Subject: Re: [PATCH v2 3/3] Makefile: run coccicheck on more source files

From: SZEDER Gábor <[email-masked]>
Date: Fri, 13 Sep 2019 13:49:52 +0200

On Thu, Sep 12, 2019 at 11:40:36AM -0700, Junio C Hamano wrote:
> Denton Liu <[email-masked]> writes:
> 
> > +FIND_C_SOURCES = $(filter %.c,$(shell $(FIND_SOURCE_FILES)))
> > +COCCI_SOURCES = $(filter-out $(THIRD_PARTY_SOURCES),$(FIND_C_SOURCES))
> 
> The former is somewhat misnamed.  FIND_SOURCE_FILES is *not* a list
> of source files---it is a procedure to list source files to its
> standard output.  FIND_C_SOUCRES sounds as if it is a similar
> procedure, which would be implemented much like
> 
> 	FIND_C_SOURCES = $(FIND_SOURCE_FILES) | sed -n -e '/\.c$/p'
> 
> but that is not what you did and that is not what you want to have.
> Perhaps call it FOUND_C_SOURCES?
> 
> I wonder if we can get rid of FIND_SOURCE_FILES that is a mere
> procedure and replace its use with a true list of source files.
> Would it make the result more pleasant to work with?
> 
> Perhaps something like the attached patch, (which would come before
> this entire thing as a clean-up, and removing the need for 2/3)?
> 
> I dunno.
> 
> Using a procedure whose output is fed to xargs has an advantage that
> a platform with very short command line limit can still work with
> many source files, but the way you create and use COCCI_SOURCES in
> this patch would defeat that advantage anyway,

COCCI_SOURCES is only used as an input to 'xargs', so that advantage
is not defeated.

> so perhaps we can get
> away with an approach like this.  Having a list of things in $(MAKE)
> variable has a longer-term benefit that we could exploit more
> parallelism if we wanted to, too.
> 
>  Makefile | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/Makefile b/Makefile
> index f9255344ae..9dddd0e88c 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -2584,7 +2584,7 @@ perl/build/man/man3/Git.3pm: perl/Git.pm
>  	$(QUIET_GEN)mkdir -p $(dir $@) && \
>  	pod2man $< $@
>  
> -FIND_SOURCE_FILES = ( \
> +SOURCE_FILES = $(patsubst ./%,%,$(shell \
>  	git ls-files \
>  		'*.[hcS]' \
>  		'*.sh' \
> @@ -2599,19 +2599,19 @@ FIND_SOURCE_FILES = ( \
>  		-o \( -name 'trash*' -type d -prune \) \
>  		-o \( -name '*.[hcS]' -type f -print \) \
>  		-o \( -name '*.sh' -type f -print \) \
> -	)
> +	))
>  
>  $(ETAGS_TARGET): FORCE
>  	$(RM) $(ETAGS_TARGET)
> -	$(FIND_SOURCE_FILES) | xargs etags -a -o $(ETAGS_TARGET)
> +	etags -a -o $(ETAGS_TARGET) $(SOURCE_FILES)
>  
>  tags: FORCE
>  	$(RM) tags
> -	$(FIND_SOURCE_FILES) | xargs ctags -a
> +	ctags -a $(SOURCE_FILES)
>  
>  cscope:
>  	$(RM) cscope*
> -	$(FIND_SOURCE_FILES) | xargs cscope -b
> +	cscope -b $(SOURCE_FILES)
>  
>  ### Detect prefix changes
>  TRACK_PREFIX = $(bindir_SQ):$(gitexecdir_SQ):$(template_dir_SQ):$(prefix_SQ):\
> 
> 
> 
>