Clang's sanitizer implementation seems to work better than GCC's.
* jk/ci-use-clang-for-sanitizer-jobs:
ci: drop linux-clang job
ci: run ASan/UBSan in a single job
ci: use clang for ASan/UBSan checks
Code clean-up.
* ps/fetch-cleanups:
fetch: use `fetch_config` to store "submodule.fetchJobs" value
fetch: use `fetch_config` to store "fetch.parallel" value
fetch: use `fetch_config` to store "fetch.recurseSubmodules" value
fetch: use `fetch_config` to store "fetch.showForcedUpdates" value
fetch: use `fetch_config` to store "fetch.pruneTags" value
fetch: use `fetch_config` to store "fetch.prune" value
fetch: pass through `fetch_config` directly
fetch: drop unneeded NULL-check for `remote_ref`
fetch: drop unused DISPLAY_FORMAT_UNKNOWN enum value
Some atoms that can be used in "--format=<format>" for "git ls-tree"
were not supported by "git ls-files", even though they were relevant
in the context of the latter.
* zh/ls-files-format-atoms:
ls-files: align format atoms with ls-tree
"git pack-refs" learns "--include" and "--exclude" to tweak the ref
hierarchy to be packed using pattern matching.
* jc/pack-ref-exclude-include:
pack-refs: teach pack-refs --include option
pack-refs: teach --exclude option to exclude refs from being packed
docs: clarify git-pack-refs --all will pack all refs
Doc update.
* sa/doc-ls-remote:
ls-remote doc: document the output format
ls-remote doc: explain what each example does
ls-remote doc: show peeled tags in examples
ls-remote doc: remove redundant --tags example
show-branch doc: say <ref>, not <reference>
show-ref doc: update for internal consistency
The "-s" (silent, squelch) option of the "diff" family of commands
did not interact with other options that specify the output format
well. This has been cleaned up so that it will clear all the
formatting options given before.
* jc/diff-s-with-other-options:
diff: fix interaction between the "-s" option and other options
"git tag" learned to leave the "$GIT_DIR/TAG_EDITMSG" file when the
command failed, so that the user can salvage what they typed.
* kh/keep-tag-editmsg-upon-failure:
tag: keep the message file in case ref transaction fails
t/t7004-tag: add regression test for successful tag creation
doc: tag: document `TAG_EDITMSG`
Since the linux-asan-ubsan job runs using clang under Linux, there is
not much point in running a separate clang job. Any errors that a normal
clang compile-and-test cycle would find are likely to be a subset of
what the sanitizer job will find. Since this job takes ~14 minutes to
run in CI, this shaves off some of our CPU load (though it does not
affect end-to-end runtime, since it's typically run in parallel and is
not the longest job).
Technically this provides us with slightly less signal for a given run,
since you won't immediately know if a failure in the sanitizer job is
from using clang or from the sanitizers themselves. But it's generally
obvious from the logs, and anyway your next step would be to fix the
probvlem and re-run CI, since we expect all of these jobs to pass
normally.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we started running sanitizers in CI via 1c0962c0c4 (ci: add address
and undefined sanitizer tasks, 2022-10-20), we ran them as two separate
CI jobs, since as that commit notes, the combination "seems to take
forever".
And indeed, it does with gcc. However, since the previous commit
switched to using clang, the situation is different, and we can save
some CPU by using a single job for both. Comparing before/after CI runs,
this saved about 14 minutes (the single combined job took 54m, versus
44m plus 24m for ASan and UBSan jobs, respectively). That's wall-clock
and not CPU, but since our jobs are mostly CPU-bound, the two should be
closely proportional.
This does increase the end-to-end time of a CI run, though, since before
this patch the two jobs could run in parallel, and the sanitizer job is
our longest single job. It also means that we won't get a separate
result for "this passed with UBSan but not with ASan" or vice versa).
But as 1c0962c0c4 noted, that is not a very useful signal in practice.
Below are some more detailed timings of gcc vs clang that I measured by
running the test suite on my local workstation. Each measurement counts
only the time to run the test suite with each compiler (not the compile
time itself). We'll focus on the wall-clock times for simplicity, though
the CPU times follow roughly similar trends.
Here's a run with CC=gcc as a baseline:
real 1m12.931s
user 9m30.566s
sys 8m9.538s
Running with SANITIZE=address increases the time by a factor of ~4.7x:
real 5m40.352s
user 49m37.044s
sys 36m42.950s
Running with SANITIZE=undefined increases the time by a factor of ~1.7x:
real 2m5.956s
user 12m42.847s
sys 19m27.067s
So let's call that 6.4 time units to run them separately (where a unit
is the time it takes to run the test suite with no sanitizers). As a
simplistic model, we might imagine that running them together would take
5.4 units (we save 1 unit because we are no longer running the test
suite twice, but just paying the sanitizer overhead on top of a single
run).
But that's not what happens. Running with SANITIZE=address,undefined
results in a factor of 9.3x:
real 11m9.817s
user 77m31.284s
sys 96m40.454s
So not only did we not get faster when doing them together, we actually
spent 1.5x as much CPU as doing them separately! And while those
wall-clock numbers might not look too terrible, keep in mind that this
is on an unloaded 8-core machine. In the CI environment, wall-clock
times will be much closer to CPU times. So not only are we wasting CPU,
but we risk hitting timeouts.
Now let's try the same thing with clang. Here's our no-sanitizer
baseline run, which is almost identical to the gcc one (which is quite
convenient, because we can keep using the same "time units" to get an
apples-to-apples comparison):
real 1m11.844s
user 9m28.313s
sys 8m8.240s
And now again with SANITIZE=address, we get a 5x factor (so slightly
worse than gcc's 4.7x, though I wouldn't read too much into it; there is
a fair bit of run-to-run noise):
real 6m7.662s
user 49m24.330s
sys 44m13.846s
And with SANITIZE=undefined, we are at 1.5x, slightly outperforming gcc
(though again, that's probably mostly noise):
real 1m50.028s
user 11m0.973s
sys 16m42.731s
So running them separately, our total cost is 6.5x. But if we combine
them in a single run (SANITIZE=address,undefined), we get:
real 6m51.804s
user 52m32.049s
sys 51m46.711s
which is a factor of 5.7x. That's along the lines we'd hoped for!
Running them together saves us almost a whole time unit. And that's not
counting any time spent outside the test suite itself (starting the job,
setting up the environment, compiling) that we're no longer duplicating
by having two jobs.
So clang behaves like we'd hope: the overhead to run the sanitizers is
additive as you add more sanitizers. Whereas gcc's numbers seem very
close to multiplicative, almost as if the sanitizers were enforcing
their overheads on each other (though that is purely a guess on what is
going on; ultimately what matters to us is the amount of time it takes).
And that roughly matches the CI improvement I saw. A "time unit" there
is more like 12 minutes, and the observed time savings was 14 minutes
(with the extra presumably coming from avoiding duplicated setup, etc).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Both gcc and clang support the "address" and "undefined" sanitizers.
However, they may produce different results. We've seen at least two
real world cases where gcc missed a UBSan problem but clang found it:
1. Clang's UBSan (using clang 14.0.6) found a string index that was
subtracted to "-1", causing an out-of-bounds read (curiously this
didn't trigger ASan, but that may be because the string was in the
argv memory, not stack or heap). Using gcc (version 12.2.0) didn't
find the same problem.
Original thread:
https://lore.kernel.org/git/20230519005447.GA2955320@coredump.intra.peff.net/
2. Clang's UBSan (using clang 4.0.1) complained about pointer
arithmetic with NULL, but gcc at the time did not. This was in
2017, and modern gcc does seem to find the issue, though.
Original thread:
https://lore.kernel.org/git/32a8b949-638a-1784-7fba-948ae32206fc@web.de/
Since we don't otherwise have a particular preference for one compiler
over the other for this test, let's switch to the one that we think may
be more thorough.
Note that it's entirely possible that the two are simply _different_,
and we are trading off problems that gcc would find that clang wouldn't.
However, my subjective and anecdotal experience has been that clang's
sanitizer support is a bit more mature (e.g., I recall other oddities
around leak-checking where clang performed more sensibly).
Obviously running both and cross-checking the results would give us the
best coverage, but that's very expensive to run (and these are already
some of our most expensive CI jobs). So let's use clang as our best
guess, and we can re-evaluate if we get more data points.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The output may become confusing to recognize if the user
accidentally gave an extra opening space, like:
$ git commit --fixup=" 6d6360b67e99c2fd82d64619c971fdede98ee74b"
fatal: could not lookup commit 6d6360b67e99c2fd82d64619c971fdede98ee74b
and it will be better if we surround the %s specifier with single quotes.
Signed-off-by: Teng Long <dyroneteng@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
OpenSSH-9.0 requires a namespace option with `-Y check-novalidate`.
This was added in openssh-portable commit a0b5816f8 (upstream:
ssh-keygen -Y check-novalidate requires namespace or SEGV, 2022-03-18).
The -n option was documented as a required option since check-novalidate
was added in openssh-portable 8aa2aa3cd (upstream: Allow testing
signature syntax and validity without verifying, 2019-09-16).
Signed-off-by: Todd Zullinger <tmz@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git ls-files --format" can be used to format the output of
multiple file entries in the index, while "git ls-tree --format"
can be used to format the contents of a tree object. However,
the current set of %(objecttype), "(objectsize)", and
"%(objectsize:padded)" atoms supported by "git ls-files --format"
is a subset of what is available in "git ls-tree --format".
Users sometimes need to establish a unified view between the index
and tree, which can help with comparison or conversion between the two.
Therefore, this patch adds the missing atoms to "git ls-files --format".
"%(objecttype)" can be used to retrieve the object type corresponding
to a file in the index, "(objectsize)" can be used to retrieve the
object size corresponding to a file in the index, and "%(objectsize:padded)"
is the same as "(objectsize)", except with padded format.
Signed-off-by: ZheNing Hu <adlternative@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* 'master' of github.com:git/git:
A few more topics after 2.41-rc1
Git 2.41-rc1
t/lib-httpd: make CGIPassAuth support conditional
t9001: mark the script as no longer leak checker clean
send-email: clear the $message_id after validation
upload-pack: advertise capabilities when cloning empty repos
A bit more before -rc1
imap-send: include strbuf.h
run-command.c: fix missing include under `NO_PTHREADS`
test: do not negate test_path_is_* to assert absense
t2021: do not negate test_path_is_dir
tests: do not negate test_path_exists
doc/git-config: add unit for http.lowSpeedLimit
rebase -r: fix the total number shown in the progress
rebase --update-refs: fix loops
attr: teach "--attr-source=<tree>" global option to "git"
A few bugs in the sequencer machinery that results in miscounting
the steps have been corrected.
* js/rebase-count-fixes:
rebase -r: fix the total number shown in the progress
rebase --update-refs: fix loops
Small fixes.
* jc/do-not-negate-test-helpers:
test: do not negate test_path_is_* to assert absense
t2021: do not negate test_path_is_dir
tests: do not negate test_path_exists
When we are showing multiple patches with format-patch, we have to
repeatedly overwrite the rev.message_id field. We take care to avoid
leaking the old value by either freeing it, or adding it to
ref_message_ids, a string list of ids to reference in subsequent
messages.
But unfortunately we do leak the value via that string list. We try
to clear the string list, courtesy of 89f45cf4eb (format-patch: don't
leak "extra_headers" or "ref_message_ids", 2022-04-13). But since it was
initialized as "nodup", the string list doesn't realize it owns the
strings, and it leaks them.
We have two options here:
1. Continue to init with "nodup", but then tweak the value of
ref_message_ids.strdup_strings just before clearing.
2. Init with "dup", but use "append_nodup" when transferring ownership
of strings to the list. Clearing just works.
I picked the second here, as I think it calls attention to the tricky
part (transferring ownership via the nodup call).
There's one other related fix we have to do, though. We also insert the
result of clean_message_id() into the list. This _sometimes_ allocates
and sometimes does not, depending on whether we have to remove cruft
from the end of the string. Let's teach it to consistently return an
allocated string, so that the caller knows it must be freed.
There's no new test here, as the leak can already be seen in t4014.44 (as
well as others in that script). We can't mark all of t4014 as leak-free,
though, as there are other unrelated leaks that it triggers.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
