// findIdentifier looks for an identifier at byte-offset searchpos
// inside the parsed source represented by node.
// If it is part of a selector expression, it returns
// that expression rather than the identifier itself.
//
// As a special case, if it finds an import
// spec, it returns ImportSpec.
//
func findIdentifier(f *ast.File, searchpos int) ast.Node {
ec := make(chan ast.Node)
found := func(startPos, endPos token.Pos) bool {
start := types.FileSet.Position(startPos).Offset
end := start + int(endPos-startPos)
return start <= searchpos && searchpos <= end
}
go func() {
var visit func(ast.Node) bool
visit = func(n ast.Node) bool {
var startPos token.Pos
switch n := n.(type) {
default:
return true
case *ast.Ident:
startPos = n.NamePos
case *ast.SelectorExpr:
startPos = n.Sel.NamePos
case *ast.ImportSpec:
startPos = n.Pos()
case *ast.StructType:
// If we find an anonymous bare field in a
// struct type, its definition points to itself,
// but we actually want to go elsewhere,
// so assume (dubiously) that the expression
// works globally and return a new node for it.
for _, field := range n.Fields.List {
if field.Names != nil {
continue
}
t := field.Type
if pt, ok := field.Type.(*ast.StarExpr); ok {
t = pt.X
}
if id, ok := t.(*ast.Ident); ok {
if found(id.NamePos, id.End()) {
ec <- parseExpr(f.Scope, id.Name)
runtime.Goexit()
}
}
}
return true
}
if found(startPos, n.End()) {
ec <- n
runtime.Goexit()
}
return true
}
ast.Walk(FVisitor(visit), f)
ec <- nil
}()
ev := <-ec
if ev == nil {
fail("no identifier found")
}
return ev
}
// constainsNode returns true if x is found somewhere
// inside node.
func containsNode(node, x ast.Node) (found bool) {
ast.Walk(funcVisitor(func(n ast.Node) bool {
if !found {
found = n == x
}
return !found
}),
node)
return
}
func (v identVisitor) Visit(n ast.Node) ast.Visitor {
switch n := n.(type) {
case *ast.Ident:
if strings.HasPrefix(n.Name, prefix) {
v <- n
}
return nil
case *ast.SelectorExpr:
ast.Walk(v, n.X)
if strings.HasPrefix(n.Sel.Name, prefix) {
v <- n
}
return nil
}
return v
}
func TestOneFile(t *testing.T) {
code, offsetMap := translateSymbols(testCode)
//fmt.Printf("------------------- {%s}\n", code)
f, err := parser.ParseFile(FileSet, "xx.go", code, 0, ast.NewScope(parser.Universe))
if err != nil {
t.Fatalf("parse failed: %v", err)
}
v := make(identVisitor)
go func() {
ast.Walk(v, f)
close(v)
}()
for e := range v {
testExpr(t, FileSet, e, offsetMap)
}
}
// IterateSyms calls visitf for each identifier in the given file. If
// visitf returns false, the iteration stops. If visitf changes
// info.Ident.Name, the file is added to ctxt.ChangedFiles.
func (ctxt *Context) IterateSyms(f *ast.File, visitf func(info *Info) bool) {
var visit astVisitor
ok := true
local := false // TODO set to true inside function body
visit = func(n ast.Node) bool {
if !ok {
return false
}
switch n := n.(type) {
case *ast.ImportSpec:
// If the file imports a package to ".", abort
// because we don't support that (yet).
if n.Name != nil && n.Name.Name == "." {
ctxt.logf(n.Pos(), "import to . not supported")
ok = false
return false
}
return true
case *ast.FuncDecl:
// add object for init functions
if n.Recv == nil && n.Name.Name == "init" {
n.Name.Obj = ast.NewObj(ast.Fun, "init")
}
if n.Recv != nil {
ast.Walk(visit, n.Recv)
}
var e ast.Expr = n.Name
if n.Recv != nil {
// It's a method, so we need to synthesise a
// selector expression so that visitExpr doesn't
// just see a blank name.
if len(n.Recv.List) != 1 {
ctxt.logf(n.Pos(), "expected one receiver only!")
return true
}
e = &ast.SelectorExpr{
X: n.Recv.List[0].Type,
Sel: n.Name,
}
}
ok = ctxt.visitExpr(f, e, false, visitf)
local = true
ast.Walk(visit, n.Type)
if n.Body != nil {
ast.Walk(visit, n.Body)
}
local = false
return false
case *ast.Ident:
ok = ctxt.visitExpr(f, n, local, visitf)
return false
case *ast.KeyValueExpr:
// don't try to resolve the key part of a key-value
// because it might be a map key which doesn't
// need resolving, and we can't tell without being
// complicated with types.
ast.Walk(visit, n.Value)
return false
case *ast.SelectorExpr:
ast.Walk(visit, n.X)
ok = ctxt.visitExpr(f, n, local, visitf)
return false
case *ast.File:
for _, d := range n.Decls {
ast.Walk(visit, d)
}
return false
}
return true
}
ast.Walk(visit, f)
}
func checkExprs(t *testing.T, pkg *ast.File, importer Importer) {
var visit astVisitor
stopped := false
visit = func(n ast.Node) bool {
if stopped {
return false
}
mustResolve := false
var e ast.Expr
switch n := n.(type) {
case *ast.ImportSpec:
// If the file imports a package to ".", abort
// because we don't support that (yet).
if n.Name != nil && n.Name.Name == "." {
stopped = true
return false
}
return true
case *ast.FuncDecl:
// add object for init functions
if n.Recv == nil && n.Name.Name == "init" {
n.Name.Obj = ast.NewObj(ast.Fun, "init")
}
return true
case *ast.Ident:
if n.Name == "_" {
return false
}
e = n
mustResolve = true
case *ast.KeyValueExpr:
// don't try to resolve the key part of a key-value
// because it might be a map key which doesn't
// need resolving, and we can't tell without being
// complicated with types.
ast.Walk(visit, n.Value)
return false
case *ast.SelectorExpr:
ast.Walk(visit, n.X)
e = n
mustResolve = true
case *ast.File:
for _, d := range n.Decls {
ast.Walk(visit, d)
}
return false
case ast.Expr:
e = n
default:
return true
}
defer func() {
if err := recover(); err != nil {
t.Fatalf("panic (%v) on %T", err, e)
//t.Fatalf("panic (%v) on %v at %v\n", err, e, FileSet.Position(e.Pos()))
}
}()
obj, _ := ExprType(e, importer)
if obj == nil && mustResolve {
t.Errorf("no object for %v(%p, %T) at %v\n", e, e, e, FileSet.Position(e.Pos()))
}
return false
}
ast.Walk(visit, pkg)
}