| // 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/telemetry/log" |
| "golang.org/x/tools/internal/telemetry/tag" |
| ) |
| |
| func (s *Server) signatureHelp(ctx context.Context, params *protocol.SignatureHelpParams) (*protocol.SignatureHelp, error) { |
| uri := params.TextDocument.URI.SpanURI() |
| view, err := s.session.ViewOf(uri) |
| if err != nil { |
| return nil, err |
| } |
| snapshot := view.Snapshot() |
| fh, err := snapshot.GetFile(uri) |
| if err != nil { |
| return nil, err |
| } |
| if fh.Identity().Kind != source.Go { |
| return nil, nil |
| } |
| info, activeParameter, err := source.SignatureHelp(ctx, snapshot, fh, params.Position) |
| if err != nil { |
| log.Print(ctx, "no signature help", tag.Of("At", params.Position), tag.Of("Failure", err)) |
| return nil, nil |
| } |
| return &protocol.SignatureHelp{ |
| Signatures: []protocol.SignatureInformation{*info}, |
| ActiveParameter: float64(activeParameter), |
| }, nil |
| } |