Corrected cross-platform stat nanosecond code

When nanosecond time resolution was added for identifying config file
changes, it didn't cover all of the myriad of ways that one might obtain
nanosecond time resolution off of struct stat.

Rather than complicate the #if even further figuring out one system from
the next, this patch directly tests for the three struct members I know
about today, and #ifdef's accordingly.

Review: https://reviewboard.asterisk.org/r/3273/
........

Merged revisions 409833 from http://svn.asterisk.org/svn/asterisk/branches/1.8


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/11@409834 65c4cc65-6c06-0410-ace0-fbb531ad65f3

configure

@@ -1,5 +1,5 @@
 #! /bin/sh
-# From configure.ac Revision: 405091 .
+# From configure.ac Revision: 406802 .
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.69 for asterisk trunk.
 #
@@ -12960,6 +12960,43 @@ _ACEOF
 
 fi
 
+stat_nsec_found=no
+ac_fn_c_check_member "$LINENO" "struct stat" "st_mtim" "ac_cv_member_struct_stat_st_mtim" "#include <sys/stat.h>
+"
+if test "x$ac_cv_member_struct_stat_st_mtim" = xyes; then :
+
+cat >>confdefs.h <<_ACEOF
+#define HAVE_STRUCT_STAT_ST_MTIM 1
+_ACEOF
+
+stat_nsec_found=yes
+fi
+ac_fn_c_check_member "$LINENO" "struct stat" "st_mtimensec" "ac_cv_member_struct_stat_st_mtimensec" "#include <sys/stat.h>
+"
+if test "x$ac_cv_member_struct_stat_st_mtimensec" = xyes; then :
+
+cat >>confdefs.h <<_ACEOF
+#define HAVE_STRUCT_STAT_ST_MTIMENSEC 1
+_ACEOF
+
+stat_nsec_found=yes
+fi
+ac_fn_c_check_member "$LINENO" "struct stat" "st_mtimespec" "ac_cv_member_struct_stat_st_mtimespec" "#include <sys/stat.h>
+"
+if test "x$ac_cv_member_struct_stat_st_mtimespec" = xyes; then :
+
+cat >>confdefs.h <<_ACEOF
+#define HAVE_STRUCT_STAT_ST_MTIMESPEC 1
+_ACEOF
+
+stat_nsec_found=yes
+fi
+
+
+if test "${stat_nsec_found}" != yes; then
+	{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: Cannot determine nanosecond field of struct stat" >&5
+$as_echo "$as_me: WARNING: Cannot determine nanosecond field of struct stat" >&2;}
+fi
 
 # Checks for library functions.
 for ac_header in unistd.h

configure.ac

@@ -562,6 +562,12 @@ AC_HEADER_TIME
 AC_STRUCT_TM
 AC_C_VOLATILE
 AC_CHECK_TYPES([ptrdiff_t])
+stat_nsec_found=no
+AC_CHECK_MEMBERS([struct stat.st_mtim, struct stat.st_mtimensec, struct stat.st_mtimespec], [stat_nsec_found=yes], [], [[#include <sys/stat.h>]])
+
+if test "${stat_nsec_found}" != yes; then
+	AC_MSG_WARN(Cannot determine nanosecond field of struct stat)
+fi
 
 # Checks for library functions.
 AC_FUNC_CHOWN

include/asterisk/autoconfig.h.in

@@ -866,6 +866,15 @@
 /* Define to 1 if `st_blksize' is a member of `struct stat'. */
 #undef HAVE_STRUCT_STAT_ST_BLKSIZE
 
+/* Define to 1 if `st_mtim' is a member of `struct stat'. */
+#undef HAVE_STRUCT_STAT_ST_MTIM
+
+/* Define to 1 if `st_mtimensec' is a member of `struct stat'. */
+#undef HAVE_STRUCT_STAT_ST_MTIMENSEC
+
+/* Define to 1 if `st_mtimespec' is a member of `struct stat'. */
+#undef HAVE_STRUCT_STAT_ST_MTIMESPEC
+
 /* Define to 1 if `cr_uid' is a member of `struct ucred'. */
 #undef HAVE_STRUCT_UCRED_CR_UID
 

main/config.c

@@ -1212,10 +1212,14 @@ static void cfmstat_clear(struct cache_file_mtime *cfmtime)
 static void cfmstat_save(struct cache_file_mtime *cfmtime, struct stat *statbuf)
 {
 	cfmtime->stat_size = statbuf->st_size;
-#if defined(_BSD_SOURCE) || defined(_SVID_SOURCE) || (defined(_POSIX_C_SOURCE) && 200809L <= _POSIX_C_SOURCE) || (defined(_XOPEN_SOURCE) && 700 <= _XOPEN_SOURCE)
+#if defined(HAVE_STRUCT_STAT_ST_MTIM)
 	cfmtime->stat_mtime_nsec = statbuf->st_mtim.tv_nsec;
-#else
+#elif defined(HAVE_STRUCT_STAT_ST_MTIMENSEC)
 	cfmtime->stat_mtime_nsec = statbuf->st_mtimensec;
+#elif defined(HAVE_STRUCT_STAT_ST_MTIMESPEC)
+	cfmtime->stat_mtime_nsec = statbuf->st_mtimespec.tv_nsec;
+#else
+	cfmtime->stat_mtime_nsec = 0;
 #endif
 	cfmtime->stat_mtime = statbuf->st_mtime;
 }