[deliverable/binutils-gdb.git] / gdb / registry.h

/* Macros for general registry objects.

   Copyright (C) 2011-2020 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)					\
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 */
Commit	Line	Data
8e260fc0 TT	1	/* Macros for general registry objects.
8e260fc0 TT	2
11bc5fe4	3	Copyright (C) 2011-2020 Free Software Foundation, Inc.
8e260fc0 TT	4
	5	This file is part of GDB.
	6
	7	This program is free software; you can redistribute it and/or modify
	8	it under the terms of the GNU General Public License as published by
	9	the Free Software Foundation; either version 3 of the License, or
	10	(at your option) any later version.
	11
	12	This program is distributed in the hope that it will be useful,
	13	but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	GNU General Public License for more details.
	16
	17	You should have received a copy of the GNU General Public License
	18	along with this program. If not, see <http://www.gnu.org/licenses/>. */
	19
	20	#ifndef REGISTRY_H
	21	#define REGISTRY_H
	22
5f6e90a0 TT	23	#include <type_traits>
5f6e90a0 TT	24
8e260fc0 TT	25	/* The macros here implement a template type and functions for
	26	associating some user data with a container object.
	27
6b81941e TT	28	A registry is associated with a struct tag name. To attach a
	29	registry to a structure, use DEFINE_REGISTRY. This takes the
	30	structure tag and an access method as arguments. In the usual
	31	case, where the registry fields appear directly in the struct, you
	32	can use the 'REGISTRY_FIELDS' macro to declare the fields in the
	33	struct definition, and you can pass 'REGISTRY_ACCESS_FIELD' as the
	34	access argument to DEFINE_REGISTRY. In other cases, use
	35	REGISTRY_FIELDS to define the fields in the appropriate spot, and
	36	then define your own accessor to find the registry field structure
	37	given an instance of your type.
	38
8e260fc0 TT	39	The API user requests a key from a registry during gdb
	40	initialization. Later this key can be used to associate some
	41	module-specific data with a specific container object.
	42
8e260fc0 TT	43	The exported API is best used via the wrapper macros:
	44
	45	- register_TAG_data(TAG)
	46	Get a new key for the container type TAG.
	47
	48	- register_TAG_data_with_cleanup(TAG, SAVE, FREE)
	49	Get a new key for the container type TAG.
487ad57c YQ	50	SAVE and FREE are defined as void () (struct TAG object, void *data)
487ad57c YQ	51	When the container object OBJECT is destroyed, first all registered SAVE
8e260fc0 TT	52	functions are called.
8e260fc0 TT	53	Then all FREE functions are called.
487ad57c YQ	54	Either or both may be NULL. DATA is the data associated with the
487ad57c YQ	55	container object OBJECT.
8e260fc0 TT	56
	57	- clear_TAG_data(TAG, OBJECT)
	58	Clear all the data associated with OBJECT. Should be called by the
	59	container implementation when a container object is destroyed.
	60
	61	- set_TAG_data(TAG, OBJECT, KEY, DATA)
	62	Set the data on an object.
	63
	64	- TAG_data(TAG, OBJECT, KEY)
	65	Fetch the data for an object; returns NULL if it has not been set.
	66	*/
	67
6b81941e TT	68	/* This structure is used in a container to hold the data that the
	69	registry uses. */
	70
	71	struct registry_fields
	72	{
	73	void **data;
	74	unsigned num_data;
	75	};
	76
8e260fc0 TT	77	/* This macro is used in a container struct definition to define the
	78	fields used by the registry code. */
	79
	80	#define REGISTRY_FIELDS \
6b81941e TT	81	struct registry_fields registry_data
	82
	83	/* A convenience macro for the typical case where the registry data is
	84	kept as fields of the object. This can be passed as the ACCESS
	85	method to DEFINE_REGISTRY. */
	86
	87	#define REGISTRY_ACCESS_FIELD(CONTAINER) \
	88	(CONTAINER)
8e260fc0	89
aa0fbdd8 PA	90	/* Opaque type representing a container type with a registry. This
	91	type is never defined. This is used to factor out common
	92	functionality of all struct tag names into common code. IOW,
	93	"struct tag name" pointers are cast to and from "struct
	94	registry_container" pointers when calling the common registry
	95	"backend" functions. */
	96	struct registry_container;
	97
	98	/* Registry callbacks have this type. */
	99	typedef void (registry_data_callback) (struct registry_container , void *);
	100
	101	struct registry_data
	102	{
	103	unsigned index;
	104	registry_data_callback save;
	105	registry_data_callback free;
	106	};
	107
	108	struct registry_data_registration
	109	{
	110	struct registry_data *data;
	111	struct registry_data_registration *next;
	112	};
	113
	114	struct registry_data_registry
	115	{
	116	struct registry_data_registration *registrations;
	117	unsigned num_registrations;
	118	};
	119
	120	/* Registry backend functions. Client code uses the frontend
	121	functions defined by DEFINE_REGISTRY below instead. */
	122
	123	const struct registry_data *register_data_with_cleanup
	124	(struct registry_data_registry *registry,
	125	registry_data_callback save,
	126	registry_data_callback free);
	127
	128	void registry_alloc_data (struct registry_data_registry *registry,
	129	struct registry_fields *registry_fields);
	130
	131	/* Cast FUNC and CONTAINER to the real types, and call FUNC, also
	132	passing DATA. */
	133	typedef void (*registry_callback_adaptor) (registry_data_callback func,
	134	struct registry_container *container,
	135	void *data);
	136
	137	void registry_clear_data (struct registry_data_registry *data_registry,
	138	registry_callback_adaptor adaptor,
	139	struct registry_container *container,
	140	struct registry_fields *fields);
	141
	142	void registry_container_free_data (struct registry_data_registry *data_registry,
	143	registry_callback_adaptor adaptor,
	144	struct registry_container *container,
	145	struct registry_fields *fields);
	146
	147	void registry_set_data (struct registry_fields *fields,
	148	const struct registry_data *data,
	149	void *value);
	150
	151	void registry_data (struct registry_fields fields,
	152	const struct registry_data *data);
	153
8e260fc0 TT	154	/* Define a new registry implementation. */
8e260fc0 TT	155
6b81941e	156	#define DEFINE_REGISTRY(TAG, ACCESS) \
aa0fbdd8	157	struct registry_data_registry TAG ## _data_registry = { NULL, 0 }; \
8e260fc0 TT	158	\
	159	const struct TAG ## _data * \
	160	register_ ## TAG ## _data_with_cleanup (void (save) (struct TAG , void *), \
aa0fbdd8	161	void (free) (struct TAG , void *)) \
8e260fc0	162	{ \
aa0fbdd8 PA	163	return (struct TAG ## _data *) \
	164	register_data_with_cleanup (&TAG ## _data_registry, \
	165	(registry_data_callback) save, \
	166	(registry_data_callback) free); \
8e260fc0 TT	167	} \
	168	\
	169	const struct TAG ## _data * \
	170	register_ ## TAG ## _data (void) \
	171	{ \
	172	return register_ ## TAG ## _data_with_cleanup (NULL, NULL); \
	173	} \
	174	\
	175	static void \
	176	TAG ## _alloc_data (struct TAG *container) \
	177	{ \
6b81941e	178	struct registry_fields *rdata = &ACCESS (container)->registry_data; \
aa0fbdd8 PA	179	\
aa0fbdd8 PA	180	registry_alloc_data (&TAG ## _data_registry, rdata); \
8e260fc0 TT	181	} \
8e260fc0 TT	182	\
aa0fbdd8 PA	183	static void \
	184	TAG ## registry_callback_adaptor (registry_data_callback func, \
	185	struct registry_container *container, \
	186	void *data) \
8e260fc0	187	{ \
aa0fbdd8	188	struct TAG tagged_container = (struct TAG ) container; \
8e260fc0	189	\
aa0fbdd8 PA	190	registry_ ## TAG ## _callback tagged_func \
aa0fbdd8 PA	191	= (registry_ ## TAG ## _callback) func; \
8e260fc0	192	\
aa0fbdd8 PA	193	tagged_func (tagged_container, data); \
aa0fbdd8 PA	194	} \
8e260fc0	195	\
aa0fbdd8 PA	196	void \
	197	clear_ ## TAG ## _data (struct TAG *container) \
	198	{ \
	199	struct registry_fields *rdata = &ACCESS (container)->registry_data; \
8e260fc0	200	\
aa0fbdd8 PA	201	registry_clear_data (&TAG ## _data_registry, \
	202	TAG ## registry_callback_adaptor, \
	203	(struct registry_container *) container, \
	204	rdata); \
8e260fc0 TT	205	} \
	206	\
	207	static void \
	208	TAG ## _free_data (struct TAG *container) \
	209	{ \
6b81941e	210	struct registry_fields *rdata = &ACCESS (container)->registry_data; \
aa0fbdd8 PA	211	\
	212	registry_container_free_data (&TAG ## _data_registry, \
	213	TAG ## registry_callback_adaptor, \
	214	(struct registry_container *) container, \
	215	rdata); \
8e260fc0 TT	216	} \
	217	\
	218	void \
aa0fbdd8 PA	219	set_ ## TAG ## _data (struct TAG *container, \
	220	const struct TAG ## _data *data, \
	221	void *value) \
8e260fc0	222	{ \
6b81941e	223	struct registry_fields *rdata = &ACCESS (container)->registry_data; \
aa0fbdd8 PA	224	\
	225	registry_set_data (rdata, \
	226	(struct registry_data *) data, \
	227	value); \
8e260fc0 TT	228	} \
	229	\
	230	void * \
	231	TAG ## _data (struct TAG container, const struct TAG ## _data data) \
	232	{ \
6b81941e	233	struct registry_fields *rdata = &ACCESS (container)->registry_data; \
aa0fbdd8 PA	234	\
	235	return registry_data (rdata, \
	236	(struct registry_data *) data); \
8e260fc0 TT	237	}
	238
	239
	240	/* External declarations for the registry functions. */
	241
	242	#define DECLARE_REGISTRY(TAG) \
aa0fbdd8 PA	243	struct TAG ## _data; \
aa0fbdd8 PA	244	typedef void (registry_ ## TAG ## _callback) (struct TAG , void *); \
8e260fc0 TT	245	extern const struct TAG ## _data *register_ ## TAG ## _data (void); \
8e260fc0 TT	246	extern const struct TAG ## _data *register_ ## TAG ## _data_with_cleanup \
aa0fbdd8	247	(registry_ ## TAG ## _callback save, registry_ ## TAG ## _callback free); \
5f6e90a0 TT	248	extern void clear_ ## TAG ## _data (struct TAG *); \
	249	extern void set_ ## TAG ## _data (struct TAG *, \
	250	const struct TAG ## _data *data, \
	251	void *value); \
	252	extern void TAG ## _data (struct TAG , \
	253	const struct TAG ## _data *data); \
	254	\
	255	template<typename DATA, typename Deleter = std::default_delete<DATA>> \
	256	class TAG ## _key \
	257	{ \
	258	public: \
	259	\
	260	TAG ## _key () \
	261	: m_key (register_ ## TAG ## _data_with_cleanup (nullptr, \
	262	cleanup)) \
	263	{ \
	264	} \
	265	\
	266	DATA get (struct TAG obj) const \
	267	{ \
	268	return (DATA *) TAG ## _data (obj, m_key); \
	269	} \
	270	\
	271	void set (struct TAG obj, DATA data) const \
	272	{ \
	273	set_ ## TAG ## _data (obj, m_key, data); \
	274	} \
	275	\
	276	template<typename Dummy = DATA *, typename... Args> \
	277	typename std::enable_if<std::is_same<Deleter, \
	278	std::default_delete<DATA>>::value, \
	279	Dummy>::type \
	280	emplace (struct TAG *obj, Args &&...args) const \
	281	{ \
	282	DATA *result = new DATA (std::forward<Args> (args)...); \
	283	set (obj, result); \
	284	return result; \
	285	} \
	286	\
	287	void clear (struct TAG *obj) const \
	288	{ \
	289	DATA *datum = get (obj); \
	290	if (datum != nullptr) \
	291	{ \
	292	cleanup (obj, datum); \
	293	set (obj, nullptr); \
	294	} \
	295	} \
	296	\
	297	private: \
	298	\
	299	static void cleanup (struct TAG obj, void arg) \
	300	{ \
	301	DATA datum = (DATA ) arg; \
	302	Deleter d; \
	303	d (datum); \
	304	} \
	305	\
	306	const struct TAG ## _data *m_key; \
	307	};
8e260fc0 TT	308
8e260fc0 TT	309	#endif /* REGISTRY_H */