Mercurial > hg > octave-lojdl > gnulib-hg
changeset 12928:ab37e90dc2cd
New module 'c++defs'.
| author | Bruno Haible <bruno@clisp.org> |
|---|---|
| date | Mon, 08 Mar 2010 00:45:37 +0100 |
| parents | d3ea0f2aacfc |
| children | c71f3c9363b0 |
| files | ChangeLog build-aux/c++defs.h modules/c++defs |
| diffstat | 3 files changed, 255 insertions(+), 0 deletions(-) [+] |
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--- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,10 @@ +2010-03-07 Bruno Haible <bruno@clisp.org> + + New module 'c++defs'. + * modules/c++defs: New file. + * build-aux/c++defs.h: New file. + Reported by John W. Eaton <jwe@gnu.org>. + 2010-03-07 Bruno Haible <bruno@clisp.org> logb: Provide missing declaration for Cygwin.
new file mode 100644 --- /dev/null +++ b/build-aux/c++defs.h @@ -0,0 +1,209 @@ +/* C++ compatible function declaration macros. + Copyright (C) 2010 Free Software Foundation, Inc. + + This program is free software: you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published + by the Free Software Foundation; either version 2 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser 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_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 +# define _GL_CXXALIAS_SYS_CAST2(func,rettype,parameters,rettype2,parameters2) \ + namespace GNULIB_NAMESPACE \ + { \ + static rettype (*func) parameters = \ + reinterpret_cast<rettype(*)parameters>( \ + reinterpret_cast<rettype2(*)parameters2>(::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_CXXALIASWARN (func); + causes a warning to be emitted when ::func is used but not when + GNULIB_NAMESPACE::func is used. */ +#if defined __cplusplus && defined GNULIB_NAMESPACE +# define _GL_CXXALIASWARN(func) \ + _GL_CXXALIASWARN1 (func, GNULIB_NAMESPACE) +# define _GL_CXXALIASWARN1(func,namespace) \ + _GL_CXXALIASWARN2 (func, namespace) +# define _GL_CXXALIASWARN2(func,namespace) \ + _GL_WARN_ON_USE (func, \ + "The symbol ::" #func " refers to the system function. " \ + "Use " #namespace "::" #func " instead.") +#else +# define _GL_CXXALIASWARN(func) \ + _GL_EXTERN_C int _gl_cxxalias_dummy +#endif + +#endif /* _GL_CXXDEFS_H */
new file mode 100644 --- /dev/null +++ b/modules/c++defs @@ -0,0 +1,39 @@ +Description: +Function declaration macros with C++ support. + +Applicability: +all + +Files: +build-aux/c++defs.h + +Depends-on: + +configure.ac: + +Makefile.am: +# The BUILT_SOURCES created by this Makefile snippet are not used via #include +# statements but through direct file reference. Therefore this snippet must be +# present in all Makefile.am that need it. This is ensured by the applicability +# 'all' defined above. + +BUILT_SOURCES += c++defs.h +# The c++defs.h that gets inserted into generated .h files is the same as +# build-aux/c++defs.h, except that it has the copyright header cut off. +c++defs.h: $(top_srcdir)/build-aux/c++defs.h + $(AM_V_GEN)rm -f $@-t $@ && \ + sed -n -e '/_GL_CXXDEFS/,$$p' \ + < $(top_srcdir)/build-aux/c++defs.h \ + > $@-t && \ + mv $@-t $@ +MOSTLYCLEANFILES += c++defs.h c++defs.h-t + +CXXDEFS_H=c++defs.h + +Include: + +License: +LGPLv2+ + +Maintainer: +Bruno Haible