1 files changed, 60 insertions, 0 deletions
diff --git a/gopls/internal/lsp/symbols.go b/gopls/internal/lsp/symbols.go
new file mode 100644
index 000000000..40fa0d05e
--- /dev/null
+++ b/gopls/internal/lsp/symbols.go
@@ -0,0 +1,60 @@
+// 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 lsp
+
+import (
+	"context"
+
+	"golang.org/x/tools/gopls/internal/lsp/protocol"
+	"golang.org/x/tools/gopls/internal/lsp/source"
+	"golang.org/x/tools/gopls/internal/lsp/template"
+	"golang.org/x/tools/internal/event"
+	"golang.org/x/tools/internal/event/tag"
+)
+
+func (s *Server) documentSymbol(ctx context.Context, params *protocol.DocumentSymbolParams) ([]interface{}, error) {
+	ctx, done := event.Start(ctx, "lsp.Server.documentSymbol")
+	defer done()
+
+	snapshot, fh, ok, release, err := s.beginFileRequest(ctx, params.TextDocument.URI, source.UnknownKind)
+	defer release()
+	if !ok {
+		return []interface{}{}, err
+	}
+	var docSymbols []protocol.DocumentSymbol
+	switch snapshot.View().FileKind(fh) {
+	case source.Tmpl:
+		docSymbols, err = template.DocumentSymbols(snapshot, fh)
+	case source.Go:
+		docSymbols, err = source.DocumentSymbols(ctx, snapshot, fh)
+	default:
+		return []interface{}{}, nil
+	}
+	if err != nil {
+		event.Error(ctx, "DocumentSymbols failed", err, tag.URI.Of(fh.URI()))
+		return []interface{}{}, nil
+	}
+	// Convert the symbols to an interface array.
+	// TODO: Remove this once the lsp deprecates SymbolInformation.
+	symbols := make([]interface{}, len(docSymbols))
+	for i, s := range docSymbols {
+		if snapshot.View().Options().HierarchicalDocumentSymbolSupport {
+			symbols[i] = s
+			continue
+		}
+		// If the client does not support hierarchical document symbols, then
+		// we need to be backwards compatible for now and return SymbolInformation.
+		symbols[i] = protocol.SymbolInformation{
+			Name:       s.Name,
+			Kind:       s.Kind,
+			Deprecated: s.Deprecated,
+			Location: protocol.Location{
+				URI:   params.TextDocument.URI,
+				Range: s.Range,
+			},
+		}
+	}
+	return symbols, nil
+}