Re: [DTrace-devel] [PATCH 2/3] usdt parser: handle encoded hyphens

[Nick Alcock <nick.alcock@oracle.com>]

On 24 Jun 2025, Kris Van Hees via DTrace-devel outgrape:

> Signed-off-by: Kris Van Hees <kris.van.hees@oracle.com>

How did I miss this case? And yes, no probe with embedded hyphens will
work without this (such as foo-entry above): they'll show up, but as
e.g. foo__entry instead.

You could probably make the test fail by explicitly naming one of those
hyphenated probes in the D script: right now, the script just uses
wildcards, which will catch everything whether the de-double-underscore
code kicks in or not.

> ---
>  libcommon/usdt_parser_notes.c | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
>
> diff --git a/libcommon/usdt_parser_notes.c b/libcommon/usdt_parser_notes.c
> index fb57f119..d3d744fb 100644
> --- a/libcommon/usdt_parser_notes.c
> +++ b/libcommon/usdt_parser_notes.c
> @@ -471,6 +471,23 @@ parse_usdt_note(int out, dof_helper_t *dhp, usdt_data_t *data,
>  	}
>  	prbt.off = off;
>  
> +	/*
> +	 * If the probe name has encoded hyphens, perform in-place changing
> +	 * from "__" into "-".
> +	 */
> +	if (strstr(prbt.prb, "__") != NULL) {
> +		char		*q;
> +		const char	*s = prbt.prb, *e = p;
> +
> +		for (q = (char *)s; s < e; s++, q++) {
> +			if (s[0] == '_' && s[1] == '_') {
> +				*q = '-';
> +				s++;
> +			} else if (s > q)
> +				*q = *s;
> +		}
> +	}
> +

This seems OK to me. I mean, fairly horrible, but C string handling *is*
fairly horrible. :)

-- 
NULL && (void)