Add --check-code-pointer flag for debug builds

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"
 #include "vm/runtime_entry.h"
 #include "vm/simulator.h"
 #include "vm/stack_frame.h"
 #include "vm/stub_code.h"
 
 // An extra check since we are assuming the existence of /proc/cpuinfo below.
 #if !defined(USING_SIMULATOR) && !defined(__linux__) && !defined(ANDROID) && \
     !TARGET_OS_IOS
 #error ARM64 cross-compile only supported on Linux
 #endif
 
 namespace dart {
 
 DECLARE_FLAG(bool, allow_absolute_addresses);
+DECLARE_FLAG(bool, check_code_pointer);
+DECLARE_FLAG(bool, inline_alloc);
+
 DEFINE_FLAG(bool, use_far_branches, false, "Always use far branches");
 DEFINE_FLAG(bool, print_stop_message, false, "Print stop message.");
-DECLARE_FLAG(bool, inline_alloc);
 
 
 Assembler::Assembler(bool use_far_branches)
     : buffer_(),
       prologue_offset_(-1),
       use_far_branches_(use_far_branches),
       comments_(),
       constant_pool_allowed_(false) {
 }
 
@@ skipping 1036 matching lines @@
 
 
 void Assembler::RestoreCodePointer() {
   ldr(CODE_REG, Address(FP, kPcMarkerSlotFromFp * kWordSize));
   CheckCodePointer();
 }
 
 
 void Assembler::CheckCodePointer() {
 #ifdef DEBUG
+  if (!FLAG_check_code_pointer) {
+    return;
+  }
   Comment("CheckCodePointer");
   Label cid_ok, instructions_ok;
   Push(R0);
   CompareClassId(CODE_REG, kCodeCid);
   b(&cid_ok, EQ);
   brk(0);
   Bind(&cid_ok);
 
   const intptr_t entry_offset =
       CodeSize() + Instructions::HeaderSize() - kHeapObjectTag;
@@ skipping 373 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