Lazy deopt:

runtime/vm/stack_frame.h

 // Copyright (c) 2011, 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.
 
 #ifndef VM_STACK_FRAME_H_
 #define VM_STACK_FRAME_H_
 
 #include "vm/allocation.h"
 #include "vm/object.h"
 #include "vm/stub_code.h"
@@ skipping 33 matching lines @@
 
   // The pool pointer is not implemented on all architectures.
   static int SavedCallerPpSlotFromFp() {
     if (kSavedCallerPpSlotFromFp != kSavedCallerFpSlotFromFp) {
       return kSavedCallerPpSlotFromFp;
     }
     UNREACHABLE();
     return 0;
   }
 
+  uword IsMarkedForLazyDeopt() const {
+    uword raw_pc = *reinterpret_cast<uword*>(
+        sp() + (kSavedPcSlotFromSp * kWordSize));
+    return raw_pc == StubCode::DeoptimizeLazyFromReturn_entry()->EntryPoint();
+  }
+  void MarkForLazyDeopt() {
+    set_pc(StubCode::DeoptimizeLazyFromReturn_entry()->EntryPoint());
+  }
+  void UnmarkForLazyDeopt() {

[Florian Schneider, 2016/10/04 21:32:41]

This reads a little weird: Maybe comment that pc_ is computed by consulting the
pending deopt table if necessary. Or can you use GetCallerPc directly here?

ASSERT(pc() != StubCode::DeoptimizeLazyFromReturn_entry()->EntryPoint());

[rmacnak, 2016/10/04 22:11:28]

Added comment and assert.  Can't use GetCallerPc here; pc_ in this frame came
from GetCallerPc on the callee frame in the iterator.

+    set_pc(pc());
+  }
+
   void set_pc(uword value) {
     *reinterpret_cast<uword*>(sp() + (kSavedPcSlotFromSp * kWordSize)) = value;
     pc_ = value;
   }
 
   void set_pc_marker(RawCode* code) {
     *reinterpret_cast<RawCode**>(fp() + (kPcMarkerSlotFromFp * kWordSize)) =
         code;
   }
 
@@ skipping 291 matching lines @@
   TypedData& deopt_info_;
   Function& function_;
   uword pc_;
   GrowableArray<DeoptInstr*> deopt_instructions_;
   ObjectPool& object_table_;
 
   DISALLOW_COPY_AND_ASSIGN(InlinedFunctionsIterator);
 };
 
 
+void ValidateFrames();

[Florian Schneider, 2016/10/04 21:32:41]

#ifdef DEBUG

[rmacnak, 2016/10/04 22:11:28]

Done.

+
+
 #if !defined(TARGET_ARCH_DBC)
 DART_FORCE_INLINE static intptr_t LocalVarIndex(intptr_t fp_offset,
                                                 intptr_t var_index) {
   return fp_offset + var_index;
 }
 
 
 DART_FORCE_INLINE static uword ParamAddress(uword fp, intptr_t reverse_index) {
   return fp + (kParamEndSlotFromFp * kWordSize) + (reverse_index * kWordSize);
 }
@@ skipping 11 matching lines @@
 
 
 DART_FORCE_INLINE static uword LocalVarAddress(uword fp, intptr_t index) {
   return fp + LocalVarIndex(0, index) * kWordSize;
 }
 
 
 }  // namespace dart
 
 #endif  // VM_STACK_FRAME_H_