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

On Fri, Sep 13, 2019 at 01:49:52PM +0200, SZEDER Gábor wrote:

On Thu, Sep 12, 2019 at 11:40:36AM -0700, Junio C Hamano wrote:

quoted

Denton Liu [off-list ref] writes:

quoted

+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.

I think it still does matter; the relevant snippet is as follows:

	if ! echo $(COCCI_SOURCES) | xargs $$limit \
		$(SPATCH) --sp-file $< $(SPATCH_FLAGS) \
		>$@+ 2>$@.log; \

which means that a really big COCCI_SOURCES could exceed the limit.

That being said, COCCI_SOURCES should be smaller than the future
SOURCE_FILES variable since we're only taking %.c files (and filtering
out some of them too!).

I dunno, either. I'm mostly in favour of this change since it makes a
lot of sense to keep lists in make variables if possible as opposed to
command invocations. I guess worst case, if someone complains in the
future, we can always change it back.

quoted

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):\