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authorZack Weinberg <zackw@panix.com>2017-04-03 08:45:41 -0400
committerZack Weinberg <zackw@panix.com>2017-04-07 07:52:29 -0400
commit0f3be8721a86299600eae2d266934f661bf7c990 (patch)
tree51085f8f01905cd53c041869b25ed3688ad59abd /include
parentaeacb9f9127cff0ed099026156ca35c025f343b7 (diff)
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getopt: merge _GL_UNUSED annotations from gnulib
gnulib now has annotations on at least some functions to cater to compilation with -Wunused-parameter. In order to follow suit cleanly, I've added to libc-symbols.h some of the _GL_* macros that gnulib-common.m4 puts into config.h. (I don't think they belong in sys/cdefs.h, at least not without further thought.) At this point all gnulib-side changes to getopt.c have been merged. * include/libc-symbols.h: For gnulib compatibility, define _GL_UNUSED, _GL_UNUSED_LABEL, _GL_ATTRIBUTE_PURE, and _GL_ATTRIBUTE_CONST. * posix/getopt.c (_getopt_initialize): Mark argc and argv parameters with _GL_UNUSED.
Diffstat (limited to 'include')
-rw-r--r--include/libc-symbols.h43
1 files changed, 43 insertions, 0 deletions
diff --git a/include/libc-symbols.h b/include/libc-symbols.h
index 0783ade0b3..18f26b2e61 100644
--- a/include/libc-symbols.h
+++ b/include/libc-symbols.h
@@ -892,5 +892,48 @@ for linking")
#else
# define inhibit_loop_to_libcall
#endif
+
+/* These macros facilitate sharing source files with gnulib.
+
+ They are here instead of sys/cdefs.h because they should not be
+ used in public header files.
+
+ Their definitions should be kept consistent with the definitions in
+ gnulib-common.m4, but it is not necessary to cater to old non-GCC
+ compilers, since they will only be used while building glibc itself.
+ (Note that _GNUC_PREREQ cannot be used in this file.) */
+
+/* Define as a marker that can be attached to declarations that might not
+ be used. This helps to reduce warnings, such as from
+ GCC -Wunused-parameter. */
+#if __GNUC__ >= 3 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 7)
+# define _GL_UNUSED __attribute__ ((__unused__))
+#else
+# define _GL_UNUSED
+#endif
+
+/* gcc supports the "unused" attribute on possibly unused labels, and
+ g++ has since version 4.5. Note to support C++ as well as C,
+ _GL_UNUSED_LABEL should be used with a trailing ; */
+#if !defined __cplusplus || __GNUC__ > 4 \
+ || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)
+# define _GL_UNUSED_LABEL _GL_UNUSED
+#else
+# define _GL_UNUSED_LABEL
+#endif
+
+/* The __pure__ attribute was added in gcc 2.96. */
+#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 96)
+# define _GL_ATTRIBUTE_PURE __attribute__ ((__pure__))
+#else
+# define _GL_ATTRIBUTE_PURE /* empty */
+#endif
+
+/* The __const__ attribute was added in gcc 2.95. */
+#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 95)
+# define _GL_ATTRIBUTE_CONST __attribute__ ((__const__))
+#else
+# define _GL_ATTRIBUTE_CONST /* empty */
+#endif
#endif /* libc-symbols.h */