blob: c20dcc14ffaa63f6c33e8a16571cd64a299b0ef5 [file] [log] [blame]
// 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"
"golang.org/x/tools/gopls/internal/lsp/protocol"
"golang.org/x/tools/gopls/internal/settings"
"golang.org/x/tools/internal/tool"
)
// A Definition is the result of a 'definition' query.
type Definition struct {
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 verb for gopls.
type definition struct {
app *Application
JSON bool `flag:"json" help:"emit output in JSON format"`
MarkdownSupported bool `flag:"markdown" help:"support markdown in responses"`
}
func (d *definition) Name() string { return "definition" }
func (d *definition) Parent() string { return d.app.Name() }
func (d *definition) Usage() string { return "[definition-flags] <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/cmd/definition.go:%[1]v:%[2]v
$ gopls definition internal/cmd/definition.go:#%[3]v
definition-flags:
`, exampleLine, exampleColumn, exampleOffset)
printFlagDefaults(f)
}
// 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")
}
// Plaintext makes more sense for the command line.
opts := d.app.options
d.app.options = func(o *settings.Options) {
if opts != nil {
opts(o)
}
o.PreferredContentFormat = protocol.PlainText
if d.MarkdownSupported {
o.PreferredContentFormat = protocol.Markdown
}
}
conn, err := d.app.connect(ctx, nil)
if err != nil {
return err
}
defer conn.terminate(ctx)
from := parseSpan(args[0])
file, err := conn.openFile(ctx, from.URI())
if err != nil {
return err
}
loc, err := file.spanLocation(from)
if err != nil {
return err
}
p := protocol.DefinitionParams{
TextDocumentPositionParams: protocol.LocationTextDocumentPositionParams(loc),
}
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)
}
file, err = conn.openFile(ctx, locs[0].URI)
if err != nil {
return fmt.Errorf("%v: %v", from, err)
}
definition, err := file.locationSpan(locs[0])
if err != nil {
return fmt.Errorf("%v: %v", from, err)
}
q := protocol.HoverParams{
TextDocumentPositionParams: protocol.LocationTextDocumentPositionParams(loc),
}
hover, err := conn.Hover(ctx, &q)
if err != nil {
return fmt.Errorf("%v: %v", from, err)
}
var description string
if hover != nil {
description = strings.TrimSpace(hover.Contents.Value)
}
result := &Definition{
Span: definition,
Description: description,
}
if d.JSON {
enc := json.NewEncoder(os.Stdout)
enc.SetIndent("", "\t")
return enc.Encode(result)
}
fmt.Printf("%v", result.Span)
if len(result.Description) > 0 {
fmt.Printf(": defined here as %s", result.Description)
}
fmt.Printf("\n")
return nil
}