As the v1 notes (among other things): https://lore.kernel.org/git/cover-0.8-00000000000-20211217T012902Z-avarab@xxxxxxxxx/ This speeds up noop runs of "make" by a lot. After a "make" running a "make -j1" with this is ~1.5 faster than on "master"[2], and around 3x as fast with "make -j1 NO_TCLTK=Y" (the TCL part takes a lot of time, but that's another matter). This v3 re-roll: * Addresses a minor comment/documentation issue pointed out by Taylor Blau. * Adjusts the ".SUFFIXES" commit message to note the source of the speed-up from that change, in response to a question from Taylor. * Changes the contrib/scalar/Makefile to make use of the new shared.mak, which allows for deleting some copy/pasted code in it in favor of the same shared logic. The original version of these patches was written before that file landed in-tree. For v2, see: https://lore.kernel.org/git/cover-v2-0.8-00000000000-20211224T173558Z-avarab@xxxxxxxxx/ Ævar Arnfjörð Bjarmason (9): scalar Makefile: set the default target after the includes Makefiles: add "shared.mak", move ".DELETE_ON_ERROR" to it Makefile: disable GNU make built-in wildcard rules Makefile: define $(LIB_H) in terms of $(FIND_SOURCE_FILES) Makefile: move ".SUFFIXES" rule to shared.mak Makefile: move $(comma), $(empty) and $(space) to shared.mak Makefile: add "$(QUIET)" boilerplate to shared.mak Makefile: use $(wspfx) for $(QUIET...) in shared.mak Makefiles: add and use wildcard "mkdir -p" template Documentation/Makefile | 63 ++------------------ Makefile | 118 ++++++++++++-------------------------- config.mak.uname | 1 - contrib/scalar/Makefile | 19 ++---- contrib/scalar/t/Makefile | 3 + shared.mak | 109 +++++++++++++++++++++++++++++++++++ t/Makefile | 3 + t/interop/Makefile | 3 + t/perf/Makefile | 3 + templates/Makefile | 8 +-- 10 files changed, 170 insertions(+), 160 deletions(-) create mode 100644 shared.mak Range-diff against v2: -: ----------- > 1: 2404c4d8b96 scalar Makefile: set the default target after the includes 1: 97dccacce20 ! 2: 96a490bec54 Makefiles: add "shared.mak", move ".DELETE_ON_ERROR" to it @@ Makefile: shell_compatibility_test: please_set_SHELL_PATH_to_a_more_modern_shell # The generic compilation pattern rule and automatically + ## contrib/scalar/Makefile ## +@@ ++# Import tree-wide shared Makefile behavior and libraries ++include ../../shared.mak ++ + QUIET_SUBDIR0 = +$(MAKE) -C # space to separate -C and subdir + QUIET_SUBDIR1 = + + + ## contrib/scalar/t/Makefile ## +@@ ++# Import tree-wide shared Makefile behavior and libraries ++include ../../../shared.mak ++ + # Run scalar tests + # + # Copyright (c) 2005,2021 Junio C Hamano, Johannes Schindelin + ## shared.mak (new) ## @@ +### Flags affecting all rules @@ t/interop/Makefile export GIT_TEST_OPTIONS + ## t/perf/Makefile ## +@@ ++# Import tree-wide shared Makefile behavior and libraries ++include ../../shared.mak ++ + -include ../../config.mak + export GIT_TEST_OPTIONS + + ## templates/Makefile ## @@ +# Import tree-wide shared Makefile behavior and libraries 2: b2bf32ab071 = 3: 9392e3c3e97 Makefile: disable GNU make built-in wildcard rules 3: 275aba624fa = 4: 07cf9daa9d6 Makefile: define $(LIB_H) in terms of $(FIND_SOURCE_FILES) 4: 7103c40de64 ! 5: 16f2e3ff35b Makefile: move ".SUFFIXES" rule to shared.mak @@ Commit message 'make -C Documentation -j1 man' in 'HEAD~0' ran 1.25 ± 0.14 times faster than 'make -C Documentation -j1 man' in 'HEAD~1' + The reason for that can be seen when comparing that run with + "--debug=a". Without this change making a target like "git-status.1" + will cause "make" to consider not only "git-status.txt", but + "git-status.txt.o", as well as numerous other implicit suffixes such + as ".c", ".cc", ".cpp" etc. See [1] for a more detailed before/after + example. + + So this is causing us to omit a bunch of work we didn't need to + do. For making "git-status.1" the "--debug=a" output is reduced from + ~140k lines to ~6k. + + 1. https://lore.kernel.org/git/220222.86bkyz875k.gmgdl@xxxxxxxxxxxxxxxxxxx/ + Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx> ## Makefile ## @@ shared.mak +## Likewise delete default $(SUFFIXES). See: +## -+## info make --index-search=.DELETE_ON_ERROR ++## info make --index-search=.SUFFIXES +.SUFFIXES: + ### Flags affecting all rules 5: 4a5c647b5e7 = 6: 1b6ecb27f02 Makefile: move $(comma), $(empty) and $(space) to shared.mak 6: 940299d2a03 ! 7: 471067deefc Makefile: add "$(QUIET)" boilerplate to shared.mak @@ config.mak.uname: vcxproj: git add -f git.sln {*,*/lib,t/helper/*}/*.vcxproj + ## contrib/scalar/Makefile ## +@@ + # Import tree-wide shared Makefile behavior and libraries + include ../../shared.mak + +-QUIET_SUBDIR0 = +$(MAKE) -C # space to separate -C and subdir +-QUIET_SUBDIR1 = +- +-ifneq ($(findstring s,$(MAKEFLAGS)),s) +-ifndef V +- QUIET_GEN = @echo ' ' GEN $@; +- QUIET_SUBDIR0 = +@subdir= +- QUIET_SUBDIR1 = ;$(NO_SUBDIR) echo ' ' SUBDIR $$subdir; \ +- $(MAKE) $(PRINT_DIR) -C $$subdir +-else +- export V +-endif +-endif +- + include ../../config.mak.uname + -include ../../config.mak.autogen + -include ../../config.mak + ## shared.mak ## @@ comma = , 7: 1e13fee526d = 8: 510306d2219 Makefile: use $(wspfx) for $(QUIET...) in shared.mak 8: 250b32540d9 = 9: 85bb74aa32f Makefiles: add and use wildcard "mkdir -p" template -- 2.35.1.1175.gf9e1b23ea35
