configure: detect st_ctim

Check stat has nanosecond precision for ctim.

acinclude.m4

@@ -37,6 +37,10 @@ AC_DEFUN([AC_TRY_CCFLAG],
     fi
 ])
 
+dnl AC_IF_YES([TEST-FOR-YES], [ACTION-IF-TRUE], [ACTION-IF-FALSE])
+dnl AS_IF() abstraction, checks shell variable for 'yes'
+AC_DEFUN([AC_IF_YES], [AS_IF([test $$1 = yes], [$2], [$3])])
+
 dnl AC_TRY_LDFLAGS([LDFLAGS], [VAR], [ACTION-IF-WORKS], [ACTION-IF-FAILS])
 dnl check if $CC supports given ld flags
 

configure

@@ -11958,6 +11958,40 @@ $as_echo "$as_me: WARNING: Disabling realtime clock" >&2;}
 	fi
 fi
 
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for struct stat has st_ctim." >&5
+$as_echo_n "checking for struct stat has st_ctim.... " >&6; }
+if ${ac_cv_stat_st_ctim+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <sys/stat.h>
+long bar(void) { struct stat s; return (long)(s.st_ctim.tv_sec + s.st_ctim.tv_nsec);}
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  ac_cv_stat_st_ctim=yes
+else
+  ac_cv_stat_st_ctim=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_stat_st_ctim" >&5
+$as_echo "$ac_cv_stat_st_ctim" >&6; }
+
+if test $ac_cv_stat_st_ctim = yes; then :
+
+$as_echo "#define HAVE_STAT_ST_CTIM 1" >>confdefs.h
+
+fi
+
 ################################################################################
 for ac_header in getopt.h
 do :

configure.in

@@ -1379,6 +1379,18 @@ if test "$REALTIME" = yes; then
 	fi
 fi
 
+dnl Check if the system has struct stat st_ctim.
+AC_CACHE_CHECK([for struct stat has st_ctim.],
+	[ac_cv_stat_st_ctim],
+	[AC_COMPILE_IFELSE([AC_LANG_PROGRAM(
+[#include <sys/stat.h>
+long bar(void) { struct stat s; return (long)(s.st_ctim.tv_sec + s.st_ctim.tv_nsec);}]
+	 )], [ac_cv_stat_st_ctim=yes], [ac_cv_stat_st_ctim=no])])
+
+AC_IF_YES(ac_cv_stat_st_ctim,
+	  AC_DEFINE(HAVE_STAT_ST_CTIM, 1,
+		    [Define if struct stat has a field st_ctim with timespec for ctime]))
+
 ################################################################################
 dnl -- Check for getopt
 AC_CHECK_HEADERS(getopt.h, AC_DEFINE([HAVE_GETOPTLONG], 1, [Define to 1 if getopt_long is available.]))

lib/misc/configure.h.in

@@ -322,6 +322,9 @@
    zero-length file name argument. */
 #undef HAVE_STAT_EMPTY_STRING_BUG
 
+/* Define if struct stat has a field st_ctim with timespec for ctime */
+#undef HAVE_STAT_ST_CTIM
+
 /* Define to 1 if you have the <stdarg.h> header file. */
 #undef HAVE_STDARG_H