go/ast/inspector: make Cursor.Enclosing inlinable
Cursor.Enclosing computed the type mask before returning its
iterator, which put its inlining cost at 89, over the budget of 80.
As it was not inlined, every call allocated three times: the iterator,
and the closure and state of the caller's range loop.
Compute the mask inside the iterator, as Inspector.PreorderSeq does.
Enclosing now costs 25, and a range loop over it does not allocate.
The 3 allocs/op left below come from the benchmark's outer Preorder
loop.
goos: darwin
goarch: arm64
pkg: golang.org/x/tools/go/ast/inspector
cpu: Apple M1 Max
│ old.txt │ new.txt │
│ sec/op │ sec/op vs base │
InspectCalls/CursorEnclosing-10 245.1µ ± 0% 100.6µ ± 2% -58.97% (p=0.000 n=20)
│ old.txt │ new.txt │
│ B/op │ B/op vs base │
InspectCalls/CursorEnclosing-10 131568.00 ± 0% 80.00 ± 0% -99.94% (p=0.000 n=20)
│ old.txt │ new.txt │
│ allocs/op │ allocs/op vs base │
InspectCalls/CursorEnclosing-10 7047.000 ± 0% 3.000 ± 0% -99.96% (p=0.000 n=20)
Fixes golang/go#82191
Change-Id: Ie7dbc00c4d784eca551f4912fef12bda7f5f6140
GitHub-Last-Rev: 75e5ac909c42be5dcb85d3a65d4c8447d240f4a8
GitHub-Pull-Request: golang/tools#696
Reviewed-on: https://go-review.googlesource.com/c/tools/+/848686
Reviewed-by: Alan Donovan <adonovan@google.com>
LUCI-TryBot-Result: golang-scoped@luci-project-accounts.iam.gserviceaccount.com <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Carlos Amedee <carlos@golang.org>
Auto-Submit: 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/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://go.dev/doc/contribute.
The git repository is https://go.googlesource.com/tools.
The main issue tracker for the tools repository is located at https://go.dev/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.