blob: 74e2fe4d6da90264e12757a55e58cc8b844bab7b [file] [log] [blame]
// 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"
"go/ast"
"go/token"
"go/types"
"golang.org/x/tools/internal/event"
"golang.org/x/tools/internal/lsp/protocol"
"golang.org/x/xerrors"
)
// ReferenceInfo holds information about reference to an identifier in Go source.
type ReferenceInfo struct {
Name string
mappedRange
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 References(ctx context.Context, s Snapshot, f FileHandle, pp protocol.Position, includeDeclaration bool) ([]*ReferenceInfo, error) {
ctx, done := event.Start(ctx, "source.References")
defer done()
qualifiedObjs, err := qualifiedObjsAtProtocolPos(ctx, s, f, pp)
// Don't return references for builtin types.
if xerrors.Is(err, errBuiltin) {
return nil, nil
}
if err != nil {
return nil, err
}
return references(ctx, s, qualifiedObjs, includeDeclaration)
}
// references is a helper function used by both References and Rename,
// to avoid recomputing qualifiedObjsAtProtocolPos.
func references(ctx context.Context, s Snapshot, qos []qualifiedObject, includeDeclaration bool) ([]*ReferenceInfo, error) {
var (
references []*ReferenceInfo
seen = make(map[token.Position]bool)
fset = s.View().Session().Cache().FileSet()
)
// Make sure declaration is the first item in the response.
if includeDeclaration {
rng, err := objToMappedRange(s.View(), qos[0].pkg, qos[0].obj)
if err != nil {
return nil, err
}
ident, _ := qos[0].node.(*ast.Ident)
references = append(references, &ReferenceInfo{
mappedRange: rng,
Name: qos[0].obj.Name(),
ident: ident,
obj: qos[0].obj,
pkg: qos[0].pkg,
isDeclaration: true,
})
}
for _, qo := range qos {
var searchPkgs []Package
// Only search dependents if the object is exported.
if qo.obj.Exported() {
reverseDeps, err := s.GetReverseDependencies(ctx, qo.pkg.ID())
if err != nil {
return nil, err
}
for _, ph := range reverseDeps {
pkg, err := ph.Check(ctx)
if err != nil {
return nil, err
}
searchPkgs = append(searchPkgs, pkg)
}
}
// Add the package in which the identifier is declared.
searchPkgs = append(searchPkgs, qo.pkg)
for _, pkg := range searchPkgs {
for ident, obj := range pkg.GetTypesInfo().Uses {
if obj != qo.obj {
continue
}
pos := fset.Position(ident.Pos())
if seen[pos] {
continue
}
seen[pos] = true
rng, err := posToMappedRange(s.View(), pkg, ident.Pos(), ident.End())
if err != nil {
return nil, err
}
references = append(references, &ReferenceInfo{
Name: ident.Name,
ident: ident,
pkg: pkg,
obj: obj,
mappedRange: rng,
})
}
}
}
return references, nil
}