In the early days of Git, Perl was used quite prominently throughout the
project. This has changed significantly as almost all of the executables
we ship nowadays have eventually been rewritten in C. Only a handful of
subsystems remain that require Perl:
- gitweb, a read-only web interface.
- A couple of scripts that allow importing repositories from GNU Arch,
CVS and Subversion.
- git-send-email(1), which can be used to send mails.
- git-request-pull(1), which is used to request somebody to pull from
a URL by sending an email.
- git-filter-branch(1), which uses Perl with the `--state-branch`
option. This command is typically recommended against nowadays in
favor of git-filter-repo(1).
- Our Perl bindings for Git.
- The netrc Git credential helper.
None of these subsystems can really be considered to be part of the
"core" of Git, and an installation without them is fully functional.
It is more likely than not that an end user wouldn't even notice that
any features are missing if those tools weren't installed. But while
Perl nowadays very much is an optional dependency of Git, there is a
significant limitation when Perl isn't available: developers cannot run
our test suite.
Preceding commits have started to lift this restriction by removing the
strict dependency on Perl in many central parts of the test library. But
there are still many tests that rely on small Perl helpers to do various
different things.
Introduce a new PERL_TEST_HELPERS prerequisite that guards all tests
that require Perl. This prerequisite is explicitly different than the
preexisting PERL prerequisite:
- PERL records whether or not features depending on the Perl
interpreter are built.
- PERL_TEST_HELPERS records whether or not a Perl interpreter is
available for our tests.
By having these two separate prerequisites we can thus distinguish
between tests that inherently depend on Perl because the underlying
feature does, and those tests that depend on Perl because the test
itself is using Perl.
Adapt all tests to set the PERL_TEST_HELPERS prerequisite as needed.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Now that the default value for TEST_PASSES_SANITIZE_LEAK is `true` there
is no longer a need to have that variable declared in all of our tests.
Drop it.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Similar as with the preceding commit, `handle_builtin()` does not
properly track lifetimes of the `argv` array and its strings. As it may
end up modifying the array this can lead to memory leaks in case it
contains allocated strings.
Refactor the function to use a `struct strvec` instead.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
After building Git with NO_LIBCURL, we're lacking `git remote-http` and
`git http-fetch`, so when we test that they trace as they should, we're
bound to fail. Add the LIBCURL prereq to those tests.
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The bug went unnoticed because grep with null RE matches everything.
Signed-off-by: Marcel Telka <marcel@telka.sk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some commands do not cause a set of 'def_param' events to be emitted.
This includes "git-remote-https", "git-http-fetch", and various
"query" commands, like "git --man-path".
Since all of these commands do emit a 'cmd_name' event, add code to
the "trace2_cmd_name()" function to generate the set of 'def_param'
events.
Remove explicit calls to "trace2_cmd_list_config()" and
"trace2_cmd_list_env_vars()" in git.c since they are no longer needed.
Reviewed-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Jeff Hostetler <jeffhostetler@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
During nested alias expansion it is possible for
"trace2_cmd_list_config()" and "trace2_cmd_list_env_vars()"
to be called more than once. This causes a full set of
'def_param' events to be emitted each time. Let's avoid
that.
Add code to those two functions to only emit them once.
Signed-off-by: Jeff Hostetler <jeffhostetler@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some Git commands fail to emit 'def_param' events for interesting
config and environment variable settings.
Add unit tests to demonstrate this.
Most commands are considered "builtin" and are based upon git.c.
These typically do emit 'def_param' events. Exceptions are some of
the "query" commands, the "run-dashed" mechanism, and alias handling.
Commands built from remote-curl.c (instead of git.c), such as
"git-remote-https", do not emit 'def_param' events.
Likewise, "git-http-fetch" is built http-fetch.c and does not emit
them.
Signed-off-by: Jeff Hostetler <jeffhostetler@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This transmogrifies the test case that was just added to t0210, to also
cover the `GIT_TRACE2_PERF` backend.
Just like t0211, we now have to toggle the `TEST_PASSES_SANITIZE_LEAK`
annotation.
Signed-off-by: Jeff Hostetler <jeffhostetler@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The prereq guard added in 14903c8e92 (trace2 tests: guard pthread test
with "PTHREAD", 2022-11-24) lacks the S in PTHREADS, causing it to never
be satisfied. Fix the spelling of the prereq.
Signed-off-by: Todd Zullinger <tmz@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since 81071626ba (trace2: add global counter mechanism, 2022-10-24)
these tests have been failing when git is compiled with NO_PTHREADS=Y,
which is always the case e.g. if 'uname -s' is "NONSTOP_KERNEL".
Reported-by: Randall S. Becker <randall.becker@nexbridge.ca>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add global counters mechanism to Trace2.
The Trace2 counters mechanism adds the ability to create a set of
global counter variables and an API to increment them efficiently.
Counters can optionally report per-thread usage in addition to the sum
across all threads.
Counter events are emitted to the Trace2 logs when a thread exits and
at process exit.
Counters are an alternative to `data` and `data_json` events.
Counters are useful when you want to measure something across the life
of the process, when you don't want per-measurement events for
performance reasons, when the data does not fit conveniently within a
region, or when your control flow does not easily let you write the
final total. For example, you might use this to report the number of
calls to unzip() or the number of de-delta steps during a checkout.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add stopwatch timer mechanism to Trace2.
Timers are an alternative to Trace2 Regions. Regions are useful for
measuring the time spent in various computation phases, such as the
time to read the index, time to scan for unstaged files, time to scan
for untracked files, and etc.
However, regions are not appropriate in all places. For example,
during a checkout, it would be very inefficient to use regions to
measure the total time spent inflating objects from the ODB from
across the entire lifetime of the process; a per-unzip() region would
flood the output and significantly slow the command; and some form of
post-processing would be requried to compute the time spent in unzip().
Timers can be used to measure a series of timer intervals and emit
a single summary event (at thread and/or process exit).
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Mark all tests that match "*trace2*" as passing when git is compiled
with SANITIZE=leak. They'll now be listed as running under the
"GIT_TEST_PASSING_SANITIZE_LEAK=true" test mode (the "linux-leaks" CI
target).
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Make use of new sq_append_quote_argv_pretty() to normalize
how we handle leading whitespace in perf format messages.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
For an environment variable that is supposed to be set by users, the
GIT_TR2* env vars are just too unclear, inconsistent, and ugly.
Most of the established GIT_* environment variables don't use
abbreviations, and in case of the few that do (GIT_DIR,
GIT_COMMON_DIR, GIT_DIFF_OPTS) it's quite obvious what the
abbreviations (DIR and OPTS) stand for. But what does TR stand for?
Track, traditional, trailer, transaction, transfer, transformation,
transition, translation, transplant, transport, traversal, tree,
trigger, truncate, trust, or ...?!
The trace2 facility, as the '2' suffix in its name suggests, is
supposed to eventually supercede Git's original trace facility. It's
reasonable to expect that the corresponding environment variables
follow suit, and after the original GIT_TRACE variables they are
called GIT_TRACE2; there is no such thing is 'GIT_TR'.
All trace2-specific config variables are, very sensibly, in the
'trace2' section, not in 'tr2'.
OTOH, we don't gain anything at all by omitting the last three
characters of "trace" from the names of these environment variables.
So let's rename all GIT_TR2* environment variables to GIT_TRACE2*,
before they make their way into a stable release.
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach git to read the system and global config files for
default Trace2 settings. This allows system-wide Trace2 settings to
be installed and inherited to make it easier to manage a collection of
systems.
The original GIT_TR2* environment variables are loaded afterwards and
can be used to override the system settings.
Only the system and global config files are used. Repo and worktree
local config files are ignored. Likewise, the "-c" command line
arguments are also ignored. These limits are for performance reasons.
(1) For users not using Trace2, there should be minimal overhead to
detect that Trace2 is not enabled. In particular, Trace2 should not
allocate lots of otherwise unused data strucutres.
(2) For accurate performance measurements, Trace2 should be initialized
as early in the git process as possible, and before most of the normal
git process initialization (which involves discovering the .git directory
and reading a hierarchy of config files).
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add elapsed process time to "start" event to measure
the performance of early process startup.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Patrick Steinhardt