1
0
mirror of https://github.com/golang/go synced 2024-11-18 16:54:43 -07:00
go/internal/lsp/source/references.go
Rebecca Stambler 62ee03427e internal/lsp: use memoize package to cache source.Packages
This change eliminates the need for the package cache map, and instead
stores package type information in the store. We still have to maintain
invalidation logic because the key is not computed correctly.

Change-Id: I1c2a7502b99491ef0ff68d68c9f439503d531ff1
Reviewed-on: https://go-review.googlesource.com/c/tools/+/185438
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Cottrell <iancottrell@google.com>
2019-08-13 21:41:43 +00:00

100 lines
2.9 KiB
Go

// 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/types"
"golang.org/x/tools/internal/lsp/telemetry/trace"
"golang.org/x/tools/internal/span"
errors "golang.org/x/xerrors"
)
// 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, errors.Errorf("no references for an import spec")
}
pkgs, err := i.File.GetPackages(ctx)
if err != nil {
return nil, err
}
for _, pkg := range pkgs {
info := pkg.GetTypesInfo()
if info == nil {
return nil, errors.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()
}