[PATCH 16/29] tools include: Adopt __same_type() and __must_be_array() from the kernel

Greg Kroah-Hartman
2018-06-03T12:32:07Z

From: Arnaldo Carvalho de Melo <acme@redhat.com>

commit f6441aff8946f7fd6ab730d7eb9eba18a9ebeba4 upstream.

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

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-d85dpvay1hoqscpezlntyd8x@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
tools/include/linux/compiler-gcc.h | 3 +++
tools/include/linux/compiler.h | 5 +++++
2 files changed, 8 insertions(+)

diff --git a/tools/include/linux/compiler-gcc.h b/tools/include/linux/compiler-gcc.h
index 616935f1ff56..825d44f89a29 100644
--- a/tools/include/linux/compiler-gcc.h
+++ b/tools/include/linux/compiler-gcc.h
@@ -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]))
diff --git a/tools/include/linux/compiler.h b/tools/include/linux/compiler.h
index c9e65e8faacd..23299d7e7160 100644
--- a/tools/include/linux/compiler.h
+++ b/tools/include/linux/compiler.h
@@ -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:
--
2.17.1