| // Copyright 2018 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 lsp |
| |
| import ( |
| "context" |
| |
| "golang.org/x/tools/internal/lsp/protocol" |
| "golang.org/x/tools/internal/lsp/source" |
| "golang.org/x/tools/internal/span" |
| "golang.org/x/tools/internal/telemetry/log" |
| "golang.org/x/tools/internal/telemetry/tag" |
| ) |
| |
| func (s *Server) signatureHelp(ctx context.Context, params *protocol.SignatureHelpParams) (*protocol.SignatureHelp, error) { |
| uri := span.NewURI(params.TextDocument.URI) |
| view, err := s.session.ViewOf(uri) |
| if err != nil { |
| return nil, err |
| } |
| snapshot := view.Snapshot() |
| f, err := view.GetFile(ctx, uri) |
| if err != nil { |
| return nil, err |
| } |
| if f.Kind() != source.Go { |
| return nil, nil |
| } |
| info, err := source.SignatureHelp(ctx, snapshot, f, params.Position) |
| if err != nil { |
| log.Print(ctx, "no signature help", tag.Of("At", params.Position), tag.Of("Failure", err)) |
| return nil, nil |
| } |
| return toProtocolSignatureHelp(info), nil |
| } |
| |
| func toProtocolSignatureHelp(info *source.SignatureInformation) *protocol.SignatureHelp { |
| return &protocol.SignatureHelp{ |
| ActiveParameter: float64(info.ActiveParameter), |
| ActiveSignature: 0, // there is only ever one possible signature |
| Signatures: []protocol.SignatureInformation{ |
| { |
| Label: info.Label, |
| Documentation: info.Documentation, |
| Parameters: toProtocolParameterInformation(info.Parameters), |
| }, |
| }, |
| } |
| } |
| |
| func toProtocolParameterInformation(info []source.ParameterInformation) []protocol.ParameterInformation { |
| var result []protocol.ParameterInformation |
| for _, p := range info { |
| result = append(result, protocol.ParameterInformation{ |
| Label: p.Label, |
| }) |
| } |
| return result |
| } |