Add a type-safe C++ interface to a registry

This changes DECLARE_REGISTRY to add a type-safe interface.  This
interface is a C++ class that handles the details of registering a
key, and provides various useful methods, including policy-based
cleanup.

gdb/ChangeLog
2019-05-08  Tom Tromey  <tom@tromey.com>

	* registry.h (DECLARE_REGISTRY): Define the _key class.
This commit is contained in:
Tom Tromey 2019-04-09 20:21:06 -06:00
parent 1bd0c6e496
commit 5f6e90a0ce
2 changed files with 66 additions and 6 deletions

View File

@ -1,3 +1,7 @@
2019-05-08 Tom Tromey <tom@tromey.com>
* registry.h (DECLARE_REGISTRY): Define the _key class.
2019-05-08 Andrew Burgess <andrew.burgess@embecosm.com>
* NEWS: Merge two 'New commands' sections.

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@ -20,6 +20,8 @@
#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.
@ -243,11 +245,65 @@ 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);
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 */