[Buildroot] call with hooks

[Buildroot] call with hooks

[Danomi Manchego]

 Hello all,

I noticed a possible inconsistency, and thought I should post it.
Looking at places where buildroot uses hooks:

$ grep -r '$(hook))$(sep)' .
./Makefile: $(foreach hook,$(TARGET_FINALIZE_HOOKS),$($(hook))$(sep))
./package/pkg-generic.mk: $(foreach
hook,$($(PKG)_PRE_DOWNLOAD_HOOKS),$(call $(hook))$(sep))
./package/pkg-generic.mk: $(foreach
hook,$($(PKG)_POST_DOWNLOAD_HOOKS),$(call $(hook))$(sep))
./package/pkg-generic.mk: $(foreach
hook,$($(PKG)_PRE_EXTRACT_HOOKS),$(call $(hook))$(sep))
./package/pkg-generic.mk: $(foreach
hook,$($(PKG)_POST_EXTRACT_HOOKS),$(call $(hook))$(sep))
./package/pkg-generic.mk: $(foreach
hook,$($(PKG)_PRE_RSYNC_HOOKS),$(call $(hook))$(sep))
./package/pkg-generic.mk: $(foreach
hook,$($(PKG)_POST_RSYNC_HOOKS),$(call $(hook))$(sep))
./package/pkg-generic.mk: $(foreach
hook,$($(PKG)_PRE_PATCH_HOOKS),$(call $(hook))$(sep))
./package/pkg-generic.mk: $(foreach
hook,$($(PKG)_POST_PATCH_HOOKS),$(call $(hook))$(sep))
./package/pkg-generic.mk: $(foreach
hook,$($(PKG)_POST_PREPARE_HOOKS),$(call $(hook))$(sep))
./package/pkg-generic.mk: $(foreach
hook,$($(PKG)_PRE_CONFIGURE_HOOKS),$(call $(hook))$(sep))
./package/pkg-generic.mk: $(foreach
hook,$($(PKG)_POST_CONFIGURE_HOOKS),$(call $(hook))$(sep))
./package/pkg-generic.mk: $(foreach
hook,$($(PKG)_PRE_BUILD_HOOKS),$(call $(hook))$(sep))
./package/pkg-generic.mk: $(foreach
hook,$($(PKG)_POST_BUILD_HOOKS),$(call $(hook))$(sep))
./package/pkg-generic.mk: $(foreach
hook,$($(PKG)_PRE_INSTALL_HOOKS),$(call $(hook))$(sep))
./package/pkg-generic.mk: $(foreach
hook,$($(PKG)_POST_INSTALL_HOOKS),$(call $(hook))$(sep))
./package/pkg-generic.mk: $(foreach
hook,$($(PKG)_PRE_INSTALL_STAGING_HOOKS),$(call $(hook))$(sep))
./package/pkg-generic.mk: $(foreach
hook,$($(PKG)_POST_INSTALL_STAGING_HOOKS),$(call $(hook))$(sep))
./package/pkg-generic.mk: $(foreach
hook,$($(PKG)_PRE_INSTALL_IMAGES_HOOKS),$(call $(hook))$(sep))
./package/pkg-generic.mk: $(foreach
hook,$($(PKG)_POST_INSTALL_IMAGES_HOOKS),$(call $(hook))$(sep))
./package/pkg-generic.mk: $(foreach
hook,$($(PKG)_PRE_INSTALL_TARGET_HOOKS),$(call $(hook))$(sep))
./package/pkg-generic.mk: $(foreach
hook,$($(PKG)_POST_INSTALL_TARGET_HOOKS),$(call $(hook))$(sep))

Notice that the one hit in Makefile uses "$($(hook))$(sep)" while the
hits in pkg-generic.mk use "$(call $(hook))$(sep)".  My Make-fu isn't
powerful enough to understand if there is an actual problem - should
there be a "call" in the Makefile line?  The general syntax for call
is "$(call variable,param,param,…)" so I don't follow what the extra
call in $(call $(hook) is doing for us.

Thanks,
Danomi -
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Re: [Buildroot] call with hooks

[Arnout Vandecappelle]

On 05/01/2022 17:20, Danomi Manchego wrote:
>   Hello all,
> 
> I noticed a possible inconsistency, and thought I should post it.
> Looking at places where buildroot uses hooks:
> 
> $ grep -r '$(hook))$(sep)' .

[snip]
> 
> Notice that the one hit in Makefile uses "$($(hook))$(sep)" while the
> hits in pkg-generic.mk use "$(call $(hook))$(sep)".  My Make-fu isn't
> powerful enough to understand if there is an actual problem - should
> there be a "call" in the Makefile line?  The general syntax for call
> is "$(call variable,param,param,…)" so I don't follow what the extra
> call in $(call $(hook) is doing for us.

  Historical accident.

  The person who first introduced the hooks back in the days didn't realize that 
$(call ...) is not for "something that looks like a function", but rather it is 
for "whenever you want to pass arguments". Reviewers also didn't realize this 
and just applied, and when more hooks were added later they copied the pattern.

  Regards,
  Arnout

> 
> Thanks,
> Danomi -
> _______________________________________________
> buildroot mailing list
> buildroot@buildroot.org
> https://lists.buildroot.org/mailman/listinfo/buildroot
> 
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Re: [Buildroot] call with hooks

[Danomi Manchego]

Hu Arnout,

Thanks for the explanation.  I feel better now :)

Danomi -


On Thu, Jan 6, 2022 at 4:39 AM Arnout Vandecappelle <arnout@mind.be> wrote:
>
>
>
> On 05/01/2022 17:20, Danomi Manchego wrote:
> >   Hello all,
> >
> > I noticed a possible inconsistency, and thought I should post it.
> > Looking at places where buildroot uses hooks:
> >
> > $ grep -r '$(hook))$(sep)' .
>
> [snip]
> >
> > Notice that the one hit in Makefile uses "$($(hook))$(sep)" while the
> > hits in pkg-generic.mk use "$(call $(hook))$(sep)".  My Make-fu isn't
> > powerful enough to understand if there is an actual problem - should
> > there be a "call" in the Makefile line?  The general syntax for call
> > is "$(call variable,param,param,…)" so I don't follow what the extra
> > call in $(call $(hook) is doing for us.
>
>   Historical accident.
>
>   The person who first introduced the hooks back in the days didn't realize that
> $(call ...) is not for "something that looks like a function", but rather it is
> for "whenever you want to pass arguments". Reviewers also didn't realize this
> and just applied, and when more hooks were added later they copied the pattern.
>
>   Regards,
>   Arnout
>
> >
> > Thanks,
> > Danomi -
> > _______________________________________________
> > buildroot mailing list
> > buildroot@buildroot.org
> > https://lists.buildroot.org/mailman/listinfo/buildroot
> >
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