[Scons-users] Value/Alias Nodes default to up-to-date

[Bill Deegan]

Still don't really understand what you're trying to do.

What do you mean by this "allowing me to make Action()'s with dependency
orderings"?

On Sun, Jan 2, 2022 at 3:10 PM Brad Kraemer <computerpro_58 at hotmail.com>
wrote:

> * Fixed subject line (the original line from the mailer daemon added JUNK,
> as this one doesn't allow unconfirmed posters, i.e. I should have waited
> for the mailing-list confirmation before sending the first e-mail off)
>
>
> Currently, just experimenting with some SCons features. At this time I was
> creating an Alias() because I wanted the Alias() object (which is
> namespaced outside the regular FS namespace), allowing me to make
> Action()'s with dependency orderings. While not having these actions kicked
> off by running something like '$ scons /' (which something like Command()
> would).
>
>
> I realize this is outside the intended use of these functions. However,
> the doc's don't forbid it so it's clean in my eyes.
>
> The Command() part is just for something to depend on (can replace it with
> Program() or any other builder, my issue is with the Alias() lines).
>
>
> Your reasoning makes sense, however, if my Alias is never out of date
> (i.e. on creation it's meant to be considered already built), why can I run
> AlwaysBuild() and thus force it to build (is this the equivalent of
> rebuilding something already up-to-date)?
>
> Just looking at the sources, it seems these Node's are meant to be built
> at least once (however, Value() in particular does seem to have a parameter
> to be considered built on creation). Or am I off base with this?
>
>
> On 2022-01-02 5:30 p.m., Bill Deegan wrote:
>
> Maybe you explain what you're trying to do, rather than how you're
> currently trying to do it?
> Because this looks like a mess of hard to understand code and there's very
> likely a better way to do this.
>
> Those aliases would never be out of date with a static source.
> Your command has no source listed, so it will also never be out of
> date..(after the first time, if the file t1 was actually built).
>
> -Bill
>
>
> On Sun, Jan 2, 2022 at 2:20 PM Bill Deegan <bill at baddogconsulting.com>
> wrote:
>
>> also why **JUNK** in subject?
>>
>> On Sun, Jan 2, 2022 at 2:20 PM Bill Deegan <bill at baddogconsulting.com>
>> wrote:
>>
>>> What output do you see when you run your example?
>>>
>>>
>>> On Sun, Jan 2, 2022 at 7:56 AM Brad Kraemer <computerpro_58 at hotmail.com>
>>> wrote:
>>>
>>>> Hello,
>>>>
>>>> I filed a GitHub Issue <https://github.com/SCons/scons/issues/4079>
>>>> and got bounced to this mailing list. So here we go again:
>>>>
>>>> Value/Alias nodes (as created by the Alias() and Value()
>>>> functions/methods receptively) default to up-to-date.
>>>>
>>>> SCons 4.1.0
>>>>
>>>> Python 3.9
>>>>
>>>> Installed from nixpkgs (NixOS, $ nix-env -iA nixos.scons)
>>>>
>>>> Linux
>>>>
>>>> Reproduction (SConstruct):
>>>>
>>>> def print_target_1(target, source, env):
>>>>    print("Target 1 built")
>>>>
>>>> def print_alias_1(target, source, env):
>>>>    print("[I'm not getting called]")
>>>>
>>>> def print_alias_2(target, source, env):
>>>>    print("I'm getting called because of AlwaysBuild() workaround")
>>>>
>>>> t1 = Command("t1", [], Action(print_target_1, cmdstr=None))
>>>> Default(t1)
>>>>
>>>> v = Value("_")
>>>> a1 = Alias("a1", v, Action(print_alias_1, cmdstr=None))
>>>> a2 = Alias("a2", v, Action(print_alias_2, cmdstr=None))
>>>> Depends(t1, a1)
>>>> Depends(t1, a2)
>>>>
>>>> AlwaysBuild(a2)
>>>>
>>>>
>>>> Invoke via executing '$ scons' from the directory where the above
>>>> SConstruct file exists.
>>>>
>>>>
>>>> Thanks,
>>>>
>>>> simplejack-src
>>>>
>>>>
>>>> _______________________________________________
>>>> Scons-users mailing list
>>>> Scons-users at scons.org
>>>> https://pairlist4.pair.net/mailman/listinfo/scons-users
>>>>
>>>
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