--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tools/time.c	Wed May 12 00:32:41 2010 -0500
@@ -0,0 +1,116 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ *
+ * Copyright (c) 2010, Oracle and/or it's affiliates.  All rights reserved.
+ */
+
+/*
+ * This compiles to a module that can be preloaded during a build.  If this
+ * is preloaded, it interposes on time(2) and returns a constant value when
+ * the execname matches one of the desired "programs" and TIME_CONSTANT
+ * contains an integer value to be returned.
+ */
+
+#include <stdlib.h>
+#include <ucontext.h>
+#include <dlfcn.h>
+#include <strings.h>
+
+/* The list of programs that we want to use a constant time. */
+static char *programs[] = { "date", "cpp", "cc1", "perl", NULL };
+
+static int
+stack_info(uintptr_t pc, int signo, void *arg)
+{
+	Dl_info info;
+	void *sym;
+
+	if (dladdr1((void *)pc, &info, &sym, RTLD_DL_SYMENT) != NULL) {
+		*(char **)arg = (char *)info.dli_fname;
+	}
+
+	return (0);
+}
+
+static char *
+my_execname()
+{
+	static char *execname;
+
+	if (execname == NULL) {
+		ucontext_t ctx;
+
+		if (getcontext(&ctx) == 0)
+			walkcontext(&ctx, stack_info, &execname);
+
+		if (execname != NULL) {
+			char *s = strrchr(execname, '/');
+
+			if (s != NULL)
+				execname = ++s;
+		}
+	}
+
+	return (execname);
+}
+
+static time_t
+intercept()
+{
+	char *execname = my_execname();
+	time_t result = -1;
+
+	if (execname != NULL) {
+		int i;
+
+		for (i = 0; programs[i] != NULL; i++)
+			if (strcmp(execname, programs[i]) == 0) {
+				static char *time_constant;
+
+				if (time_constant == NULL)
+					time_constant = getenv("TIME_CONSTANT");
+
+				if (time_constant != NULL)
+					result = atoll(time_constant);
+
+				break;
+			}
+	}
+
+	return (result);
+}
+
+time_t
+time(time_t *ptr)
+{
+	time_t result = intercept();
+
+	if (result == (time_t)-1) {
+		static time_t (*fptr)(time_t *);
+
+		if (fptr == NULL)
+			fptr = (time_t (*)(time_t *))dlsym(RTLD_NEXT, "time");
+
+		result = (fptr)(ptr);
+	} else if (ptr != NULL)
+			*ptr = result;
+
+	return (result);
+}