runtime/vm/flags.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_FLAGS_H_
#define VM_FLAGS_H_

#include "platform/assert.h"
#include "vm/globals.h"

typedef const char* charp;

#define DECLARE_FLAG(type, name)                                               \
  extern type FLAG_##name

#define DEFINE_FLAG(type, name, default_value, comment)                        \
  type FLAG_##name = Flags::Register_##type(&FLAG_##name,                      \
                                            #name,                             \
                                            default_value,                     \
                                            comment)

#define DEFINE_FLAG_HANDLER(handler, name, comment)                            \
  bool DUMMY_##name = Flags::Register_func(handler, #name, comment)


#if defined(DEBUG)
#define DECLARE_DEBUG_FLAG(type, name) DECLARE_FLAG(type, name)
#define DEFINE_DEBUG_FLAG(type, name, default_value, comment)                  \
  DEFINE_FLAG(type, name, default_value, comment)
#else
#define DECLARE_DEBUG_FLAG(type, name)
#define DEFINE_DEBUG_FLAG(type, name, default_value, comment)
#endif

namespace dart {

typedef void (*FlagHandler)(bool value);

// Forward declarations.
class Flag;
class JSONArray;
class JSONStream;

class Flags {
 public:
  static bool Register_bool(bool* addr,
                            const char* name,
                            bool default_value,
                            const char* comment);

  static int Register_int(int* addr,
                          const char* name,
                          int default_value,
                          const char* comment);

  static uint64_t Register_uint64_t(uint64_t* addr,
                                    const char* name,
                                    uint64_t default_value,
                                    const char* comment);

  static const char* Register_charp(charp* addr,
                                    const char* name,
                                    const char* default_value,
                                    const char* comment);

  static bool Register_func(FlagHandler handler,
                            const char* name,
                            const char* comment);

  static bool ProcessCommandLineFlags(int argc, const char** argv);

  static Flag* Lookup(const char* name);

  static bool IsSet(const char* name);

  static bool Initialized() { return initialized_; }

  static void PrintJSON(JSONStream* js);

  static bool SetFlag(const char* name,
                      const char* value,
                      const char** error);

 private:
  static Flag** flags_;
  static intptr_t capacity_;
  static intptr_t num_flags_;

  static bool initialized_;

  static void AddFlag(Flag* flag);

  static bool SetFlagFromString(Flag* flag, const char* argument);

  static void Parse(const char* option);

  static int CompareFlagNames(const void* left, const void* right);

  static void PrintFlags();

  static void PrintFlagToJSONArray(JSONArray* jsarr, const Flag* flag);

  // Testing needs direct access to private methods.
  friend void Dart_TestParseFlags();

  DISALLOW_ALLOCATION();
  DISALLOW_IMPLICIT_CONSTRUCTORS(Flags);
};

}  // namespace dart

#endif  // VM_FLAGS_H_