Add a helper function for allocation of deoptimization history.

runtime/vm/object.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/object.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/cpu.h"
@@ skipping 35 matching lines @@
     "instead of showing the corresponding interface names (e.g. \"String\")");
 DEFINE_FLAG(bool, trace_disabling_optimized_code, false,
     "Trace disabling optimized code.");
 DEFINE_FLAG(int, huge_method_cutoff_in_tokens, 20000,
     "Huge method cutoff in tokens: Disables optimizations for huge methods.");
 DEFINE_FLAG(int, huge_method_cutoff_in_code_size, 200000,
     "Huge method cutoff in unoptimized code size (in bytes).");
 DECLARE_FLAG(bool, trace_compiler);
 DECLARE_FLAG(bool, eliminate_type_checks);
 DECLARE_FLAG(bool, enable_type_checks);
+DECLARE_FLAG(int, deoptimization_counter_threshold);
 
 static const char* kGetterPrefix = "get:";
 static const intptr_t kGetterPrefixLength = strlen(kGetterPrefix);
 static const char* kSetterPrefix = "set:";
 static const intptr_t kSetterPrefixLength = strlen(kSetterPrefix);
 
 cpp_vtable Object::handle_vtable_ = 0;
 cpp_vtable Object::builtin_vtables_[kNumPredefinedCids] = { 0 };
 cpp_vtable Smi::handle_vtable_ = 0;
 
@@ skipping 3345 matching lines @@
 void Function::set_unoptimized_code(const Code& value) const {
   StorePointer(&raw_ptr()->unoptimized_code_, value.raw());
 }
 
 
 void Function::set_deopt_history(const Array& value) const {
   StorePointer(&raw_ptr()->deopt_history_, value.raw());
 }
 
 
+void Function::EnsureDeoptHistory() const {
+  Array& array = Array::Handle(deopt_history());
+  if (array.IsNull()) {
+    array = Array::New(FLAG_deoptimization_counter_threshold);
+    set_deopt_history(array);
+  }
+}
+
+
 RawContextScope* Function::context_scope() const {
   if (IsClosureFunction()) {
     const Object& obj = Object::Handle(raw_ptr()->data_);
     ASSERT(!obj.IsNull());
     return ClosureData::Cast(obj).context_scope();
   }
   return ContextScope::null();
 }
 
 
@@ skipping 9899 matching lines @@
   }
   return result.raw();
 }
 
 
 const char* WeakProperty::ToCString() const {
   return "_WeakProperty";
 }
 
 }  // namespace dart