1// Copyright 2019 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5package cmd
6
7import (
8	"context"
9	"flag"
10	"fmt"
11	"sort"
12
13	"golang.org/x/tools/internal/lsp/protocol"
14	"golang.org/x/tools/internal/span"
15	"golang.org/x/tools/internal/tool"
16)
17
18// implementation implements the implementation verb for gopls
19type implementation struct {
20	app *Application
21}
22
23func (i *implementation) Name() string      { return "implementation" }
24func (i *implementation) Usage() string     { return "<position>" }
25func (i *implementation) ShortHelp() string { return "display selected identifier's implementation" }
26func (i *implementation) DetailedHelp(f *flag.FlagSet) {
27	fmt.Fprint(f.Output(), `
28Example:
29
30  $ # 1-indexed location (:line:column or :#offset) of the target identifier
31  $ gopls implementation helper/helper.go:8:6
32  $ gopls implementation helper/helper.go:#53
33
34  gopls implementation flags are:
35`)
36	f.PrintDefaults()
37}
38
39func (i *implementation) Run(ctx context.Context, args ...string) error {
40	if len(args) != 1 {
41		return tool.CommandLineErrorf("implementation expects 1 argument (position)")
42	}
43
44	conn, err := i.app.connect(ctx)
45	if err != nil {
46		return err
47	}
48	defer conn.terminate(ctx)
49
50	from := span.Parse(args[0])
51	file := conn.AddFile(ctx, from.URI())
52	if file.err != nil {
53		return file.err
54	}
55
56	loc, err := file.mapper.Location(from)
57	if err != nil {
58		return err
59	}
60
61	p := protocol.ImplementationParams{
62		TextDocumentPositionParams: protocol.TextDocumentPositionParams{
63			TextDocument: protocol.TextDocumentIdentifier{URI: loc.URI},
64			Position:     loc.Range.Start,
65		},
66	}
67
68	implementations, err := conn.Implementation(ctx, &p)
69	if err != nil {
70		return err
71	}
72
73	var spans []string
74	for _, impl := range implementations {
75		f := conn.AddFile(ctx, fileURI(impl.URI))
76		span, err := f.mapper.Span(impl)
77		if err != nil {
78			return err
79		}
80		spans = append(spans, fmt.Sprint(span))
81	}
82	sort.Strings(spans)
83
84	for _, s := range spans {
85		fmt.Println(s)
86	}
87
88	return nil
89}
90