blob: 4c78327459924c4cfb67b1b59e53e92fc1e82094 [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"
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
}