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Diffstat (limited to 'build-aux/link-warning.h')
| -rw-r--r-- | build-aux/link-warning.h | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/build-aux/link-warning.h b/build-aux/link-warning.h new file mode 100644 index 00000000..fda01941 --- /dev/null +++ b/build-aux/link-warning.h @@ -0,0 +1,28 @@ +/* GL_LINK_WARNING("literal string") arranges to emit the literal string as + a linker warning on most glibc systems. + We use a linker warning rather than a preprocessor warning, because + #warning cannot be used inside macros. */ +#ifndef GL_LINK_WARNING + /* This works on platforms with GNU ld and ELF object format. + Testing __GLIBC__ is sufficient for asserting that GNU ld is in use. + Testing __ELF__ guarantees the ELF object format. + Testing __GNUC__ is necessary for the compound expression syntax. */ +# if defined __GLIBC__ && defined __ELF__ && defined __GNUC__ +# define GL_LINK_WARNING(message) \ + GL_LINK_WARNING1 (__FILE__, __LINE__, message) +# define GL_LINK_WARNING1(file, line, message) \ + GL_LINK_WARNING2 (file, line, message) /* macroexpand file and line */ +# define GL_LINK_WARNING2(file, line, message) \ + GL_LINK_WARNING3 (file ":" #line ": warning: " message) +# define GL_LINK_WARNING3(message) \ + ({ static const char warning[sizeof (message)] \ + __attribute__ ((__unused__, \ + __section__ (".gnu.warning"), \ + __aligned__ (1))) \ + = message "\n"; \ + (void)0; \ + }) +# else +# define GL_LINK_WARNING(message) ((void) 0) +# endif +#endif |