lib/libc/tests/string: add unit tests for strcspn(3)

We currently use the NetBSD test suite to cover strcspn(3).  It only
contains a very rudimentary test of this function.  This all new set
of unit tests for the FreeBSD test suite should cover many more edge
cases relating to alignment issues.

Sponsored by:	The FreeBSD Foundation
Approved by:	mjg
MFC after:	1 week
MFC to:		stable/14
Differential Revision: https://reviews.freebsd.org/D41557

2 files changed, 138 insertions, 1 deletions

diff --git a/lib/libc/tests/string/Makefile b/lib/libc/tests/string/Makefile
index a7545b75e0e9..639b7f2d2d2d 100644
--- a/lib/libc/tests/string/Makefile
+++ b/lib/libc/tests/string/Makefile
@@ -11,6 +11,7 @@ ATF_TESTS_C+=		flsll_test
 ATF_TESTS_C+=		memcmp_test
 ATF_TESTS_C+=		memset_s_test
 ATF_TESTS_C+=		stpncpy_test
+ATF_TESTS_C+=		strcspn_test
 ATF_TESTS_C+=		strerror2_test
 ATF_TESTS_C+=		strverscmp_test
 ATF_TESTS_C+=		strxfrm_test
@@ -29,7 +30,6 @@ NETBSD_ATF_TESTS_C+=	strchr_test
 NETBSD_ATF_TESTS_C+=	strchrnul_test
 NETBSD_ATF_TESTS_C+=	strcmp_test
 NETBSD_ATF_TESTS_C+=	strcpy_test
-NETBSD_ATF_TESTS_C+=	strcspn_test
 NETBSD_ATF_TESTS_C+=	strerror_test
 NETBSD_ATF_TESTS_C+=	strlen_test
 NETBSD_ATF_TESTS_C+=	strpbrk_test
diff --git a/lib/libc/tests/string/strcspn_test.c b/lib/libc/tests/string/strcspn_test.c
new file mode 100644
index 000000000000..59da497c16c6
--- /dev/null
+++ b/lib/libc/tests/string/strcspn_test.c
@@ -0,0 +1,137 @@
+/*-
+ * Copyright (c) 2023 The FreeBSD Foundation
+ *
+ * This software was developed by Robert Clausecker <fuz@FreeBSD.org>
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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
+ */
+
+#include <sys/cdefs.h>
+
+#include <atf-c.h>
+#include <assert.h>
+#include <limits.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <string.h>
+
+enum {
+	MAXALIGN = 16,	/* test all offsets from this alignment */
+	MAXBUF = 64,	/* test up to this buffer length */
+};
+
+enum { NOMATCH, MATCH };
+
+static void
+testcase(char *buf, size_t buflen, char *set, size_t setlen, int want_match)
+{
+	size_t i, outcome, expected;
+
+	assert(setlen < UCHAR_MAX - 2);
+
+	for (i = 0; i < buflen; i++)
+		buf[i] = 1 + i % (UCHAR_MAX - setlen - 1);
+
+	buf[i] = '\0';
+
+	for (i = 0; i < setlen; i++)
+		set[i] = UCHAR_MAX - i;
+
+	set[i] = '\0';
+
+	if (want_match == MATCH && buflen > 0 && setlen > 0) {
+		buf[buflen - 1] = UCHAR_MAX;
+		expected = buflen - 1;
+	} else
+		expected = buflen;
+
+	outcome = strcspn(buf, set);
+	ATF_CHECK_EQ_MSG(expected, outcome, "strcspn(%p[%zu], %p[%zu]) = %zu != %zu",
+	    buf, buflen, set, setlen, outcome, expected);
+}
+
+/* test set with all alignments and lengths of buf */
+static void
+test_buf_alignments(char *set, size_t setlen, int want_match)
+{
+	char buf[MAXALIGN + MAXBUF + 1];
+	size_t i, j;
+
+	for (i = 0; i < MAXALIGN; i++)
+		for (j = 0; j <= MAXBUF; j++)
+			testcase(buf + i, j, set, setlen, want_match);
+}
+
+/* test buf with all alignments and lengths of set */
+static void
+test_set_alignments(char *buf, size_t buflen, int want_match)
+{
+	char set[MAXALIGN + MAXBUF + 1];
+	size_t i, j;
+
+	for (i = 0; i < MAXALIGN; i++)
+		for (j = 0; j <= MAXBUF; j++)
+			testcase(buf, buflen, set + i, j, want_match);
+}
+
+ATF_TC_WITHOUT_HEAD(buf_alignments);
+ATF_TC_BODY(buf_alignments, tc)
+{
+	char set[41];
+
+	test_buf_alignments(set, 0, MATCH);
+	test_buf_alignments(set, 1, MATCH);
+	test_buf_alignments(set, 5, MATCH);
+	test_buf_alignments(set, 20, MATCH);
+	test_buf_alignments(set, 40, MATCH);
+
+	test_buf_alignments(set, 0, NOMATCH);
+	test_buf_alignments(set, 1, NOMATCH);
+	test_buf_alignments(set, 5, NOMATCH);
+	test_buf_alignments(set, 20, NOMATCH);
+	test_buf_alignments(set, 40, NOMATCH);
+}
+
+ATF_TC_WITHOUT_HEAD(set_alignments);
+ATF_TC_BODY(set_alignments, tc)
+{
+	char buf[31];
+
+	test_set_alignments(buf,  0, MATCH);
+	test_set_alignments(buf, 10, MATCH);
+	test_set_alignments(buf, 20, MATCH);
+	test_set_alignments(buf, 30, MATCH);
+
+	test_set_alignments(buf,  0, NOMATCH);
+	test_set_alignments(buf, 10, NOMATCH);
+	test_set_alignments(buf, 20, NOMATCH);
+	test_set_alignments(buf, 30, NOMATCH);
+}
+
+ATF_TP_ADD_TCS(tp)
+{
+	ATF_TP_ADD_TC(tp, buf_alignments);
+	ATF_TP_ADD_TC(tp, set_alignments);
+
+	return (atf_no_error());
+}