AUTOTOOLS: More robust detection of inotify.

We checked only header file "sys/inotify" for detection whether inotify
works. Some platforms do not have built in inotify, but contain library,
which provides inotify-compatible interface.

This patch adds more robust detection of inotify in configuration time and
appends linker flags to Makefile if inotify is provided by library.

1 files changed, 32 insertions, 0 deletions

diff --git a/src/external/inotify.m4 b/src/external/inotify.m4
new file mode 100644
index 00000000..9572f6d2
--- /dev/null
+++ b/src/external/inotify.m4
@@ -0,0 +1,32 @@
+dnl A macro to check if inotify works
+AC_DEFUN([AM_CHECK_INOTIFY],
+[
+    AC_CHECK_HEADERS([sys/inotify.h])
+
+    AC_MSG_CHECKING([whether sys/inotify.h actually works])
+    AC_LINK_IFELSE(
+        [AC_LANG_SOURCE([
+#ifdef HAVE_SYS_INOTITY_H
+#include <sys/inotify.h>,
+#endif
+int main () {
+    return (-1 == inotify_init());
+}])],
+        [AC_MSG_RESULT([yes]); inotify_works=yes],
+        [AC_MSG_RESULT([no])]
+    )
+
+    SSS_AC_EXPAND_LIB_DIR()
+    AS_IF([test x"$inotify_works" != xyes],
+          [AC_CHECK_LIB([inotify],
+                        [inotify_init],
+                        [INOTIFY_LIBS="$sss_extra_libdir -linotify"
+                         inotify_works=yes],
+                        [inotify_works=no],
+                        [$sss_extra_libdir])]
+    )
+
+    AS_IF([test x"$inotify_works" = xyes],
+          [AC_DEFINE_UNQUOTED([HAVE_INOTIFY], [1], [Inotify works])])
+    AC_SUBST(INOTIFY_LIBS)
+])