We haven't used this in a while and it's going to complicate later
changes to dist, so drop support. This was primarily for supporting
slow QEMU-based builders, but an alternative and simpler way to do
that if we need to in the future is to supply a go_exec wrapper to run
tests in QEMU, like we do for other emulated platforms.

Simplification for #37486.

Change-Id: Idc0383f59c61d8546ea3b4d2eede4acdaf30d9b6
Reviewed-on: https://go-review.googlesource.com/c/go/+/431256
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Austin Clements <austin@google.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
Run-TryBot: Austin Clements <austin@google.com>

The testasan test was added back in 2013 (CL 10126044), many years
before Go added ASAN support in 2021 (CL 298611). So, in fact,
testasan does not test Go ASAN support at all, as you might expect
(misc/cgo/testsanitizers does that). It's intended to test whether the
Go memory allocator works in a mixed C/Go binary where the C code is
compiled with ASAN. The test doesn't actually use ASAN in any way; it
just simulates where ASAN of 2013 put its shadow mappings. This made
sense to test at the time because Go was picky about where its heap
landed and ASAN happened to put its mappings exactly where Go wanted
to put its heap. These days, Go is totally flexible about its heap
placement, and I wouldn't be surprised if ASAN also works differently.

Given all of this, this test adds almost no value today. Drop it.

For #37486, since it eliminates a non-go-test from dist.

Change-Id: I0292f8efbdc0e1e39650715604535c445fbaa87f
Reviewed-on: https://go-review.googlesource.com/c/go/+/443067
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Austin Clements <austin@google.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

This code was introduced in CL 17903 but has never executed. It's also
fundamentally non-deterministic. Delete it.

Simplification for #37486.

Change-Id: I049564123fb4fba401154e2ea0fc429e552d4749
Reviewed-on: https://go-review.googlesource.com/c/go/+/431258
Reviewed-by: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>

This migrates testsigfwd, which uses some one-off build
infrastructure, to be part of the runtime's testprogcgo.

The test is largely unchanged. Because it's part of a larger binary,
this CL renames a few things and gates the constructor-time signal
handler registration on an environment variable. This CL also replaces
an errant fmt.Errorf with fmt.Fprintf.

For #37486, since it eliminates a non-go-test from dist.

Change-Id: I0efd146ea0a0a3f0b361431349a419af0f0ecc61
Reviewed-on: https://go-review.googlesource.com/c/go/+/443068
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

Currently, the entry-point to this test is a Bash script that smoke
tests the FORTRAN compiler and then runs a FORTRAN-containing Go test.
This CL rearranges things so a pure Go Go test smoke tests the FORTRAN
compiler and then runs a non-test FORTRAN-containing Go binary.

While we're here, we fix a discrepancy when the host is GOARCH=amd64,
but the target is GOARCH=386. Previously, we would pick the wrong
libgfortran path because we didn't account for the cross-compilation,
causing the link to fail. Except for some reason this was ignored and
the test nevertheless "passed". In the new test we're a little more
strict, so this build failure will cause the test to fail, so we add a
little logic to account for cross-compilation with the host toolchain.

For #37486.

Change-Id: Ie6f70066885d6fbb4e1b5a2b1e13b85dee5b359b
Reviewed-on: https://go-review.googlesource.com/c/go/+/443069
Reviewed-by: Ian Lance Taylor <iant@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Bryan Mills <bcmills@google.com>
Run-TryBot: Austin Clements <austin@google.com>

The go1 benchmark suite does a lot of work at package init time, which
makes it take quite a while to run even if you're not running any of
the benchmarks, or if you're only running a subset of them. This leads
to an awkward workaround in dist test to compile but not run the
package, unlike roughly all other packages. It also reduces isolation
between benchmarks by affecting the starting heap size of all
benchmarks.

Fix this by initializing all data required by a benchmark when that
benchmark runs, and keeping it local so it gets freed by the GC and
doesn't leak between benchmarks. Now, none of the benchmarks depend on
global state.

Re-initializing the data on each benchmark run does add overhead to an
actual benchmark run, as each benchmark function is called several
times with different values of b.N. A full run of all benchmarks at
the default -benchtime=1s now takes ~10% longer; higher -benchtimes
would be less. It would be quite difficult to cache this data between
invocations of the same benchmark function without leaking between
different benchmarks and affecting GC overheads, as the testing
package doesn't provide any mechanism for this.

This reduces the time to run the binary with no benchmarks from 1.5
seconds to 10 ms, and also reduces the memory required to do this from
342 MiB to 17 MiB.

To make sure data was not leaking between different benchmarks, I ran
the benchmarks with -shuffle=on. The variance remained low: mostly
under 3%. A few benchmarks had higher variance, but in all cases it
was similar to the variance between this change.

This CL naturally changes the measured performance of several of the
benchmarks because it dramatically changes the heap size and hence GC
overheads. However, going forward the benchmarks should be much better
isolated.

For #37486.

Change-Id: I252ebea703a9560706cc1990dc5ad22d1927c7a0
Reviewed-on: https://go-review.googlesource.com/c/go/+/443336
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
Run-TryBot: Austin Clements <austin@google.com>

This introduces the concept of test variants in dist, which are
different configurations of the same package. The variant of a test is
a short string summarizing the configuration.

The "variant name" of a test is either the package name if the variant
is empty, or package:variant if not. Currently this isn't used for
anything, but soon we'll use this as the Package field of the test
JSON output so that we can disambiguate output from differently
configured runs of the same test package, and naturally flow this
through to any test result viewer.

The long-term plan is to use variant names as dist's own test names
and eliminate the ad hoc names it has right now. Unfortunately, the
build coordinator is aware of many of the ad hoc dist test names, so
some more work is needed to get to that point. This CL keeps almost
all test names the same, with the exception of tests registered by
registerCgoTests, where we regularize test names a bit using variants
to avoid some unnecessary complexity (I believe nothing depends on the
names of these tests).

For #37486.

Change-Id: I119fec2872e40b12c1973cf2cddc7f413d62a48c
Reviewed-on: https://go-review.googlesource.com/c/go/+/495016
Reviewed-by: Bryan Mills <bcmills@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

There are no uses of addCmd, so delete it. The only use of bgDirCmd is
dirCmd, so inline it. Now the only function that interacts with the
work queue is registerTest and dist's "background commands" are used
exclusively in goTest.bgCommand and registerTest (which calls
goTest.bgCommand).

For #37486.

Change-Id: Iebbb24cf9dbee45f3975fe9504d858493e1cd947
Reviewed-on: https://go-review.googlesource.com/c/go/+/494956
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>

Many of the commands dist test executes are "background" commands run
by a work queue system. The work queue allows it to run commands in
parallel, but still serialize their output. Currently, the work queue
system assumes that exec.Cmd.Stdout and Stderr will be nil and that it
can take complete control over them.

We're about to inject output filters on many of these commands, so we
need a way to interpose on Stdout and Stderr. This CL rearranges
responsibilities in the work queue system to make that possible. Now,
the thing enqueuing the work item is responsible to constructing the
Cmd to write its output to work.out. There's only one place that
constructs work objects (there used to be many more), so that's
relatively easy, and sets us up to add filters.

For #37486.

Change-Id: I55ab71ddd456a12fdbf676bb49f698fc08a5689b
Reviewed-on: https://go-review.googlesource.com/c/go/+/494957
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>

Currently, all uses of rtPreFunc are to print a message and skip a
test. When we move to JSON, the logic to just "print a message" is
going to be more complicated, so refactor this so the function returns
the skip message and we print it in just one place. We also rename the
option to rtSkipFunc to better represent what we use it for.

For #37486.

Change-Id: Ibd537064fa646a956a1c0f85a5d8c6febd098dde
Reviewed-on: https://go-review.googlesource.com/c/go/+/495856
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>

These are some follow-up tweaks to CL 494958. This CL drops a stale
and unnecessary check and passes through trailing non-JSON output.

Updates #37486.

Change-Id: I7cdb73a103f9cd49767d5491812d5ad011ee5c14
Reviewed-on: https://go-review.googlesource.com/c/go/+/496297
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Austin Clements <austin@google.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
Run-TryBot: Austin Clements <austin@google.com>

Currently, if a test prints an incomplete line and then exits, in JSON
mode, the filter we use to rewrite Package lines will keep the last
incomplete line in an internal buffer and never print it. In theory
this should never happen anyway because the test should only write
JSON to stdout, but we try pretty hard to pass through any non-JSON,
so it seems inconsistent to swallow incomplete lines.

Fix this by adding a testJSONFilter.Flush method and calling it in the
right places. Unfortunately this is a bit tricky because the filter is
constructed pretty far from where we run the exec.Cmd, so we return
the flush function through the various layers in order to route it to
the place where we call Cmd.Run.

Updates #37486.

Change-Id: I38af67e8ad23458598a32fd428779bb0ec21ac3c
Reviewed-on: https://go-review.googlesource.com/c/go/+/496516
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Austin Clements <austin@google.com>
Reviewed-by: Bryan Mills <bcmills@google.com>

The coordinator has some custom logic for "go_test:*" dist test names
involved in partitioning, merging, and sorting them using historical
test timing data. We also have many builder-specific dist test adjust
policies, and some parts of them have become out of date (e.g.,
macTestPolicy skips "wiki", a dist test that's long gone).

Go 1.21 is simplifying the naming pattern for dist test names, and
we want to do that without having to manually update the (many!)
existing adjust policies, as well as to avoid breaking or creating
a need to re-engineer the existing mechanisms that make "go_test:*"
dist test names special.

Make that possible by remapping the 'go tool dist test -list' output
from the new "pkg[:variant]" format to the previous format (or pass it
through unmodified if it's already in the old format) for the purpose
of dist test adjust policies only. Also keep the raw unmodified dist
test name around since it's needed for invoking said dist tests.

For golang/go#37486.
For golang/go#59990.

Change-Id: Ie958609de2a810fa0053a00091a0c54c3f8bfd83
Reviewed-on: https://go-review.googlesource.com/c/build/+/496190
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Austin Clements <austin@google.com>
Auto-Submit: Dmitri Shuralyov <dmitshur@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>

The work to add the -json flag to the 'dist test' command also cleaned
how dist tests are tracked and registered. By now, a pair of (import
path, variant) strings is sufficient to uniquely identify every dist
test that exists. Some of the custom dist test names have been improved
along the way. And since the names are already changing a little anyway,
we use this opportunity to make them more uniform and predictable.

The mapping from the old dist test names to the new is as follows:

- "go_test:pkg"       → "pkg"  (this is the most common case)
- "go_test_bench:pkg" → "pkg:racebench"
- all other custom names are now called "pkg:variant", where variant
  is a description of their test configuration and pkg is the import
  path of the Go package under test

CL 495016 introduced test variants and used variant names for rewriting
the Package field in JSON events, and now that same name starts to also
be used as the dist test name.

Like previously done in CL 494496, registering a test variant involving
multiple Go packages creates a "pkg:variant" dist test name for each.
In the future we may combine their 'go test' invocation purely as an
optimization.

We can do this with the support of CL 496190 that keeps the coordinator
happy and capable of working with both new and old names.

In the end, all dist tests now have a consistent "pkg[:variant]" name.

For #37486.
For #59990.

Change-Id: I7eb02a42792a9831a2f3eeab583ff635d24269e8
Co-authored-by: Austin Clements <austin@google.com>
Reviewed-on: https://go-review.googlesource.com/c/go/+/496181
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>
Auto-Submit: Dmitri Shuralyov <dmitshur@golang.org>
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Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>

The -json flag is new to Go 1.21, but missed skips in runPending.
This CL adds minimal code to fix that. CL 512115 cleans up a bit.

For #37486.
Fixes (via backport) #61557.

Change-Id: I53e426c9a5585b2703f0ff6661a0470e1993f960
Reviewed-on: https://go-review.googlesource.com/c/go/+/512719
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Austin Clements <austin@google.com>
Auto-Submit: Dmitri Shuralyov <dmitshur@golang.org>

…nimal)

The -json flag is new to Go 1.21, but missed skips in runPending.
This CL adds minimal code to fix that. CL 512115 cleans up a bit.

For #37486.
Fixes #61557.

Change-Id: I53e426c9a5585b2703f0ff6661a0470e1993f960
Reviewed-on: https://go-review.googlesource.com/c/go/+/513761
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>
Auto-Submit: Dmitri Shuralyov <dmitshur@golang.org>

Document work fields a bit more, and move code that
synthesizes JSON-encoded skip events to testjson.go.

For #37486.
For #61557.

Change-Id: Iffc23cf990bc39696e1e3fce8ce5a6790fc44e78
Reviewed-on: https://go-review.googlesource.com/c/go/+/512115
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Auto-Submit: Dmitri Shuralyov <dmitshur@golang.org>
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Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>

The dist test name changed from "race" to "flag:race", "net:race",
"os:race" and so on in CL 496181, we missed that this skip was checking
the exact dist test name, and no builder reported a problem despite the
skip becoming inactive.

I considered deleting it as obsolete, but it may still be helpful
if someone runs race.bash on a linux/arm64 machine configured with
something other than the supported 48-bit VMA. So for now apply a
simple change to restore the existing skip.

Hopefully one day there will be a good way to check for unsupported VMA
size and disable the race detector conditionally instead of relying on
tests running, failing, and getting marked as skipped in cmd/dist.

For #29948.
For #37486.

Change-Id: I8af6862c92fb0ee538ab27327d43c50921bd1873
Reviewed-on: https://go-review.googlesource.com/c/go/+/512116
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Auto-Submit: Dmitri Shuralyov <dmitshur@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

…nimal)

The -json flag is new to Go 1.21, but missed skips in runPending.
This CL adds minimal code to fix that. CL 512115 cleans up a bit.

For golang#37486.
Fixes golang#61557.

Change-Id: I53e426c9a5585b2703f0ff6661a0470e1993f960
Reviewed-on: https://go-review.googlesource.com/c/go/+/513761
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>
Auto-Submit: Dmitri Shuralyov <dmitshur@golang.org>