gopls/internal/golang: Implementations for func types

This CL adds support to the Implementations query for function
types. The query relates two sets of locations:

  1. the "func" token of each function declaration (FuncDecl or
     FuncLit). These are analogous to declarations of concrete
     methods.

  2. uses of abstract functions:

     (a) the "func" token of each FuncType that is not part of
     Func{Decl,Lit}. These are analogous to interface{...} types.

     (b) the "(" paren of each dynamic call on a value of an
     abstract function type. These are analogous to references to
     interface method names, but no names are involved, which has
     historically made them hard to search for.

An Implementations query on a location in set 1 returns set 2,
and vice versa.

Only the local algorithm is implemented for now; the global
one (using an index analogous to methodsets) will follow.

This CL supersedes CL 448035 and CL 619515, both of which attempt
to unify the treatment of functions and interfaces in the methodsets
algorithm and in the index; but the two problems are not precisely
analogous, and I think we'll end up with more but simpler code
if we implement themn separately.

+ tests, docs, relnotes

Updates golang/go#56572

Change-Id: I18e1a7cc2f6c320112b9f3589323d04f9a52ef3c
Reviewed-on: https://go-review.googlesource.com/c/tools/+/654556
Commit-Queue: Alan Donovan <adonovan@google.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Alan Donovan <adonovan@google.com>
6 files changed
tree: bd1916900be6a76cec3f3cf785a0c9598aee0100
  1. benchmark/
  2. blog/
  3. cmd/
  4. container/
  5. copyright/
  6. cover/
  7. go/
  8. godoc/
  9. gopls/
  10. imports/
  11. internal/
  12. playground/
  13. present/
  14. refactor/
  15. txtar/
  16. .gitattributes
  17. .gitignore
  18. .prettierrc
  19. codereview.cfg
  20. CONTRIBUTING.md
  21. go.mod
  22. go.sum
  23. LICENSE
  24. PATENTS
  25. README.md
README.md

Go Tools

PkgGoDev

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.

Contributing

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.

JavaScript and CSS Formatting

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.