// hasDots reports whether the last argument in the call is followed by ...
func hasDots(call *syntax.CallExpr) bool { return call.HasDots }

// dddErrPos returns the node (poser) for reporting an invalid ... use in a call.
func dddErrPos(call *syntax.CallExpr) *syntax.CallExpr {
	// TODO(gri) should use "..." instead of call position
	return call
}

func fixAtPosCall(f *ast.File) {
	ast.Inspect(f, func(n ast.Node) bool {
		switch n := n.(type) {
		case *ast.CallExpr:
			if selx, _ := n.Fun.(*ast.SelectorExpr); selx != nil && selx.Sel.Name == "dump" {
				for i, arg := range n.Args {
					if call, _ := arg.(*ast.CallExpr); call != nil {
						// rewrite xxx.dump(..., atPos(x), ...) to xxx.dump(..., x.Pos(), ...)
						if isIdent(call.Fun, "atPos") {

func hasDots(call *ast.CallExpr) bool { return call.Ellipsis.IsValid() }

// dddErrPos returns the positioner for reporting an invalid ... use in a call.
func dddErrPos(call *ast.CallExpr) positioner { return atPos(call.Ellipsis) }

// argErrPos returns positioner for reporting an invalid argument count.
func argErrPos(call *ast.CallExpr) positioner { return inNode(call, call.Rparen) }

	x = astutil.Unparen(x) // ignore parens on rhs

	if _, ok := x.(*ast.CompositeLit); ok {
		return nil
	}
	if _, ok := x.(*ast.CallExpr); ok {
		// A call may return a zero value.
		return nil
	}
	if star, ok := x.(*ast.StarExpr); ok {
		if _, ok := astutil.Unparen(star.X).(*ast.CallExpr); ok {
			// A call may return a pointer to a zero value.
			return nil
		}
	}

	case ir.OCALLFUNC:
		n := n.(*ir.CallExpr)
		if ir.IsIntrinsicCall(n) {
			return s.intrinsicCall(n)
		}
		fallthrough

	case ir.OCALLINTER:
		n := n.(*ir.CallExpr)
		return s.callResult(n, callNormal)

	case ir.OGETG:
		n := n.(*ir.CallExpr)
		return s.newValue1(ssa.OpGetG, n.Type(), s.mem())

	case ir.OGETCALLERPC:
		n := n.(*ir.CallExpr)

}

// isFuzzTargetDotFuzz reports whether call is (*testing.F).Fuzz().
func isFuzzTargetDotFuzz(pass *analysis.Pass, call *ast.CallExpr) bool {
	return isFuzzTargetDot(pass, call, "Fuzz")
}

// isFuzzTargetDotAdd reports whether call is (*testing.F).Add().
func isFuzzTargetDotAdd(pass *analysis.Pass, call *ast.CallExpr) bool {
	return isFuzzTargetDot(pass, call, "Add")
}

// isFuzzTargetDot reports whether call is (*testing.F).<name>().

		left, right = n.X, n.Y
	}

	// Recognize m[k] = append(m[k], ...) so we can reuse
	// the mapassign call.
	var mapAppend *ir.CallExpr
	if left.Op() == ir.OINDEXMAP && right.Op() == ir.OAPPEND {
		left := left.(*ir.IndexExpr)
		mapAppend = right.(*ir.CallExpr)
		if !ir.SameSafeExpr(left, mapAppend.Args[0]) {
			base.Fatalf("not same expressions: %v != %v", left, mapAppend.Args[0])
		}
	}

	return ""
}

func run(pass *analysis.Pass) (interface{}, error) {
	inspect := pass.ResultOf[inspect.Analyzer].(*inspector.Inspector)
	nodeFilter := []ast.Node{
		(*ast.CallExpr)(nil),
	}
	inspect.Preorder(nodeFilter, func(n ast.Node) {
		call := n.(*ast.CallExpr)

		if len(call.Args) != 1 {
			return
		}
		arg := call.Args[0]

		// Retrieve target type name.
		var tname *types.TypeName
		switch fun := call.Fun.(type) {

			m = n.X
		case *TypeSwitchGuard:
			if n.Lhs != nil {
				m = n.Lhs
				continue
			}
			m = n.X
		case *Operation:
			if n.Y != nil {
				m = n.X
				continue
			}
			return n.Pos()
		case *CallExpr:
			m = n.Fun
		case *ListExpr:
			if len(n.ElemList) > 0 {
				m = n.ElemList[0]
				continue
			}
			return n.Pos()
		// types
		// case *ArrayType:
		// case *SliceType:
		// case *DotsType:

// HasSideEffects reports whether evaluation of e has side effects.
func HasSideEffects(info *types.Info, e ast.Expr) bool {
	safe := true
	ast.Inspect(e, func(node ast.Node) bool {
		switch n := node.(type) {
		case *ast.CallExpr:
			typVal := info.Types[n.Fun]
			switch {
			case typVal.IsType():
				// Type conversion, which is safe.
			case typVal.IsBuiltin():
				// Builtin func, conservatively assumed to not
				// be safe for now.