[PATCH v2 3/5] Makefile: don't needlessly "rm $@ $@+" before "mv $@+ $@"
flat view
STALE2020d
From: Ævar Arnfjörð Bjarmason <hidden>
Date: 2021-03-29 16:21:21
Subsystem:
kernel build + files below scripts/ (unless maintained elsewhere), the rest · Maintainers:
Nathan Chancellor, Nicolas Schier, Linus Torvalds
Now that preceding commits have moved the generation of objects and
scripts in the Makefile to use the "[...] -o $@+ && mv $@+ $@" pattern
we can stop removing "$@" and "$@+" before the rule is run.
I suppose that we could leave this at removing "$@" before we start
out, per the "age old convention" comment in[1]. I.e. instead of:
rm -f thing thing+
prepare contents for thing >thing+
mv thing+ thing
Do:
rm -f thing
prepare contents for thing >thing+
mv thing+ thing
Since the removal of "thing+" is redundant as we're about to clobber
it anyway, but we might be so paranoid as to be guarding against mv(1)
leaving behind a corrupt "thing".
But I think guarding against "mv" failing is a step too far in
paranoia, let's just rely on the "[...] -o $@+ && mv $@+ $@" pattern
working instead.
Especially as we'll see in a follow-up commit, we're just about to use
the GNU make ".DELETE_ON_ERROR" feature, which will reliably do this
for us.
1. http://lore.kernel.org/git/xmqqpn097e9o.fsf@gitster.c.googlers.com (local)
Signed-off-by: Ævar Arnfjörð Bjarmason <redacted>
---
Makefile | 16 +++++-----------
1 file changed, 5 insertions(+), 11 deletions(-)
diff --git a/Makefile b/Makefile
index ef2d4a9973b..f08635067b3 100644
--- a/Makefile
+++ b/Makefile@@ -2210,7 +2210,6 @@ SCRIPT_DEFINES = $(SHELL_PATH_SQ):$(DIFF_SQ):$(GIT_VERSION):\ $(gitwebdir_SQ):$(PERL_PATH_SQ):$(SANE_TEXT_GREP):$(PAGER_ENV):\ $(perllibdir_SQ) define cmd_munge_script -$(RM) $@ $@+ && \ sed -e '1s|#!.*/sh|#!$(SHELL_PATH_SQ)|' \ -e 's|@SHELL_PATH@|$(SHELL_PATH_SQ)|' \ -e 's|@@DIFF@@|$(DIFF_SQ)|' \
@@ -2278,8 +2277,7 @@ endif PERL_DEFINES += $(gitexecdir) $(perllibdir) $(localedir) $(SCRIPT_PERL_GEN): % : %.perl GIT-PERL-DEFINES GIT-PERL-HEADER GIT-VERSION-FILE - $(QUIET_GEN)$(RM) $@ $@+ && \ - sed -e '1{' \ + $(QUIET_GEN)sed -e '1{' \ -e ' s|#!.*perl|#!$(PERL_PATH_SQ)|' \ -e ' r GIT-PERL-HEADER' \ -e ' G' \
@@ -2299,8 +2297,7 @@ GIT-PERL-DEFINES: FORCE fi GIT-PERL-HEADER: $(PERL_HEADER_TEMPLATE) GIT-PERL-DEFINES Makefile - $(QUIET_GEN)$(RM) $@ && \ - INSTLIBDIR='$(perllibdir_SQ)' && \ + $(QUIET_GEN)INSTLIBDIR='$(perllibdir_SQ)' && \ INSTLIBDIR_EXTRA='$(PERLLIB_EXTRA_SQ)' && \ INSTLIBDIR="$$INSTLIBDIR$${INSTLIBDIR_EXTRA:+:$$INSTLIBDIR_EXTRA}" && \ sed -e 's=@@PATHSEP@@=$(pathsep)=g' \
@@ -2325,8 +2322,7 @@ git-instaweb: git-instaweb.sh GIT-SCRIPT-DEFINES mv $@+ $@ else # NO_PERL $(SCRIPT_PERL_GEN) git-instaweb: % : unimplemented.sh - $(QUIET_GEN)$(RM) $@ $@+ && \ - sed -e '1s|#!.*/sh|#!$(SHELL_PATH_SQ)|' \ + $(QUIET_GEN)sed -e '1s|#!.*/sh|#!$(SHELL_PATH_SQ)|' \ -e 's|@@REASON@@|NO_PERL=$(NO_PERL)|g' \ unimplemented.sh >$@+ && \ chmod +x $@+ && \
@@ -2339,15 +2335,13 @@ $(SCRIPT_PYTHON_GEN): GIT-BUILD-OPTIONS ifndef NO_PYTHON $(SCRIPT_PYTHON_GEN): GIT-CFLAGS GIT-PREFIX GIT-PYTHON-VARS $(SCRIPT_PYTHON_GEN): % : %.py - $(QUIET_GEN)$(RM) $@ $@+ && \ - sed -e '1s|#!.*python|#!$(PYTHON_PATH_SQ)|' \ + $(QUIET_GEN)sed -e '1s|#!.*python|#!$(PYTHON_PATH_SQ)|' \ $< >$@+ && \ chmod +x $@+ && \ mv $@+ $@ else # NO_PYTHON $(SCRIPT_PYTHON_GEN): % : unimplemented.sh - $(QUIET_GEN)$(RM) $@ $@+ && \ - sed -e '1s|#!.*/sh|#!$(SHELL_PATH_SQ)|' \ + $(QUIET_GEN)sed -e '1s|#!.*/sh|#!$(SHELL_PATH_SQ)|' \ -e 's|@@REASON@@|NO_PYTHON=$(NO_PYTHON)|g' \ unimplemented.sh >$@+ && \ chmod +x $@+ && \
--
2.31.1.461.gd47399f6574