| // Copyright 2019 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| package cmd |
| |
| import ( |
| "context" |
| "encoding/json" |
| "flag" |
| "fmt" |
| "os" |
| "strings" |
| |
| guru "golang.org/x/tools/cmd/guru/serial" |
| "golang.org/x/tools/internal/lsp/protocol" |
| "golang.org/x/tools/internal/span" |
| "golang.org/x/tools/internal/tool" |
| ) |
| |
| // A Definition is the result of a 'definition' query. |
| type Definition struct { |
| Span span.Span `json:"span"` // span of the definition |
| Description string `json:"description"` // description of the denoted object |
| } |
| |
| // These constant is printed in the help, and then used in a test to verify the |
| // help is still valid. |
| // They refer to "Set" in "flag.FlagSet" from the DetailedHelp method below. |
| const ( |
| exampleLine = 44 |
| exampleColumn = 47 |
| exampleOffset = 1270 |
| ) |
| |
| // definition implements the definition noun for the query command. |
| type definition struct { |
| query *query |
| } |
| |
| func (d *definition) Name() string { return "definition" } |
| func (d *definition) Usage() string { return "<position>" } |
| func (d *definition) ShortHelp() string { return "show declaration of selected identifier" } |
| func (d *definition) DetailedHelp(f *flag.FlagSet) { |
| fmt.Fprintf(f.Output(), ` |
| Example: show the definition of the identifier at syntax at offset %[1]v in this file (flag.FlagSet): |
| |
| $ gopls definition internal/lsp/cmd/definition.go:%[1]v:%[2]v |
| $ gopls definition internal/lsp/cmd/definition.go:#%[3]v |
| |
| gopls query definition flags are: |
| `, exampleLine, exampleColumn, exampleOffset) |
| f.PrintDefaults() |
| } |
| |
| // Run performs the definition query as specified by args and prints the |
| // results to stdout. |
| func (d *definition) Run(ctx context.Context, args ...string) error { |
| if len(args) != 1 { |
| return tool.CommandLineErrorf("definition expects 1 argument") |
| } |
| conn, err := d.query.app.connect(ctx) |
| if err != nil { |
| return err |
| } |
| defer conn.terminate(ctx) |
| from := span.Parse(args[0]) |
| file := conn.AddFile(ctx, from.URI()) |
| if file.err != nil { |
| return file.err |
| } |
| loc, err := file.mapper.Location(from) |
| if err != nil { |
| return err |
| } |
| p := protocol.TextDocumentPositionParams{ |
| TextDocument: protocol.TextDocumentIdentifier{URI: loc.URI}, |
| Position: loc.Range.Start, |
| } |
| locs, err := conn.Definition(ctx, &p) |
| if err != nil { |
| return fmt.Errorf("%v: %v", from, err) |
| } |
| |
| if len(locs) == 0 { |
| return fmt.Errorf("%v: not an identifier", from) |
| } |
| hover, err := conn.Hover(ctx, &p) |
| if err != nil { |
| return fmt.Errorf("%v: %v", from, err) |
| } |
| if hover == nil { |
| return fmt.Errorf("%v: not an identifier", from) |
| } |
| file = conn.AddFile(ctx, span.NewURI(locs[0].URI)) |
| if file.err != nil { |
| return fmt.Errorf("%v: %v", from, file.err) |
| } |
| definition, err := file.mapper.Span(locs[0]) |
| if err != nil { |
| return fmt.Errorf("%v: %v", from, err) |
| } |
| description := strings.TrimSpace(hover.Contents.Value) |
| var result interface{} |
| switch d.query.Emulate { |
| case "": |
| result = &Definition{ |
| Span: definition, |
| Description: description, |
| } |
| case emulateGuru: |
| pos := span.New(definition.URI(), definition.Start(), definition.Start()) |
| result = &guru.Definition{ |
| ObjPos: fmt.Sprint(pos), |
| Desc: description, |
| } |
| default: |
| return fmt.Errorf("unknown emulation for definition: %s", d.query.Emulate) |
| } |
| if err != nil { |
| return err |
| } |
| if d.query.JSON { |
| enc := json.NewEncoder(os.Stdout) |
| enc.SetIndent("", "\t") |
| return enc.Encode(result) |
| } |
| switch d := result.(type) { |
| case *Definition: |
| fmt.Printf("%v: defined here as %s", d.Span, d.Description) |
| case *guru.Definition: |
| fmt.Printf("%s: defined here as %s", d.ObjPos, d.Desc) |
| default: |
| return fmt.Errorf("no printer for type %T", result) |
| } |
| return nil |
| } |