// tcFor typechecks an OFOR node.
func tcFor(n *ir.ForStmt) ir.Node {
	Stmts(n.Init())
	n.Cond = Expr(n.Cond)
	n.Cond = DefaultLit(n.Cond, nil)
	if n.Cond != nil {
		t := n.Cond.Type()
		if t != nil && !t.IsBoolean() {
			base.Errorf("non-bool %L used as for condition", n.Cond)
		}
	}
	n.Post = Stmt(n.Post)
	Stmts(n.Body)
	return n
}

// tcGoDefer typechecks (normalizes) an OGO/ODEFER statement.

		// can't be converted to int (see issue #41500).
		if !n.X.Type().IsBoolean() {
			base.Errorf("invalid operation: %v (operator %v not defined on %s)", n, n.Op(), typekind(n.X.Type()))
			n.SetType(nil)
			return n
		}
		if !n.Y.Type().IsBoolean() {
			base.Errorf("invalid operation: %v (operator %v not defined on %s)", n, n.Op(), typekind(n.Y.Type()))
			n.SetType(nil)

		under = n.Underlying()
	}
	switch under := under.(type) {
	case *types.Basic:
		switch {
		case under.Info()&types.IsNumeric != 0:
			return &ast.BasicLit{Kind: token.INT, Value: "0"}
		case under.Info()&types.IsBoolean != 0:
			return &ast.Ident{Name: "false"}
		case under.Info()&types.IsString != 0:
			return &ast.BasicLit{Kind: token.STRING, Value: `""`}
		default:
			panic(fmt.Sprintf("unknown basic type %v", under))
		}

	//
	// We can replace the "a" in the phi with the constant true.
	var ct, cf *Value
	for _, b := range f.Blocks {
		for _, v := range b.Values {
			if v.Op != OpPhi {
				continue
			}
			if !v.Type.IsBoolean() {
				continue
			}
			for i, a := range v.Args {
				e := b.Preds[i]
				p := e.b
				if p.Kind != BlockIf {
					continue
				}
				if p.Controls[0] != a {
					continue
				}

	if r.p.exportVersion >= iexportVersionGo1_18 {
		// TODO: add support for using the kind
		_ = constant.Kind(r.int64())
	}

	switch b := typ.Underlying().(*types.Basic); b.Info() & types.IsConstType {
	case types.IsBoolean:
		val = constant.MakeBool(r.bool())

	case types.IsString:
		val = constant.MakeString(r.string())

	case types.IsInteger:
		var x big.Int
		r.mpint(&x, b)
		val = constant.Make(&x)

pkg go/types, const Int64 BasicKind
pkg go/types, const Int8 = 3
pkg go/types, const Int8 BasicKind
pkg go/types, const Invalid = 0
pkg go/types, const Invalid BasicKind
pkg go/types, const IsBoolean = 1
pkg go/types, const IsBoolean BasicInfo
pkg go/types, const IsComplex = 16
pkg go/types, const IsComplex BasicInfo
pkg go/types, const IsConstType = 59
pkg go/types, const IsConstType BasicInfo
pkg go/types, const IsFloat = 8

	// mapaccess2* returns a typed bool, but due to spec changes,
	// the boolean result of i.(T) is now untyped so we make it the
	// same type as the variable on the lhs.
	if ok := n.Lhs[1]; !ir.IsBlank(ok) && ok.Type().IsBoolean() {
		call.Type().Field(1).Type = ok.Type()
	}
	n.Rhs = []ir.Node{call}
	n.SetOp(ir.OAS2FUNC)

	// don't generate a = *var if a is _
	if ir.IsBlank(a) {
		return walkExpr(typecheck.Stmt(n), init)
	}

		// assert(pred) causes a typechecker error if pred is false.
		// The result of assert is the value of pred if there is no error.
		// Note: assert is only available in self-test mode.
		if x.mode != constant_ || !isBoolean(x.typ) {
			check.errorf(x, Test, invalidArg+"%s is not a boolean constant", x)
			return
		}
		if x.val.Kind() != constant.Bool {
			check.errorf(x, Test, "internal error: value of %s should be a boolean constant", x)

		// assert(pred) causes a typechecker error if pred is false.
		// The result of assert is the value of pred if there is no error.
		// Note: assert is only available in self-test mode.
		if x.mode != constant_ || !isBoolean(x.typ) {
			check.errorf(x, Test, invalidArg+"%s is not a boolean constant", x)
			return
		}
		if x.val.Kind() != constant.Bool {
			check.errorf(x, Test, "internal error: value of %s should be a boolean constant", x)

		assert(cb.Recv() == nil)
		switch {
		case cb.Params().Len() > 2:
			return bad("func must be func(yield func(...) bool): yield func has too many parameters")
		case cb.Results().Len() != 1 || !isBoolean(cb.Results().At(0).Type()):
			return bad("func must be func(yield func(...) bool): yield func does not return bool")
		}
		if cb.Params().Len() >= 1 {
			key = cb.Params().At(0).Type()
		}