Add regression test for strerror()/strerror_r().

Based on:	src/lib/libc/string/strerror.c (rev 1.8)

tools/regression/lib/libc/string/Makefile

@@ -0,0 +1,11 @@
+# $FreeBSD$
+
+TESTS=	test-strerror
+
+.PHONY: tests
+tests: ${TESTS}
+	for p in ${TESTS}; do ${.OBJDIR}/$$p; done
+
+.PHONY: clean
+clean:
+	-rm -f ${TESTS}

tools/regression/lib/libc/string/test-strerror.c

@@ -0,0 +1,130 @@
+/*-
+ * Copyright (c) 2001 Wes Peters <wes@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#include <assert.h>
+#include <errno.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+int
+main(void)
+{
+	char buf[64];
+	char *sret;
+	int iret;
+
+	/*
+	 * strerror() failure tests.
+	 */
+	errno = 0;
+	sret = strerror(0);
+	assert(strcmp(sret, "Unknown error: 0") == 0);
+	assert(errno == EINVAL);
+
+	errno = 0;
+	sret = strerror(INT_MAX);
+	snprintf(buf, sizeof(buf), "Unknown error: %d", INT_MAX);
+	assert(strcmp(sret, buf) == 0);
+	assert(errno == EINVAL);
+
+	/*
+	 * strerror() success tests.
+	 */
+	errno = 0;
+	sret = strerror(EPERM);
+	assert(strcmp(sret, "Operation not permitted") == 0);
+	assert(errno == 0);
+
+	errno = 0;
+	sret = strerror(EPFNOSUPPORT);
+	assert(strcmp(sret, "Protocol family not supported") == 0);
+	assert(errno == 0);
+
+	errno = 0;
+	sret = strerror(ELAST);
+	assert(errno == 0);
+
+	printf("PASS strerror()\n");
+
+	/*
+	 * strerror_r() failure tests.
+	 */
+	memset(buf, '*', sizeof(buf));
+	iret = strerror_r(0, buf, sizeof(buf));
+	assert(strcmp(buf, "Unknown error: 0") == 0);
+	assert(iret == EINVAL);
+
+	memset(buf, '*', sizeof(buf));
+	/* One byte too short. */
+	iret = strerror_r(EPERM, buf, strlen("Operation not permitted"));
+	assert(strcmp(buf, "Operation not permitte") == 0);
+	assert(iret == ERANGE);
+
+	memset(buf, '*', sizeof(buf));
+	/* One byte too short. */
+	iret = strerror_r(-1, buf, strlen("Unknown error: -1"));
+	assert(strcmp(buf, "Unknown error: -") == 0);
+	assert(iret == EINVAL);
+
+	memset(buf, '*', sizeof(buf));
+	/* Two bytes too short. */
+	iret = strerror_r(-2, buf, strlen("Unknown error: -2") - 1);
+	assert(strcmp(buf, "Unknown error: ") == 0);
+	assert(iret == EINVAL);
+
+	memset(buf, '*', sizeof(buf));
+	/* Three bytes too short. */
+	iret = strerror_r(-2, buf, strlen("Unknown error: -2") - 2);
+	assert(strcmp(buf, "Unknown error:") == 0);
+	assert(iret == EINVAL);
+
+	memset(buf, '*', sizeof(buf));
+	/* One byte too short. */
+	iret = strerror_r(12345, buf, strlen("Unknown error: 12345"));
+	assert(strcmp(buf, "Unknown error: 1234") == 0);
+	assert(iret == EINVAL);
+
+	/*
+	 * strerror_r() success tests.
+	 */
+	memset(buf, '*', sizeof(buf));
+	iret = strerror_r(EDEADLK, buf, sizeof(buf));
+	assert(strcmp(buf, "Resource deadlock avoided") == 0);
+	assert(iret == 0);
+
+	memset(buf, '*', sizeof(buf));
+	iret = strerror_r(EPROCLIM, buf, sizeof(buf));
+	assert(strcmp(buf, "Too many processes") == 0);
+	assert(iret == 0);
+
+	printf("PASS strerror_r()\n");
+
+	exit(0);
+}