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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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 | /* 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 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 Lesser 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 */ |