Add deopt info to code object and print it

runtime/vm/deopt_instructions.h

+// 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.
+
+#ifndef VM_DEOPT_INSTRUCTIONS_H_
+#define VM_DEOPT_INSTRUCTIONS_H_
+
+#include "vm/allocation.h"
+#include "vm/growable_array.h"
+#include "vm/object.h"
+
+namespace dart {
+
+class Location;
+class Value;
+
+// Represents one deopt instruction, e.g, setup return address, store object,
+// store register, etc. The target is defined by instruction's position in
+// the deopt-info array.
+class DeoptInstr : public ZoneAllocated {
+ public:
+  static DeoptInstr* Create(intptr_t kind_as_int, intptr_t from_index);
+
+  virtual const char* ToCString() const = 0;
+
+ protected:
+  enum Kind {
+    kSetRetAddress,
+    kCopyConstant,
+    kCopyRegister,
+    kCopyStackSlot,
+    kSetPcMarker,
+    kSetCallerFp,
+    kSetCallerPc,
+  };
+
+  DeoptInstr() {}
+
+  virtual DeoptInstr::Kind kind() const = 0;
+  virtual intptr_t from_index() const = 0;
+
+  friend class DeoptInfoBuilder;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(DeoptInstr);
+};
+
+
+
+// Builds one instance of DeoptInfo. Call AddXXX methods in the order of
+// their target, starting wih deoptimized code continuation pc and ending with
+// the first argument of the deoptimized code.
+class DeoptInfoBuilder : public ValueObject {
+ public:
+  // 'object_table' holds all objects referred to by DeoptInstr in
+  // all DeoptInfo instances for a single Code object.
+  DeoptInfoBuilder(const GrowableObjectArray& object_table,
+                   const intptr_t num_args)
+      : instructions_(),
+        object_table_(object_table),
+        num_args_(num_args) {}
+
+  // Will be neeeded for inlined functions, currently trivial.
+  void AddReturnAddress(const Function& function,
+                        intptr_t deopt_id,
+                        intptr_t to_index);
+  // Copy from optimized frame to unoptimized.
+  void AddCopy(const Location& from_loc,
+               const Value& from_value,
+               intptr_t to_index);
+  void AddPcMarker(const Function& function, intptr_t to_index);
+  void AddCallerFp(intptr_t to_index);
+  void AddCallerPc(intptr_t to_index);
+
+  RawDeoptInfo* CreateDeoptInfo() const;
+
+ private:
+  intptr_t FindOrAddObjectInTable(const Object& obj) const;
+
+  GrowableArray<DeoptInstr*> instructions_;
+  const GrowableObjectArray& object_table_;
+  const intptr_t num_args_;
+
+  DISALLOW_COPY_AND_ASSIGN(DeoptInfoBuilder);
+};
+
+}  // namespace dart
+
+#endif  // VM_DEOPT_INSTRUCTIONS_H_
+