aboutsummaryrefslogtreecommitdiff
path: root/include
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 /include
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 'include')
-rw-r--r--include/features.h19
1 files changed, 15 insertions, 4 deletions
diff --git a/include/features.h b/include/features.h
index f2cd148..554c5c8 100644
--- a/include/features.h
+++ b/include/features.h
@@ -138,13 +138,13 @@
# define __KERNEL_STRICT_NAMES
#endif
-/* Convenience macros to test the versions of glibc and gcc.
- Use them like this:
+/* Convenience macro to test the version of gcc.
+ Use like this:
#if __GNUC_PREREQ (2,8)
... code requiring gcc 2.8 or later ...
#endif
- Note - they won't work for gcc1 or glibc1, since the _MINOR macros
- were not defined then. */
+ Note: only works for GCC 2.0 and later, because __GNUC_MINOR__ was
+ added in 2.0. */
#if defined __GNUC__ && defined __GNUC_MINOR__
# define __GNUC_PREREQ(maj, min) \
((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
@@ -152,6 +152,17 @@
# define __GNUC_PREREQ(maj, min) 0
#endif
+/* Similarly for clang. Features added to GCC after version 4.2 may
+ or may not also be available in clang, and clang's definitions of
+ __GNUC(_MINOR)__ are fixed at 4 and 2 respectively. Not all such
+ features can be queried via __has_extension/__has_feature. */
+#if defined __clang_major__ && defined __clang_minor__
+# define __glibc_clang_prereq(maj, min) \
+ ((__clang_major__ << 16) + __clang_minor__ >= ((maj) << 16) + (min))
+#else
+# define __glibc_clang_prereq(maj, min) 0
+#endif
+
/* Whether to use feature set F. */
#define __GLIBC_USE(F) __GLIBC_USE_ ## F