internal/lsp: refactor definition and hover to share functionality
The source package now exposes an Identifier method that returns information
about an identifier, which can be used to implement Definition, TypeDefinition
and Hover, as well as other command line functions in a later cl.
Change-Id: I03629c2c940215b4e2c86ee45bee8a18b79ee0e1
Reviewed-on: https://go-review.googlesource.com/c/159337
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
diff --git a/internal/lsp/server.go b/internal/lsp/server.go
index 4460816..98510de 100644
--- a/internal/lsp/server.go
+++ b/internal/lsp/server.go
@@ -218,16 +218,21 @@
return nil, err
}
pos := fromProtocolPosition(tok, params.Position)
- contents, rng, err := source.Hover(ctx, f, pos)
+ ident, err := source.Identifier(ctx, s.view, f, pos)
if err != nil {
return nil, err
}
+ content, err := ident.Hover(nil)
+ if err != nil {
+ return nil, err
+ }
+ markdown := "```go\n" + content + "\n```"
return &protocol.Hover{
Contents: protocol.MarkupContent{
Kind: protocol.Markdown,
- Value: contents,
+ Value: markdown,
},
- Range: toProtocolRange(tok, rng),
+ Range: toProtocolRange(tok, ident.Range),
}, nil
}
@@ -258,11 +263,11 @@
return nil, err
}
pos := fromProtocolPosition(tok, params.Position)
- r, err := source.Definition(ctx, s.view, f, pos)
+ ident, err := source.Identifier(ctx, s.view, f, pos)
if err != nil {
return nil, err
}
- return []protocol.Location{toProtocolLocation(s.view.FileSet(), r)}, nil
+ return []protocol.Location{toProtocolLocation(s.view.FileSet(), ident.Declaration.Range)}, nil
}
func (s *server) TypeDefinition(ctx context.Context, params *protocol.TextDocumentPositionParams) ([]protocol.Location, error) {
@@ -275,11 +280,11 @@
return nil, err
}
pos := fromProtocolPosition(tok, params.Position)
- r, err := source.TypeDefinition(ctx, s.view, f, pos)
+ ident, err := source.Identifier(ctx, s.view, f, pos)
if err != nil {
return nil, err
}
- return []protocol.Location{toProtocolLocation(s.view.FileSet(), r)}, nil
+ return []protocol.Location{toProtocolLocation(s.view.FileSet(), ident.Type.Range)}, nil
}
func (s *server) Implementation(context.Context, *protocol.TextDocumentPositionParams) ([]protocol.Location, error) {
diff --git a/internal/lsp/source/definition.go b/internal/lsp/source/definition.go
index 7863728..8024d63 100644
--- a/internal/lsp/source/definition.go
+++ b/internal/lsp/source/definition.go
@@ -15,103 +15,67 @@
"golang.org/x/tools/go/ast/astutil"
)
-func Definition(ctx context.Context, v View, f File, pos token.Pos) (Range, error) {
- fAST, err := f.GetAST()
- if err != nil {
- return Range{}, err
+// IdentifierInfo holds information about an identifier in Go source.
+type IdentifierInfo struct {
+ Name string
+ Range Range
+ File File
+ Type struct {
+ Range Range
+ Object types.Object
}
- pkg, err := f.GetPackage()
- if err != nil {
- return Range{}, err
+ Declaration struct {
+ Range Range
+ Object types.Object
}
- i, err := findIdentifier(fAST, pos)
- if err != nil {
- return Range{}, err
- }
- if i.ident == nil {
- return Range{}, fmt.Errorf("not a valid identifier")
- }
- obj := pkg.TypesInfo.ObjectOf(i.ident)
- if obj == nil {
- return Range{}, fmt.Errorf("no object")
- }
- if i.wasEmbeddedField {
- // The original position was on the embedded field declaration, so we
- // try to dig out the type and jump to that instead.
- if v, ok := obj.(*types.Var); ok {
- if n, ok := v.Type().(*types.Named); ok {
- obj = n.Obj()
- }
- }
- }
- return objToRange(ctx, v, obj)
-}
-func TypeDefinition(ctx context.Context, v View, f File, pos token.Pos) (Range, error) {
- fAST, err := f.GetAST()
- if err != nil {
- return Range{}, err
- }
- pkg, err := f.GetPackage()
- if err != nil {
- return Range{}, err
- }
- i, err := findIdentifier(fAST, pos)
- if err != nil {
- return Range{}, err
- }
- if i.ident == nil {
- return Range{}, fmt.Errorf("not a valid identifier")
- }
- typ := pkg.TypesInfo.TypeOf(i.ident)
- if typ == nil {
- return Range{}, fmt.Errorf("no type for %s", i.ident.Name)
- }
- obj := typeToObject(typ)
- if obj == nil {
- return Range{}, fmt.Errorf("no object for type %s", typ.String())
- }
- return objToRange(ctx, v, obj)
-}
-
-func typeToObject(typ types.Type) (obj types.Object) {
- switch typ := typ.(type) {
- case *types.Named:
- obj = typ.Obj()
- case *types.Pointer:
- obj = typeToObject(typ.Elem())
- }
- return obj
-}
-
-// ident returns the ident plus any extra information needed
-type ident struct {
ident *ast.Ident
wasEmbeddedField bool
}
-// findIdentifier returns the ast.Ident for a position
+// Identifier returns identifier information for a position
// in a file, accounting for a potentially incomplete selector.
-func findIdentifier(f *ast.File, pos token.Pos) (ident, error) {
- m, err := checkIdentifier(f, pos)
- if err != nil {
- return ident{}, err
- }
- if m.ident != nil {
- return m, nil
+func Identifier(ctx context.Context, v View, f File, pos token.Pos) (*IdentifierInfo, error) {
+ if result, err := identifier(ctx, v, f, pos); err != nil || result != nil {
+ return result, err
}
// If the position is not an identifier but immediately follows
// an identifier or selector period (as is common when
// requesting a completion), use the path to the preceding node.
- return checkIdentifier(f, pos-1)
+ return identifier(ctx, v, f, pos-1)
}
-// checkIdentifier checks a single position for a potential identifier.
-func checkIdentifier(f *ast.File, pos token.Pos) (ident, error) {
- path, _ := astutil.PathEnclosingInterval(f, pos, pos)
- result := ident{}
+func (i *IdentifierInfo) Hover(q types.Qualifier) (string, error) {
+ if q == nil {
+ fAST, err := i.File.GetAST()
+ if err != nil {
+ return "", err
+ }
+ pkg, err := i.File.GetPackage()
+ if err != nil {
+ return "", err
+ }
+ q = qualifier(fAST, pkg.Types, pkg.TypesInfo)
+ }
+ return types.ObjectString(i.Declaration.Object, q), nil
+}
+
+// identifier checks a single position for a potential identifier.
+func identifier(ctx context.Context, v View, f File, pos token.Pos) (*IdentifierInfo, error) {
+ fAST, err := f.GetAST()
+ if err != nil {
+ return nil, err
+ }
+ pkg, err := f.GetPackage()
+ if err != nil {
+ return nil, err
+ }
+ path, _ := astutil.PathEnclosingInterval(fAST, pos, pos)
+ result := &IdentifierInfo{
+ File: f,
+ }
if path == nil {
- return result, fmt.Errorf("can't find node enclosing position")
+ return nil, fmt.Errorf("can't find node enclosing position")
}
switch node := path[0].(type) {
case *ast.Ident:
@@ -119,16 +83,56 @@
case *ast.SelectorExpr:
result.ident = node.Sel
}
- if result.ident != nil {
- for _, n := range path[1:] {
- if field, ok := n.(*ast.Field); ok {
- result.wasEmbeddedField = len(field.Names) == 0
+ if result.ident == nil {
+ return nil, nil
+ }
+ for _, n := range path[1:] {
+ if field, ok := n.(*ast.Field); ok {
+ result.wasEmbeddedField = len(field.Names) == 0
+ }
+ }
+ result.Name = result.ident.Name
+ result.Range = Range{Start: result.ident.Pos(), End: result.ident.End()}
+ result.Declaration.Object = pkg.TypesInfo.ObjectOf(result.ident)
+ if result.Declaration.Object == nil {
+ return nil, fmt.Errorf("no object for ident %v", result.Name)
+ }
+ if result.wasEmbeddedField {
+ // The original position was on the embedded field declaration, so we
+ // try to dig out the type and jump to that instead.
+ if v, ok := result.Declaration.Object.(*types.Var); ok {
+ if n, ok := v.Type().(*types.Named); ok {
+ result.Declaration.Object = n.Obj()
}
}
}
+ if result.Declaration.Range, err = objToRange(ctx, v, result.Declaration.Object); err != nil {
+ return nil, err
+ }
+ typ := pkg.TypesInfo.TypeOf(result.ident)
+ if typ == nil {
+ return nil, fmt.Errorf("no type for %s", result.Name)
+ }
+ result.Type.Object = typeToObject(typ)
+ if result.Type.Object != nil {
+ if result.Type.Range, err = objToRange(ctx, v, result.Type.Object); err != nil {
+ return nil, err
+ }
+ }
return result, nil
}
+func typeToObject(typ types.Type) types.Object {
+ switch typ := typ.(type) {
+ case *types.Named:
+ return typ.Obj()
+ case *types.Pointer:
+ return typeToObject(typ.Elem())
+ default:
+ return nil
+ }
+}
+
func objToRange(ctx context.Context, v View, obj types.Object) (Range, error) {
p := obj.Pos()
if !p.IsValid() {
diff --git a/internal/lsp/source/hover.go b/internal/lsp/source/hover.go
deleted file mode 100644
index e449434..0000000
--- a/internal/lsp/source/hover.go
+++ /dev/null
@@ -1,50 +0,0 @@
-// 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 source
-
-import (
- "context"
- "fmt"
- "go/token"
- "go/types"
-)
-
-func Hover(ctx context.Context, f File, pos token.Pos) (string, Range, error) {
- fAST, err := f.GetAST()
- if err != nil {
- return "", Range{}, err
- }
- pkg, err := f.GetPackage()
- if err != nil {
- return "", Range{}, err
- }
- i, err := findIdentifier(fAST, pos)
- if err != nil {
- return "", Range{}, err
- }
- if i.ident == nil {
- return "", Range{}, fmt.Errorf("not a valid identifier")
- }
- obj := pkg.TypesInfo.ObjectOf(i.ident)
- if obj == nil {
- return "", Range{}, fmt.Errorf("no object")
- }
- if i.wasEmbeddedField {
- // the original position was on the embedded field declaration
- // so we try to dig out the type and jump to that instead
- if v, ok := obj.(*types.Var); ok {
- if n, ok := v.Type().(*types.Named); ok {
- obj = n.Obj()
- }
- }
- }
- // TODO(rstambler): Add documentation and improve quality of object string.
- content := types.ObjectString(obj, qualifier(fAST, pkg.Types, pkg.TypesInfo))
- markdown := "```go\n" + content + "\n```"
- return markdown, Range{
- Start: i.ident.Pos(),
- End: i.ident.End(),
- }, nil
-}
