From: Jens Axboe <axboe@fb.com>
Date: Tue, 30 Jun 2015 02:46:31 +0000 (-0600)
Subject: configure: fixup clang stupidity
X-Git-Tag: fio-2.2.10~50
X-Git-Url: https://git.kernel.dk/?p=fio.git;a=commitdiff_plain;h=94815a5c8366a9290167e8539f29994c2d43d15c;hp=3fb1aa3074b085273a1a80149527d9ac9b3ef1e5

configure: fixup clang stupidity

Doesn't like doing _Static_assert() on our structure offset
definition:

error: static_assert expression is not an integral constant expression

Lets just include that in the configure test, so we can avoid using
_Static_assert() if that kind of check fails.

Signed-off-by: Jens Axboe <axboe@fb.com>
---

diff --git a/configure b/configure
index 085f0165..a3f83d34 100755
--- a/configure
+++ b/configure
@@ -1497,9 +1497,25 @@ echo "getmntinfo                    $getmntinfo"
 static_assert="no"
 cat > $TMPC << EOF
 #include <assert.h>
+#include <stdlib.h>
+#undef offsetof
+#ifdef __compiler_offsetof
+#define offsetof(TYPE,MEMBER) __compiler_offsetof(TYPE,MEMBER)
+#else
+#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
+#endif
+
+#define container_of(ptr, type, member) ({			\
+	const typeof( ((type *)0)->member ) *__mptr = (ptr);	\
+	(type *)( (char *)__mptr - offsetof(type,member) );})
+
+struct foo {
+  int a, b;
+};
+
 int main(int argc, char **argv)
 {
-  _Static_assert( 1 == 1 , "Check");
+  _Static_assert(offsetof(struct foo, a) == 0 , "Check");
   return 0 ;
 }
 EOF