[PATCH 1/3] libbb: GETOPT_RESET macro

Bartosz Gołaszewski bartekgola at gmail.com
Wed Apr 12 06:38:52 UTC 2017


2017-04-11 23:58 GMT+02:00 Kaarle Ritvanen <kaarle.ritvanen at datakunkku.fi>:
> Signed-off-by: Kaarle Ritvanen <kaarle.ritvanen at datakunkku.fi>
> ---
>  include/libbb.h            | 19 +++++++++++++++++++
>  libbb/getopt32.c           |  8 +-------
>  libbb/vfork_daemon_rexec.c | 28 ++--------------------------
>  runit/sv.c                 |  7 +------
>  shell/shell_common.c       |  8 +-------
>  util-linux/getopt.c        |  7 +------
>  6 files changed, 25 insertions(+), 52 deletions(-)
>
> diff --git a/include/libbb.h b/include/libbb.h
> index 0407163..eb78619 100644
> --- a/include/libbb.h
> +++ b/include/libbb.h
> @@ -1178,6 +1178,25 @@ extern uint32_t option_mask32;
>  extern uint32_t getopt32(char **argv, const char *applet_opts, ...) FAST_FUNC;
>
>
> +/* BSD-derived getopt() functions require that optind be set to 1 in
> + * order to reset getopt() state.  This used to be generally accepted
> + * way of resetting getopt().  However, glibc's getopt()
> + * has additional getopt() state beyond optind, and requires that
> + * optind be set to zero to reset its state.  So the unfortunate state of
> + * affairs is that BSD-derived versions of getopt() misbehave if
> + * optind is set to 0 in order to reset getopt(), and glibc's getopt()
> + * will core dump if optind is set 1 in order to reset getopt().
> + *
> + * More modern versions of BSD require that optreset be set to 1 in

s/optreset/optind

> + * order to reset getopt().  Sigh.  Standards, anyone?
> + */
> +#ifdef __GLIBC__
> +#define GETOPT_RESET optind = 0;
> +#else /* BSD style */
> +#define GETOPT_RESET optind = 1;
> +#endif
> +

This should be

#define GETOPT_RESET() do { \
        optind = 0; \
        } while (0)

> +
>  /* Having next pointer as a first member allows easy creation
>   * of "llist-compatible" structs, and using llist_FOO functions
>   * on them.
> diff --git a/libbb/getopt32.c b/libbb/getopt32.c
> index 497fc01..38fac14 100644
> --- a/libbb/getopt32.c
> +++ b/libbb/getopt32.c
> @@ -576,13 +576,7 @@ getopt32(char **argv, const char *applet_opts, ...)
>          * run_nofork_applet() does this, but we might end up here
>          * also via gunzip_main() -> gzip_main(). Play safe.
>          */
> -#ifdef __GLIBC__
> -       optind = 0;
> -#else /* BSD style */
> -       optind = 1;
> -       /* optreset = 1; */
> -#endif
> -       /* optarg = NULL; opterr = 0; optopt = 0; - do we need this?? */
> +       GETOPT_RESET
>
>         /* Note: just "getopt() <= 0" will not work well for
>          * "fake" short options, like this one:
> diff --git a/libbb/vfork_daemon_rexec.c b/libbb/vfork_daemon_rexec.c
> index 2e7dc2d..e2a6b39 100644
> --- a/libbb/vfork_daemon_rexec.c
> +++ b/libbb/vfork_daemon_rexec.c
> @@ -121,28 +121,8 @@ int FAST_FUNC run_nofork_applet(int applet_no, char **argv)
>
>         /* In case getopt() or getopt32() was already called:
>          * reset the libc getopt() function, which keeps internal state.
> -        *
> -        * BSD-derived getopt() functions require that optind be set to 1 in
> -        * order to reset getopt() state.  This used to be generally accepted
> -        * way of resetting getopt().  However, glibc's getopt()
> -        * has additional getopt() state beyond optind, and requires that
> -        * optind be set to zero to reset its state.  So the unfortunate state of
> -        * affairs is that BSD-derived versions of getopt() misbehave if
> -        * optind is set to 0 in order to reset getopt(), and glibc's getopt()
> -        * will core dump if optind is set 1 in order to reset getopt().
> -        *
> -        * More modern versions of BSD require that optreset be set to 1 in
> -        * order to reset getopt().  Sigh.  Standards, anyone?
>          */
> -#ifdef __GLIBC__
> -       optind = 0;
> -#else /* BSD style */
> -       optind = 1;
> -       /* optreset = 1; */
> -#endif
> -       /* optarg = NULL; opterr = 1; optopt = 63; - do we need this too? */
> -       /* (values above are what they initialized to in glibc and uclibc) */
> -       /* option_mask32 = 0; - not needed, no applet depends on it being 0 */
> +       GETOPT_RESET
>
>         argc = 1;
>         while (argv[argc])
> @@ -167,11 +147,7 @@ int FAST_FUNC run_nofork_applet(int applet_no, char **argv)
>         restore_nofork_data(&old);
>
>         /* Other globals can be simply reset to defaults */
> -#ifdef __GLIBC__
> -       optind = 0;
> -#else /* BSD style */
> -       optind = 1;
> -#endif
> +       GETOPT_RESET
>
>         return rc & 0xff; /* don't confuse people with "exitcodes" >255 */
>  }
> diff --git a/runit/sv.c b/runit/sv.c
> index 9e21322..4ba5df7 100644
> --- a/runit/sv.c
> +++ b/runit/sv.c
> @@ -688,12 +688,7 @@ int svc_main(int argc UNUSED_PARAM, char **argv)
>         /* getopt32() was already called:
>          * reset the libc getopt() function, which keeps internal state.
>          */
> -#ifdef __GLIBC__
> -       optind = 0;
> -#else /* BSD style */
> -       optind = 1;
> -       /* optreset = 1; */
> -#endif
> +       GETOPT_RESET
>
>         do {
>                 if (opts & 1) {
> diff --git a/shell/shell_common.c b/shell/shell_common.c
> index 549b17c..cc9ac15 100644
> --- a/shell/shell_common.c
> +++ b/shell/shell_common.c
> @@ -401,13 +401,7 @@ shell_builtin_ulimit(char **argv)
>         /* In case getopt was already called:
>          * reset the libc getopt() function, which keeps internal state.
>          */
> -#ifdef __GLIBC__
> -       optind = 0;
> -#else /* BSD style */
> -       optind = 1;
> -       /* optreset = 1; */
> -#endif
> -       /* optarg = NULL; opterr = 0; optopt = 0; - do we need this?? */
> +       GETOPT_RESET
>
>         argc = 1;
>         while (argv[argc])
> diff --git a/util-linux/getopt.c b/util-linux/getopt.c
> index 63294c5..9621582 100644
> --- a/util-linux/getopt.c
> +++ b/util-linux/getopt.c
> @@ -246,12 +246,7 @@ static int generate_output(char **argv, int argc, const char *optstr, const stru
>
>         /* We used it already in main() in getopt32(),
>          * we *must* reset getopt(3): */
> -#ifdef __GLIBC__
> -       optind = 0;
> -#else /* BSD style */
> -       optind = 1;
> -       /* optreset = 1; */
> -#endif
> +       GETOPT_RESET
>
>         while (1) {
>  #if ENABLE_FEATURE_GETOPT_LONG
> --
> 2.9.3
>
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> http://lists.busybox.net/mailman/listinfo/busybox

-- 
Best regards,
Bartosz Golaszewski


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