blob: 4e7daf0f9bcd1a29f2602237380f415a0025fada [file] [log] [blame]
// Copyright 2020 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"
"errors"
"fmt"
"go/ast"
"go/token"
"go/types"
"path/filepath"
"golang.org/x/tools/go/ast/astutil"
"golang.org/x/tools/internal/event"
"golang.org/x/tools/internal/lsp/debug/tag"
"golang.org/x/tools/internal/lsp/protocol"
"golang.org/x/tools/internal/span"
)
// PrepareCallHierarchy returns an array of CallHierarchyItem for a file and the position within the file.
func PrepareCallHierarchy(ctx context.Context, snapshot Snapshot, fh FileHandle, pos protocol.Position) ([]protocol.CallHierarchyItem, error) {
ctx, done := event.Start(ctx, "source.PrepareCallHierarchy")
defer done()
identifier, err := Identifier(ctx, snapshot, fh, pos)
if err != nil {
if errors.Is(err, ErrNoIdentFound) || errors.Is(err, errNoObjectFound) {
return nil, nil
}
return nil, err
}
// The identifier can be nil if it is an import spec.
if identifier == nil || identifier.Declaration.obj == nil {
return nil, nil
}
if _, ok := identifier.Declaration.obj.Type().Underlying().(*types.Signature); !ok {
return nil, nil
}
if len(identifier.Declaration.MappedRange) == 0 {
return nil, nil
}
declMappedRange := identifier.Declaration.MappedRange[0]
rng, err := declMappedRange.Range()
if err != nil {
return nil, err
}
callHierarchyItem := protocol.CallHierarchyItem{
Name: identifier.Name,
Kind: protocol.Function,
Tags: []protocol.SymbolTag{},
Detail: fmt.Sprintf("%s • %s", identifier.Declaration.obj.Pkg().Path(), filepath.Base(declMappedRange.URI().Filename())),
URI: protocol.DocumentURI(declMappedRange.URI()),
Range: rng,
SelectionRange: rng,
}
return []protocol.CallHierarchyItem{callHierarchyItem}, nil
}
// IncomingCalls returns an array of CallHierarchyIncomingCall for a file and the position within the file.
func IncomingCalls(ctx context.Context, snapshot Snapshot, fh FileHandle, pos protocol.Position) ([]protocol.CallHierarchyIncomingCall, error) {
ctx, done := event.Start(ctx, "source.IncomingCalls")
defer done()
refs, err := References(ctx, snapshot, fh, pos, false)
if err != nil {
if errors.Is(err, ErrNoIdentFound) || errors.Is(err, errNoObjectFound) {
return nil, nil
}
return nil, err
}
return toProtocolIncomingCalls(ctx, snapshot, refs)
}
// toProtocolIncomingCalls returns an array of protocol.CallHierarchyIncomingCall for ReferenceInfo's.
// References inside same enclosure are assigned to the same enclosing function.
func toProtocolIncomingCalls(ctx context.Context, snapshot Snapshot, refs []*ReferenceInfo) ([]protocol.CallHierarchyIncomingCall, error) {
// an enclosing node could have multiple calls to a reference, we only show the enclosure
// once in the result but highlight all calls using FromRanges (ranges at which the calls occur)
var incomingCalls = map[protocol.Location]*protocol.CallHierarchyIncomingCall{}
for _, ref := range refs {
refRange, err := ref.Range()
if err != nil {
return nil, err
}
callItem, err := enclosingNodeCallItem(snapshot, ref.pkg, ref.URI(), ref.ident.NamePos)
if err != nil {
event.Error(ctx, "error getting enclosing node", err, tag.Method.Of(ref.Name))
continue
}
loc := protocol.Location{
URI: callItem.URI,
Range: callItem.Range,
}
if incomingCall, ok := incomingCalls[loc]; ok {
incomingCall.FromRanges = append(incomingCall.FromRanges, refRange)
continue
}
incomingCalls[loc] = &protocol.CallHierarchyIncomingCall{
From: callItem,
FromRanges: []protocol.Range{refRange},
}
}
incomingCallItems := make([]protocol.CallHierarchyIncomingCall, 0, len(incomingCalls))
for _, callItem := range incomingCalls {
incomingCallItems = append(incomingCallItems, *callItem)
}
return incomingCallItems, nil
}
// enclosingNodeCallItem creates a CallHierarchyItem representing the function call at pos
func enclosingNodeCallItem(snapshot Snapshot, pkg Package, uri span.URI, pos token.Pos) (protocol.CallHierarchyItem, error) {
pgf, err := pkg.File(uri)
if err != nil {
return protocol.CallHierarchyItem{}, err
}
var funcDecl *ast.FuncDecl
var funcLit *ast.FuncLit // innermost function literal
var litCount int
// Find the enclosing function, if any, and the number of func literals in between.
path, _ := astutil.PathEnclosingInterval(pgf.File, pos, pos)
outer:
for _, node := range path {
switch n := node.(type) {
case *ast.FuncDecl:
funcDecl = n
break outer
case *ast.FuncLit:
litCount++
if litCount > 1 {
continue
}
funcLit = n
}
}
nameIdent := path[len(path)-1].(*ast.File).Name
kind := protocol.Package
if funcDecl != nil {
nameIdent = funcDecl.Name
kind = protocol.Function
}
nameStart, nameEnd := nameIdent.Pos(), nameIdent.End()
if funcLit != nil {
nameStart, nameEnd = funcLit.Type.Func, funcLit.Type.Params.Pos()
kind = protocol.Function
}
rng, err := NewMappedRange(pgf.Tok, pgf.Mapper, nameStart, nameEnd).Range()
if err != nil {
return protocol.CallHierarchyItem{}, err
}
name := nameIdent.Name
for i := 0; i < litCount; i++ {
name += ".func()"
}
return protocol.CallHierarchyItem{
Name: name,
Kind: kind,
Tags: []protocol.SymbolTag{},
Detail: fmt.Sprintf("%s • %s", pkg.PkgPath(), filepath.Base(uri.Filename())),
URI: protocol.DocumentURI(uri),
Range: rng,
SelectionRange: rng,
}, nil
}
// OutgoingCalls returns an array of CallHierarchyOutgoingCall for a file and the position within the file.
func OutgoingCalls(ctx context.Context, snapshot Snapshot, fh FileHandle, pos protocol.Position) ([]protocol.CallHierarchyOutgoingCall, error) {
ctx, done := event.Start(ctx, "source.OutgoingCalls")
defer done()
identifier, err := Identifier(ctx, snapshot, fh, pos)
if err != nil {
if errors.Is(err, ErrNoIdentFound) || errors.Is(err, errNoObjectFound) {
return nil, nil
}
return nil, err
}
if _, ok := identifier.Declaration.obj.Type().Underlying().(*types.Signature); !ok {
return nil, nil
}
node := identifier.Declaration.node
if node == nil {
return nil, nil
}
if len(identifier.Declaration.MappedRange) == 0 {
return nil, nil
}
declMappedRange := identifier.Declaration.MappedRange[0]
// TODO(adonovan): avoid Fileset.File call by somehow getting at
// declMappedRange.spanRange.TokFile, or making Identifier retain the
// token.File of the identifier and its declaration, since it looks up both anyway.
tokFile := snapshot.FileSet().File(node.Pos())
if tokFile == nil {
return nil, fmt.Errorf("no file for position")
}
callExprs, err := collectCallExpressions(tokFile, declMappedRange.m, node)
if err != nil {
return nil, err
}
return toProtocolOutgoingCalls(ctx, snapshot, fh, callExprs)
}
// collectCallExpressions collects call expression ranges inside a function.
func collectCallExpressions(tokFile *token.File, mapper *protocol.ColumnMapper, node ast.Node) ([]protocol.Range, error) {
type callPos struct {
start, end token.Pos
}
callPositions := []callPos{}
ast.Inspect(node, func(n ast.Node) bool {
if call, ok := n.(*ast.CallExpr); ok {
var start, end token.Pos
switch n := call.Fun.(type) {
case *ast.SelectorExpr:
start, end = n.Sel.NamePos, call.Lparen
case *ast.Ident:
start, end = n.NamePos, call.Lparen
case *ast.FuncLit:
// while we don't add the function literal as an 'outgoing' call
// we still want to traverse into it
return true
default:
// ignore any other kind of call expressions
// for ex: direct function literal calls since that's not an 'outgoing' call
return false
}
callPositions = append(callPositions, callPos{start: start, end: end})
}
return true
})
callRanges := []protocol.Range{}
for _, call := range callPositions {
callRange, err := NewMappedRange(tokFile, mapper, call.start, call.end).Range()
if err != nil {
return nil, err
}
callRanges = append(callRanges, callRange)
}
return callRanges, nil
}
// toProtocolOutgoingCalls returns an array of protocol.CallHierarchyOutgoingCall for ast call expressions.
// Calls to the same function are assigned to the same declaration.
func toProtocolOutgoingCalls(ctx context.Context, snapshot Snapshot, fh FileHandle, callRanges []protocol.Range) ([]protocol.CallHierarchyOutgoingCall, error) {
// Multiple calls could be made to the same function, defined by "same declaration
// AST node & same identifier name" to provide a unique identifier key even when
// the func is declared in a struct or interface.
type key struct {
decl ast.Node
name string
}
outgoingCalls := map[key]*protocol.CallHierarchyOutgoingCall{}
for _, callRange := range callRanges {
identifier, err := Identifier(ctx, snapshot, fh, callRange.Start)
if err != nil {
if errors.Is(err, ErrNoIdentFound) || errors.Is(err, errNoObjectFound) {
continue
}
return nil, err
}
// ignore calls to builtin functions
if identifier.Declaration.obj.Pkg() == nil {
continue
}
if outgoingCall, ok := outgoingCalls[key{identifier.Declaration.node, identifier.Name}]; ok {
outgoingCall.FromRanges = append(outgoingCall.FromRanges, callRange)
continue
}
if len(identifier.Declaration.MappedRange) == 0 {
continue
}
declMappedRange := identifier.Declaration.MappedRange[0]
rng, err := declMappedRange.Range()
if err != nil {
return nil, err
}
outgoingCalls[key{identifier.Declaration.node, identifier.Name}] = &protocol.CallHierarchyOutgoingCall{
To: protocol.CallHierarchyItem{
Name: identifier.Name,
Kind: protocol.Function,
Tags: []protocol.SymbolTag{},
Detail: fmt.Sprintf("%s • %s", identifier.Declaration.obj.Pkg().Path(), filepath.Base(declMappedRange.URI().Filename())),
URI: protocol.DocumentURI(declMappedRange.URI()),
Range: rng,
SelectionRange: rng,
},
FromRanges: []protocol.Range{callRange},
}
}
outgoingCallItems := make([]protocol.CallHierarchyOutgoingCall, 0, len(outgoingCalls))
for _, callItem := range outgoingCalls {
outgoingCallItems = append(outgoingCallItems, *callItem)
}
return outgoingCallItems, nil
}