Since GNU make 4.4 the semantics of the $(MAKEFLAGS) variable has
changed in a backward-incompatible way, as its "NEWS" file notes:
Previously only simple (one-letter) options were added to the MAKEFLAGS
variable that was visible while parsing makefiles. Now, all options are
available in MAKEFLAGS. If you want to check MAKEFLAGS for a one-letter
option, expanding "$(firstword -$(MAKEFLAGS))" is a reliable way to return
the set of one-letter options which can be examined via findstring, etc.
This upstream change meant that e.g.:
make man
Would become very noisy, because in shared.mak we rely on extracting
"s" from the $(MAKEFLAGS), which now contains long options like
"--jobserver-auth=fifo:<path>", which we'll conflate with the "-s"
option.
So, let's change this idiom we've been carrying since [1], [2] and [3]
as the "NEWS" suggests.
Note that the "-" in "-$(MAKEFLAGS)" is critical here, as the variable
will always contain leading whitespace if there are no short options,
but long options are present. Without it e.g. "make --debug=all" would
yield "--debug=all" as the first word, but with it we'll get "-" as
intended. Then "-s" for "-s", "-Bs" for "-s -B" etc.
1. 0c3b4aac8e (git-gui: Support of "make -s" in: do not output
anything of the build itself, 2007-03-07)
2. b777434383 (Support of "make -s": do not output anything of the
build itself, 2007-03-07)
3. bb2300976b (Documentation/Makefile: make most operations "quiet",
2009-03-27)
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix a couple of issues in the recently merged 0f3c55d4c2b (Merge
branch 'ab/coccicheck-incremental' into next, 2022-11-08):
In copying over the "contrib/coccinelle/" rules to
".build/contrib/coccinelle/" we inadvertently ended up with a
".build/.build/contrib/coccinelle/" as well. We'd generate the
per-file patches in the former, and keep the rule and overall result
in the latter. E.g. running:
make contrib/coccinelle/free.cocci.patch COCCI_SOURCES="attr.c grep.c"
Would, per "tree -a .build" yield the following result:
.build
├── .build
│ └── contrib
│ └── coccinelle
│ └── free.cocci.patch
│ ├── attr.c
│ ├── attr.c.log
│ ├── grep.c
│ └── grep.c.log
└── contrib
└── coccinelle
├── FOUND_H_SOURCES
├── free.cocci
└── free.cocci.patch
Now we'll instead generate all of our files in
".build/contrib/coccinelle/". Fixing this required renaming the
directory where we keep our per-file patches, as we'd otherwise
conflict with the result.
Now the per-file patch directory is named e.g. "free.cocci.d". And the
end result will now be:
.build
└── contrib
└── coccinelle
├── FOUND_H_SOURCES
├── free.cocci
├── free.cocci.d
│ ├── attr.c.patch
│ ├── attr.c.patch.log
│ ├── grep.c.patch
│ └── grep.c.patch.log
└── free.cocci.patch
The per-file patches now have a ".patch" file suffix, which fixes
another issue reported against 0f3c55d4c2b: The summary output was
confusing. Before for the "make" command above we'd emit:
[...]
MKDIR -p .build/contrib/coccinelle
CP contrib/coccinelle/free.cocci .build/contrib/coccinelle/free.cocci
GEN .build/contrib/coccinelle/FOUND_H_SOURCES
MKDIR -p .build/.build/contrib/coccinelle/free.cocci.patch
SPATCH .build/.build/contrib/coccinelle/free.cocci.patch/grep.c
SPATCH .build/.build/contrib/coccinelle/free.cocci.patch/attr.c
SPATCH CAT $^ >.build/contrib/coccinelle/free.cocci.patch
CP .build/contrib/coccinelle/free.cocci.patch contrib/coccinelle/free.cocci.patch
But now we'll instead emit (identical output at the start omitted):
[...]
MKDIR -p .build/contrib/coccinelle/free.cocci.d
SPATCH grep.c >.build/contrib/coccinelle/free.cocci.d/grep.c.patch
SPATCH attr.c >.build/contrib/coccinelle/free.cocci.d/attr.c.patch
SPATCH CAT .build/contrib/coccinelle/free.cocci.d/**.patch >.build/contrib/coccinelle/free.cocci.patch
CP .build/contrib/coccinelle/free.cocci.patch contrib/coccinelle/free.cocci.patch
I.e. we have an "SPATCH" line that makes it clear that we're running
against the "{attr,grep}.c" file. The "SPATCH CAT" is then altered to
correspond to it, showing that we're concatenating the
"free.cocci.d/**.patch" files into one generated "free.cocci.patch" at
the end.
Reported-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Change the "coccinelle" rule so that we first copy the *.cocci source
in e.g. "contrib/coccinelle/strbuf.cocci" to
".build/contrib/coccinelle/strbuf.cocci" before operating on it.
For now this serves as a rather pointless indirection, but prepares us
for the subsequent commit where we'll be able to inject generated
*.cocci files. Having the entire dependency tree live inside .build/*
simplifies both the globbing we'd need to do, and any "clean" rules.
It will also help for future targets which will want to act on the
generated patches or the logs, e.g. targets to alert if we can't parse
certain files (or, less so than usual) with "spatch", and e.g. a
replacement for "ci/run-static-analysis.sh". Such a replacement won't
care about placing the patches in the in-tree, only whether they're
"OK" (and about the diff).
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Optimize the very slow "coccicheck" target to take advantage of
incremental rebuilding, and fix outstanding dependency problems with
the existing rule.
The rule is now faster both on the initial run as we can make better
use of GNU make's parallelism than the old ad-hoc combination of
make's parallelism combined with $(SPATCH_BATCH_SIZE) and/or the
"--jobs" argument to "spatch(1)".
It also makes us *much* faster when incrementally building, it's now
viable to "make coccicheck" as topic branches are merged down.
The rule didn't use FORCE (or its equivalents) before, so a:
make coccicheck
make coccicheck
Would report nothing to do on the second iteration. But all of our
patch output depended on all $(COCCI_SOURCES) files, therefore e.g.:
make -W grep.c coccicheck
Would do a full re-run, i.e. a a change in a single file would force
us to do a full re-run.
The reason for this (not the initial rationale, but my analysis) is:
* Since we create a single "*.cocci.patch+" we don't know where to
pick up where we left off, or how to incrementally merge e.g. a
"grep.c" change with an existing *.cocci.patch.
* We've been carrying forward the dependency on the *.c files since
63f0a758a0 (add coccicheck make target, 2016-09-15) the rule was
initially added as a sort of poor man's dependency discovery.
As we don't include other *.c files depending on other *.c files
has always been broken, as could be trivially demonstrated
e.g. with:
make coccicheck
make -W strbuf.h coccicheck
However, depending on the corresponding *.c files has been doing
something, namely that *if* an API change modified both *.c and *.h
files we'd catch the change to the *.h we care about via the *.c
being changed.
For API changes that happened only via *.h files we'd do the wrong
thing before this change, but e.g. for function additions (not
"static inline" ones) catch the *.h change by proxy.
Now we'll instead:
* Create a <RULE>/<FILE> pair in the .build directory, E.g. for
swap.cocci and grep.c we'll create
.build/contrib/coccinelle/swap.cocci.patch/grep.c.
That file is the diff we'll apply for that <RULE>-<FILE>
combination, if there's no changes to me made (the common case)
it'll be an empty file.
* Our generated *.patch
file (e.g. contrib/coccinelle/swap.cocci.patch) is now a simple "cat
$^" of all of all of the <RULE>/<FILE> files for a given <RULE>.
In the case discussed above of "grep.c" being changed we'll do the
full "cat" every time, so they resulting *.cocci.patch will always
be correct and up-to-date, even if it's "incrementally updated".
See 1cc0425a27 (Makefile: have "make pot" not "reset --hard",
2022-05-26) for another recent rule that used that technique.
As before we'll:
* End up generating a contrib/coccinelle/swap.cocci.patch, if we
"fail" by creating a non-empty patch we'll still exit with a zero
exit code.
Arguably we should move to a more Makefile-native way of doing
this, i.e. fail early, and if we want all of the "failed" changes
we can use "make -k", but as the current
"ci/run-static-analysis.sh" expects us to behave this way let's
keep the existing behavior of exhaustively discovering all cocci
changes, and only failing if spatch itself errors out.
Further implementation details & notes:
* Before this change running "make coccicheck" would by default end
up pegging just one CPU at the very end for a while, usually as
we'd finish whichever *.cocci rule was the most expensive.
This could be mitigated by combining "make -jN" with
SPATCH_BATCH_SIZE, see 960154b9c1 (coccicheck: optionally batch
spatch invocations, 2019-05-06).
There will be cases where getting rid of "SPATCH_BATCH_SIZE" makes
things worse, but a from-scratch "make coccicheck" with the default
of SPATCH_BATCH_SIZE=1 (and tweaking it doesn't make a difference)
is faster (~3m36s v.s. ~3m56s) with this approach, as we can feed
the CPU more work in a less staggered way.
* Getting rid of "SPATCH_BATCH_SIZE" particularly helps in cases
where the default of 1 yields parallelism under "make coccicheck",
but then running e.g.:
make -W contrib/coccinelle/swap.cocci coccicheck
I.e. before that would use only one CPU core, until the user
remembered to adjust "SPATCH_BATCH_SIZE" differently than the
setting that makes sense when doing a non-incremental run of "make
coccicheck".
* Before the "make coccicheck" rule would have to clean
"contrib/coccinelle/*.cocci.patch*", since we'd create "*+" and
"*.log" files there. Now those are created in
.build/contrib/coccinelle/, which is covered by the "cocciclean" rule
already.
Outstanding issues & future work:
* We could get rid of "--all-includes" in favor of manually
specifying a list of includes to give to "spatch(1)".
As noted upthread of [1] a naïve removal of "--all-includes" will
result in broken *.cocci patches, but if we know the exhaustive
list of includes via COMPUTE_HEADER_DEPENDENCIES we don't need to
re-scan for them, we could grab the headers to include from the
.depend.d/<file>.o.d and supply them with the "--include" option to
spatch(1).q
1. https://lore.kernel.org/git/87ft18tcog.fsf@evledraar.gmail.com/
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
In f7ff6597a7 (cocci: add a "coccicheck-test" target and test *.cocci
rules, 2022-07-05) we abbreviated "_TEST" to "_T" to have it align
with the rest of the "="'s above it.
Subsequent commits will add more QUIET_SPATCH_* variables, so let's
stop abbreviating this, and indent it in preparation for adding more
of these variables.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Add a "coccicheck-test" target to test our *.cocci rules, and as a
demonstration add tests for the rules added in 39ea59a257 (remove
unnecessary NULL check before free(3), 2016-10-08) and
1b83d1251e (coccinelle: add a rule to make "expression" code use
FREE_AND_NULL(), 2017-06-15).
I considered making use of the "spatch --test" option, and the choice
of a "tests" over a "t" directory is to make these tests compatible
with such a future change.
Unfortunately "spatch --test" doesn't return meaningful exit codes,
AFAICT you need to "grep" its output to see if the *.res is what you
expect. There's "--test-okfailed", but I didn't find a way to sensibly
integrate those (it relies on some in-between status files, but
doesn't help with the status codes).
Instead let's use a "--sp-file" pattern similar to the main
"coccicheck" rule, with the difference that we use and compare the
two *.res files with cmp(1).
The --very-quiet and --no-show-diff options ensure that we don't need
to pipe stdout and stderr somewhere. Unlike the "%.cocci.patch" rule
we're not using the diff.
The "cmp || git diff" is optimistically giving us better output on
failure, but even if we only have POSIX cmp and no system git
installed we'll still fail with the "cmp", just with an error message
that isn't as friendly. The "2>/dev/null" is in case we don't have a
"git" installed.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The core translation is the minimum set of work that must be done for a
new language translation.
There are over 5000 messages in the template message file "po/git.pot"
that need to be translated. It is not a piece of cake for such a huge
workload. So we used to define a small set of messages called "core
translation" that a new l10n contributor must complete before sending
pull request to the l10n coordinator.
By pulling in some parts of the git-po-helper[^1] logic, we add a new
rule to create this core translation message "po/git-core.pot":
make po/git-core.pot
To help new l10n contributors to initialized their "po/XX.pot" from
"po/git-core.pot", we also add new rules "po-init":
make po-init PO_FILE=po/XX.po
[^1]: https://github.com/git-l10n/git-po-helper/
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since there is no longer a "po/git.pot" file in tree, a l10n team leader
has to run several commands to update their "po/XX.po" file:
$ make pot
$ msgmerge --add-location --backup=off -U po/XX.po po/git.pot
To make this process easier, add a new rule so that l10n team leaders
can update their "po/XX.po" with one command. E.g.:
$ make po-update PO_FILE=po/zh_CN.po
Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change the use of a non-existing variable added in my
0b6d0bc924 (Makefiles: add and use wildcard "mkdir -p" template,
2022-03-03) to use the hardcoded whitespace padding for "QUIET" rules
instead. The wspfx_SQ was left from an earlier (rebased out) commit
preceding 0b6d0bc9246[1].
1. https://lore.kernel.org/git/patch-v4-8.9-3733b0c8df1-20220302T124320Z-avarab@gmail.com/
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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 in
8650c6298c (doc lint: make "lint-docs" non-.PHONY, 2021-10-15).
As seen in 4c64fb5aad (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>
The $(QUIET) variables we define are largely duplicated between our
various Makefiles, let's define them in the new "shared.mak" instead.
Since we're not using the environment to pass these around we don't
need to export the "QUIET_GEN" and "QUIET_BUILT_IN" variables
anymore. The "QUIET_GEN" variable is used in "git-gui/Makefile" and
"gitweb/Makefile", but they've got their own definition for those. The
"QUIET_BUILT_IN" variable is only used in the top-level "Makefile". We
still need to export the "V" variable.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move these variables over to the shared.mak, we'll make use of them in
a subsequent commit.
Note that there's reason for these to be "simply expanded variables",
i.e. to use ":=" assignments instead of lazily expanded "="
assignments. We could use "=", but let's leave this as-is for now for
ease of review.
See 425ca6710b (Makefile: allow combining UBSan with other
sanitizers, 2017-07-15) for the commit that introduced these.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This was added in 30248886ce (Makefile: disable default implicit
rules, 2010-01-26), let's move it to the top of "shared.mak" so it'll
apply to all our Makefiles.
This doesn't benefit the main Makefile at all, since it already had
the rule, but since we're including shared.mak in other Makefiles
starts to benefit them. E.g. running the 'man" target is now faster:
$ git -c hyperfine.hook.setup= hyperfine -L rev HEAD~1,HEAD~0 -s 'make -C Documentation man' 'make -C Documentation -j1 man'
Benchmark 1: make -C Documentation -j1 man' in 'HEAD~1
Time (mean ± σ): 121.7 ms ± 8.8 ms [User: 105.8 ms, System: 18.6 ms]
Range (min … max): 112.8 ms … 148.4 ms 26 runs
Benchmark 2: make -C Documentation -j1 man' in 'HEAD~0
Time (mean ± σ): 97.5 ms ± 8.0 ms [User: 80.1 ms, System: 20.1 ms]
Range (min … max): 89.8 ms … 111.8 ms 32 runs
Summary
'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@evledraar.gmail.com/
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Override built-in rules of GNU make that use a wildcard target. This
can speeds things up significantly as we don't need to stat() so many
files. GNU make does that by default to see if it can retrieve their
contents from RCS or SCCS. See [1] for an old mailing list discussion
about how to disable these.
The speed-up may vary. I've seen 1-10% depending on the speed of the
local disk, caches, -jN etc. Running:
strace -f -c -S calls make -j1 NO_TCLTK=Y
Shows that we reduce the number of syscalls we make, mostly in "stat"
calls.
We could also invoke make with "-r" by setting "MAKEFLAGS = -r"
early. Doing so might make us a bit faster still. But doing so is a
much bigger hammer, since it will disable all built-in rules,
some (all?) of which can be seen with:
make -f/dev/null -p | grep -v -e ^# -e ^$
We may have something that relies on them, so let's go for the more
isolated optimization here that gives us most or all of the wins.
1. https://lists.gnu.org/archive/html/help-make/2002-11/msg00063.html
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We have various behavior that's shared across our Makefiles, or that
really should be (e.g. via defined templates). Let's create a
top-level "shared.mak" to house those sorts of things, and start by
adding the ".DELETE_ON_ERROR" flag to it.
See my own 7b76d6bf22 (Makefile: add and use the ".DELETE_ON_ERROR"
flag, 2021-06-29) and db10fc6c09 (doc: simplify Makefile using
.DELETE_ON_ERROR, 2021-05-21) for the addition and use of the
".DELETE_ON_ERROR" flag.
I.e. this changes the behavior of existing rules in the altered
Makefiles (except "Makefile" & "Documentation/Makefile"). I'm
confident that this is safe having read the relevant rules in those
Makfiles, and as the GNU make manual notes that it isn't the default
behavior is out of an abundance of backwards compatibility
caution. From edition 0.75 of its manual, covering GNU make 4.3:
[Enabling '.DELETE_ON_ERROR' is] almost always what you want
'make' to do, but it is not historical practice; so for
compatibility, you must explicitly request it.
This doesn't introduce a bug by e.g. having this
".DELETE_ON_ERROR" flag only apply to this new shared.mak, Makefiles
have no such scoping semantics.
It does increase the danger that any Makefile without an explicit "The
default target of this Makefile is..." snippet to define the default
target as "all" could have its default rule changed if our new
shared.mak ever defines a "real" rule. In subsequent commits we'll be
careful not to do that, and such breakage would be obvious e.g. in the
case of "make -C t".
We might want to make that less fragile still (e.g. by using
".DEFAULT_GOAL" as noted in the preceding commit), but for now let's
simply include "shared.mak" without adding that boilerplate to all the
Makefiles that don't have it already. Most of those are already
exposed to that potential caveat e.g. due to including "config.mak*".
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano
Ævar Arnfjörð Bjarmason
Jiang Xin