test: Add a test for snprintf() and the banner/version

Add a simple test to make sure that these functions obey the buffer size
passed into them.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Stephen Warren <swarren@nvidia.com>

test/Makefile

@@ -8,4 +8,5 @@ obj-$(CONFIG_UNIT_TEST) += cmd_ut.o
 obj-$(CONFIG_UNIT_TEST) += ut.o
 obj-$(CONFIG_SANDBOX) += command_ut.o
 obj-$(CONFIG_SANDBOX) += compression.o
+obj-$(CONFIG_SANDBOX) += print_ut.o
 obj-$(CONFIG_UT_TIME) += time_ut.o

test/print_ut.c

@@ -0,0 +1,83 @@
+/*
+ * Copyright (c) 2012, The Chromium Authors
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#define DEBUG
+
+#include <common.h>
+#include <display_options.h>
+#include <version.h>
+
+#define FAKE_BUILD_TAG	"jenkins-u-boot-denx_uboot_dm-master-build-aarch64" \
+			"and a lot more text to come"
+
+static int do_ut_print(cmd_tbl_t *cmdtp, int flag, int argc,
+		       char *const argv[])
+{
+	char big_str[400];
+	int big_str_len;
+	char str[10], *s;
+	int len;
+
+	printf("%s: Testing print\n", __func__);
+
+	snprintf(str, sizeof(str), "testing");
+	assert(!strcmp("testing", str));
+
+	snprintf(str, sizeof(str), "testing but too long");
+	assert(!strcmp("testing b", str));
+
+	snprintf(str, 1, "testing none");
+	assert(!strcmp("", str));
+
+	*str = 'x';
+	snprintf(str, 0, "testing none");
+	assert(*str == 'x');
+
+	/* Test the banner function */
+	s = display_options_get_banner(true, str, sizeof(str));
+	assert(s == str);
+	assert(!strcmp("\n\nU-Boo\n\n", s));
+
+	s = display_options_get_banner(true, str, 1);
+	assert(s == str);
+	assert(!strcmp("", s));
+
+	s = display_options_get_banner(true, str, 2);
+	assert(s == str);
+	assert(!strcmp("\n", s));
+
+	s = display_options_get_banner(false, str, sizeof(str));
+	assert(s == str);
+	assert(!strcmp("U-Boot \n\n", s));
+
+	/* Give it enough space for some of the version */
+	big_str_len = strlen(version_string) - 5;
+	s = display_options_get_banner_priv(false, FAKE_BUILD_TAG, big_str,
+					    big_str_len);
+	assert(s == big_str);
+	assert(!strncmp(version_string, s, big_str_len - 3));
+	assert(!strcmp("\n\n", s + big_str_len - 3));
+
+	/* Give it enough space for the version and some of the build tag */
+	big_str_len = strlen(version_string) + 9 + 20;
+	s = display_options_get_banner_priv(false, FAKE_BUILD_TAG, big_str,
+					    big_str_len);
+	assert(s == big_str);
+	len = strlen(version_string);
+	assert(!strncmp(version_string, s, len));
+	assert(!strncmp(", Build: ", s + len, 9));
+	assert(!strncmp(FAKE_BUILD_TAG, s + 9 + len, 12));
+	assert(!strcmp("\n\n", s + big_str_len - 3));
+
+	printf("%s: Everything went swimmingly\n", __func__);
+	return 0;
+}
+
+U_BOOT_CMD(
+	ut_print,	1,	1,	do_ut_print,
+	"Very basic test of printf(), etc.",
+	""
+);