Encode any deoptimizer entry in serialized data.

src/snapshot/deserializer.cc

Index: src/snapshot/deserializer.cc
diff --git a/src/snapshot/deserializer.cc b/src/snapshot/deserializer.cc
index b74b10b7eff9108d8c2c05cebd1b746f1b6caaf7..5ec265bd74458d1cd275fc65954073b67374cae9 100644
--- a/src/snapshot/deserializer.cc
+++ b/src/snapshot/deserializer.cc
@@ -7,6 +7,7 @@
 #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"
@@ -732,6 +733,33 @@ bool Deserializer::ReadData(Object** current, Object** limit, int source_space,
         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