Encode any deoptimizer entry in serialized data.

src/snapshot/deserializer.cc

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/snapshot/deserializer.h"
 
 #include "src/api.h"
 #include "src/assembler-inl.h"
 #include "src/bootstrapper.h"
+#include "src/deoptimizer.h"
 #include "src/external-reference-table.h"
 #include "src/heap/heap-inl.h"
 #include "src/isolate.h"
 #include "src/macro-assembler.h"
 #include "src/objects-inl.h"
 #include "src/snapshot/natives.h"
 #include "src/v8.h"
 #include "src/v8threads.h"
 
 namespace v8 {
@@ skipping 705 matching lines @@
 #undef CASE_BODY
 #undef ALL_SPACES
 
       case kSkip: {
         int size = source_.GetInt();
         current = reinterpret_cast<Object**>(
             reinterpret_cast<intptr_t>(current) + size);
         break;
       }
 
+      case kDeoptimizerEntryFromCode:
+      case kDeoptimizerEntryPlain: {
+        int skip = source_.GetInt();
+        current = reinterpret_cast<Object**>(
+            reinterpret_cast<Address>(current) + skip);

[Yang, 2017/04/04 07:59:21]

Can we cast to intptr_t like everywhere else with skips?

[Slava Chigrin, 2017/04/04 10:12:24]

Done.

+        Deoptimizer::BailoutType bailout_type =
+            static_cast<Deoptimizer::BailoutType>(source_.Get());
+        int entry_id = source_.GetInt();
+        HandleScope scope(isolate);

[Yang, 2017/04/04 07:59:21]

why do we need a handlescope here?

[Slava Chigrin, 2017/04/04 10:12:24]

Deoptimizer::EnsureCodeForDeoptimizationEntry creates MacroAssembler object here

https://cs.chromium.org/chromium/src/v8/src/deoptimizer.cc?q=Deoptimizer::Ens...

and MacroAssembler constructor creates some handles here
https://cs.chromium.org/chromium/src/v8/src/x64/macro-assembler-x64.cc?l=37

so without HandleScope it does not work

+        Address address = Deoptimizer::GetDeoptimizationEntry(
+            isolate_, entry_id, bailout_type, Deoptimizer::ENSURE_ENTRY_CODE);
+        if (data == kDeoptimizerEntryFromCode) {
+          Address location_of_branch_data = reinterpret_cast<Address>(current);
+          Assembler::deserialization_set_special_target_at(
+              isolate, location_of_branch_data,
+              Code::cast(HeapObject::FromAddress(current_object_address)),
+              address);
+          location_of_branch_data += Assembler::kSpecialTargetSize;
+          current = reinterpret_cast<Object**>(location_of_branch_data);
+        } else {
+          Object* new_object = reinterpret_cast<Object*>(address);
+          UnalignedCopy(current, &new_object);
+          current++;
+        }
+        break;
+      }
+
       case kInternalReferenceEncoded:
       case kInternalReference: {
         // Internal reference address is not encoded via skip, but by offset
         // from code entry.
         int pc_offset = source_.GetInt();
         int target_offset = source_.GetInt();
         Code* code =
             Code::cast(HeapObject::FromAddress(current_object_address));
         DCHECK(0 <= pc_offset && pc_offset <= code->instruction_size());
         DCHECK(0 <= target_offset && target_offset <= code->instruction_size());
@@ skipping 145 matching lines @@
 
       default:
         CHECK(false);
     }
   }
   CHECK_EQ(limit, current);
   return true;
 }
 }  // namespace internal
 }  // namespace v8