commit | 79df971312162b7c79cfdf1725e6c479ee62ab8e | [log] [tgz] |
---|---|---|
author | Robert Findley <rfindley@google.com> | Tue Apr 09 14:07:32 2024 -0400 |
committer | Robert Findley <rfindley@google.com> | Wed Apr 10 18:53:13 2024 +0000 |
tree | 2c8fc25fd75a4ad0747f477e1c301e31258b7e9b | |
parent | bcd607e0402e99fe759a9720a5614d3ae7c7663f [diff] |
gopls/internal/server: avoid duplicate diagnoses and loads With gopls@v0.15.0, zero config gopls made it much more likely that sessions would have multiple Views. Additionally, with improved build tag support, it made it more likely that these Views would share files. As a result, we encountered (and fixed) this latent bug: 1. User changes file x.go, invalidating view A and B. A and B are scheduled for diagnosis. 2. User changes file y.go, invalidating only view B. Step (1) is cancelled and view B is scheduled for diagnosis. 3. View A never gets rediagnosed. The fix was naive: just mark view A and B as dirty, and schedule a goroutine to diagnose all dirty views after each step. As before, step (2) would cancel the context from step (1). But there's a problem: diagnoses were happening on the *Snapshot* context, not the operation context. Therefore, if the goroutines of step (1) and (2) both find the same snapshots, the diagnostics of step (1) would *not* be cancelled, and would be performed in addition to the diagnostics of (2). In other words, following a sequence of invalidations, we could theoretically be collecting diagnostics N times rather than 1 time. In practice, this is not so much of a problem for smaller repositories. Most of the time, changes are arriving at the speed of keystrokes, and diagnostics are being scheduled faster than we can type. However, on slower machines, or when there is more overall work being scheduled, or when changes arrive simultaneously (such as with a 'save all' command or branch switch), it is quite possible in practice to cause gopls to do more work than necessary, including redundant loads. I'm not sure if this is what conspires to cause the regressions described in golang/go#66647, but it certainly is a real regression. Fix this by threading the correct context into diagnoseSnapshot. Additionally, add earlier context cancellation in a few cases where redundant work was being performed despite a context cancellation. For golang/go#66647 Change-Id: I67da1c186848286ca7b6221330a655d23820fd5d Reviewed-on: https://go-review.googlesource.com/c/tools/+/577695 LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Alan Donovan <adonovan@google.com>
This repository provides the golang.org/x/tools
module, comprising various tools and packages mostly for static analysis of Go programs, some of which are listed below. Use the “Go reference” link above for more information about any package.
It also contains the golang.org/x/tools/gopls
module, whose root package is a language-server protocol (LSP) server for Go. An LSP server analyses the source code of a project and responds to requests from a wide range of editors such as VSCode and Vim, allowing them to support IDE-like functionality.
Selected commands:
cmd/goimports
formats a Go program like go fmt
and additionally inserts import statements for any packages required by the file after it is edited.cmd/callgraph
prints the call graph of a Go program.cmd/digraph
is a utility for manipulating directed graphs in textual notation.cmd/stringer
generates declarations (including a String
method) for “enum” types.cmd/toolstash
is a utility to simplify working with multiple versions of the Go toolchain.These commands may be fetched with a command such as
go install golang.org/x/tools/cmd/goimports@latest
Selected packages:
go/ssa
provides a static single-assignment form (SSA) intermediate representation (IR) for Go programs, similar to a typical compiler, for use by analysis tools.
go/packages
provides a simple interface for loading, parsing, and type checking a complete Go program from source code.
go/analysis
provides a framework for modular static analysis of Go programs.
go/callgraph
provides call graphs of Go programs using a variety of algorithms with different trade-offs.
go/ast/inspector
provides an optimized means of traversing a Go parse tree for use in analysis tools.
go/cfg
provides a simple control-flow graph (CFG) for a Go function.
go/expect
reads Go source files used as test inputs and interprets special comments within them as queries or assertions for testing.
go/gcexportdata
and go/gccgoexportdata
read and write the binary files containing type information used by the standard and gccgo
compilers.
go/types/objectpath
provides a stable naming scheme for named entities (“objects”) in the go/types
API.
Numerous other packages provide more esoteric functionality.
This repository uses Gerrit for code changes. To learn how to submit changes, see https://golang.org/doc/contribute.html.
The main issue tracker for the tools repository is located at https://github.com/golang/go/issues. Prefix your issue with “x/tools/(your subdir):” in the subject line, so it is easy to find.
This repository uses prettier to format JS and CSS files.
The version of prettier
used is 1.18.2.
It is encouraged that all JS and CSS code be run through this before submitting a change. However, it is not a strict requirement enforced by CI.