Pass new pool pointer to the JumpToException stub instead of reloading in through the frame's Code …

runtime/vm/simulator_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 <setjmp.h>  // NOLINT
 #include <stdlib.h>
 
 #include "vm/globals.h"
 #if defined(TARGET_ARCH_ARM64)
 
@@ skipping 3557 matching lines @@
   } else {
     return_value = get_register(R0);
   }
   return return_value;
 }
 
 
 void Simulator::Longjmp(uword pc,
                         uword sp,
                         uword fp,
+                        uword pp,
                         RawObject* raw_exception,
                         RawObject* raw_stacktrace,
                         Thread* thread) {
   // Walk over all setjmp buffers (simulated --> C++ transitions)
   // and try to find the setjmp associated with the simulated stack pointer.
   SimulatorSetjmpBuffer* buf = last_setjmp_buffer();
   while (buf->link() != NULL && buf->link()->sp() <= sp) {
     buf = buf->link();
   }
   ASSERT(buf != NULL);
 
   // The C++ caller has not cleaned up the stack memory of C++ frames.
   // Prepare for unwinding frames by destroying all the stack resources
   // in the previous C++ frames.
   StackResource::Unwind(thread);
 
   // Unwind the C++ stack and continue simulation in the target frame.
   set_pc(static_cast<int64_t>(pc));
   set_register(NULL, SP, static_cast<int64_t>(sp));
   set_register(NULL, FP, static_cast<int64_t>(fp));
+  // In the PP register, the pool pointer is untagged.
+  set_register(NULL, PP, static_cast<int64_t>(pp) - kHeapObjectTag);
   set_register(NULL, THR, reinterpret_cast<int64_t>(thread));
   // Set the tag.
   thread->set_vm_tag(VMTag::kDartTagId);
   // Clear top exit frame.
   thread->set_top_exit_frame_info(0);
 
   ASSERT(raw_exception != Object::null());
   set_register(NULL, kExceptionObjectReg, bit_cast<int64_t>(raw_exception));
   set_register(NULL, kStackTraceObjectReg, bit_cast<int64_t>(raw_stacktrace));
-  // Restore pool pointer.
-  int64_t code = *reinterpret_cast<int64_t*>(
-      fp + kPcMarkerSlotFromFp * kWordSize);
-  int64_t pp = *reinterpret_cast<int64_t*>(
-      code + Code::object_pool_offset() - kHeapObjectTag);
-  pp -= kHeapObjectTag;  // In the PP register, the pool pointer is untagged.
-  set_register(NULL, CODE_REG, code);
-  set_register(NULL, PP, pp);
   buf->Longjmp();
 }
 
 }  // namespace dart
 
 #endif  // !defined(USING_SIMULATOR)
 
 #endif  // defined TARGET_ARCH_ARM64