On Fri, May 12, 2017 at 11:28:50PM -0400, Jeff King wrote:
> +static NORETURN void BUG_vfl(const char *file, int line, const char *fmt, va_list params)
> +{
> + char prefix[256];
> +
> + /* truncation via snprintf is OK here */
> + if (file)
> + snprintf(prefix, sizeof(prefix), "BUG: %s:%d: ", file, line);
> + else
> + snprintf(prefix, sizeof(prefix), "BUG: ");
> +
> + vreportf(prefix, fmt, params);
> + abort();
> +}
I used vreportf() here to match die(). But the two things that function
does are:
1. Respect error_handle. But after bw/forking-and-threading is merged,
nobody will ever set error_handle (and I just sent a patch to drop
it entirely).
2. Quotes non-printable characters. I don't know how useful this is.
Most of the assertion messages are pretty vanilla (because anything
that relies on user input probably should be a regular die, not an
assertion failure). But a few of them do actually print arbitrary
strings in a reasonable way (e.g., a BUG() which is handling user
string which was supposed to be vetted by an earlier function is
still a reasonable assertion, but it's useful to show the string).
So an alternative would be just:
fprintf(stderr, "BUG: ");
if (file)
fprintf(stderr, "%s:%d ", file, line);
vfprintf(stderr, fmt, params);
fputc('\n', stderr);
which is perhaps a bit simpler (not much in lines of code, but there's
no extra buffer to reason about). But given the discussion in (2) above,
it's probably worth continuing to use vreportf.
-Peff