svn commit: r352953 - in head/usr.bin: killall split

[Conrad Meyer]

Hi Alexander,

Coverity has millions of spurious warnings of this class and they're
basically all false positives.  I think we should instead try to
figure out how to disable this class of warning on our codebase, since
it is largely incorrect.

I would encourage reverting this change, because it uglies up the code
for no functional benefit.  The code was correct before the change;
only Coverity was wrong.

Best,
Conrad

On Tue, Oct 1, 2019 at 11:15 PM Alexander Kabaev <kan at freebsd.org> wrote:
>
> Author: kan
> Date: Wed Oct  2 06:15:30 2019
> New Revision: 352953
> URL: https://svnweb.freebsd.org/changeset/base/352953
>
> Log:
>   Convert pnmatch to single element array in regexec calls
>
>   The regexec function is declared as taking an array of regmatch_t
>   elements, and passing in the pointer to singleton element, while
>   correct, triggers a Coverity warning. Convert the singleton into
>   an array of one to silence the warning.
>
>   Reported by:  Coverity
>   Coverity CID: 1009732, 1009733
>   MFC after:    2 weeks
>
> Modified:
>   head/usr.bin/killall/killall.c
>   head/usr.bin/split/split.c
>
> Modified: head/usr.bin/killall/killall.c
> ==============================================================================
> --- head/usr.bin/killall/killall.c      Wed Oct  2 02:37:34 2019        (r352952)
> +++ head/usr.bin/killall/killall.c      Wed Oct  2 06:15:30 2019        (r352953)
> @@ -98,7 +98,7 @@ main(int ac, char **av)
>         struct stat     sb;
>         struct passwd   *pw;
>         regex_t         rgx;
> -       regmatch_t      pmatch;
> +       regmatch_t      pmatch[1];
>         int             i, j, ch;
>         char            buf[256];
>         char            first;
> @@ -361,9 +361,9 @@ main(int ac, char **av)
>                                 }
>                         }
>                         if (mflag) {
> -                               pmatch.rm_so = 0;
> -                               pmatch.rm_eo = strlen(thiscmd);
> -                               if (regexec(&rgx, thiscmd, 0, &pmatch,
> +                               pmatch[0].rm_so = 0;
> +                               pmatch[0].rm_eo = strlen(thiscmd);
> +                               if (regexec(&rgx, thiscmd, 0, pmatch,
>                                     REG_STARTEND) != 0)
>                                         matched = 0;
>                                 regfree(&rgx);
> @@ -387,9 +387,9 @@ main(int ac, char **av)
>                                 }
>                         }
>                         if (mflag) {
> -                               pmatch.rm_so = 0;
> -                               pmatch.rm_eo = strlen(thiscmd);
> -                               if (regexec(&rgx, thiscmd, 0, &pmatch,
> +                               pmatch[0].rm_so = 0;
> +                               pmatch[0].rm_eo = strlen(thiscmd);
> +                               if (regexec(&rgx, thiscmd, 0, pmatch,
>                                     REG_STARTEND) == 0)
>                                         matched = 1;
>                                 regfree(&rgx);
>
> Modified: head/usr.bin/split/split.c
> ==============================================================================
> --- head/usr.bin/split/split.c  Wed Oct  2 02:37:34 2019        (r352952)
> +++ head/usr.bin/split/split.c  Wed Oct  2 06:15:30 2019        (r352953)
> @@ -281,11 +281,11 @@ split2(void)
>
>                 /* Check if we need to start a new file */
>                 if (pflag) {
> -                       regmatch_t pmatch;
> +                       regmatch_t pmatch[1];
>
> -                       pmatch.rm_so = 0;
> -                       pmatch.rm_eo = len - 1;
> -                       if (regexec(&rgx, bfr, 0, &pmatch, REG_STARTEND) == 0)
> +                       pmatch[0].rm_so = 0;
> +                       pmatch[0].rm_eo = len - 1;
> +                       if (regexec(&rgx, bfr, 0, pmatch, REG_STARTEND) == 0)
>                                 newfile();
>                 } else if (lcnt++ == numlines) {
>                         newfile();