Re: [PATCH v2 1/2] perf: Suggest inbuilt commands for unknown command

From: Arnaldo Carvalho de Melo
Date: Wed Mar 20 2024 - 11:00:27 EST


On Wed, Mar 20, 2024 at 11:54:09AM -0300, Arnaldo Carvalho de Melo wrote:
> On Fri, Mar 01, 2024 at 12:13:05PM -0800, Ian Rogers wrote:
> > The existing unknown command code looks for perf scripts like
> > perf-archive.sh and perf-iostat.sh, however, inbuilt commands aren't
> > suggested. Add the inbuilt commands so they may be suggested too.
> >
> > Before:
> > ```
> > $ perf reccord
> > perf: 'reccord' is not a perf-command. See 'perf --help'.
> > ```
> >
> > After:
> > ```
> > $ perf reccord
> > perf: 'reccord' is not a perf-command. See 'perf --help'.
> >
> > Did you mean this?
> > record
> > ```
> >
> > Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
> > ---
> > v2. Drops a merged patch and rebases. No functional change. Arnaldo
> > reported the patch not working for him, but I've not found a
>
> Not working:
>
> root@number:~# perf reccord
> Failed to run command 'reccord': No such file or directory
> root@number:~#
>
> ⬢[acme@toolbox perf-tools-next]$ git log --oneline -1
> a65ef8052854ba75 (HEAD) perf: Suggest inbuilt commands for unknown command
> ⬢[acme@toolbox perf-tools-next]$
>
> I use O= with install-bin, trying:
>
> ⬢[acme@toolbox perf-tools-next]$ make -C tools/perf install-bin
> ⬢[acme@toolbox perf-tools-next]$ perf raccord
> Failed to run command 'raccord': No such file or directory
> ⬢[acme@toolbox perf-tools-next]$
>
> Also didn't work
>
> Trying to figure this out...

It somehow gets done_help set to 32767, and this will not run help_unknown_cmd(), continuing after a conf call...

(gdb) p *argv
$7 = 0x7fffffffe4c5 "raccord"
(gdb) s
run_argv (argcp=0x7fffffffdfbc, argv=0x7fffffffdfb0) at perf.c:445
445 {
(gdb) n
447 handle_internal_command(*argcp, *argv);
(gdb) n
450 execv_dashed_external(*argv);
(gdb) p *argv
$8 = (const char **) 0x7fffffffe1d0
(gdb) p **argv
$9 = 0x7fffffffe4c5 "raccord"
(gdb) n
[Detaching after fork from child process 3245070]
451 return 0;
(gdb) n
452 }
(gdb) n
main (argc=1, argv=0x7fffffffe1d0) at perf.c:565
565 if (errno != ENOENT)
(gdb) p; errno
Invalid character ';' in expression.
(gdb) p errno
$10 = 2
(gdb) n
568 if (!done_help) {
(gdb) p done_help
$11 = 32767
(gdb) list
563 run_argv(&argc, &argv);
564
565 if (errno != ENOENT)
566 break;
567
568 if (!done_help) {
569 struct cmdnames main_cmds;
570
571 for (unsigned int i = 0; i < ARRAY_SIZE(commands); i++) {
572 add_cmdname(&main_cmds,
(gdb)
573 commands[i].cmd,
574 strlen(commands[i].cmd));
575 }
576 cmd = argv[0] = help_unknown_cmd(cmd, &main_cmds);
577 clean_cmdnames(&main_cmds);
578 done_help = 1;
579 if (!cmd)
580 break;
581 } else
582 break;
(gdb)