// insertImportPath inserts the given import path.
// There must be at least one import declaration present already.
func insertImportPath(f *ast.File, path string) {
	for _, d := range f.Decls {
		if g, _ := d.(*ast.GenDecl); g != nil && g.Tok == token.IMPORT {
			g.Specs = append(g.Specs, &ast.ImportSpec{Path: &ast.BasicLit{ValuePos: g.End(), Kind: token.STRING, Value: path}})
			return
		}
	}
	panic("no import declaration present")
}

	switch n := n.(type) {
	case *ast.Field:
		return n.Doc
	case *ast.ImportSpec:
		return n.Doc
	case *ast.ValueSpec:
		return n.Doc
	case *ast.TypeSpec:
		return n.Doc
	case *ast.GenDecl:
		return n.Doc
	case *ast.FuncDecl:
		return n.Doc
	case *ast.File:
		return n.Doc
	}
	return nil
}

func getLastComment(n ast.Node) *ast.CommentGroup {
	switch n := n.(type) {

				r.walkLHS(lhs)
				r.shortVarDecl(as)
			} else {
				r.walkExprs(lhs)
			}
		}
		ast.Walk(r, n.Body)

	// Declarations
	case *ast.GenDecl:
		switch n.Tok {
		case token.CONST, token.VAR:
			for i, spec := range n.Specs {
				spec := spec.(*ast.ValueSpec)
				kind := ast.Con
				if n.Tok == token.VAR {
					kind = ast.Var
				}

		return x.Op == token.TILDE
	case *ast.ParenExpr:
		return isTypeElem(x.X)
	}
	return false
}

func (p *parser) parseGenDecl(keyword token.Token, f parseSpecFunction) *ast.GenDecl {
	if p.trace {
		defer un(trace(p, "GenDecl("+keyword.String()+")"))
	}

	doc := p.leadComment
	pos := p.expect(keyword)
	var lparen, rparen token.Pos
	var list []ast.Spec
	if p.tok == token.LPAREN {

			// Record typeof[fn.Name.Obj] for future references to fn.Name.
			typeof[fn.Name.Obj] = t
		}
	}

	// gather struct declarations
	for _, decl := range f.Decls {
		d, ok := decl.(*ast.GenDecl)
		if ok {
			for _, s := range d.Specs {
				switch s := s.(type) {
				case *ast.TypeSpec:
					if cfg1.Type[s.Name.Name] != nil {
						break
					}
					if !copied {
						copied = true

	for _, d := range decls {
		check.walkDecl(d, f)
	}
}

func (check *Checker) walkDecl(d ast.Decl, f func(decl)) {
	switch d := d.(type) {
	case *ast.BadDecl:
		// ignore
	case *ast.GenDecl:
		var last *ast.ValueSpec // last ValueSpec with type or init exprs seen
		for iota, s := range d.Specs {
			switch s := s.(type) {
			case *ast.ImportSpec:
				f(importDecl{s})
			case *ast.ValueSpec:

		{"FuncType.Params", Field, 0},
		{"FuncType.Results", Field, 0},
		{"FuncType.TypeParams", Field, 18},
		{"GenDecl", Type, 0},
		{"GenDecl.Doc", Field, 0},
		{"GenDecl.Lparen", Field, 0},
		{"GenDecl.Rparen", Field, 0},
		{"GenDecl.Specs", Field, 0},
		{"GenDecl.Tok", Field, 0},
		{"GenDecl.TokPos", Field, 0},
		{"GoStmt", Type, 0},
		{"GoStmt.Call", Field, 0},
		{"GoStmt.Go", Field, 0},

	if err != nil {
		t.Fatal(err)
	}

	// map import paths to importDecl
	imports := make(map[string]*ast.ImportSpec)
	for _, s := range f.Decls[0].(*ast.GenDecl).Specs {
		if imp, _ := s.(*ast.ImportSpec); imp != nil {
			imports[imp.Path.Value] = imp
		}
	}

	for _, test := range tests {
		imp := imports[test.path]
		if imp == nil {

				r.Align = p.PtrSize
			}
			return r
		}
		// Look up the type in the top level declarations.
		// TODO: Handle types defined within a function.
		for _, d := range p.Decl {
			gd, ok := d.(*ast.GenDecl)
			if !ok || gd.Tok != token.TYPE {
				continue
			}
			for _, spec := range gd.Specs {
				ts, ok := spec.(*ast.TypeSpec)
				if !ok {
					continue
				}
				if ts.Name.Name == t.Name {

	case *ast.FuncType, *ast.InterfaceType, *ast.MapType, *ast.ChanType:
		return true
	case *ast.Ident:
		// TODO: Handle types defined within function.
		for _, d := range p.Decl {
			gd, ok := d.(*ast.GenDecl)
			if !ok || gd.Tok != token.TYPE {
				continue
			}
			for _, spec := range gd.Specs {
				ts, ok := spec.(*ast.TypeSpec)
				if !ok {
					continue
				}
				if ts.Name.Name == t.Name {