TMP2, dest);
 }
 
 
 void Assembler::StoreIntoObjectOffsetNoBarrier(Register object,
                                                int32_t offset,
@@ skipping 520 matching lines @@
     add(base, array, Operand(index, LSL, shift));
   }
   const OperandSize size = Address::OperandSizeFor(cid);
   ASSERT(Address::CanHoldOffset(offset, Address::Offset, size));
   return Address(base, offset, Address::Offset, size);
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM64