mirror of
https://github.com/git/git.git
synced 2024-05-10 20:06:10 +02:00
0b6d0bc924
Add a template to do the "mkdir -p" of $(@D) (the parent dir of $@) for us, and use it for the "make lint-docs" targets I added in8650c6298c(doc lint: make "lint-docs" non-.PHONY, 2021-10-15). As seen in4c64fb5aad(Documentation/Makefile: fix lint-docs mkdir dependency, 2021-10-26) maintaining these manual lists of parent directory dependencies is fragile, in addition to being obviously verbose. I used this pattern at the time because I couldn't find another method than "order-only" prerequisites to avoid doing a "mkdir -p $(@D)" for every file being created, which as noted in [1] would be significantly slower. But as it turns out we can use this neat trick of only doing a "mkdir -p" if the $(wildcard) macro tells us the path doesn't exist. A re-run of a performance test similar to that noted downthread of [1] in [2] shows that this is faster, in addition to being less verbose and more reliable (this uses my "git-hyperfine" thin wrapper for "hyperfine"[3]): $ git -c hyperfine.hook.setup= hyperfine -L rev HEAD~1,HEAD~0 -s 'make -C Documentation lint-docs' -p 'rm -rf Documentation/.build' 'make -C Documentation -j1 lint-docs' Benchmark 1: make -C Documentation -j1 lint-docs' in 'HEAD~1 Time (mean ± σ): 2.914 s ± 0.062 s [User: 2.449 s, System: 0.489 s] Range (min … max): 2.834 s … 3.020 s 10 runs Benchmark 2: make -C Documentation -j1 lint-docs' in 'HEAD~0 Time (mean ± σ): 2.315 s ± 0.062 s [User: 1.950 s, System: 0.386 s] Range (min … max): 2.229 s … 2.397 s 10 runs Summary 'make -C Documentation -j1 lint-docs' in 'HEAD~0' ran 1.26 ± 0.04 times faster than 'make -C Documentation -j1 lint-docs' in 'HEAD~1' So let's use that pattern both for the "lint-docs" target, and a few miscellaneous other targets. This method of creating parent directories is explicitly racy in that we don't know if we're going to say always create a "foo" followed by a "foo/bar" under parallelism, or skip the "foo" because we created "foo/bar" first. In this case it doesn't matter for anything except that we aren't guaranteed to get the same number of rules firing when running make in parallel. 1. https://lore.kernel.org/git/211028.861r45y3pt.gmgdl@evledraar.gmail.com/ 2. https://lore.kernel.org/git/211028.86o879vvtp.gmgdl@evledraar.gmail.com/ 3. https://gitlab.com/avar/git-hyperfine/ Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
104 lines
2.9 KiB
Makefile
104 lines
2.9 KiB
Makefile
### Remove GNU make implicit rules
|
|
|
|
## This speeds things up since we don't need to look for and stat() a
|
|
## "foo.c,v" every time a rule referring to "foo.c" is in play. See
|
|
## "make -p -f/dev/null | grep ^%::'".
|
|
%:: %,v
|
|
%:: RCS/%,v
|
|
%:: RCS/%
|
|
%:: s.%
|
|
%:: SCCS/s.%
|
|
|
|
## Likewise delete default $(SUFFIXES). See:
|
|
##
|
|
## info make --index-search=.SUFFIXES
|
|
.SUFFIXES:
|
|
|
|
### Flags affecting all rules
|
|
|
|
# A GNU make extension since gmake 3.72 (released in late 1994) to
|
|
# remove the target of rules if commands in those rules fail. The
|
|
# default is to only do that if make itself receives a signal. Affects
|
|
# all targets, see:
|
|
#
|
|
# info make --index-search=.DELETE_ON_ERROR
|
|
.DELETE_ON_ERROR:
|
|
|
|
### Global variables
|
|
|
|
## comma, empty, space: handy variables as these tokens are either
|
|
## special or can be hard to spot among other Makefile syntax.
|
|
comma := ,
|
|
empty :=
|
|
space := $(empty) $(empty)
|
|
|
|
### Quieting
|
|
## common
|
|
QUIET_SUBDIR0 = +$(MAKE) -C # space to separate -C and subdir
|
|
QUIET_SUBDIR1 =
|
|
|
|
ifneq ($(findstring w,$(MAKEFLAGS)),w)
|
|
PRINT_DIR = --no-print-directory
|
|
else # "make -w"
|
|
NO_SUBDIR = :
|
|
endif
|
|
|
|
ifneq ($(findstring s,$(MAKEFLAGS)),s)
|
|
ifndef V
|
|
## common
|
|
QUIET_SUBDIR0 = +@subdir=
|
|
QUIET_SUBDIR1 = ;$(NO_SUBDIR) echo ' ' SUBDIR $$subdir; \
|
|
$(MAKE) $(PRINT_DIR) -C $$subdir
|
|
|
|
QUIET = @
|
|
QUIET_GEN = @echo ' ' GEN $@;
|
|
|
|
QUIET_MKDIR_P_PARENT = @echo $(wspfx_SQ) MKDIR -p $(@D);
|
|
|
|
## Used in "Makefile"
|
|
QUIET_CC = @echo ' ' CC $@;
|
|
QUIET_AR = @echo ' ' AR $@;
|
|
QUIET_LINK = @echo ' ' LINK $@;
|
|
QUIET_BUILT_IN = @echo ' ' BUILTIN $@;
|
|
QUIET_LNCP = @echo ' ' LN/CP $@;
|
|
QUIET_XGETTEXT = @echo ' ' XGETTEXT $@;
|
|
QUIET_MSGFMT = @echo ' ' MSGFMT $@;
|
|
QUIET_GCOV = @echo ' ' GCOV $@;
|
|
QUIET_SP = @echo ' ' SP $<;
|
|
QUIET_HDR = @echo ' ' HDR $(<:hcc=h);
|
|
QUIET_RC = @echo ' ' RC $@;
|
|
QUIET_SPATCH = @echo ' ' SPATCH $<;
|
|
|
|
## Used in "Documentation/Makefile"
|
|
QUIET_ASCIIDOC = @echo ' ' ASCIIDOC $@;
|
|
QUIET_XMLTO = @echo ' ' XMLTO $@;
|
|
QUIET_DB2TEXI = @echo ' ' DB2TEXI $@;
|
|
QUIET_MAKEINFO = @echo ' ' MAKEINFO $@;
|
|
QUIET_DBLATEX = @echo ' ' DBLATEX $@;
|
|
QUIET_XSLTPROC = @echo ' ' XSLTPROC $@;
|
|
QUIET_GEN = @echo ' ' GEN $@;
|
|
QUIET_STDERR = 2> /dev/null
|
|
|
|
QUIET_LINT_GITLINK = @echo ' ' LINT GITLINK $<;
|
|
QUIET_LINT_MANSEC = @echo ' ' LINT MAN SEC $<;
|
|
QUIET_LINT_MANEND = @echo ' ' LINT MAN END $<;
|
|
|
|
export V
|
|
endif
|
|
endif
|
|
|
|
### Templates
|
|
|
|
## mkdir_p_parent: lazily "mkdir -p" the path needed for a $@
|
|
## file. Uses $(wildcard) to avoid the "mkdir -p" if it's not
|
|
## needed.
|
|
##
|
|
## Is racy, but in a good way; we might redundantly (and safely)
|
|
## "mkdir -p" when running in parallel, but won't need to exhaustively create
|
|
## individual rules for "a" -> "prefix" -> "dir" -> "file" if given a
|
|
## "a/prefix/dir/file". This can instead be inserted at the start of
|
|
## the "a/prefix/dir/file" rule.
|
|
define mkdir_p_parent_template
|
|
$(if $(wildcard $(@D)),,$(QUIET_MKDIR_P_PARENT)$(shell mkdir -p $(@D)))
|
|
endef
|