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We add entries to the defer list at panic/goexit time on-the-fly for frames with open-coded defers. We do this so that we can correctly process open-coded defers and non-open-coded defers in the correct order during panics/goexits. But we need to remove entries for open-coded defers from the defer list when there is a recover, since those entries may never get removed otherwise and will get stale, since their corresponding defers may now be processed normally (inline). This bug here is that we were only removing higher-up stale entries during a recover if all defers in the current frame were done. But we could have more defers in the current frame (as the new test case shows). In this case, we need to leave the current defer entry around for use by deferreturn, but still remove any stale entries further along the chain. For bug 43921, simple change that we should abort the removal loop for any defer entry that is started (i.e. in process by a still not-recovered outer panic), even if it is not an open-coded defer. This change does not fix bug 43920, which looks to be a more complex fix. Fixes #43882 Fixes #43921 Change-Id: Ie05b2fa26973aa26b25c8899a2abc916090ee4f5 Reviewed-on: https://go-review.googlesource.com/c/go/+/286712 Run-TryBot: Dan Scales <danscales@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Matthew Dempsky <mdempsky@google.com> Reviewed-by: Keith Randall <khr@golang.org> Trust: Dan Scales <danscales@google.com>
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'.