From 899062438f47189cdcc3f5d3b3185eb4cfd798a7 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=C3=86var=20Arnfj=C3=B6r=C3=B0=20Bjarmason?= Date: Thu, 5 Aug 2021 00:54:40 +0200 Subject: Makefile: normalize clobbering & xargs for tags targets MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Since the "tags", "TAGS" and "cscope.out" targets rely on piping into xargs with an "echo | xargs" pattern, we need to make sure we're in an append mode. Unlike my recent change to make use of ".DELETE_ON_ERROR" in 7b76d6bf221 (Makefile: add and use the ".DELETE_ON_ERROR" flag, 2021-06-29), we really do need the "rm $@+" at the beginning (note, not "rm $@"). This is because the xargs command may decide to invoke the program multiple times. We need to make sure we've got a union of its results at the end. For "ctags" and "etags" we used the "-a" flag for this, for cscope that behavior is the default. Its "-u" flag disables its equivalent of an implicit "-a" flag. Let's also consistently use the $@ and $@+ names instead of needlessly hardcoding or referring to more verbose names in the "tags" and "TAGS" rules. These targets could perhaps be improved in the future by factoring this "echo | xargs" pattern so that we make intermediate tags files for each source file, and then assemble them into one "tags" file at the end. The etags manual page suggests that doing that (or perhaps just --update) might be counter-productive, in any case, the tag building is fast enough for me, so I'm leaving that for now. Signed-off-by: Ævar Arnfjörð Bjarmason Signed-off-by: Junio C Hamano --- Makefile | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index b3e2c7dc7a..471765b09f 100644 --- a/Makefile +++ b/Makefile @@ -2730,18 +2730,19 @@ FIND_SOURCE_FILES = ( \ FOUND_SOURCE_FILES = $(shell $(FIND_SOURCE_FILES)) $(ETAGS_TARGET): $(FOUND_SOURCE_FILES) - $(QUIET_GEN)$(RM) "$(ETAGS_TARGET)+" && \ - echo $(FOUND_SOURCE_FILES) | xargs etags -a -o "$(ETAGS_TARGET)+" && \ - mv "$(ETAGS_TARGET)+" "$(ETAGS_TARGET)" + $(QUIET_GEN)$(RM) $@+ && \ + echo $(FOUND_SOURCE_FILES) | xargs etags -a -o $@+ && \ + mv $@+ $@ tags: $(FOUND_SOURCE_FILES) - $(QUIET_GEN)$(RM) tags+ && \ - echo $(FOUND_SOURCE_FILES) | xargs ctags -a -o tags+ && \ - mv tags+ tags + $(QUIET_GEN)$(RM) $@+ && \ + echo $(FOUND_SOURCE_FILES) | xargs ctags -a -o $@+ && \ + mv $@+ $@ cscope.out: $(FOUND_SOURCE_FILES) - $(QUIET_GEN)$(RM) $@ && \ - echo $(FOUND_SOURCE_FILES) | xargs cscope -f$@ -b + $(QUIET_GEN)$(RM) $@+ && \ + echo $(FOUND_SOURCE_FILES) | xargs cscope -f$@+ -b && \ + mv $@+ $@ .PHONY: cscope cscope: cscope.out -- cgit v1.2.3