A //go:debug line mentioning an unknown or retired setting
should be diagnosed as making the program invalid. Do that.
We agreed on this in the proposal but I forgot to implement it.
Change-Id: Ie69072a1682d4eeb6866c02adbbb426f608567c4
Reviewed-on: https://go-review.googlesource.com/c/go/+/476280
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
We have been expanding our use of GODEBUG for compatibility,
and the current implementation forces a tradeoff between
freshness and efficiency. It parses the environment variable
in full each time it is called, which is expensive. But if clients
cache the result, they won't respond to run-time GODEBUG
changes, as happened with x509sha1 (#56436).
This CL changes the GODEBUG API to provide efficient,
up-to-date results. Instead of a single Get function,
New returns a *godebug.Setting that itself has a Get method.
Clients can save the result of New, which is no more expensive
than errors.New, in a global variable, and then call that
variable's Get method to get the value. Get costs only two
atomic loads in the case where the variable hasn't changed
since the last call.
Unfortunately, these changes do require importing sync
from godebug, which will mean that sync itself will never
be able to use a GODEBUG setting. That doesn't seem like
such a hardship. If it was really necessary, the runtime could
pass a setting to package sync itself at startup, with the
caveat that that setting, like the ones used by runtime itself,
would not respond to run-time GODEBUG changes.
Change-Id: I99a3acfa24fb2a692610af26a5d14bbc62c966ac
Reviewed-on: https://go-review.googlesource.com/c/go/+/449504
Run-TryBot: Russ Cox <rsc@golang.org>
Auto-Submit: Russ Cox <rsc@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Change-Id: Id6a27d0b3f3fc4181a00569bacc578e72b04ce09
GitHub-Last-Rev: 85c063d1a2d62181d16044592a60acf970fe3c86
GitHub-Pull-Request: golang/go#53359
Reviewed-on: https://go-review.googlesource.com/c/go/+/411916
Reviewed-by: Ian Lance Taylor <iant@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Peter Zhang <binbin36520@gmail.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: Robert Griesemer <gri@google.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>
Fix up a test to insure that it does the right thing when
"go test -cover" is in effect.
Fixes#52761.
Change-Id: I0c141181e2dcaefd592fb04813f812f2800511da
Reviewed-on: https://go-review.googlesource.com/c/go/+/404715
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
With the removal of SSE2 runtime detection made in
golang.org/cl/344350 we can remove this mechanism as there
are no required features anymore.
For making sure CPUs running a go program support all
the minimal hardware requirements the go runtime should
do feature checks early in the runtime initialization
before it is likely any compiler emitted but unsupported
instructions are used. This is already the case for e.g.
checking MMX support on 386 arch targets.
Change-Id: If7b1cb6f43233841e917d37a18314d06a334a734
Reviewed-on: https://go-review.googlesource.com/c/go/+/354209
Trust: Martin Möhrmann <martin@golang.org>
Run-TryBot: Martin Möhrmann <martin@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>
On macOS, we can do "go build", can exec, and have the source
tree available, so we can enable more tests.
Skip ones that don't work. Most of them are due to that it
requires external linking (for now) and some tests don't work
with external linking (e.g. runtime deadlock detection). For
them, helper functions CanInternalLink/MustInternalLink are
introduced. I still want to have internal linking implemented,
but it is still a good idea to identify which tests don't work
with external linking.
Updates #38485.
Change-Id: I6b14697573cf3f371daf54b9ddd792acf232f2f2
Reviewed-on: https://go-review.googlesource.com/c/go/+/260719
Trust: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Change internal/cpu feature configuration to use
GODEBUG=cpu.feature1=value,cpu.feature2=value...
instead of GODEBUGCPU=feature1=value,feature2=value... .
This is not a backwards compatibility breaking change
since GODEBUGCPU was introduced in go1.11 as an
undocumented compiler experiment.
Fixes#28757
Change-Id: Ib21b3fed2334baeeb061a722ab1eb513d1137e87
Reviewed-on: https://go-review.googlesource.com/c/149578
Run-TryBot: Martin Möhrmann <martisch@uos.de>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Use information about required CPU features stored in the CPU feature
options slice to test if minimal CPU requirements are met instead
of hard coding this information in the tests directly.
Change-Id: I72d89b1cff305b8e751995d4230a2217e32f4236
Reviewed-on: https://go-review.googlesource.com/c/145118
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Martin Möhrmann <martisch@uos.de>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This CL adds the ability to enable the cpu feature FEATURE by specifying
FEATURE=on in GODEBUGCPU. Syntax support to enable cpu features is useful
in combination with a preceeding all=off to disable all but some specific
cpu features. Example:
GODEBUGCPU=all=off,sse3=on
This CL implements printing of warnings for invalid GODEBUGCPU settings:
- requests enabling features that are not supported with the current CPU
- specifying values different than 'on' or 'off' for a feature
- settings for unkown cpu feature names
Updates #27218
Change-Id: Ic13e5c4c35426a390c50eaa4bd2a408ef2ee21be
Reviewed-on: https://go-review.googlesource.com/c/141800
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Enabling GODEBUGCPU without the need to set GOEXPERIMENT=debugcpu enables
trybots and builders to run tests for GODEBUGCPU features in upcoming CLs
that will implement the new syntax and features for non-experimental
GODEBUGCPU support from proposal golang.org/issue/27218.
Updates #27218
Change-Id: Icc69e51e736711a86b02b46bd441ffc28423beba
Reviewed-on: https://go-review.googlesource.com/c/141817
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Needs the go compiler to be build with GOEXPERIMENT=debugcpu to be active.
The GODEBUGCPU environment variable can be used to disable usage of
specific processor features in the Go standard library.
This is useful for testing and benchmarking different code paths that
are guarded by internal/cpu variable checks.
Use of processor features can not be enabled through GODEBUGCPU.
To disable usage of AVX and SSE41 cpu features on GOARCH amd64 use:
GODEBUGCPU=avx=0,sse41=0
The special "all" option can be used to disable all options:
GODEBUGCPU=all=0
Updates #12805
Updates #15403
Change-Id: I699c2e6f74d98472b6fb4b1e5ffbf29b15697aab
Reviewed-on: https://go-review.googlesource.com/91737
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This change replaces the current runtime capabilities check for ppc64x with the
new internal/cpu package. It also adds support for the new POWER9 ISA and
capabilities.
Updates #15403
Change-Id: I5b64a79e782f8da3603e5529600434f602986292
Reviewed-on: https://go-review.googlesource.com/53830
Reviewed-by: Martin Möhrmann <moehrmann@google.com>
Implements detection of x86 cpu features that
are used in the go standard library.
Changes all standard library packages to use the new cpu package
instead of using runtime internal variables to check x86 cpu features.
Updates: #15403
Change-Id: I2999a10cb4d9ec4863ffbed72f4e021a1dbc4bb9
Reviewed-on: https://go-review.googlesource.com/41476
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
