tools include: Adopt __same_type() and __must_be_array() from the kernel

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2017-04-20 11:05 UTC #0 lore raw

Commit-ID:  f6441aff8946f7fd6ab730d7eb9eba18a9ebeba4
Gitweb:     http://git.kernel.org/tip/f6441aff8946f7fd6ab730d7eb9eba18a9ebeba4
Author:     Arnaldo Carvalho de Melo <[email protected]>
AuthorDate: Mon, 17 Apr 2017 11:25:00 -0300
Committer:  Arnaldo Carvalho de Melo <[email protected]>
CommitDate: Wed, 19 Apr 2017 13:01:42 -0300

tools include: Adopt __same_type() and __must_be_array() from the kernel

Will be used to adopt the more stringent version of ARRAY_SIZE(), the one in the kernel sources.

Cc Adrian Hunter <[email protected]>

Cc David Ahern <[email protected]>

Cc Jiri Olsa <[email protected]>

Cc Namhyung Kim <[email protected]>

Cc Wang Nan <[email protected]>

Link http://lkml.kernel.org/n/[email protected] open here

Signed-off-by Arnaldo Carvalho de Melo <[email protected]>

---
 tools/include/linux/compiler-gcc.h | 3 +++
 tools/include/linux/compiler.h     | 5 +++++
 2 files changed, 8 insertions(+)

tools/include/linux/compiler-gcc.h +3 -0

index 616935f..825d44f 100644
@@ -16,3 +16,6 @@
 #if GCC_VERSION >= 40300
 # define __compiletime_error(message) __attribute__((error(message)))
 #endif /* GCC_VERSION >= 40300 */
+
+/* &a[0] degrades to a pointer: a different type from an array */
+#define __must_be_array(a)	BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))

tools/include/linux/compiler.h +5 -0

index c9e65e8..23299d7 100644
@@ -17,6 +17,11 @@
 # define __always_inline	inline __attribute__((always_inline))
 #endif
 
+/* Are two types/vars the same type (ignoring qualifiers)? */
+#ifndef __same_type
+# define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
+#endif
+
 #ifdef __ANDROID__
 /*
  * FIXME: Big hammer to get rid of tons of: