[Issue 13517] Only touch .di generated file if changed

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=13517

Ketmar Dark <ketmar at ketmar.no-ip.org> changed:

           What    |Removed                     |Added
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                 CC|                            |ketmar at ketmar.no-ip.org

--- Comment #24 from Ketmar Dark <ketmar at ketmar.no-ip.org> ---
(In reply to Steven Schveighoffer from comment #23)
> Perhaps you are getting caught up in terminology. It's not a target the
> build system is trying to generate.
so it should *never* be (re)generated.

> But my point is, you don't tell it about building the .di file because the
> build of the .di file is implicit in the rule for the .o.
and build system doesn't even know that we are using implicitly regeneration
for some files and that other files can depend of this unknown files. it's a
very… strange way to using build system.

> But your project doesn't know how to build /usr/include/stdio.h, so why
> should your project care about how some other project's .di file is made?
i never need to (re)generate /usr/include/stdio.h, it's god-given. and i'm
assuming that we are talking about .di files that can be generated by various
parts of the project we are trying to build. god-given .di files can be treated
just like <stdio.h> — i.e. not mentioned at all. and not silentely regenerated
under any circumstances.


> I will say, I think the enhancement is unusual and counterintuitive. It may
> be best to enable this mechanism with a special flag. Maybe like -H+
hm. if new behavior will not be default one and must be explicitly turned on,
i'm all in for this ER, it will not hurt.

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