On Thu, Aug 15, 2024 at 10:32:27PM +0100, Dmitry Safonov via B4 Relay wrote:
From: Dmitry Safonov 0x7f454c46@gmail.com
Instead of pre-allocating a fixed-sized buffer of TEST_MSG_BUFFER_SIZE and printing into it, call vsnprintf() with str = NULL, which will return the needed size of the buffer. This hack is documented in man 3 vsnprintf.
Essentially, in C++ terms, it re-invents std::stringstream, which is going to be used to print different tracing paths and formatted strings. Use it straight away in __test_print() - which is thread-safe version of printing in selftests.
Signed-off-by: Dmitry Safonov 0x7f454c46@gmail.com
Hi Dmitry,
Some minor nits, as it looks like there will be a v4.
tools/testing/selftests/net/tcp_ao/lib/aolib.h | 59 ++++++++++++++++++++++---- 1 file changed, 50 insertions(+), 9 deletions(-)
diff --git a/tools/testing/selftests/net/tcp_ao/lib/aolib.h b/tools/testing/selftests/net/tcp_ao/lib/aolib.h index fbc7f6111815..60a63419cabb 100644 --- a/tools/testing/selftests/net/tcp_ao/lib/aolib.h +++ b/tools/testing/selftests/net/tcp_ao/lib/aolib.h @@ -37,17 +37,58 @@ extern void __test_xfail(const char *buf); extern void __test_error(const char *buf); extern void __test_skip(const char *buf); -__attribute__((__format__(__printf__, 2, 3))) -static inline void __test_print(void (*fn)(const char *), const char *fmt, ...) +static inline char *test_snprintf(const char *fmt, va_list vargs) { -#define TEST_MSG_BUFFER_SIZE 4096
- char buf[TEST_MSG_BUFFER_SIZE];
- va_list arg;
- char *ret = NULL;
- size_t size = 0;
- va_list tmp;
- int n = 0;
- va_start(arg, fmt);
- vsnprintf(buf, sizeof(buf), fmt, arg);
- va_end(arg);
- fn(buf);
- va_copy(tmp, vargs);
- n = vsnprintf(ret, size, fmt, tmp);
- if (n < 0)
return NULL;- size = (size_t) n + 1;
nit: I'm not sure this cast is needed. But if it is, then the space after ')' should be dropped.
- ret = malloc(size);
- if (ret == NULL)
nit: if (!ret)
return NULL;- n = vsnprintf(ret, size, fmt, vargs);
- if (n < 0 || n > size - 1) {
free(ret);return NULL;- }
- return ret;
+}
...