Files
golang.go/src
Austin Clements 4e1bf8ed38 runtime: add GC testing helpers for regabi signature fuzzer
This CL adds a set of helper functions for testing GC interactions.
These are intended for use in the regabi signature fuzzer, but are
generally useful for GC tests, so we make them generally available to
runtime tests.

These provide:

1. An easy way to force stack movement, for testing stack copying.

2. A simple and robust way to check the reachability of a set of
pointers.

3. A way to check what general category of memory a pointer points to,
mostly so tests can make sure they're testing what they mean to.

For #40724, but generally useful.

Change-Id: I15d33ccb3f5a792c0472a19c2cc9a8b4a9356a66
Reviewed-on: https://go-review.googlesource.com/c/go/+/305330
Trust: Austin Clements <austin@google.com>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
2021-03-29 21:50:16 +00:00
..
2021-03-15 17:37:09 +00:00
2021-03-25 21:35:05 +00:00
2021-03-15 19:02:39 +00:00
2021-03-15 19:02:39 +00:00

Vendoring in std and cmd
========================

The Go command maintains copies of external packages needed by the
standard library in the src/vendor and src/cmd/vendor directories.

In GOPATH mode, imports of vendored packages are resolved to these
directories following normal vendor directory logic
(see golang.org/s/go15vendor).

In module mode, std and cmd are modules (defined in src/go.mod and
src/cmd/go.mod). When a package outside std or cmd is imported
by a package inside std or cmd, the import path is interpreted
as if it had a "vendor/" prefix. For example, within "crypto/tls",
an import of "golang.org/x/crypto/cryptobyte" resolves to
"vendor/golang.org/x/crypto/cryptobyte". When a package with the
same path is imported from a package outside std or cmd, it will
be resolved normally. Consequently, a binary may be built with two
copies of a package at different versions if the package is
imported normally and vendored by the standard library.

Vendored packages are internally renamed with a "vendor/" prefix
to preserve the invariant that all packages have distinct paths.
This is necessary to avoid compiler and linker conflicts. Adding
a "vendor/" prefix also maintains the invariant that standard
library packages begin with a dotless path element.

The module requirements of std and cmd do not influence version
selection in other modules. They are only considered when running
module commands like 'go get' and 'go mod vendor' from a directory
in GOROOT/src.

Maintaining vendor directories
==============================

Before updating vendor directories, ensure that module mode is enabled.
Make sure GO111MODULE=off is not set ('on' or 'auto' should work).

Requirements may be added, updated, and removed with 'go get'.
The vendor directory may be updated with 'go mod vendor'.
A typical sequence might be:

    cd src
    go get -d golang.org/x/net@latest
    go mod tidy
    go mod vendor

Use caution when passing '-u' to 'go get'. The '-u' flag updates
modules providing all transitively imported packages, not only
the module providing the target package.

Note that 'go mod vendor' only copies packages that are transitively
imported by packages in the current module. If a new package is needed,
it should be imported before running 'go mod vendor'.