aboutsummaryrefslogtreecommitdiff
path: root/misc/sys
diff options
context:
space:
mode:
authorZack Weinberg <zackw@panix.com>2016-04-28 11:07:58 -0400
committerZack Weinberg <zackw@panix.com>2016-08-03 14:03:46 -0400
commitcab4d74b01320670f57dcf356ff89256f4d2fc12 (patch)
tree2a043314a5c820767e04a810eff4ecbad70a5a49 /misc/sys
parentbf91be88ea90c1ea888d5646270d66363389ce96 (diff)
downloadglibc-cab4d74b01320670f57dcf356ff89256f4d2fc12.zip
glibc-cab4d74b01320670f57dcf356ff89256f4d2fc12.tar.gz
glibc-cab4d74b01320670f57dcf356ff89256f4d2fc12.tar.bz2
Add utility macros for clang detection, and deprecation with messages.
There are three new macros added to features.h and sys/cdefs.h: * __glibc_clang_prereq: just like __GNUC_PREREQ, but for clang. * __glibc_clang_has_extension: wraps clang's intrinsic __has_extension. Writing "#if defined __clang__ && __has_extension (...)" doesn't work, because compilers other than clang will object to the unknown macro __has_extension even though they don't need to evaluate it. Instead, write "#if __glibc_clang_has_extension (...)". * __attribute_deprecated_msg__(msg): like __attribute_deprecated__, but if possible, prints a message. The first two are used to define the third. The third will be used in subsequent patches. * include/features.h (__glibc_clang_prereq): New macro. * misc/sys/cdefs.h (__glibc_clang_has_extension) (__attribute_deprecated_msg__): New macros.
Diffstat (limited to 'misc/sys')
-rw-r--r--misc/sys/cdefs.h22
1 files changed, 21 insertions, 1 deletions
diff --git a/misc/sys/cdefs.h b/misc/sys/cdefs.h
index a3c2429..6e9b840 100644
--- a/misc/sys/cdefs.h
+++ b/misc/sys/cdefs.h
@@ -77,6 +77,15 @@
#endif /* GCC. */
+/* Compilers that are not clang may object to
+ #if defined __clang__ && __has_extension(...)
+ even though they do not need to evaluate the right-hand side of the &&. */
+#if defined __clang__ && defined __has_extension
+# define __glibc_clang_has_extension(ext) __has_extension (ext)
+#else
+# define __glibc_clang_has_extension(ext) 0
+#endif
+
/* These two macros are not used in glibc anymore. They are kept here
only because some other projects expect the macros to be defined. */
#define __P(args) args
@@ -249,13 +258,24 @@
# define __attribute_noinline__ /* Ignore */
#endif
-/* gcc allows marking deprecated functions. */
+/* Since version 3.2, gcc allows marking deprecated functions. */
#if __GNUC_PREREQ (3,2)
# define __attribute_deprecated__ __attribute__ ((__deprecated__))
#else
# define __attribute_deprecated__ /* Ignore */
#endif
+/* Since version 4.5, gcc also allows one to specify the message printed
+ when a deprecated function is used. clang claims to be gcc 4.2, but
+ may also support this feature. */
+#if __GNUC_PREREQ (4,5) || \
+ __glibc_clang_has_extension (__attribute_deprecated_with_message__)
+# define __attribute_deprecated_msg__(msg) \
+ __attribute__ ((__deprecated__ (msg)))
+#else
+# define __attribute_deprecated_msg__(msg) __attribute_deprecated__
+#endif
+
/* At some point during the gcc 2.8 development the `format_arg' attribute
for functions was introduced. We don't want to use it unconditionally
(although this would be possible) since it generates warnings.