summaryrefslogtreecommitdiffstats
path: root/include/ldap_cdefs.h
blob: 79823d2dcecc05f64f52d2da109303ee8a25fc0d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
/* $OpenLDAP$ */
/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
 * 
 * Copyright 1998-2018 The OpenLDAP Foundation.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted only as authorized by the OpenLDAP
 * Public License.
 *
 * A copy of this license is available in file LICENSE in the
 * top-level directory of the distribution or, alternatively, at
 * <http://www.OpenLDAP.org/license.html>.
 */
/* LDAP C Defines */

#ifndef _LDAP_CDEFS_H
#define _LDAP_CDEFS_H

#if defined(__cplusplus) || defined(c_plusplus)
#	define LDAP_BEGIN_DECL	extern "C" {
#	define LDAP_END_DECL	}
#else
#	define LDAP_BEGIN_DECL	/* begin declarations */
#	define LDAP_END_DECL	/* end declarations */
#endif

#if !defined(LDAP_NO_PROTOTYPES) && ( defined(LDAP_NEEDS_PROTOTYPES) || \
	defined(__STDC__) || defined(__cplusplus) || defined(c_plusplus) )

	/* ANSI C or C++ */
#	define LDAP_P(protos)	protos
#	define LDAP_CONCAT1(x,y)	x ## y
#	define LDAP_CONCAT(x,y)	LDAP_CONCAT1(x,y)
#	define LDAP_STRING(x)	#x /* stringify without expanding x */
#	define LDAP_XSTRING(x)	LDAP_STRING(x) /* expand x, then stringify */

#ifndef LDAP_CONST
#	define LDAP_CONST	const
#endif

#else /* no prototypes */

	/* traditional C */
#	define LDAP_P(protos)	()
#	define LDAP_CONCAT(x,y)	x/**/y
#	define LDAP_STRING(x)	"x"

#ifndef LDAP_CONST
#	define LDAP_CONST	/* no const */
#endif

#endif /* no prototypes */

#if (__GNUC__) * 1000 + (__GNUC_MINOR__) >= 2006
#	define LDAP_GCCATTR(attrs)	__attribute__(attrs)
#else
#	define LDAP_GCCATTR(attrs)
#endif

/*
 * Support for Windows DLLs.
 *
 * When external source code includes header files for dynamic libraries,
 * the external source code is "importing" DLL symbols into its resulting
 * object code. On Windows, symbols imported from DLLs must be explicitly
 * indicated in header files with the __declspec(dllimport) directive.
 * This is not totally necessary for functions because the compiler
 * (gcc or MSVC) will generate stubs when this directive is absent.
 * However, this is required for imported variables.
 *
 * The LDAP libraries, i.e. liblber and libldap, can be built as
 * static or shared, based on configuration. Just about all other source
 * code in OpenLDAP use these libraries. If the LDAP libraries
 * are configured as shared, 'configure' defines the LDAP_LIBS_DYNAMIC
 * macro. When other source files include LDAP library headers, the
 * LDAP library symbols will automatically be marked as imported. When
 * the actual LDAP libraries are being built, the symbols will not
 * be marked as imported because the LBER_LIBRARY or LDAP_LIBRARY macros
 * will be respectively defined.
 *
 * Any project outside of OpenLDAP with source code wanting to use
 * LDAP dynamic libraries should explicitly define LDAP_LIBS_DYNAMIC.
 * This will ensure that external source code appropriately marks symbols
 * that will be imported.
 *
 * The slapd executable, itself, can be used as a dynamic library.
 * For example, if a backend module is compiled as shared, it will
 * import symbols from slapd. When this happens, the slapd symbols
 * must be marked as imported in header files that the backend module
 * includes. Remember that slapd links with various static libraries.
 * If the LDAP libraries were configured as static, their object
 * code is also part of the monolithic slapd executable. Thus, when
 * a backend module imports symbols from slapd, it imports symbols from
 * all of the static libraries in slapd as well. Thus, the SLAP_IMPORT
 * macro, when defined, will appropriately mark symbols as imported.
 * This macro should be used by shared backend modules as well as any
 * other external source code that imports symbols from the slapd
 * executable as if it were a DLL.
 *
 * Note that we don't actually have to worry about using the
 * __declspec(dllexport) directive anywhere. This is because both
 * MSVC and Mingw provide alternate (more effective) methods for exporting
 * symbols out of binaries, i.e. the use of a DEF file.
 *
 * NOTE ABOUT BACKENDS: Backends can be configured as static or dynamic.
 * When a backend is configured as dynamic, slapd will load the backend
 * explicitly and populate function pointer structures by calling
 * the backend's well-known initialization function. Because of this
 * procedure, slapd never implicitly imports symbols from dynamic backends.
 * This makes it unnecessary to tag various backend functions with the
 * __declspec(dllimport) directive. This is because neither slapd nor
 * any other external binary should ever be implicitly loading a backend
 * dynamic module.
 *
 * Backends are supposed to be self-contained. However, it appears that
 * back-meta DOES implicitly import symbols from back-ldap. This means
 * that the __declspec(dllimport) directive should be marked on back-ldap
 * functions (in its header files) if and only if we're compiling for
 * windows AND back-ldap has been configured as dynamic AND back-meta
 * is the client of back-ldap. When client is slapd, there is no effect
 * since slapd does not implicitly import symbols.
 *
 * TODO(?): Currently, back-meta nor back-ldap is supported for Mingw32.
 * Thus, there's no need to worry about this right now. This is something that
 * may or may not have to be addressed in the future.
 */

/* LBER library */
#if defined(_WIN32) && \
    ((defined(LDAP_LIBS_DYNAMIC) && !defined(LBER_LIBRARY)) || \
     (!defined(LDAP_LIBS_DYNAMIC) && defined(SLAPD_IMPORT)))
#	define LBER_F(type)		extern __declspec(dllimport) type
#	define LBER_V(type)		extern __declspec(dllimport) type
#else
#	define LBER_F(type)		extern type
#	define LBER_V(type)		extern type
#endif

/* LDAP library */
#if defined(_WIN32) && \
    ((defined(LDAP_LIBS_DYNAMIC) && !defined(LDAP_LIBRARY)) || \
     (!defined(LDAP_LIBS_DYNAMIC) && defined(SLAPD_IMPORT)))
#	define LDAP_F(type)		extern __declspec(dllimport) type
#	define LDAP_V(type)		extern __declspec(dllimport) type
#else
#	define LDAP_F(type)		extern type
#	define LDAP_V(type)		extern type
#endif

/* AVL library */
#if defined(_WIN32) && defined(SLAPD_IMPORT)
#	define LDAP_AVL_F(type)		extern __declspec(dllimport) type
#	define LDAP_AVL_V(type)		extern __declspec(dllimport) type
#else
#	define LDAP_AVL_F(type)		extern type
#	define LDAP_AVL_V(type)		extern type
#endif

/* LDIF library */
#if defined(_WIN32) && defined(SLAPD_IMPORT)
#	define LDAP_LDIF_F(type)	extern __declspec(dllimport) type
#	define LDAP_LDIF_V(type)	extern __declspec(dllimport) type
#else
#	define LDAP_LDIF_F(type)	extern type
#	define LDAP_LDIF_V(type)	extern type
#endif

/* LUNICODE library */
#if defined(_WIN32) && defined(SLAPD_IMPORT)
#	define LDAP_LUNICODE_F(type)	extern __declspec(dllimport) type
#	define LDAP_LUNICODE_V(type)	extern __declspec(dllimport) type
#else
#	define LDAP_LUNICODE_F(type)	extern type
#	define LDAP_LUNICODE_V(type)	extern type
#endif

/* LUTIL library */
#if defined(_WIN32) && defined(SLAPD_IMPORT)
#	define LDAP_LUTIL_F(type)	extern __declspec(dllimport) type
#	define LDAP_LUTIL_V(type)	extern __declspec(dllimport) type
#else
#	define LDAP_LUTIL_F(type)	extern type
#	define LDAP_LUTIL_V(type)	extern type
#endif

/* REWRITE library */
#if defined(_WIN32) && defined(SLAPD_IMPORT)
#	define LDAP_REWRITE_F(type)	extern __declspec(dllimport) type
#	define LDAP_REWRITE_V(type)	extern __declspec(dllimport) type
#else
#	define LDAP_REWRITE_F(type)	extern type
#	define LDAP_REWRITE_V(type)	extern type
#endif

/* SLAPD (as a dynamic library exporting symbols) */
#if defined(_WIN32) && defined(SLAPD_IMPORT)
#	define LDAP_SLAPD_F(type)	extern __declspec(dllimport) type
#	define LDAP_SLAPD_V(type)	extern __declspec(dllimport) type
#else
#	define LDAP_SLAPD_F(type)	extern type
#	define LDAP_SLAPD_V(type)	extern type
#endif

/* SLAPD (as a dynamic library exporting symbols) */
#if defined(_WIN32) && defined(SLAPD_IMPORT)
#	define LDAP_SLAPI_F(type)	extern __declspec(dllimport) type
#	define LDAP_SLAPI_V(type)	extern __declspec(dllimport) type
#else
#	define LDAP_SLAPI_F(type)	extern type
#	define LDAP_SLAPI_V(type)	extern type
#endif

/* SLAPD (as a dynamic library exporting symbols) */
#if defined(_WIN32) && defined(SLAPD_IMPORT)
#	define SLAPI_F(type)		extern __declspec(dllimport) type
#	define SLAPI_V(type)		extern __declspec(dllimport) type
#else
#	define SLAPI_F(type)		extern type
#	define SLAPI_V(type)		extern type
#endif

/*
 * C library. Mingw32 links with the dynamic C run-time library by default,
 * so the explicit definition of CSTATIC will keep dllimport from
 * being defined, if desired.
 *
 * MSVC defines the _DLL macro when the compiler is invoked with /MD or /MDd,
 * which means the resulting object code will be linked with the dynamic
 * C run-time library.
 *
 * Technically, it shouldn't be necessary to redefine any functions that
 * the headers for the C library should already contain. Nevertheless, this
 * is here as a safe-guard.
 *
 * TODO: Determine if these macros ever get expanded for Windows. If not,
 * the declspec expansion can probably be removed.
 */
#if (defined(__MINGW32__) && !defined(CSTATIC)) || \
    (defined(_MSC_VER) && defined(_DLL))
#	define LDAP_LIBC_F(type)	extern __declspec(dllimport) type
#	define LDAP_LIBC_V(type)	extern __declspec(dllimport) type
#else
#	define LDAP_LIBC_F(type)	extern type
#	define LDAP_LIBC_V(type)	extern type
#endif

#endif /* _LDAP_CDEFS_H */