diff options
authorSiddhesh Poyarekar <siddhesh@redhat.com>2014-11-24 17:25:56 +0530
committerSiddhesh Poyarekar <siddhesh@redhat.com>2014-11-24 17:25:56 +0530
commitd73ac1bb436cf1adb62335f53b4fc91a02f40a3b (patch)
parent33ceaf6187b31ea15284ac65131749e1cb68d2ae (diff)
Make __extern_always_inline usable on clang++ again
The fix for BZ #17266 (884ddc5081278f488ef8cd49951f41cfdbb480ce) removed changes that had gone into cdefs.h to make __extern_always_inline usable with clang++. This patch adds back support for clang to detect if GNU inlining semantics are available, this time without breaking the gcc use case. The check put here is based on the earlier patch and assertion[1] that checking if __GNUC_STDC_INLINE__ or __GNUC_GNU_INLINE__ is defined is sufficient to determine that clang++ suports GNU inlining semantics. Tested with a simple program that builds with __extern_always_inline with the patch and fails compilation without it. #include <stdio.h> #include <sys/cdefs.h> extern void foo_alias (void) __asm ("foo"); __extern_always_inline void foo (void) { puts ("hi oh world!"); return foo_alias (); } void foo_alias (void) { puts ("hell oh world"); } int main () { foo (); } [1] https://sourceware.org/ml/libc-alpha/2012-12/msg00306.html [BZ #17266] * misc/sys/cdefs.h: Define __extern_always_inline for clang 4.2 and newer. (cherry picked from commit 602f80ec8b966cfad3b61914cbe14ee606cedf6e)
2 files changed, 14 insertions, 2 deletions
diff --git a/ChangeLog b/ChangeLog
index f9f3407f88b..ac7d980d889 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2014-11-24 Siddhesh Poyarekar <siddhesh@redhat.com>
+ [BZ #17266]
+ * misc/sys/cdefs.h: Define __extern_always_inline for clang
+ 4.2 and newer.
2014-11-19 Carlos O'Donell <carlos@redhat.com>
Florian Weimer <fweimer@redhat.com>
Joseph Myers <joseph@codesourcery.com>
diff --git a/misc/sys/cdefs.h b/misc/sys/cdefs.h
index 01e81ba9f17..711ac1d912c 100644
--- a/misc/sys/cdefs.h
+++ b/misc/sys/cdefs.h
@@ -321,8 +321,14 @@
inline semantics, unless -fgnu89-inline is used. Using __GNUC_STDC_INLINE__
or __GNUC_GNU_INLINE is not a good enough check for gcc because gcc versions
older than 4.3 may define these macros and still not guarantee GNU inlining
- semantics. */
-#if !defined __cplusplus || __GNUC_PREREQ (4,3)
+ semantics.
+ clang++ identifies itself as gcc-4.2, but has support for GNU inlining
+ semantics, that can be checked fot by using the __GNUC_STDC_INLINE_ and
+ __GNUC_GNU_INLINE__ macro definitions. */
+#if (!defined __cplusplus || __GNUC_PREREQ (4,3) \
+ || (defined __clang__ && (defined __GNUC_STDC_INLINE__ \
+ || defined __GNUC_GNU_INLINE__)))
# if defined __GNUC_STDC_INLINE__ || defined __cplusplus
# define __extern_inline extern __inline __attribute__ ((__gnu_inline__))
# define __extern_always_inline \