00001 /* GL_LINK_WARNING("literal string") arranges to emit the literal string as 00002 a linker warning on most glibc systems. 00003 We use a linker warning rather than a preprocessor warning, because 00004 #warning cannot be used inside macros. */ 00005 #ifndef GL_LINK_WARNING 00006 /* This works on platforms with GNU ld and ELF object format. 00007 Testing __GLIBC__ is sufficient for asserting that GNU ld is in use. 00008 Testing __ELF__ guarantees the ELF object format. 00009 Testing __GNUC__ is necessary for the compound expression syntax. */ 00010 # if defined __GLIBC__ && defined __ELF__ && defined __GNUC__ 00011 # define GL_LINK_WARNING(message) \ 00012 GL_LINK_WARNING1 (__FILE__, __LINE__, message) 00013 # define GL_LINK_WARNING1(file, line, message) \ 00014 GL_LINK_WARNING2 (file, line, message) /* macroexpand file and line */ 00015 # define GL_LINK_WARNING2(file, line, message) \ 00016 GL_LINK_WARNING3 (file ":" #line ": warning: " message) 00017 # define GL_LINK_WARNING3(message) \ 00018 ({ static const char warning[sizeof (message)] \ 00019 __attribute__ ((__unused__, \ 00020 __section__ (".gnu.warning"), \ 00021 __aligned__ (1))) \ 00022 = message "\n"; \ 00023 (void)0; \ 00024 }) 00025 # else 00026 # define GL_LINK_WARNING(message) ((void) 0) 00027 # endif 00028 #endif