Recent compilers support __has_attribute() to check if a certain
compiler attribute is supported.
Unfortunately we have to first check if __has_attribute is supported in
the first place and then if a specific attribute is present.
These two checks can't be folded into a single condition as that would
lead to errors.
Nesting the two conditions like below works, but becomes ugly as soon
as #else blocks are used as those need to be duplicated for both levels
of #if.
#if defined __has_attribute
# if __has_attribute (nonnull)
# define ATTR_NONNULL __attribute__ ((nonnull))
# endif
#endif
Introduce a new helper which makes the usage of __has_attribute() nicer
and migrate the current user to it.
Signed-off-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
---
tools/include/nolibc/compiler.h | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/tools/include/nolibc/compiler.h b/tools/include/nolibc/compiler.h
index beddc3665d69..1730d0454a55 100644
--- a/tools/include/nolibc/compiler.h
+++ b/tools/include/nolibc/compiler.h
@@ -6,20 +6,22 @@
#ifndef _NOLIBC_COMPILER_H
#define _NOLIBC_COMPILER_H
+#if defined(__has_attribute)
+# define __nolibc_has_attribute(attr) __has_attribute(attr)
+#else
+# define __nolibc_has_attribute(attr) 0
+#endif
+
#if defined(__SSP__) || defined(__SSP_STRONG__) || defined(__SSP_ALL__) || defined(__SSP_EXPLICIT__)
#define _NOLIBC_STACKPROTECTOR
#endif /* defined(__SSP__) ... */
-#if defined(__has_attribute)
-# if __has_attribute(no_stack_protector)
-# define __no_stack_protector __attribute__((no_stack_protector))
-# else
-# define __no_stack_protector __attribute__((__optimize__("-fno-stack-protector")))
-# endif
+#if __nolibc_has_attribute(no_stack_protector)
+# define __no_stack_protector __attribute__((no_stack_protector))
#else
# define __no_stack_protector __attribute__((__optimize__("-fno-stack-protector")))
-#endif /* defined(__has_attribute) */
+#endif /* __nolibc_has_attribute(no_stack_protector) */
#endif /* _NOLIBC_COMPILER_H */
--
2.46.0
