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From: David Marchand <david.marchand@redhat.com>
To: Bruce Richardson <bruce.richardson@intel.com>
Cc: dev@dpdk.org, rjarry@redhat.com
Subject: Re: [PATCH v4 0/7] document and simplify use of cmdline
Date: Tue, 17 Oct 2023 18:23:47 +0200	[thread overview]
Message-ID: <CAJFAV8zxevRgdsUGjAkEZn790CfhdZavoTGWBpRUYm_nE_E7AA@mail.gmail.com> (raw)
In-Reply-To: <ZS5F7kQ59kAob5fA@bricha3-MOBL.ger.corp.intel.com>

On Tue, Oct 17, 2023 at 10:29 AM Bruce Richardson
<bruce.richardson@intel.com> wrote:
> >
> > - testpmd accepts both "help" and "help <section>" commands.
> > But the cmdline library does not provide a way (afair) for specifiying
> > this "optional" aspect.
> >
> > And it can't be expressed with this series current syntax since
> > generated symbols would conflict if we ask for two "help" commands.
> >
> > My quick hack was to introduce a way to select the prefix of the
> > generated symbols.
> > There may be a better way, like finding a better discriminant for
> > naming symbols...
> > But, on the other hand, the symbols prefix might be something a
> > developer wants to control (instead of currently hardcoded cmd_
> > prefix).
> >
> > @@ -20,6 +20,12 @@ def process_command(tokens, cfile, comment):
> >      """Generate the structures and definitions for a single command."""
> >      name = []
> >
> > +    prefix, sep, cmd_name = tokens[0].partition(':')
> > +    if cmd_name:
> > +        tokens[0] = cmd_name
> > +    else:
> > +        prefix = 'cmd'
> > +
> >      if tokens[0].startswith('<'):
> >          print('Error: each command must start with at least one
> > literal string', file=sys.stderr)
> >          sys.exit(1)
> >
> > (etc... I am not copying the rest of the diff)
> >
> > I then used as:
> >
> > cmd_brief:help # help: Show help
> > help <STRING>section # help: Show help
> >
>
> Interesting. I actually had no plans to even consider moving something like
> testpmd over. However, this is an interesting one, though I'm not really

Given the extensive use of the cmdline library in testpmd, it is a
good way to identify the limits of this series :-).


> sure I like it that much as a feature :-) I rather like having unique
> prefixes for each command. I wasn't actually aware of the testpmd "help
> <section>" command at all. I will have to look into it.

Let me propose an alternative hack.
I mentionned previously that we could have a better namespace /
discriminant for those symbols, and it seems easier than I thought:

@@ -25,8 +25,10 @@ def process_command(tokens, cfile, comment):
         sys.exit(1)
     for t in tokens:
         if t.startswith('<'):
-            break
-        name.append(t)
+            t_type, t_name = t[1:].split('>')
+            name.append(t_name)
+        else:
+            name.append(t)
     name = '_'.join(name)

     result_struct = []

With this, any command implementation symbol has the full chain of
token names as a prefix which will ensure there is no conflict.
WDYT?

help # help: Show help
help <STRING>section # help: Show help

Results in:

cmd_help_parsed(void *parsed_result, struct cmdline *cl, void *data);
struct cmd_help_result {
static cmdline_parse_token_string_t cmd_help_help_tok =
    TOKEN_STRING_INITIALIZER(struct cmd_help_result, help, "help");
static cmdline_parse_inst_t cmd_help = {
    .f = cmd_help_parsed,
        (void *)&cmd_help_help_tok,

And:

cmd_help_section_parsed(void *parsed_result, struct cmdline *cl, void *data);
struct cmd_help_section_result {
static cmdline_parse_token_string_t cmd_help_section_help_tok =
    TOKEN_STRING_INITIALIZER(struct cmd_help_section_result, help, "help");
static cmdline_parse_token_string_t cmd_help_section_section_tok =
    TOKEN_STRING_INITIALIZER(struct cmd_help_section_result, section, NULL);
static cmdline_parse_inst_t cmd_help_section = {
    .f = cmd_help_section_parsed,
        (void *)&cmd_help_section_help_tok,
        (void *)&cmd_help_section_section_tok,


>
> >
> > - Multi choice fixed strings is something that is often used in
> > testpmd, like here, in the help <section> command.
> > Here is my quick hack:
> >
> > diff --git a/buildtools/dpdk-cmdline-gen.py b/buildtools/dpdk-cmdline-gen.py
> > index 3b41fb0493..e8c9e079de 100755
> > --- a/buildtools/dpdk-cmdline-gen.py
> > +++ b/buildtools/dpdk-cmdline-gen.py
> > @@ -35,7 +35,11 @@ def process_command(tokens, cfile, comment):
> >      for t in tokens:
> >          if t.startswith('<'):
> >              t_type, t_name = t[1:].split('>')
> > -            t_val = 'NULL'
> > +            if len(t_type.split('(')) == 2:
> > +                t_type, t_val = t_type.split('(')
> > +                t_val = '"' + t_val.split(')')[0] + '"'
> > +            else:
> > +                t_val = 'NULL'
> >          else:
> >              t_type = 'STRING'
> >              t_name = t
> > @@ -113,7 +117,7 @@ def process_commands(infile, hfile, cfile, ctxname):
> >              continue
> >          if '#' not in line:
> >              line = line + '#'  # ensure split always works, even if
> > no help text
> > -        tokens, comment = line.split('#', 1)
> > +        tokens, comment = line.rsplit('#', 1)
> >          instances.append(process_command(tokens.strip().split(),
> > cfile, comment.strip()))
> >
> >      print(f'static __rte_used cmdline_parse_ctx_t {ctxname}[] = {{')
> >
> >
> > Which translates as:
> > cmd_brief:help # help: Show help
> > help <STRING(all#control#display#config#ports)>section # help: Show help
> >
>
> +1
> I was actualy thinking that adding support for multi-choice fixed strings
> is something we should add. One thought that I had was that "#" is not a
> particularly good choice of separator here. While, as you show, it can be
> made to work; I think - since we are defining our own syntax here - that it
> would be both simpler for the script, and simpler for the user, to have "|"
> as the option separator. It should be familiar for everyone as an option
> separator from regexes, unlike "#" which is more familar for comments.
>
> So what about:
> help <|all|control|display|config|ports|>section

I don't like using | as it gives the false impression regexp are supported...


>
> By starting with the separator, we should avoid having to provide the
> STRING type at all.

... and as a consequence, I find <|all confusing, it is like an empty
value would be acceptable.


About skipping the token type for such lists, I had considered it, but
I thought other types took an optional list of allowed values...
Now looking at the cmdline types, it is not the case.
Maybe I mixed with some other cli framework I played with in the past...

All of this to say, ok for me to omit the type.


>
> To my previous point on not liking to have a prefix-specifier, the
> alternative to making testpmd work with the script is to tweak very
> slightly the "help <section>".
>
>   help   # show general help
>   help on <|all|control|display|config|ports|>section
>
> By making the command "help on ports" rather than "help ports" we would
> avoid the need for the prefix syntax.

There are other cases where a "chain of command" returns the value of
a parameter.
And the same parameter may be set via "chain of command <UINT>value".


-- 
David Marchand


  parent reply	other threads:[~2023-10-17 16:24 UTC|newest]

Thread overview: 73+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-08-02 17:00 [RFC PATCH 0/1] make cmdline library easier to use Bruce Richardson
2023-08-02 17:00 ` [RFC PATCH 1/1] cmdline/dpdk-cmdline-gen: generate boilerplate for simple cmds Bruce Richardson
2023-08-02 18:05 ` [RFC PATCH 0/1] make cmdline library easier to use Stephen Hemminger
2023-08-03  8:11   ` Bruce Richardson
2023-09-18 13:03 ` [RFC PATCH v2 0/5] use script to simplify use of cmdline lib Bruce Richardson
2023-09-18 13:03   ` [RFC PATCH v2 1/5] buildtools/dpdk-cmdline-gen: generate boilerplate for simple cmds Bruce Richardson
2023-09-18 13:03   ` [RFC PATCH v2 2/5] examples/simple_mp: auto-generate cmdline boilerplate Bruce Richardson
2023-09-18 13:03   ` [RFC PATCH v2 3/5] examples/hotplug_mp: " Bruce Richardson
2023-09-18 13:03   ` [RFC PATCH v2 4/5] buildtools/dpdk-cmdline-gen: add IP address support Bruce Richardson
2023-09-18 13:03   ` [RFC PATCH v2 5/5] examples/bond: auto-generate cmdline boilerplate Bruce Richardson
2023-10-11 13:33 ` [PATCH v3 0/5] document and simplify use of cmdline Bruce Richardson
2023-10-11 13:33   ` [PATCH v3 1/5] doc/prog_guide: new chapter on cmdline library Bruce Richardson
2023-10-11 13:33   ` [PATCH v3 2/5] buildtools: script to generate cmdline boilerplate Bruce Richardson
2023-10-13 12:23     ` Robin Jarry
2023-10-13 12:43       ` Bruce Richardson
2023-10-11 13:33   ` [PATCH v3 3/5] examples/simple_mp: auto-generate " Bruce Richardson
2023-10-11 13:33   ` [PATCH v3 4/5] examples/hotplug_mp: " Bruce Richardson
2023-10-11 13:33   ` [PATCH v3 5/5] examples/bond: " Bruce Richardson
2023-10-12 13:21   ` [PATCH v3 0/5] document and simplify use of cmdline David Marchand
2023-10-12 13:47     ` Bruce Richardson
2023-10-12 13:51     ` Bruce Richardson
2023-10-16 14:06 ` [PATCH v4 0/7] " Bruce Richardson
2023-10-16 14:06   ` [PATCH v4 1/7] doc/prog_guide: new chapter on cmdline library Bruce Richardson
2023-10-16 14:06   ` [PATCH v4 2/7] buildtools: script to generate cmdline boilerplate Bruce Richardson
2023-10-16 14:06   ` [PATCH v4 3/7] ci: allow use of DPDK tools when building examples Bruce Richardson
2023-10-17 12:24     ` Aaron Conole
2023-10-17 12:28       ` Bruce Richardson
2023-10-16 14:06   ` [PATCH v4 4/7] examples/simple_mp: auto-generate cmdline boilerplate Bruce Richardson
2023-10-16 14:06   ` [PATCH v4 5/7] examples/hotplug_mp: " Bruce Richardson
2023-10-16 14:06   ` [PATCH v4 6/7] examples/bond: " Bruce Richardson
2023-10-16 14:06   ` [PATCH v4 7/7] examples/vdpa: " Bruce Richardson
2023-10-17  7:10   ` [PATCH v4 0/7] document and simplify use of cmdline David Marchand
2023-10-17  8:29     ` Bruce Richardson
2023-10-17 12:16       ` Bruce Richardson
2023-10-17 16:23       ` David Marchand [this message]
2023-10-17 17:02         ` Bruce Richardson
2023-10-17 17:08         ` Bruce Richardson
2023-10-18 11:21           ` David Marchand
2023-10-18 11:37             ` Bruce Richardson
2023-10-17 12:13 ` [PATCH v5 0/9] " Bruce Richardson
2023-10-17 12:13   ` [PATCH v5 1/9] doc/prog_guide: new chapter on cmdline library Bruce Richardson
2023-10-17 12:13   ` [PATCH v5 2/9] buildtools: script to generate cmdline boilerplate Bruce Richardson
2023-10-25 13:04     ` Robin Jarry
2023-10-25 13:33       ` Bruce Richardson
2023-10-17 12:13   ` [PATCH v5 3/9] ci: allow use of DPDK tools when building examples Bruce Richardson
2023-10-17 14:08     ` Aaron Conole
2023-10-17 12:13   ` [PATCH v5 4/9] examples/simple_mp: auto-generate cmdline boilerplate Bruce Richardson
2023-10-17 12:13   ` [PATCH v5 5/9] examples/hotplug_mp: " Bruce Richardson
2023-10-17 12:13   ` [PATCH v5 6/9] examples/bond: " Bruce Richardson
2023-10-17 12:13   ` [PATCH v5 7/9] examples/vdpa: " Bruce Richardson
2023-10-17 12:13   ` [PATCH v5 8/9] buildtools/dpdk-cmdline-gen: support option strings Bruce Richardson
2023-10-17 12:13   ` [PATCH v5 9/9] examples/ntb: auto-generate cmdline boilerplate Bruce Richardson
2023-10-23 13:15 ` [PATCH v6 0/9] document and simplify use of cmdline Bruce Richardson
2023-10-23 13:15   ` [PATCH v6 1/9] doc/prog_guide: new chapter on cmdline library Bruce Richardson
2023-10-23 13:15   ` [PATCH v6 2/9] buildtools: script to generate cmdline boilerplate Bruce Richardson
2023-10-23 13:15   ` [PATCH v6 3/9] ci: allow use of DPDK tools when building examples Bruce Richardson
2023-10-23 13:15   ` [PATCH v6 4/9] examples/simple_mp: auto-generate cmdline boilerplate Bruce Richardson
2023-10-23 13:15   ` [PATCH v6 5/9] examples/hotplug_mp: " Bruce Richardson
2023-10-23 13:15   ` [PATCH v6 6/9] examples/bond: " Bruce Richardson
2023-10-23 13:15   ` [PATCH v6 7/9] examples/vdpa: " Bruce Richardson
2023-10-23 13:15   ` [PATCH v6 8/9] buildtools/dpdk-cmdline-gen: support option strings Bruce Richardson
2023-10-23 13:15   ` [PATCH v6 9/9] examples/ntb: auto-generate cmdline boilerplate Bruce Richardson
2023-10-27 11:01 ` [PATCH v7 0/9] document and simplify use of cmdline Bruce Richardson
2023-10-27 11:01   ` [PATCH v7 1/9] doc/prog_guide: new chapter on cmdline library Bruce Richardson
2023-10-27 11:01   ` [PATCH v7 2/9] buildtools: script to generate cmdline boilerplate Bruce Richardson
2023-10-27 11:01   ` [PATCH v7 3/9] ci: allow use of DPDK tools when building examples Bruce Richardson
2023-10-27 11:01   ` [PATCH v7 4/9] examples/simple_mp: auto-generate cmdline boilerplate Bruce Richardson
2023-10-27 11:01   ` [PATCH v7 5/9] examples/hotplug_mp: " Bruce Richardson
2023-10-27 11:01   ` [PATCH v7 6/9] examples/bond: " Bruce Richardson
2023-10-27 11:01   ` [PATCH v7 7/9] examples/vdpa: " Bruce Richardson
2023-10-27 11:01   ` [PATCH v7 8/9] buildtools/dpdk-cmdline-gen: support option strings Bruce Richardson
2023-10-27 11:01   ` [PATCH v7 9/9] examples/ntb: auto-generate cmdline boilerplate Bruce Richardson
2023-11-10 14:16   ` [PATCH v7 0/9] document and simplify use of cmdline David Marchand

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