| // 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 source |
| |
| import ( |
| "context" |
| "fmt" |
| "go/ast" |
| "go/types" |
| |
| "golang.org/x/tools/internal/lsp/telemetry/trace" |
| "golang.org/x/tools/internal/span" |
| ) |
| |
| // ReferenceInfo holds information about reference to an identifier in Go source. |
| type ReferenceInfo struct { |
| Name string |
| Range span.Range |
| ident *ast.Ident |
| obj types.Object |
| pkg Package |
| isDeclaration bool |
| } |
| |
| // References returns a list of references for a given identifier within the packages |
| // containing i.File. Declarations appear first in the result. |
| func (i *IdentifierInfo) References(ctx context.Context) ([]*ReferenceInfo, error) { |
| ctx, done := trace.StartSpan(ctx, "source.References") |
| defer done() |
| var references []*ReferenceInfo |
| |
| // If the object declaration is nil, assume it is an import spec and do not look for references. |
| if i.decl.obj == nil { |
| return nil, fmt.Errorf("no references for an import spec") |
| } |
| |
| pkgs := i.File.GetPackages(ctx) |
| for _, pkg := range pkgs { |
| if pkg == nil || pkg.IsIllTyped() { |
| return nil, fmt.Errorf("package for %s is ill typed", i.File.URI()) |
| } |
| info := pkg.GetTypesInfo() |
| if info == nil { |
| return nil, fmt.Errorf("package %s has no types info", pkg.PkgPath()) |
| } |
| |
| if i.decl.wasImplicit { |
| // The definition is implicit, so we must add it separately. |
| // This occurs when the variable is declared in a type switch statement |
| // or is an implicit package name. Both implicits are local to a file. |
| references = append(references, &ReferenceInfo{ |
| Name: i.decl.obj.Name(), |
| Range: i.decl.rng, |
| obj: i.decl.obj, |
| pkg: pkg, |
| isDeclaration: true, |
| }) |
| } |
| for ident, obj := range info.Defs { |
| if obj == nil || !sameObj(obj, i.decl.obj) { |
| continue |
| } |
| // Add the declarations at the beginning of the references list. |
| references = append([]*ReferenceInfo{&ReferenceInfo{ |
| Name: ident.Name, |
| Range: span.NewRange(i.File.FileSet(), ident.Pos(), ident.End()), |
| ident: ident, |
| obj: obj, |
| pkg: pkg, |
| isDeclaration: true, |
| }}, references...) |
| } |
| for ident, obj := range info.Uses { |
| if obj == nil || !sameObj(obj, i.decl.obj) { |
| continue |
| } |
| references = append(references, &ReferenceInfo{ |
| Name: ident.Name, |
| Range: span.NewRange(i.File.FileSet(), ident.Pos(), ident.End()), |
| ident: ident, |
| pkg: pkg, |
| obj: obj, |
| }) |
| } |
| |
| } |
| |
| return references, nil |
| } |
| |
| // sameObj returns true if obj is the same as declObj. |
| // Objects are the same if they have the some Pos and Name. |
| func sameObj(obj, declObj types.Object) bool { |
| // TODO(suzmue): support the case where an identifier may have two different |
| // declaration positions. |
| return obj.Pos() == declObj.Pos() && obj.Name() == declObj.Name() |
| } |