sysif: work around glibc warnings about makedev macros.

The GNU C library is deprecating the practice of <sys/types.h>
defining the makedev, major and minor macros. A loud,
multi-line warning is issued for programs which include this
header and then use the macros. The new way is to rely on
the <sys/sysmacros.h> header instead. Of course, that might
not exist.

* configure (have_makedev): New variable. Upgrade the makedev
test to try it with <sys/sysmacros.h> first, then fall back
on <sys/types.h>. A new config macro HAVE_SYS_SYSMACROS_H
is created in config.h if sysmacros exists.

* sysif.c: If config.h defines HAVE_SYS_SYSMACROS_H to a
nonzero value, then include <sys/sysmacros.h>.

1 files changed, 3 insertions, 0 deletions

diff --git a/sysif.c b/sysif.c
index 8111d4f5..1020f075 100644
--- a/sysif.c
+++ b/sysif.c
@@ -53,6 +53,9 @@
 #if HAVE_SYS_TYPES_H
 #include <sys/types.h>
 #endif
+#if HAVE_SYS_SYSMACROS_H
+#include <sys/sysmacros.h>
+#endif
 #if HAVE_POLL
 #include <poll.h>
 #endif