[v4,3/5] Makefile: don't use "FORCE" for tags targets

Commit Message

Ævar Arnfjörð Bjarmason Aug. 4, 2021, 10:54 p.m. UTC

Remove the "FORCE" dependency from the "tags", "TAGS" and "cscope"
targets, instead make them depend on whether or not the relevant
source files have changed.

For the cscope target we need to change it to depend on the actual
generated file while we generate while we're at it, as the next commit
will discuss we always generate a cscope.out file.

Signed-off-by: Ævar Arnfjörð Bjarmason <[e-mail]>
---
 Makefile | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

Patch

diff --git a/Makefile b/Makefile
index 59c2e98795b..d1012cf71d2 100644
--- a/Makefile
+++ b/Makefile
@@ -2746,20 +2746,24 @@  FIND_SOURCE_FILES = ( \
 		| sed -e 's|^\./||' \
 	)
 
-$(ETAGS_TARGET): FORCE
+FOUND_SOURCE_FILES = $(shell $(FIND_SOURCE_FILES))
+
+$(ETAGS_TARGET): $(FOUND_SOURCE_FILES)
 	$(QUIET_GEN)$(RM) "$(ETAGS_TARGET)+" && \
-	$(FIND_SOURCE_FILES) | xargs etags -a -o "$(ETAGS_TARGET)+" && \
+	echo $(FOUND_SOURCE_FILES) | xargs etags -a -o "$(ETAGS_TARGET)+" && \
 	mv "$(ETAGS_TARGET)+" "$(ETAGS_TARGET)"
 
-tags: FORCE
+tags: $(FOUND_SOURCE_FILES)
 	$(QUIET_GEN)$(RM) tags+ && \
-	$(FIND_SOURCE_FILES) | xargs ctags -a -o tags+ && \
+	echo $(FOUND_SOURCE_FILES) | xargs ctags -a -o tags+ && \
 	mv tags+ tags
 
-.PHONY: cscope
-cscope:
+cscope.out: $(FOUND_SOURCE_FILES)
 	$(QUIET_GEN)$(RM) cscope* && \
-	$(FIND_SOURCE_FILES) | xargs cscope -b
+	echo $(FOUND_SOURCE_FILES) | xargs cscope -b
+
+.PHONY: cscope
+cscope: cscope.out
 
 ### Detect prefix changes
 TRACK_PREFIX = $(bindir_SQ):$(gitexecdir_SQ):$(template_dir_SQ):$(prefix_SQ):\
@@ -2943,7 +2947,7 @@  check: config-list.h command-list.h
 		exit 1; \
 	fi
 
-FOUND_C_SOURCES = $(filter %.c,$(shell $(FIND_SOURCE_FILES)))
+FOUND_C_SOURCES = $(filter %.c,$(FOUND_SOURCE_FILES))
 COCCI_SOURCES = $(filter-out $(THIRD_PARTY_SOURCES),$(FOUND_C_SOURCES))
 
 %.cocci.patch: %.cocci $(COCCI_SOURCES)