ast.Inspect(f, func(n ast.Node) bool {
		call, ok := n.(*ast.CallExpr)
		if !ok {
			return true
		}

		// Is this a C.f() call?
		var name string
		if sel, ok := astutil.Unparen(call.Fun).(*ast.SelectorExpr); ok {
			if id, ok := sel.X.(*ast.Ident); ok && id.Name == "C" {
				name = sel.Sel.Name
			}
		}
		if name == "" {
			return true // not a call we need to check
		}

			if bin.Name() != name {
				t.Errorf("%s: got built-in %s; want %s", src0, bin.Name(), name)
				return
			}
			return // we're done

		case *ast.ParenExpr:
			fun = p.X // unpack

		case *ast.SelectorExpr:
			// built-in from package unsafe - ignore details
			return // we're done

		default:
			t.Errorf("%s: invalid function call", src0)
			return
		}
	}

	// This is a call to C.xxx; set goname to "xxx".
	// It may have already been mangled by rewriteName.
	var goname string
	switch fun := call.Call.Fun.(type) {
	case *ast.SelectorExpr:
		goname = fun.Sel.Name
	case *ast.Ident:
		goname = strings.TrimPrefix(fun.Name, "_C2func_")
		goname = strings.TrimPrefix(goname, "_Cfunc_")
	}
	if goname == "" || goname == "malloc" {
		return "", false

		Uses:       make(map[*ast.Ident]types.Object),
		Implicits:  make(map[ast.Node]types.Object),
		Instances:  make(map[*ast.Ident]types.Instance),
		Scopes:     make(map[ast.Node]*types.Scope),
		Selections: make(map[*ast.SelectorExpr]*types.Selection),
	}
	versions.InitFileVersions(info)

	pkg, err := tc.Check(cfg.ImportPath, fset, files, info)
	if err != nil {
		if cfg.SucceedOnTypecheckFailure {
			// Silently succeed; let the compiler

		Instances:    make(map[*syntax.Name]Instance),
		Defs:         make(map[*syntax.Name]Object),
		Uses:         make(map[*syntax.Name]Object),
		Implicits:    make(map[syntax.Node]Object),
		Selections:   make(map[*syntax.SelectorExpr]*Selection),
		Scopes:       make(map[syntax.Node]*Scope),
		FileVersions: make(map[*syntax.PosBase]string),
	}

	// typecheck
	conf.Check(pkgName, files, &info)
	if listErrors {
		return
	}

		Instances:    make(map[*ast.Ident]Instance),
		Defs:         make(map[*ast.Ident]Object),
		Uses:         make(map[*ast.Ident]Object),
		Implicits:    make(map[ast.Node]Object),
		Selections:   make(map[*ast.SelectorExpr]*Selection),
		Scopes:       make(map[ast.Node]*Scope),
		FileVersions: make(map[*ast.File]string),
	}

	// typecheck
	conf.Check(pkgName, fset, files, &info)
	if listErrors {
		return
	}

// returns the corresponding field name. If x is not an acceptable
// anonymous field, the result is nil.
func fieldName(x Expr) *Ident {
	switch t := x.(type) {
	case *Ident:
		return t
	case *SelectorExpr:
		if _, ok := t.X.(*Ident); ok {
			return t.Sel
		}
	case *StarExpr:
		return fieldName(t.X)
	}
	return nil
}

		a.apply(n, "Body", nil, n.Body)

	case *ast.CompositeLit:
		a.apply(n, "Type", nil, n.Type)
		a.applyList(n, "Elts")

	case *ast.ParenExpr:
		a.apply(n, "X", nil, n.X)

	case *ast.SelectorExpr:
		a.apply(n, "X", nil, n.X)
		a.apply(n, "Sel", nil, n.Sel)

	case *ast.IndexExpr:
		a.apply(n, "X", nil, n.X)
		a.apply(n, "Index", nil, n.Index)

	case *ast.IndexListExpr:

			name = path[lastSlash+1:]
		}
	case "_", ".":
		// Not sure if this import is used - err on the side of caution.
		return true
	}

	ast.Walk(visitFn(func(n ast.Node) {
		sel, ok := n.(*ast.SelectorExpr)
		if ok && isTopName(sel.X, name) {
			used = true
		}
	}), f)

	return
}

type visitFn func(node ast.Node)

func (fn visitFn) Visit(node ast.Node) ast.Visitor {
	fn(node)

	//
	Implicits map[ast.Node]Object

	// Selections maps selector expressions (excluding qualified identifiers)
	// to their corresponding selections.
	Selections map[*ast.SelectorExpr]*Selection

	// Scopes maps ast.Nodes to the scopes they define. Package scopes are not
	// associated with a specific node but with all files belonging to a package.