Adding upstream version 3.4.23.upstream/3.4.23upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 93 insertions, 0 deletions

diff --git a/src/util/timecmp.c b/src/util/timecmp.c
new file mode 100644
index 0000000..607a9ae
--- /dev/null
+++ b/src/util/timecmp.c
@@ -0,0 +1,93 @@
+/*++
+/* NAME
+/*	timecmp 3
+/* SUMMARY
+/*	compare two time_t values
+/* SYNOPSIS
+/*	#include <timecmp.h>
+/*
+/*	int	timecmp(t1, t2)
+/*	time_t	t1;
+/*	time_t	t2;
+/* DESCRIPTION
+/*	The timecmp() function return an integer greater than, equal to, or
+/*	less than 0, according as the time t1 is greater than, equal to, or
+/*	less than the time t2.  The comparison is made in a manner that is
+/*	insensitive to clock wrap-around, provided the underlying times are
+/*	within half of the time interval between the smallest and largest
+/*	representable time values.
+/* LICENSE
+/* .ad
+/* .fi
+/*	The Secure Mailer license must be distributed with this software.
+/* AUTHOR(S)
+/*	Wietse Venema
+/*	IBM T.J. Watson Research
+/*	P.O. Box 704
+/*	Yorktown Heights, NY 10598, USA
+/*
+/*	Viktor Dukhovni
+/*--*/
+
+#include "timecmp.h"
+
+/* timecmp - wrap-safe time_t comparison */
+
+int     timecmp(time_t t1, time_t t2)
+{
+    time_t  delta = t1 - t2;
+
+    if (delta == 0)
+	return 0;
+
+#define UNSIGNED(type) ( ((type)-1) > ((type)0) )
+
+    /*
+     * With a constant switch value, the compiler will emit only the code for
+     * the correct case, so the signed/unsigned test happens at compile time.
+     */
+    switch (UNSIGNED(time_t) ? 0 : 1) {
+    case 0:
+	return ((2 * delta > delta) ? 1 : -1);
+    case 1:
+	return ((delta > (time_t) 0) ? 1 : -1);
+    }
+}
+
+#ifdef TEST
+#include <assert.h>
+
+ /*
+  * Bit banging!! There is no official constant that defines the INT_MAX
+  * equivalent of the off_t type. Wietse came up with the following macro
+  * that works as long as off_t is some two's complement number.
+  * 
+  * Note, however, that C99 permits signed integer representations other than
+  * two's complement.
+  */
+#include <limits.h>
+#define __MAXINT__(T) ((T) (((((T) 1) << ((sizeof(T) * CHAR_BIT) - 1)) ^ ((T) -1))))
+
+int     main(void)
+{
+    time_t  now = time((time_t *) 0);
+
+    /* Test that it works for normal times */
+    assert(timecmp(now + 10, now) > 0);
+    assert(timecmp(now, now) == 0);
+    assert(timecmp(now - 10, now) < 0);
+
+    /* Test that it works at a boundary time */
+    if (UNSIGNED(time_t))
+	now = (time_t) -1;
+    else
+	now = __MAXINT__(time_t);
+
+    assert(timecmp(now + 10, now) > 0);
+    assert(timecmp(now, now) == 0);
+    assert(timecmp(now - 10, now) < 0);
+
+    return (0);
+}
+
+#endif