strerror() is commonly used.
For example in kselftest which currently needs to do an #ifdef NOLIBC to
handle the lack of strerror().
Keep it simple and reuse the output format of perror() for strerror().
Signed-off-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
---
tools/include/nolibc/stdio.h | 10 ++++++++++
tools/testing/selftests/nolibc/nolibc-test.c | 4 ++++
2 files changed, 14 insertions(+)
diff --git a/tools/include/nolibc/stdio.h b/tools/include/nolibc/stdio.h
index 16cd4d807251..c968dbbc4ef8 100644
--- a/tools/include/nolibc/stdio.h
+++ b/tools/include/nolibc/stdio.h
@@ -376,6 +376,16 @@ int setvbuf(FILE *stream __attribute__((unused)),
return 0;
}
+static __attribute__((unused))
+const char *strerror(int errno)
+{
+ static char buf[18] = "errno=";
+
+ i64toa_r(errno, &buf[6]);
+
+ return buf;
+}
+
/* make sure to include all global symbols */
#include "nolibc.h"
diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index dadc9b8f2727..1c23776713f5 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -1208,6 +1208,10 @@ int run_stdlib(int min, int max)
CASE_TEST(strtol_underflow); EXPECT_STRTOX(1, strtol, "-0x8000000000000001", 16, LONG_MIN, -1, ERANGE); break;
CASE_TEST(strtoul_negative); EXPECT_STRTOX(1, strtoul, "-0x1", 16, ULONG_MAX, 4, 0); break;
CASE_TEST(strtoul_overflow); EXPECT_STRTOX(1, strtoul, "0x10000000000000000", 16, ULONG_MAX, -1, ERANGE); break;
+ CASE_TEST(strerror_success); EXPECT_STREQ(is_nolibc, strerror(0), "errno=0"); break;
+ CASE_TEST(strerror_EINVAL); EXPECT_STREQ(is_nolibc, strerror(EINVAL), "errno=22"); break;
+ CASE_TEST(strerror_int_max); EXPECT_STREQ(is_nolibc, strerror(INT_MAX), "errno=2147483647"); break;
+ CASE_TEST(strerror_int_min); EXPECT_STREQ(is_nolibc, strerror(INT_MIN), "errno=-2147483648"); break;
case __LINE__:
return ret; /* must be last */
--
2.44.0
