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Diffstat (limited to 'include/ldap_cdefs.h')
| -rw-r--r-- | include/ldap_cdefs.h | 248 |
1 files changed, 248 insertions, 0 deletions
diff --git a/include/ldap_cdefs.h b/include/ldap_cdefs.h new file mode 100644 index 0000000..ae90ecc --- /dev/null +++ b/include/ldap_cdefs.h @@ -0,0 +1,248 @@ +/* $OpenLDAP$ */ +/* This work is part of OpenLDAP Software <http://www.openldap.org/>. + * + * Copyright 1998-2021 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 */ |