Fix for issues 6080 - pass in the Isolate's top context into the stub for invoking dart code from n…

runtime/vm/stack_frame_x64.cc

 // Copyright (c) 2012, 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"
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/instructions.h"
 #include "vm/isolate.h"
 #include "vm/stack_frame.h"
 
 namespace dart {
 
 // The constant kExitLinkOffsetInEntryFrame must be kept in sync with the
 // code in the InvokeDartCode stub.
+static const int kSavedContextOffsetInEntryFrame = -9 * kWordSize;
 static const int kExitLinkOffsetInEntryFrame = -8 * kWordSize;
 static const int kPcAddressOffsetFromSp = -1 * kWordSize;
 static const int kSpOffsetFromPreviousFp = 2 * kWordSize;
 
 
 intptr_t StackFrame::PcAddressOffsetFromSp() {
   return kPcAddressOffsetFromSp;
 }
 
 
 uword StackFrame::GetCallerSp() const {
   return fp() + kSpOffsetFromPreviousFp;
 }
 
 
 uword StackFrame::GetCallerFp() const {
   return *(reinterpret_cast<uword*>(fp()));
 }
 
 
-intptr_t EntryFrame::ExitLinkOffset() {
+intptr_t EntryFrame::ExitLinkOffset() const {
   return kExitLinkOffsetInEntryFrame;
 }
 
 
+intptr_t EntryFrame::SavedContextOffset() const {
+  return kSavedContextOffsetInEntryFrame;
+}
+
+
 void StackFrameIterator::SetupLastExitFrameData() {
   Isolate* current = Isolate::Current();
   uword exit_marker = current->top_exit_frame_info();
   frames_.fp_ = exit_marker;
 }
 
 
 void StackFrameIterator::SetupNextExitFrameData() {
   uword exit_address = entry_.fp() + kExitLinkOffsetInEntryFrame;
   uword exit_marker = *reinterpret_cast<uword*>(exit_address);
   frames_.fp_ = exit_marker;
   frames_.sp_ = 0;
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64