blob: 0b199e6898a77547b761a2e8b13c91055687cd36 [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"
"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
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, ts := trace.StartSpan(ctx, "source.References")
defer ts.End()
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")
}
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,
isDeclaration: true,
})
}
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())
}
for ident, obj := range info.Defs {
// TODO(suzmue): support the case where an identifier may have two different declarations.
if obj == nil || obj.Pos() != i.decl.obj.Pos() {
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,
isDeclaration: true,
}}, references...)
}
for ident, obj := range info.Uses {
if obj == nil || obj.Pos() != i.decl.obj.Pos() {
continue
}
references = append(references, &ReferenceInfo{
Name: ident.Name,
Range: span.NewRange(i.File.FileSet(), ident.Pos(), ident.End()),
ident: ident,
obj: obj,
})
}
}
return references, nil
}