On Wed, Mar 08, 2023 at 08:35:14AM +0100, Stefano Brivio wrote:
> From: Chris Kuhn <kuhnchris+github@kuhnchris.eu>
> 
> While building against musl, gcc informs us that 'stderr' is a
> protected keyword. This probably comes from a #define stderr (stderr)
> in musl's stdio.h, to avoid a clash with extern FILE *const stderr,
> but I didn't really track it down. Just rename it to force_stderr, it
> makes more sense.
> 
> [sbrivio: Added commit message]
> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

Shadowing a libc global is not a great idea.  Since it's a field, not
a variable we're not *exactly* doing that, but it's close enough that
I think this is better regardless of musl constraints.

(I once had a particularly wonderful time tracking down a bizarre bug
because 'index' ended up resolving to index(3) instead of the local
variable I expected it to).

> ---
>  conf.c  | 6 +++---
>  passt.c | 2 +-
>  passt.h | 4 ++--
>  3 files changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/conf.c b/conf.c
> index 15506ec..07b0b7b 100644
> --- a/conf.c
> +++ b/conf.c
> @@ -1356,13 +1356,13 @@ void conf(struct ctx *c, int argc, char **argv)
>  			if (logfile)
>  				die("Can't log to both file and stderr");
>  
> -			if (c->stderr)
> +			if (c->force_stderr)
>  				die("Multiple --stderr options given");
>  
> -			c->stderr = 1;
> +			c->force_stderr = 1;
>  			break;
>  		case 'l':
> -			if (c->stderr)
> +			if (c->force_stderr)
>  				die("Can't log to both stderr and file");
>  
>  			if (logfile)
> diff --git a/passt.c b/passt.c
> index 5b8146e..f67213a 100644
> --- a/passt.c
> +++ b/passt.c
> @@ -241,7 +241,7 @@ int main(int argc, char **argv)
>  	conf(&c, argc, argv);
>  	trace_init(c.trace);
>  
> -	if (c.stderr || isatty(fileno(stdout)))
> +	if (c.force_stderr || isatty(fileno(stdout)))
>  		__openlog(log_name, LOG_PERROR, LOG_DAEMON);
>  
>  	quit_fd = pasta_netns_quit_init(&c);
> diff --git a/passt.h b/passt.h
> index b73f4ff..006d1c1 100644
> --- a/passt.h
> +++ b/passt.h
> @@ -158,7 +158,7 @@ struct ip6_ctx {
>   * @trace:		Enable tracing (extra debug) mode
>   * @quiet:		Don't print informational messages
>   * @foreground:		Run in foreground, don't log to stderr by default
> - * @stderr:		Force logging to stderr
> + * @force_stderr:	Force logging to stderr
>   * @nofile:		Maximum number of open files (ulimit -n)
>   * @sock_path:		Path for UNIX domain socket
>   * @pcap:		Path for packet capture file
> @@ -207,7 +207,7 @@ struct ctx {
>  	int trace;
>  	int quiet;
>  	int foreground;
> -	int stderr;
> +	int force_stderr;
>  	int nofile;
>  	char sock_path[UNIX_PATH_MAX];
>  	char pcap[PATH_MAX];

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson