gdb/registry.h - binutils-gdb - Git at Google

 /* Macros for general registry objects.

    Copyright (C) 2011-2021 Free Software Foundation, Inc.

    This file is part of GDB.

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

 #ifndef REGISTRY_H
 #define REGISTRY_H

 #include <type_traits>

 /* The macros here implement a template type and functions for
    associating some user data with a container object.

    A registry is associated with a struct tag name.  To attach a
    registry to a structure, use DEFINE_REGISTRY.  This takes the
    structure tag and an access method as arguments.  In the usual
    case, where the registry fields appear directly in the struct, you
    can use the 'REGISTRY_FIELDS' macro to declare the fields in the
    struct definition, and you can pass 'REGISTRY_ACCESS_FIELD' as the
    access argument to DEFINE_REGISTRY.  In other cases, use
    REGISTRY_FIELDS to define the fields in the appropriate spot, and
    then define your own accessor to find the registry field structure
    given an instance of your type.

    The API user requests a key from a registry during gdb
    initialization.  Later this key can be used to associate some
    module-specific data with a specific container object.

    The exported API is best used via the wrapper macros:

    - register_TAG_data(TAG)
    Get a new key for the container type TAG.

    - register_TAG_data_with_cleanup(TAG, SAVE, FREE)
    Get a new key for the container type TAG.
    SAVE and FREE are defined as void (*) (struct TAG *object, void *data)
    When the container object OBJECT is destroyed, first all registered SAVE
    functions are called.
    Then all FREE functions are called.
    Either or both may be NULL.  DATA is the data associated with the
    container object OBJECT.

    - clear_TAG_data(TAG, OBJECT)
    Clear all the data associated with OBJECT.  Should be called by the
    container implementation when a container object is destroyed.

    - set_TAG_data(TAG, OBJECT, KEY, DATA)
    Set the data on an object.

    - TAG_data(TAG, OBJECT, KEY)
    Fetch the data for an object; returns NULL if it has not been set.
 */

 /* This structure is used in a container to hold the data that the
    registry uses.  */

 struct registry_fields
 {
   void **data;
   unsigned num_data;
 };

 /* This macro is used in a container struct definition to define the
    fields used by the registry code.  */

 #define REGISTRY_FIELDS				\
   struct registry_fields registry_data

 /* A convenience macro for the typical case where the registry data is
    kept as fields of the object.  This can be passed as the ACCESS
    method to DEFINE_REGISTRY.  */

 #define REGISTRY_ACCESS_FIELD(CONTAINER) \
   (CONTAINER)

 /* Opaque type representing a container type with a registry.  This
    type is never defined.  This is used to factor out common
    functionality of all struct tag names into common code.  IOW,
    "struct tag name" pointers are cast to and from "struct
    registry_container" pointers when calling the common registry
    "backend" functions.  */
 struct registry_container;

 /* Registry callbacks have this type.  */
 typedef void (*registry_data_callback) (struct registry_container *, void *);

 struct registry_data
 {
   unsigned index;
   registry_data_callback save;
   registry_data_callback free;
 };

 struct registry_data_registration
 {
   struct registry_data *data;
   struct registry_data_registration *next;
 };

 struct registry_data_registry
 {
   struct registry_data_registration *registrations;
   unsigned num_registrations;
 };

 /* Registry backend functions.  Client code uses the frontend
    functions defined by DEFINE_REGISTRY below instead.  */

 const struct registry_data *register_data_with_cleanup
   (struct registry_data_registry *registry,
    registry_data_callback save,
    registry_data_callback free);

 void registry_alloc_data (struct registry_data_registry *registry,
 			  struct registry_fields *registry_fields);

 /* Cast FUNC and CONTAINER to the real types, and call FUNC, also
    passing DATA.  */
 typedef void (*registry_callback_adaptor) (registry_data_callback func,
 					   struct registry_container *container,
 					   void *data);

 void registry_clear_data (struct registry_data_registry *data_registry,
 			  registry_callback_adaptor adaptor,
 			  struct registry_container *container,
 			  struct registry_fields *fields);

 void registry_container_free_data (struct registry_data_registry *data_registry,
 				   registry_callback_adaptor adaptor,
 				   struct registry_container *container,
 				   struct registry_fields *fields);

 void registry_set_data (struct registry_fields *fields,
 			const struct registry_data *data,
 			void *value);

 void *registry_data (struct registry_fields *fields,
 		     const struct registry_data *data);

 /* Define a new registry implementation.  */

 #define DEFINE_REGISTRY(TAG, ACCESS)					\
 static struct registry_data_registry TAG ## _data_registry = { NULL, 0 }; \
 									\
 const struct TAG ## _data *						\
 register_ ## TAG ## _data_with_cleanup (void (*save) (struct TAG *, void *), \
 					void (*free) (struct TAG *, void *)) \
 {									\
   return (struct TAG ## _data *)					\
     register_data_with_cleanup (&TAG ## _data_registry,			\
 				(registry_data_callback) save,		\
 				(registry_data_callback) free);		\
 }									\
 									\
 const struct TAG ## _data *						\
 register_ ## TAG ## _data (void)					\
 {									\
   return register_ ## TAG ## _data_with_cleanup (NULL, NULL);		\
 }									\
 									\
 static void								\
 TAG ## _alloc_data (struct TAG *container)				\
 {									\
   struct registry_fields *rdata = &ACCESS (container)->registry_data;	\
 									\
   registry_alloc_data (&TAG ## _data_registry, rdata);			\
 }									\
 									\
 static void								\
 TAG ## registry_callback_adaptor (registry_data_callback func,		\
 				  struct registry_container *container, \
 				  void *data)				\
 {									\
   struct TAG *tagged_container = (struct TAG *) container;		\
 									\
   registry_ ## TAG ## _callback tagged_func				\
     = (registry_ ## TAG ## _callback) func;				\
 									\
   tagged_func (tagged_container, data);					\
 }									\
 									\
 void									\
 clear_ ## TAG ## _data (struct TAG *container)				\
 {									\
   struct registry_fields *rdata = &ACCESS (container)->registry_data;	\
 									\
   registry_clear_data (&TAG ## _data_registry,				\
 		       TAG ## registry_callback_adaptor,		\
 		       (struct registry_container *) container,		\
 		       rdata);						\
 }									\
 									\
 static void								\
 TAG ## _free_data (struct TAG *container)				\
 {									\
   struct registry_fields *rdata = &ACCESS (container)->registry_data;	\
 									\
   registry_container_free_data (&TAG ## _data_registry,			\
 				TAG ## registry_callback_adaptor,	\
 				(struct registry_container *) container, \
 				rdata);					\
 }									\
 									\
 void									\
 set_ ## TAG ## _data (struct TAG *container,				\
 		      const struct TAG ## _data *data,			\
 		      void *value)					\
 {									\
   struct registry_fields *rdata = &ACCESS (container)->registry_data;	\
 									\
   registry_set_data (rdata,						\
 		     (struct registry_data *) data,			\
 		     value);						\
 }									\
 									\
 void *									\
 TAG ## _data (struct TAG *container, const struct TAG ## _data *data)	\
 {									\
   struct registry_fields *rdata = &ACCESS (container)->registry_data;	\
 									\
   return registry_data (rdata,						\
 			(struct registry_data *) data);			\
 }


 /* External declarations for the registry functions.  */

 #define DECLARE_REGISTRY(TAG)						\
 struct TAG ## _data;							\
 typedef void (*registry_ ## TAG ## _callback) (struct TAG *, void *);	\
 extern const struct TAG ## _data *register_ ## TAG ## _data (void);	\
 extern const struct TAG ## _data *register_ ## TAG ## _data_with_cleanup \
  (registry_ ## TAG ## _callback save, registry_ ## TAG ## _callback free); \
 extern void clear_ ## TAG ## _data (struct TAG *);			\
 extern void set_ ## TAG ## _data (struct TAG *,				\
 				  const struct TAG ## _data *data,	\
 				  void *value);				\
 extern void *TAG ## _data (struct TAG *,				\
 			   const struct TAG ## _data *data);		\
 									\
 template<typename DATA, typename Deleter = std::default_delete<DATA>>	\
 class TAG ## _key							\
 {									\
 public:									\
 									\
   TAG ## _key ()							\
     : m_key (register_ ## TAG ## _data_with_cleanup (nullptr,		\
 						     cleanup))		\
   {									\
   }									\
 									\
   DATA *get (struct TAG *obj) const					\
   {									\
     return (DATA *) TAG ## _data (obj, m_key);				\
   }									\
 									\
   void set (struct TAG *obj, DATA *data) const				\
   {									\
     set_ ## TAG ## _data (obj, m_key, data);				\
   }									\
 									\
   template<typename Dummy = DATA *, typename... Args>			\
   typename std::enable_if<std::is_same<Deleter,				\
 				       std::default_delete<DATA>>::value, \
 			  Dummy>::type					\
   emplace (struct TAG *obj, Args &&...args) const			\
   {									\
     DATA *result = new DATA (std::forward<Args> (args)...);		\
     set (obj, result);							\
     return result;							\
   }									\
 									\
   void clear (struct TAG *obj) const					\
   {									\
     DATA *datum = get (obj);						\
     if (datum != nullptr)						\
       {									\
 	cleanup (obj, datum);						\
 	set (obj, nullptr);						\
       }									\
   }									\
 									\
 private:								\
 									\
   static void cleanup (struct TAG *obj, void *arg)			\
   {									\
     DATA *datum = (DATA *) arg;						\
     Deleter d;								\
     d (datum);								\
   }									\
 									\
   const struct TAG ## _data *m_key;					\
 };

 #endif /* REGISTRY_H */
	/* Macros for general registry objects.

	Copyright (C) 2011-2021 Free Software Foundation, Inc.

	This file is part of GDB.

	This program is free software; you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation; either version 3 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program. If not, see <http://www.gnu.org/licenses/>. */

	#ifndef REGISTRY_H
	#define REGISTRY_H

	#include <type_traits>

	/* The macros here implement a template type and functions for
	associating some user data with a container object.

	A registry is associated with a struct tag name. To attach a
	registry to a structure, use DEFINE_REGISTRY. This takes the
	structure tag and an access method as arguments. In the usual
	case, where the registry fields appear directly in the struct, you
	can use the 'REGISTRY_FIELDS' macro to declare the fields in the
	struct definition, and you can pass 'REGISTRY_ACCESS_FIELD' as the
	access argument to DEFINE_REGISTRY. In other cases, use
	REGISTRY_FIELDS to define the fields in the appropriate spot, and
	then define your own accessor to find the registry field structure
	given an instance of your type.

	The API user requests a key from a registry during gdb
	initialization. Later this key can be used to associate some
	module-specific data with a specific container object.

	The exported API is best used via the wrapper macros:

	- register_TAG_data(TAG)
	Get a new key for the container type TAG.

	- register_TAG_data_with_cleanup(TAG, SAVE, FREE)
	Get a new key for the container type TAG.
	SAVE and FREE are defined as void () (struct TAG object, void *data)
	When the container object OBJECT is destroyed, first all registered SAVE
	functions are called.
	Then all FREE functions are called.
	Either or both may be NULL. DATA is the data associated with the
	container object OBJECT.

	- clear_TAG_data(TAG, OBJECT)
	Clear all the data associated with OBJECT. Should be called by the
	container implementation when a container object is destroyed.

	- set_TAG_data(TAG, OBJECT, KEY, DATA)
	Set the data on an object.

	- TAG_data(TAG, OBJECT, KEY)
	Fetch the data for an object; returns NULL if it has not been set.
	*/

	/* This structure is used in a container to hold the data that the
	registry uses. */

	struct registry_fields
	{
	void **data;
	unsigned num_data;
	};

	/* This macro is used in a container struct definition to define the
	fields used by the registry code. */

	#define REGISTRY_FIELDS \
	struct registry_fields registry_data

	/* A convenience macro for the typical case where the registry data is
	kept as fields of the object. This can be passed as the ACCESS
	method to DEFINE_REGISTRY. */

	#define REGISTRY_ACCESS_FIELD(CONTAINER) \
	(CONTAINER)

	/* Opaque type representing a container type with a registry. This
	type is never defined. This is used to factor out common
	functionality of all struct tag names into common code. IOW,
	"struct tag name" pointers are cast to and from "struct
	registry_container" pointers when calling the common registry
	"backend" functions. */
	struct registry_container;

	/* Registry callbacks have this type. */
	typedef void (registry_data_callback) (struct registry_container , void *);

	struct registry_data
	{
	unsigned index;
	registry_data_callback save;
	registry_data_callback free;
	};

	struct registry_data_registration
	{
	struct registry_data *data;
	struct registry_data_registration *next;
	};

	struct registry_data_registry
	{
	struct registry_data_registration *registrations;
	unsigned num_registrations;
	};

	/* Registry backend functions. Client code uses the frontend
	functions defined by DEFINE_REGISTRY below instead. */

	const struct registry_data *register_data_with_cleanup
	(struct registry_data_registry *registry,
	registry_data_callback save,
	registry_data_callback free);

	void registry_alloc_data (struct registry_data_registry *registry,
	struct registry_fields *registry_fields);

	/* Cast FUNC and CONTAINER to the real types, and call FUNC, also
	passing DATA. */
	typedef void (*registry_callback_adaptor) (registry_data_callback func,
	struct registry_container *container,
	void *data);

	void registry_clear_data (struct registry_data_registry *data_registry,
	registry_callback_adaptor adaptor,
	struct registry_container *container,
	struct registry_fields *fields);

	void registry_container_free_data (struct registry_data_registry *data_registry,
	registry_callback_adaptor adaptor,
	struct registry_container *container,
	struct registry_fields *fields);

	void registry_set_data (struct registry_fields *fields,
	const struct registry_data *data,
	void *value);

	void registry_data (struct registry_fields fields,
	const struct registry_data *data);

	/* Define a new registry implementation. */

	#define DEFINE_REGISTRY(TAG, ACCESS) \
	static struct registry_data_registry TAG ## _data_registry = { NULL, 0 }; \
	\
	const struct TAG ## _data * \
	register_ ## TAG ## _data_with_cleanup (void (save) (struct TAG , void *), \
	void (free) (struct TAG , void *)) \
	{ \
	return (struct TAG ## _data *) \
	register_data_with_cleanup (&TAG ## _data_registry, \
	(registry_data_callback) save, \
	(registry_data_callback) free); \
	} \
	\
	const struct TAG ## _data * \
	register_ ## TAG ## _data (void) \
	{ \
	return register_ ## TAG ## _data_with_cleanup (NULL, NULL); \
	} \
	\
	static void \
	TAG ## _alloc_data (struct TAG *container) \
	{ \
	struct registry_fields *rdata = &ACCESS (container)->registry_data; \
	\
	registry_alloc_data (&TAG ## _data_registry, rdata); \
	} \
	\
	static void \
	TAG ## registry_callback_adaptor (registry_data_callback func, \
	struct registry_container *container, \
	void *data) \
	{ \
	struct TAG tagged_container = (struct TAG ) container; \
	\
	registry_ ## TAG ## _callback tagged_func \
	= (registry_ ## TAG ## _callback) func; \
	\
	tagged_func (tagged_container, data); \
	} \
	\
	void \
	clear_ ## TAG ## _data (struct TAG *container) \
	{ \
	struct registry_fields *rdata = &ACCESS (container)->registry_data; \
	\
	registry_clear_data (&TAG ## _data_registry, \
	TAG ## registry_callback_adaptor, \
	(struct registry_container *) container, \
	rdata); \
	} \
	\
	static void \
	TAG ## _free_data (struct TAG *container) \
	{ \
	struct registry_fields *rdata = &ACCESS (container)->registry_data; \
	\
	registry_container_free_data (&TAG ## _data_registry, \
	TAG ## registry_callback_adaptor, \
	(struct registry_container *) container, \
	rdata); \
	} \
	\
	void \
	set_ ## TAG ## _data (struct TAG *container, \
	const struct TAG ## _data *data, \
	void *value) \
	{ \
	struct registry_fields *rdata = &ACCESS (container)->registry_data; \
	\
	registry_set_data (rdata, \
	(struct registry_data *) data, \
	value); \
	} \
	\
	void * \
	TAG ## _data (struct TAG container, const struct TAG ## _data data) \
	{ \
	struct registry_fields *rdata = &ACCESS (container)->registry_data; \
	\
	return registry_data (rdata, \
	(struct registry_data *) data); \
	}


	/* External declarations for the registry functions. */

	#define DECLARE_REGISTRY(TAG) \
	struct TAG ## _data; \
	typedef void (registry_ ## TAG ## _callback) (struct TAG , void *); \
	extern const struct TAG ## _data *register_ ## TAG ## _data (void); \
	extern const struct TAG ## _data *register_ ## TAG ## _data_with_cleanup \
	(registry_ ## TAG ## _callback save, registry_ ## TAG ## _callback free); \
	extern void clear_ ## TAG ## _data (struct TAG *); \
	extern void set_ ## TAG ## _data (struct TAG *, \
	const struct TAG ## _data *data, \
	void *value); \
	extern void TAG ## _data (struct TAG , \
	const struct TAG ## _data *data); \
	\
	template<typename DATA, typename Deleter = std::default_delete<DATA>> \
	class TAG ## _key \
	{ \
	public: \
	\
	TAG ## _key () \
	: m_key (register_ ## TAG ## _data_with_cleanup (nullptr, \
	cleanup)) \
	{ \
	} \
	\
	DATA get (struct TAG obj) const \
	{ \
	return (DATA *) TAG ## _data (obj, m_key); \
	} \
	\
	void set (struct TAG obj, DATA data) const \
	{ \
	set_ ## TAG ## _data (obj, m_key, data); \
	} \
	\
	template<typename Dummy = DATA *, typename... Args> \
	typename std::enable_if<std::is_same<Deleter, \
	std::default_delete<DATA>>::value, \
	Dummy>::type \
	emplace (struct TAG *obj, Args &&...args) const \
	{ \
	DATA *result = new DATA (std::forward<Args> (args)...); \
	set (obj, result); \
	return result; \
	} \
	\
	void clear (struct TAG *obj) const \
	{ \
	DATA *datum = get (obj); \
	if (datum != nullptr) \
	{ \
	cleanup (obj, datum); \
	set (obj, nullptr); \
	} \
	} \
	\
	private: \
	\
	static void cleanup (struct TAG obj, void arg) \
	{ \
	DATA datum = (DATA ) arg; \
	Deleter d; \
	d (datum); \
	} \
	\
	const struct TAG ## _data *m_key; \
	};

	#endif /* REGISTRY_H */