Apache Portable Runtime
usr
include
apr-1
apr_optional.h
Go to the documentation of this file.
1
/* Licensed to the Apache Software Foundation (ASF) under one or more
2
* contributor license agreements. See the NOTICE file distributed with
3
* this work for additional information regarding copyright ownership.
4
* The ASF licenses this file to You under the Apache License, Version 2.0
5
* (the "License"); you may not use this file except in compliance with
6
* the License. You may obtain a copy of the License at
7
*
8
* http://www.apache.org/licenses/LICENSE-2.0
9
*
10
* Unless required by applicable law or agreed to in writing, software
11
* distributed under the License is distributed on an "AS IS" BASIS,
12
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13
* See the License for the specific language governing permissions and
14
* limitations under the License.
15
*/
16
17
#ifndef APR_OPTIONAL_H
18
#define APR_OPTIONAL_H
19
20
#include "apu.h"
21
/**
22
* @file apr_optional.h
23
* @brief APR-UTIL registration of functions exported by modules
24
*/
25
#ifdef __cplusplus
26
extern
"C"
{
27
#endif
28
29
/**
30
* @defgroup APR_Util_Opt Optional Functions
31
* @ingroup APR_Util
32
*
33
* Typesafe registration and retrieval of functions that may not be present
34
* (i.e. functions exported by optional modules)
35
* @{
36
*/
37
38
/**
39
* The type of an optional function.
40
* @param name The name of the function
41
*/
42
#define APR_OPTIONAL_FN_TYPE(name) apr_OFN_##name##_t
43
44
/**
45
* Declare an optional function.
46
* @param ret The return type of the function
47
* @param name The name of the function
48
* @param args The function arguments (including brackets)
49
*/
50
#define APR_DECLARE_OPTIONAL_FN(ret,name,args) \
51
typedef ret (APR_OPTIONAL_FN_TYPE(name)) args
52
53
/**
54
* XXX: This doesn't belong here, then!
55
* Private function! DO NOT USE!
56
* @internal
57
*/
58
59
typedef
void (
apr_opt_fn_t
)(void);
60
/** @internal */
61
APU_DECLARE_NONSTD(
void
) apr_dynamic_fn_register(
const
char
*szName,
62
apr_opt_fn_t
*pfn);
63
64
/**
65
* Register an optional function. This can be later retrieved, type-safely, by
66
* name. Like all global functions, the name must be unique. Note that,
67
* confusingly but correctly, the function itself can be static!
68
* @param name The name of the function
69
*/
70
#define APR_REGISTER_OPTIONAL_FN(name) do { \
71
APR_OPTIONAL_FN_TYPE(name) *apu__opt = name; \
72
apr_dynamic_fn_register(#name,(apr_opt_fn_t *)apu__opt); \
73
} while (0)
74
75
/** @internal
76
* Private function! DO NOT USE!
77
*/
78
APU_DECLARE(
apr_opt_fn_t
*) apr_dynamic_fn_retrieve(
const
char
*szName);
79
80
/**
81
* Retrieve an optional function. Returns NULL if the function is not present.
82
* @param name The name of the function
83
*/
84
#define APR_RETRIEVE_OPTIONAL_FN(name) \
85
(APR_OPTIONAL_FN_TYPE(name) *)apr_dynamic_fn_retrieve(#name)
86
87
/** @} */
88
#ifdef __cplusplus
89
}
90
#endif
91
92
#endif
/* APR_OPTIONAL_H */
apr_opt_fn_t
void() apr_opt_fn_t(void)
Definition:
apr_optional.h:59
Generated by
1.8.17