Add deopt info to code object and print it

runtime/vm/deopt_instructions.h

Index: runtime/vm/deopt_instructions.h
===================================================================
--- runtime/vm/deopt_instructions.h	(revision 0)
+++ runtime/vm/deopt_instructions.h	(revision 0)
@@ -0,0 +1,86 @@
+// 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 {
+ protected:
+  enum Kind {
+    kReturnAddress,
+    kConstant,
+    kRegister,
+    kStackSlot,
+    kPcMarker,
+    kCallerFp,
+    kCallerPc,

[siva, 2012/08/04 01:21:50]

These names don't seem to convey the intent that the instruction is setting
something, how about
kSetRetAddress
kSetStackslot
kSetPCMarker
etc.

[srdjan, 2012/08/06 20:09:05]

Did a mixture of kSet and kCopy, e.g., kCopyRegister

+  };
+
+  DeoptInstr() {}
+
+  virtual DeoptInstr::Kind kind() const = 0;
+  virtual intptr_t from_index() const = 0;

[siva, 2012/08/04 01:21:50]

It seems too heavy weight to have these methods as virtual functions, why not
put the fields
intptr_t from_index_;
Kind kind;
here in the base class and call the base constructor
: DeoptInstr(kind, from_index) in the sub class constructors.

[srdjan, 2012/08/06 20:09:05]

Discussed and left it like that. Let's see once the copying code (instruction
'execution') is in if the virtual are justified (as I think they are).

+
+  friend class DeoptInfoBuilder;
+
+ public:
+  static DeoptInstr* Create(intptr_t kind_as_int, intptr_t from_index);
+
+  virtual const char* ToCString() const = 0;

[siva, 2012/08/04 01:21:50]

The public part should come first in the class right (per C++ coding style).

[srdjan, 2012/08/06 20:09:05]

Done.

+
+ 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' hold all objects referred to by DeoptInstr in

[siva, 2012/08/04 01:21:50]

holds

[srdjan, 2012/08/06 20:09:05]

Done.

+  // all of DeoptInfo instances for a single Code object.

[siva, 2012/08/04 01:21:50]

all the DeoptInfo instances ....

[srdjan, 2012/08/06 20:09:05]

Done.

+  DeoptInfoBuilder(GrowableArray<const Object*>* 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);
+  // Copy from optimized frame to unoptimized.
+  void AddCopy(const Location& loc, const Value& value);
+  void AddPcMarker(const Function& function);
+  void AddCallerFp();
+  void AddCallerPc();
+
+  RawDeoptInfo* CreateDeoptInfo();

[siva, 2012/08/04 01:21:50]

RawDeoptInfo* CreateDeoptInfo() const;

+
+ private:
+  intptr_t FindOrAddObjectInTable(const Object& obj) const;
+
+  GrowableArray<DeoptInstr*> instructions_;
+  GrowableArray<const Object*>* object_table_;
+  const intptr_t num_args_;
+
+  DISALLOW_COPY_AND_ASSIGN(DeoptInfoBuilder);
+};
+
+}  // namespace dart
+
+#endif  // VM_DEOPT_INSTRUCTIONS_H_
+