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

runtime/vm/assembler_ia32.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"  // NOLINT
 #if defined(TARGET_ARCH_IA32)
 
 #include "vm/assembler.h"
 #include "vm/code_generator.h"
 #include "vm/cpu.h"
@@ skipping 2145 matching lines @@
 }
 
 
 void Assembler::LoadIsolate(Register dst) {
   movl(dst, Address(THR, Thread::isolate_offset()));
 }
 
 
 void Assembler::LoadObject(Register dst, const Object& object) {
   ASSERT(!object.IsICData() || ICData::Cast(object).IsOriginal());
+  ASSERT(!object.IsField() || Field::Cast(object).IsOriginal());
   if (object.IsSmi() || object.InVMHeap()) {
     movl(dst, Immediate(reinterpret_cast<int32_t>(object.raw())));
   } else {
     ASSERT(object.IsNotTemporaryScopedHandle());
     ASSERT(object.IsOld());
     AssemblerBuffer::EnsureCapacity ensured(&buffer_);
     EmitUint8(0xB8 + dst);
     buffer_.EmitObject(object);
   }
 }
 
 
 void Assembler::LoadObjectSafely(Register dst, const Object& object) {
   ASSERT(!object.IsICData() || ICData::Cast(object).IsOriginal());
+  ASSERT(!object.IsField() || Field::Cast(object).IsOriginal());
   if (Assembler::IsSafe(object)) {
     LoadObject(dst, object);
   } else {
     int32_t cookie = jit_cookie();
     movl(dst, Immediate(reinterpret_cast<int32_t>(object.raw()) ^ cookie));
     xorl(dst, Immediate(cookie));
   }
 }
 
 
 void Assembler::PushObject(const Object& object) {
   ASSERT(!object.IsICData() || ICData::Cast(object).IsOriginal());
+  ASSERT(!object.IsField() || Field::Cast(object).IsOriginal());
   if (object.IsSmi() || object.InVMHeap()) {
     pushl(Immediate(reinterpret_cast<int32_t>(object.raw())));
   } else {
     ASSERT(object.IsNotTemporaryScopedHandle());
     ASSERT(object.IsOld());
     AssemblerBuffer::EnsureCapacity ensured(&buffer_);
     EmitUint8(0x68);
     buffer_.EmitObject(object);
   }
 }
 
 
 void Assembler::CompareObject(Register reg, const Object& object) {
   ASSERT(!object.IsICData() || ICData::Cast(object).IsOriginal());
+  ASSERT(!object.IsField() || Field::Cast(object).IsOriginal());
   if (object.IsSmi() || object.InVMHeap()) {
     cmpl(reg, Immediate(reinterpret_cast<int32_t>(object.raw())));
   } else {
     ASSERT(object.IsNotTemporaryScopedHandle());
     ASSERT(object.IsOld());
     AssemblerBuffer::EnsureCapacity ensured(&buffer_);
     if (reg == EAX) {
       EmitUint8(0x05 + (7 << 3));
       buffer_.EmitObject(object);
     } else {
@@ skipping 179 matching lines @@
   Bind(&done);
   popl(value);
 #endif  // defined(DEBUG)
   // No store buffer update.
 }
 
 
 void Assembler::UnverifiedStoreOldObject(const Address& dest,
                                          const Object& value) {
   ASSERT(!value.IsICData() || ICData::Cast(value).IsOriginal());
+  ASSERT(!value.IsField() || Field::Cast(value).IsOriginal());
   ASSERT(value.IsOld());
   ASSERT(!value.InVMHeap());
   AssemblerBuffer::EnsureCapacity ensured(&buffer_);
   EmitUint8(0xC7);
   EmitOperand(0, dest);
   buffer_.EmitObject(value);
 }
 
 
 void Assembler::StoreIntoObjectNoBarrier(Register object,
                                          const Address& dest,
                                          const Object& value,
                                          FieldContent old_content) {
   ASSERT(!value.IsICData() || ICData::Cast(value).IsOriginal());
+  ASSERT(!value.IsField() || Field::Cast(value).IsOriginal());
   VerifyHeapWord(dest, old_content);
   if (value.IsSmi() || value.InVMHeap()) {
     Immediate imm_value(reinterpret_cast<int32_t>(value.raw()));
     movl(dest, imm_value);
     if (VerifiedMemory::enabled()) {
       Register temp = ECX;
       pushl(temp);
       leal(temp, dest);
       movl(Address(temp, VerifiedMemory::offset()), imm_value);
       popl(temp);
@@ skipping 788 matching lines @@
 
 const char* Assembler::FpuRegisterName(FpuRegister reg) {
   ASSERT((0 <= reg) && (reg < kNumberOfXmmRegisters));
   return xmm_reg_names[reg];
 }
 
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_IA32