mirror of
https://git.savannah.gnu.org/git/emacs.git
synced 2024-12-26 10:49:33 +00:00
272 lines
12 KiB
C++
272 lines
12 KiB
C++
/* C++ compatible function declaration macros.
|
|
Copyright (C) 2010-2011 Free Software Foundation, Inc.
|
|
|
|
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 _GL_CXXDEFS_H
|
|
#define _GL_CXXDEFS_H
|
|
|
|
/* The three most frequent use cases of these macros are:
|
|
|
|
* For providing a substitute for a function that is missing on some
|
|
platforms, but is declared and works fine on the platforms on which
|
|
it exists:
|
|
|
|
#if @GNULIB_FOO@
|
|
# if !@HAVE_FOO@
|
|
_GL_FUNCDECL_SYS (foo, ...);
|
|
# endif
|
|
_GL_CXXALIAS_SYS (foo, ...);
|
|
_GL_CXXALIASWARN (foo);
|
|
#elif defined GNULIB_POSIXCHECK
|
|
...
|
|
#endif
|
|
|
|
* For providing a replacement for a function that exists on all platforms,
|
|
but is broken/insufficient and needs to be replaced on some platforms:
|
|
|
|
#if @GNULIB_FOO@
|
|
# if @REPLACE_FOO@
|
|
# if !(defined __cplusplus && defined GNULIB_NAMESPACE)
|
|
# undef foo
|
|
# define foo rpl_foo
|
|
# endif
|
|
_GL_FUNCDECL_RPL (foo, ...);
|
|
_GL_CXXALIAS_RPL (foo, ...);
|
|
# else
|
|
_GL_CXXALIAS_SYS (foo, ...);
|
|
# endif
|
|
_GL_CXXALIASWARN (foo);
|
|
#elif defined GNULIB_POSIXCHECK
|
|
...
|
|
#endif
|
|
|
|
* For providing a replacement for a function that exists on some platforms
|
|
but is broken/insufficient and needs to be replaced on some of them and
|
|
is additionally either missing or undeclared on some other platforms:
|
|
|
|
#if @GNULIB_FOO@
|
|
# if @REPLACE_FOO@
|
|
# if !(defined __cplusplus && defined GNULIB_NAMESPACE)
|
|
# undef foo
|
|
# define foo rpl_foo
|
|
# endif
|
|
_GL_FUNCDECL_RPL (foo, ...);
|
|
_GL_CXXALIAS_RPL (foo, ...);
|
|
# else
|
|
# if !@HAVE_FOO@ or if !@HAVE_DECL_FOO@
|
|
_GL_FUNCDECL_SYS (foo, ...);
|
|
# endif
|
|
_GL_CXXALIAS_SYS (foo, ...);
|
|
# endif
|
|
_GL_CXXALIASWARN (foo);
|
|
#elif defined GNULIB_POSIXCHECK
|
|
...
|
|
#endif
|
|
*/
|
|
|
|
/* _GL_EXTERN_C declaration;
|
|
performs the declaration with C linkage. */
|
|
#if defined __cplusplus
|
|
# define _GL_EXTERN_C extern "C"
|
|
#else
|
|
# define _GL_EXTERN_C extern
|
|
#endif
|
|
|
|
/* _GL_FUNCDECL_RPL (func, rettype, parameters_and_attributes);
|
|
declares a replacement function, named rpl_func, with the given prototype,
|
|
consisting of return type, parameters, and attributes.
|
|
Example:
|
|
_GL_FUNCDECL_RPL (open, int, (const char *filename, int flags, ...)
|
|
_GL_ARG_NONNULL ((1)));
|
|
*/
|
|
#define _GL_FUNCDECL_RPL(func,rettype,parameters_and_attributes) \
|
|
_GL_FUNCDECL_RPL_1 (rpl_##func, rettype, parameters_and_attributes)
|
|
#define _GL_FUNCDECL_RPL_1(rpl_func,rettype,parameters_and_attributes) \
|
|
_GL_EXTERN_C rettype rpl_func parameters_and_attributes
|
|
|
|
/* _GL_FUNCDECL_SYS (func, rettype, parameters_and_attributes);
|
|
declares the system function, named func, with the given prototype,
|
|
consisting of return type, parameters, and attributes.
|
|
Example:
|
|
_GL_FUNCDECL_SYS (open, int, (const char *filename, int flags, ...)
|
|
_GL_ARG_NONNULL ((1)));
|
|
*/
|
|
#define _GL_FUNCDECL_SYS(func,rettype,parameters_and_attributes) \
|
|
_GL_EXTERN_C rettype func parameters_and_attributes
|
|
|
|
/* _GL_CXXALIAS_RPL (func, rettype, parameters);
|
|
declares a C++ alias called GNULIB_NAMESPACE::func
|
|
that redirects to rpl_func, if GNULIB_NAMESPACE is defined.
|
|
Example:
|
|
_GL_CXXALIAS_RPL (open, int, (const char *filename, int flags, ...));
|
|
*/
|
|
#define _GL_CXXALIAS_RPL(func,rettype,parameters) \
|
|
_GL_CXXALIAS_RPL_1 (func, rpl_##func, rettype, parameters)
|
|
#if defined __cplusplus && defined GNULIB_NAMESPACE
|
|
# define _GL_CXXALIAS_RPL_1(func,rpl_func,rettype,parameters) \
|
|
namespace GNULIB_NAMESPACE \
|
|
{ \
|
|
rettype (*const func) parameters = ::rpl_func; \
|
|
} \
|
|
_GL_EXTERN_C int _gl_cxxalias_dummy
|
|
#else
|
|
# define _GL_CXXALIAS_RPL_1(func,rpl_func,rettype,parameters) \
|
|
_GL_EXTERN_C int _gl_cxxalias_dummy
|
|
#endif
|
|
|
|
/* _GL_CXXALIAS_RPL_CAST_1 (func, rpl_func, rettype, parameters);
|
|
is like _GL_CXXALIAS_RPL_1 (func, rpl_func, rettype, parameters);
|
|
except that the C function rpl_func may have a slightly different
|
|
declaration. A cast is used to silence the "invalid conversion" error
|
|
that would otherwise occur. */
|
|
#if defined __cplusplus && defined GNULIB_NAMESPACE
|
|
# define _GL_CXXALIAS_RPL_CAST_1(func,rpl_func,rettype,parameters) \
|
|
namespace GNULIB_NAMESPACE \
|
|
{ \
|
|
rettype (*const func) parameters = \
|
|
reinterpret_cast<rettype(*)parameters>(::rpl_func); \
|
|
} \
|
|
_GL_EXTERN_C int _gl_cxxalias_dummy
|
|
#else
|
|
# define _GL_CXXALIAS_RPL_CAST_1(func,rpl_func,rettype,parameters) \
|
|
_GL_EXTERN_C int _gl_cxxalias_dummy
|
|
#endif
|
|
|
|
/* _GL_CXXALIAS_SYS (func, rettype, parameters);
|
|
declares a C++ alias called GNULIB_NAMESPACE::func
|
|
that redirects to the system provided function func, if GNULIB_NAMESPACE
|
|
is defined.
|
|
Example:
|
|
_GL_CXXALIAS_SYS (open, int, (const char *filename, int flags, ...));
|
|
*/
|
|
#if defined __cplusplus && defined GNULIB_NAMESPACE
|
|
/* If we were to write
|
|
rettype (*const func) parameters = ::func;
|
|
like above in _GL_CXXALIAS_RPL_1, the compiler could optimize calls
|
|
better (remove an indirection through a 'static' pointer variable),
|
|
but then the _GL_CXXALIASWARN macro below would cause a warning not only
|
|
for uses of ::func but also for uses of GNULIB_NAMESPACE::func. */
|
|
# define _GL_CXXALIAS_SYS(func,rettype,parameters) \
|
|
namespace GNULIB_NAMESPACE \
|
|
{ \
|
|
static rettype (*func) parameters = ::func; \
|
|
} \
|
|
_GL_EXTERN_C int _gl_cxxalias_dummy
|
|
#else
|
|
# define _GL_CXXALIAS_SYS(func,rettype,parameters) \
|
|
_GL_EXTERN_C int _gl_cxxalias_dummy
|
|
#endif
|
|
|
|
/* _GL_CXXALIAS_SYS_CAST (func, rettype, parameters);
|
|
is like _GL_CXXALIAS_SYS (func, rettype, parameters);
|
|
except that the C function func may have a slightly different declaration.
|
|
A cast is used to silence the "invalid conversion" error that would
|
|
otherwise occur. */
|
|
#if defined __cplusplus && defined GNULIB_NAMESPACE
|
|
# define _GL_CXXALIAS_SYS_CAST(func,rettype,parameters) \
|
|
namespace GNULIB_NAMESPACE \
|
|
{ \
|
|
static rettype (*func) parameters = \
|
|
reinterpret_cast<rettype(*)parameters>(::func); \
|
|
} \
|
|
_GL_EXTERN_C int _gl_cxxalias_dummy
|
|
#else
|
|
# define _GL_CXXALIAS_SYS_CAST(func,rettype,parameters) \
|
|
_GL_EXTERN_C int _gl_cxxalias_dummy
|
|
#endif
|
|
|
|
/* _GL_CXXALIAS_SYS_CAST2 (func, rettype, parameters, rettype2, parameters2);
|
|
is like _GL_CXXALIAS_SYS (func, rettype, parameters);
|
|
except that the C function is picked among a set of overloaded functions,
|
|
namely the one with rettype2 and parameters2. Two consecutive casts
|
|
are used to silence the "cannot find a match" and "invalid conversion"
|
|
errors that would otherwise occur. */
|
|
#if defined __cplusplus && defined GNULIB_NAMESPACE
|
|
/* The outer cast must be a reinterpret_cast.
|
|
The inner cast: When the function is defined as a set of overloaded
|
|
functions, it works as a static_cast<>, choosing the designated variant.
|
|
When the function is defined as a single variant, it works as a
|
|
reinterpret_cast<>. The parenthesized cast syntax works both ways. */
|
|
# define _GL_CXXALIAS_SYS_CAST2(func,rettype,parameters,rettype2,parameters2) \
|
|
namespace GNULIB_NAMESPACE \
|
|
{ \
|
|
static rettype (*func) parameters = \
|
|
reinterpret_cast<rettype(*)parameters>( \
|
|
(rettype2(*)parameters2)(::func)); \
|
|
} \
|
|
_GL_EXTERN_C int _gl_cxxalias_dummy
|
|
#else
|
|
# define _GL_CXXALIAS_SYS_CAST2(func,rettype,parameters,rettype2,parameters2) \
|
|
_GL_EXTERN_C int _gl_cxxalias_dummy
|
|
#endif
|
|
|
|
/* _GL_CXXALIASWARN (func);
|
|
causes a warning to be emitted when ::func is used but not when
|
|
GNULIB_NAMESPACE::func is used. func must be defined without overloaded
|
|
variants. */
|
|
#if defined __cplusplus && defined GNULIB_NAMESPACE
|
|
# define _GL_CXXALIASWARN(func) \
|
|
_GL_CXXALIASWARN_1 (func, GNULIB_NAMESPACE)
|
|
# define _GL_CXXALIASWARN_1(func,namespace) \
|
|
_GL_CXXALIASWARN_2 (func, namespace)
|
|
/* To work around GCC bug <http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43881>,
|
|
we enable the warning only when not optimizing. */
|
|
# if !__OPTIMIZE__
|
|
# define _GL_CXXALIASWARN_2(func,namespace) \
|
|
_GL_WARN_ON_USE (func, \
|
|
"The symbol ::" #func " refers to the system function. " \
|
|
"Use " #namespace "::" #func " instead.")
|
|
# elif __GNUC__ >= 3 && GNULIB_STRICT_CHECKING
|
|
# define _GL_CXXALIASWARN_2(func,namespace) \
|
|
extern __typeof__ (func) func
|
|
# else
|
|
# define _GL_CXXALIASWARN_2(func,namespace) \
|
|
_GL_EXTERN_C int _gl_cxxalias_dummy
|
|
# endif
|
|
#else
|
|
# define _GL_CXXALIASWARN(func) \
|
|
_GL_EXTERN_C int _gl_cxxalias_dummy
|
|
#endif
|
|
|
|
/* _GL_CXXALIASWARN1 (func, rettype, parameters_and_attributes);
|
|
causes a warning to be emitted when the given overloaded variant of ::func
|
|
is used but not when GNULIB_NAMESPACE::func is used. */
|
|
#if defined __cplusplus && defined GNULIB_NAMESPACE
|
|
# define _GL_CXXALIASWARN1(func,rettype,parameters_and_attributes) \
|
|
_GL_CXXALIASWARN1_1 (func, rettype, parameters_and_attributes, \
|
|
GNULIB_NAMESPACE)
|
|
# define _GL_CXXALIASWARN1_1(func,rettype,parameters_and_attributes,namespace) \
|
|
_GL_CXXALIASWARN1_2 (func, rettype, parameters_and_attributes, namespace)
|
|
/* To work around GCC bug <http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43881>,
|
|
we enable the warning only when not optimizing. */
|
|
# if !__OPTIMIZE__
|
|
# define _GL_CXXALIASWARN1_2(func,rettype,parameters_and_attributes,namespace) \
|
|
_GL_WARN_ON_USE_CXX (func, rettype, parameters_and_attributes, \
|
|
"The symbol ::" #func " refers to the system function. " \
|
|
"Use " #namespace "::" #func " instead.")
|
|
# elif __GNUC__ >= 3 && GNULIB_STRICT_CHECKING
|
|
# define _GL_CXXALIASWARN1_2(func,rettype,parameters_and_attributes,namespace) \
|
|
extern __typeof__ (func) func
|
|
# else
|
|
# define _GL_CXXALIASWARN1_2(func,rettype,parameters_and_attributes,namespace) \
|
|
_GL_EXTERN_C int _gl_cxxalias_dummy
|
|
# endif
|
|
#else
|
|
# define _GL_CXXALIASWARN1(func,rettype,parameters_and_attributes) \
|
|
_GL_EXTERN_C int _gl_cxxalias_dummy
|
|
#endif
|
|
|
|
#endif /* _GL_CXXDEFS_H */
|