Re: [PATCH v6] build: regenerate config-list.h when Documentation changes

> On Mon, Feb 23, 2026 at 04:41:48PM -0500, Ben Knoble wrote:
>>> Le 23 févr. 2026 à 01:55, SZEDER Gábor <szeder.dev@gmail.com> a écrit :
>>> On Sat, Feb 21, 2026 at 09:07:17AM -0500, D. Ben Knoble wrote:
>>>> diff --git a/Makefile b/Makefile
>>>> index 7f37ad8f58..6f926ffb1f 100644
>>>> --- a/Makefile
>>>> +++ b/Makefile
>>>> @@ -2688,9 +2688,10 @@ $(BUILT_INS): git$X
>>>>     cp $< $@
>>>>
>>>> config-list.h: generate-configlist.sh
>>>> +    @mkdir -p .depend
>>>> +    $(QUIET_GEN)$(SHELL_PATH) ./generate-configlist.sh . $@ .depend/config-list.h.d
>>>>
>>>> -config-list.h: Documentation/*config.adoc Documentation/config/*.adoc
>>>> -    $(QUIET_GEN)$(SHELL_PATH) ./generate-configlist.sh . $@
>>>> +-include .depend/config-list.h.d
>>>
>>> This breaks the build when something disappears from
>>> Documentation/config/:
>>>
>>>   $ git checkout origin/seen
>>>   HEAD is now at 57edfa3ce8 Merge branch 'ty/setup-error-tightening' into seen
>>>   $ ls -l Documentation/config/hook.adoc
>>>   -rw-rw-r-- 1 szeder szeder 3828 Feb 23 07:50 Documentation/config/hook.adoc
>>>   $ git grep hook.adoc
>>>   Documentation/git-hook.adoc:include::config/hook.adoc[]
>>>   Documentation/howto/meson.build:  'rebuild-from-update-hook.adoc',
>>>   Documentation/meson.build:  'git-hook.adoc' : 1,
>>>   $ make V=1 config-list.h
>>>   /bin/sh ./generate-configlist.sh . config-list.h .depend/config-list.h.d
>>>   $ git checkout 0aabf70f60
>>>   Previous HEAD position was 57edfa3ce8 Merge branch 'ty/setup-error-tightening' into seen
>>>   HEAD is now at 0aabf70f60 build: regenerate config-list.h when Documentation changes
>>>   $ ls -l Documentation/config/hook.adoc
>>>   ls: cannot access 'Documentation/config/hook.adoc': No such file or directory
>>>   $ git grep hook.adoc
>>>   Documentation/howto/meson.build:  'rebuild-from-update-hook.adoc',
>>>   Documentation/meson.build:  'git-hook.adoc' : 1,
>>>   $ make V=1 config-list.h
>>>   GIT_VERSION=2.53.0.119.g0aabf70f60
>>>   make: *** No rule to make target 'Documentation/config/hook.adoc', needed by 'config-list.h'.  Stop.
>>>   $ grep hook.adoc .depend/config-list.h.d
>>>   config-list.h: ./Documentation/config/hook.adoc
>>
>> Indeed. This might arise while bisecting, which was my original
>> motivation. Thoughts on a path forward? At least this issue (to me) is
>> clearer than a spurious test failure :)
> 
> For Meson this case works alright. So maybe we just drop the changes to
> the Makefile and call it a day?
> 
> An alternative would be to have the following patch on top:
> 
> diff --git a/generate-configlist.sh b/generate-configlist.sh
> index 39ac8845ab..e28054f9e0 100755
> --- a/generate-configlist.sh
> +++ b/generate-configlist.sh
> @@ -41,7 +41,12 @@ EOF
>   if test -n "$DEPFILE"
>   then
>   	QUOTED_OUTPUT="$(printf '%s\n' "$OUTPUT" | sed 's,[&/\],\\&,g')"
> -	printf '%s\n' "$SOURCE_DIR"/Documentation/*config.adoc \
> -		"$SOURCE_DIR"/Documentation/config/*.adoc |
> -		sed -e 's/[# ]/\\&/g' -e "s/^/$QUOTED_OUTPUT: /" >"$DEPFILE"
> +	{
> +		printf '%s\n' "$SOURCE_DIR"/Documentation/*config.adoc \
> +			"$SOURCE_DIR"/Documentation/config/*.adoc |
> +			sed -e 's/[# ]/\\&/g' -e "s/^/$QUOTED_OUTPUT: /"
> +		printf '%s:\n' "$SOURCE_DIR"/Documentation/*config.adoc \
> +			"$SOURCE_DIR"/Documentation/config/*.adoc |
> +			sed -e 's/[# ]/\\&/g'
> +	} >"$DEPFILE"
>   fi
> 
> What it does is to also create an empty target for all of the
> dependencies. Which is in fact what GCC/Clang also do when you pass -MP:

> 
>      $ cat main.c
>      #include "foo.h"
>      int main()
>      {
>          puts("foobar");
>          return 0;
>      }
> 
>      $ clang -MMD -MP main.c
>      $ cat main.d
>      main.o: main.c foo.h
>      foo.h:
> 
> Patrick