[PATCH 3/3] lib/test_string: add some testcases for strchr and strnchr

From: Peter Rosin
Date: Mon May 06 2019 - 08:43:24 EST


Make sure that the trailing NUL is considered part of the string and can
be found.

Signed-off-by: Peter Rosin <peda@xxxxxxxxxx>
---
lib/test_string.c | 77 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 77 insertions(+)

diff --git a/lib/test_string.c b/lib/test_string.c
index 98a787e7a1fd..613fd5cc9872 100644
--- a/lib/test_string.c
+++ b/lib/test_string.c
@@ -111,6 +111,73 @@ static __init int memset64_selftest(void)
return 0;
}

+static __init int strchr_selftest(void)
+{
+ const char *test_string = "abcdefghijkl";
+ const char *empty_string = "";
+ char *result;
+ int i;
+
+ for (i = 0; i < strlen(test_string) + 1; i++) {
+ result = strchr(test_string, test_string[i]);
+ if (result - test_string != i)
+ return i + 'a';
+ }
+
+ result = strchr(empty_string, '\0');
+ if (result != empty_string)
+ return 0x101;
+
+ result = strchr(empty_string, 'a');
+ if (result)
+ return 0x102;
+
+ result = strchr(test_string, 'z');
+ if (result)
+ return 0x103;
+
+ return 0;
+}
+
+static __init int strnchr_selftest(void)
+{
+ const char *test_string = "abcdefghijkl";
+ const char *empty_string = "";
+ char *result;
+ int i, j;
+
+ for (i = 0; i < strlen(test_string) + 1; i++) {
+ for (j = 0; j < strlen(test_string) + 2; j++) {
+ result = strnchr(test_string, j, test_string[i]);
+ if (j <= i) {
+ if (!result)
+ continue;
+ return ((i + 'a') << 8) | j;
+ }
+ if (result - test_string != i)
+ return ((i + 'a') << 8) | j;
+ }
+ }
+
+ result = strnchr(empty_string, 0, '\0');
+ if (result)
+ return 0x10001;
+
+ result = strnchr(empty_string, 1, '\0');
+ if (result != empty_string)
+ return 0x10002;
+
+ result = strnchr(empty_string, 1, 'a');
+ if (result)
+ return 0x10003;
+
+ result = strnchr(NULL, 0, '\0');
+ if (result)
+ return 0x10004;
+
+ return 0;
+}
+
static __init int string_selftest_init(void)
{
int test, subtest;
@@ -130,6 +197,16 @@ static __init int string_selftest_init(void)
if (subtest)
goto fail;

+ test = 4;
+ subtest = strchr_selftest();
+ if (subtest)
+ goto fail;
+
+ test = 5;
+ subtest = strnchr_selftest();
+ if (subtest)
+ goto fail;
+
pr_info("String selftests succeeded\n");
return 0;
fail:
--
2.11.0