test: Add a test for getopt

A few of these tests were inspired by those in glibc. The syntax for
invoking test_getopt is a bit funky, but it's necessary so that the CPP can
parse the arguments correctly.

Signed-off-by: Sean Anderson <seanga2@gmail.com>

test/lib/Makefile

@@ -14,3 +14,4 @@ obj-$(CONFIG_ERRNO_STR) += test_errno_str.o
 obj-$(CONFIG_UT_LIB_ASN1) += asn1.o
 obj-$(CONFIG_UT_LIB_RSA) += rsa.o
 obj-$(CONFIG_AES) += test_aes.o
+obj-$(CONFIG_GETOPT) += getopt.o

test/lib/getopt.c

@@ -0,0 +1,123 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2020 Sean Anderson <seanga2@gmail.com>
+ *
+ * Portions of these tests were inspired by glibc's posix/bug-getopt1.c and
+ * posix/tst-getopt-cancel.c
+ */
+
+#include <common.h>
+#include <getopt.h>
+#include <test/lib.h>
+#include <test/test.h>
+#include <test/ut.h>
+
+static int do_test_getopt(struct unit_test_state *uts, int line,
+			  struct getopt_state *gs, const char *optstring,
+			  int args, char *argv[], int expected_count,
+			  int expected[])
+{
+	int opt;
+
+	getopt_init_state(gs);
+	for (int i = 0; i < expected_count; i++) {
+		opt = getopt_silent(gs, args, argv, optstring);
+		if (expected[i] != opt) {
+			/*
+			 * Fudge the line number so we can tell which test
+			 * failed
+			 */
+			ut_failf(uts, __FILE__, line, __func__,
+				 "expected[i] == getopt()",
+				 "Expected '%c' (%d) with i=%d, got '%c' (%d)",
+				 expected[i], expected[i], i, opt, opt);
+			return CMD_RET_FAILURE;
+		}
+	}
+
+	opt = getopt_silent(gs, args, argv, optstring);
+	if (opt != -1) {
+		ut_failf(uts, __FILE__, line, __func__,
+			 "getopt() != -1",
+			 "Expected -1, got '%c' (%d)", opt, opt);
+		return CMD_RET_FAILURE;
+	}
+
+	return 0;
+}
+
+#define test_getopt(optstring, argv, expected) do { \
+	int ret = do_test_getopt(uts, __LINE__, &gs, optstring, \
+				 ARRAY_SIZE(argv) - 1, argv, \
+				 ARRAY_SIZE(expected), expected); \
+	if (ret) \
+		return ret; \
+} while (0)
+
+static int lib_test_getopt(struct unit_test_state *uts)
+{
+	struct getopt_state gs;
+
+	/* Happy path */
+	test_getopt("ab:c",
+		    ((char *[]){ "program", "-cb", "x", "-a", "foo", 0 }),
+		    ((int []){ 'c', 'b', 'a' }));
+	ut_asserteq(4, gs.index);
+
+	/* Make sure we pick up the optional argument */
+	test_getopt("a::b:c",
+		    ((char *[]){ "program", "-cbx", "-a", "foo", 0 }),
+		    ((int []){ 'c', 'b', 'a' }));
+	ut_asserteq(4, gs.index);
+
+	/* Test required arguments */
+	test_getopt("a:b", ((char *[]){ "program", "-a", 0 }),
+		    ((int []){ ':' }));
+	ut_asserteq('a', gs.opt);
+	test_getopt("a:b", ((char *[]){ "program", "-b", "-a", 0 }),
+		    ((int []){ 'b', ':' }));
+	ut_asserteq('a', gs.opt);
+
+	/* Test invalid arguments */
+	test_getopt("ab:c", ((char *[]){ "program", "-d", 0 }),
+		    ((int []){ '?' }));
+	ut_asserteq('d', gs.opt);
+
+	/* Test arg */
+	test_getopt("a::b:c",
+		    ((char *[]){ "program", "-a", 0 }),
+		    ((int []){ 'a' }));
+	ut_asserteq(2, gs.index);
+	ut_assertnull(gs.arg);
+
+	test_getopt("a::b:c",
+		    ((char *[]){ "program", "-afoo", 0 }),
+		    ((int []){ 'a' }));
+	ut_asserteq(2, gs.index);
+	ut_assertnonnull(gs.arg);
+	ut_asserteq_str("foo", gs.arg);
+
+	test_getopt("a::b:c",
+		    ((char *[]){ "program", "-a", "foo", 0 }),
+		    ((int []){ 'a' }));
+	ut_asserteq(3, gs.index);
+	ut_assertnonnull(gs.arg);
+	ut_asserteq_str("foo", gs.arg);
+
+	test_getopt("a::b:c",
+		    ((char *[]){ "program", "-bfoo", 0 }),
+		    ((int []){ 'b' }));
+	ut_asserteq(2, gs.index);
+	ut_assertnonnull(gs.arg);
+	ut_asserteq_str("foo", gs.arg);
+
+	test_getopt("a::b:c",
+		    ((char *[]){ "program", "-b", "foo", 0 }),
+		    ((int []){ 'b' }));
+	ut_asserteq(3, gs.index);
+	ut_assertnonnull(gs.arg);
+	ut_asserteq_str("foo", gs.arg);
+
+	return 0;
+}
+LIB_TEST(lib_test_getopt, 0);