Documentation
¶
Overview ¶
Package goexperiment implements support for toolchain experiments.
Toolchain experiments are controlled by the GOEXPERIMENT environment variable. GOEXPERIMENT is a comma-separated list of experiment names. GOEXPERIMENT can be set at make.bash time, which sets the default experiments for binaries built with the tool chain; or it can be set at build time. GOEXPERIMENT can also be set to "none", which disables any experiments that were enabled at make.bash time.
Experiments are exposed to the build in the following ways:
- Build tag goexperiment.x is set if experiment x (lower case) is enabled.
- For each experiment x (in camel case), this package contains a boolean constant x and an integer constant xInt.
- In runtime assembly, the macro GOEXPERIMENT_x is defined if experiment x (lower case) is enabled.
In the toolchain, the set of experiments enabled for the current build should be accessed via objabi.Experiment.
The set of experiments is included in the output of runtime.Version() and "go version <binary>" if it differs from the default experiments.
For the set of experiments supported by the current toolchain, see "go doc goexperiment.Flags".
Note that this package defines the set of experiments (in Flags) and records the experiments that were enabled when the package was compiled (as boolean and integer constants).
Note especially that this package does not itself change behavior at run time based on the GOEXPERIMENT variable. The code used in builds to interpret the GOEXPERIMENT variable is in the separate package internal/buildcfg.
Index ¶
Constants ¶
const FieldTrack = false
const FieldTrackInt = 0
const HeapMinimum512KiB = false
const HeapMinimum512KiBInt = 0
const PacerRedesign = false
const PacerRedesignInt = 0
const PreemptibleLoops = false
const PreemptibleLoopsInt = 0
const RegabiArgs = false
const RegabiArgsInt = 0
const RegabiReflect = false
const RegabiReflectInt = 0
const RegabiWrappers = false
const RegabiWrappersInt = 0
const StaticLockRanking = false
const StaticLockRankingInt = 0
const Unified = false
const UnifiedInt = 0
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Flags ¶
type Flags struct {
FieldTrack bool
PreemptibleLoops bool
StaticLockRanking bool
// Unified enables the compiler's unified IR construction
// experiment.
Unified bool
// RegabiWrappers enables ABI wrappers for calling between
// ABI0 and ABIInternal functions. Without this, the ABIs are
// assumed to be identical so cross-ABI calls are direct.
RegabiWrappers bool
// RegabiReflect enables the register-passing paths in
// reflection calls. This is also gated by intArgRegs in
// reflect and runtime (which are disabled by default) so it
// can be used in targeted tests.
RegabiReflect bool
// RegabiArgs enables register arguments/results in all
// compiled Go functions.
//
// Requires wrappers (to do ABI translation), and reflect (so
// reflection calls use registers).
RegabiArgs bool
// PacerRedesign enables the new GC pacer in the runtime.
//
// Details regarding the new pacer may be found at
// https://golang.org/design/44167-gc-pacer-redesign
PacerRedesign bool
// HeapMinimum512KiB reduces the minimum heap size to 512 KiB.
//
// This was originally reduced as part of PacerRedesign, but
// has been broken out to its own experiment that is disabled
// by default.
HeapMinimum512KiB bool
}
Flags is the set of experiments that can be enabled or disabled in the current toolchain.
When specified in the GOEXPERIMENT environment variable or as build tags, experiments use the strings.ToLower of their field name.
For the baseline experimental configuration, see objabi.experimentBaseline.
If you change this struct definition, run "go generate".
Source Files