Use gettimeofday() instead of ftime()

ftime() was removed in POSIX.1-2008. gettimeofday() is deprecated but
the recommended function clock_gettime() is often not available in some
systems (e.g., macOS 10.11 or earlier).

configure.ac

@@ -609,8 +609,20 @@ AS_IF([test "x$enable_parform" = xyes && test "x$enable_debug" = xyes], [build_p
 AM_CONDITIONAL([BUILD_PARFORM], [test "x$build_parform" = xyes])
 AM_CONDITIONAL([BUILD_PARVORM], [test "x$build_parvorm" = xyes])
 
-# Check for ftime
-AC_SEARCH_LIBS([ftime], [compat], [], [])
+# Check for wall-clock time
+ok=no
+AS_IF([test $ok != yes],
+	# TODO: gettimeofday is also deprecated.
+	[AC_SEARCH_LIBS([gettimeofday], [],
+		[AC_DEFINE([HAVE_GETTIMEOFDAY], [1], [Define to 1 if you have gettimeofday.])
+		ok=yes])])
+AS_IF([test $ok != yes],
+	# Fallback: ftime. Available also on Windows. Some BSDs require -lcompat.
+	[AC_SEARCH_LIBS([ftime], [compat],
+		[AC_DEFINE([HAVE_FTIME], [1], [Define to 1 if you have ftime.])
+		ok=yes])])
+AS_IF([test $ok != yes],
+	[AC_MSG_FAILURE([Wall-clock time not available])])
 
 # Check for static linking
 STATIC_LDFLAGS=

sources/tools.c

@@ -3366,7 +3366,11 @@ int CompArg(WORD *s1, WORD *s2)
  		#[ TimeWallClock :
 */
 
+#ifdef HAVE_GETTIMEOFDAY
+#include <sys/time.h>
+#else
 #include <sys/timeb.h>
+#endif
 
 /**
  * Returns the wall-clock time.
@@ -3379,6 +3383,21 @@ LONG TimeWallClock(WORD par)
 	/*
 	 * NOTE: this function is not thread-safe. Operations on tp are not atomic.
 	 */
+#ifdef HAVE_GETTIMEOFDAY
+	struct timeval t;
+	LONG sec, msec;
+	gettimeofday(&t, NULL);
+	sec = (LONG)t.tv_sec;
+	msec = (LONG)(t.tv_usec/1000);
+	if ( par ) {
+		return (sec-AM.OldSecTime)*100 + (msec-AM.OldMilliTime)/10;
+	}
+	else {
+		AM.OldSecTime   = sec;
+		AM.OldMilliTime = msec;
+		return(0L);
+	}
+#else
 	struct timeb tp;
 	ftime(&tp);
 	if ( par ) {
@@ -3390,6 +3409,7 @@ LONG TimeWallClock(WORD par)
 		AM.OldMilliTime = (LONG)(tp.millitm);
 		return(0L);
 	}
+#endif
 }
 
 /*