Re: [PoC] coccinelle: make Coccinelle-related make targets more fine-grained

[Jeff King <peff@peff.net>]

On Thu, Aug 02, 2018 at 02:01:55PM -0400, Jeff King wrote:

> I suspect if we go with the one-spatch-per-source route, though, that we
> could do this just with regular make rules.

Yeah, it's pretty straightforward:

diff --git a/Makefile b/Makefile
index d616c0412..86fdcf567 100644
--- a/Makefile
+++ b/Makefile
@@ -2674,15 +2674,17 @@ COCCI_SOURCES = $(filter-out sha1collisiondetection/%,$(C_SOURCES))
 else
 COCCI_SOURCES = $(filter-out sha1dc/%,$(C_SOURCES))
 endif
+COCCI_COMBINED = contrib/coccinelle/combined.cocci
+COCCI_SEM_PATCHES = $(filter-out $(COCCI_COMBINED), $(wildcard contrib/coccinelle/*.cocci))
 
-%.cocci.patch: %.cocci $(COCCI_SOURCES)
+$(COCCI_COMBINED): $(COCCI_SEM_PATCHES)
+	cat $^ >$@+
+	mv $@+ $@
+
+$(COCCI_COMBINED).patches/%.patch: % $(COCCI_COMBINED)
 	@echo '    ' SPATCH $<; \
-	ret=0; \
-	for f in $(COCCI_SOURCES); do \
-		$(SPATCH) --sp-file $< $$f $(SPATCH_FLAGS) || \
-			{ ret=$$?; break; }; \
-	done >$@+ 2>$@.log; \
-	if test $$ret != 0; \
+	mkdir -p $(dir $@) || exit 1; \
+	if ! $(SPATCH) --sp-file $(COCCI_COMBINED) $< $(SPATCH_FLAGS) >$@+ 2>$@.log; \
 	then \
 		cat $@.log; \
 		exit 1; \
@@ -2692,7 +2694,8 @@ endif
 	then \
 		echo '    ' SPATCH result: $@; \
 	fi
-coccicheck: $(addsuffix .patch,$(wildcard contrib/coccinelle/*.cocci))
+
+coccicheck: $(patsubst %, $(COCCI_COMBINED).patches/%.patch, $(COCCI_SOURCES))
 
 .PHONY: coccicheck
 
@@ -2907,7 +2910,7 @@ profile-clean:
 	$(RM) $(addsuffix *.gcno,$(addprefix $(PROFILE_DIR)/, $(object_dirs)))
 
 cocciclean:
-	$(RM) contrib/coccinelle/*.cocci.patch*
+	$(RM) -r contrib/coccinelle/*.cocci.patches
 
 clean: profile-clean coverage-clean cocciclean
 	$(RM) *.res

I guess you could even replace "COCCI_COMBINED" with "COCCI_PATCH" in
most of the targets, and that would let people do individual:

  make COCCI_PATCH=contrib/coccinelle/foo.cocci coccicheck

The default would just be the concatenated version.

-Peff