unsafe /* ERROR "not used" */ .Alignof(x)

	var y S0
	assert(unsafe.Alignof(y.a) == 1)
	assert(unsafe.Alignof(y.b) == 4)
	assert(unsafe.Alignof(y.c) == 8)
	assert(unsafe.Alignof(y.d) == 1)
	assert(unsafe.Alignof(y.e) == 8)

	var s []byte
	_ = unsafe.Alignof(s)
	_ = unsafe.Alignof(s... /* ERROR "invalid use of ..." */ )
}

func Alignof2() {
	f1 := func() (x int32) { return }

}

func (s *gcSizes) Alignof(T Type) (result int64) {
	defer func() {
		assert(result >= 1)
	}()

	// For arrays and structs, alignment is defined in terms
	// of alignment of the elements and fields, respectively.
	switch t := under(T).(type) {
	case *Array:
		// spec: "For a variable x of array type: unsafe.Alignof(x)
		// is the same as unsafe.Alignof(x[0]), but at least 1."
		return s.Alignof(t.elem)

}

// stdSizes is used if Config.Sizes == nil.
var stdSizes = SizesFor("gc", "amd64")

func (conf *Config) alignof(T Type) int64 {
	f := stdSizes.Alignof
	if conf.Sizes != nil {
		f = conf.Sizes.Alignof
	}
	if a := f(T); a >= 1 {
		return a
	}
	panic("implementation of alignof returned an alignment < 1")
}

func (conf *Config) offsetsof(T *Struct) []int64 {
	var offsets []int64

}

func (s *gcSizes) Alignof(T Type) (result int64) {
	defer func() {
		assert(result >= 1)
	}()

	// For arrays and structs, alignment is defined in terms
	// of alignment of the elements and fields, respectively.
	switch t := under(T).(type) {
	case *Array:
		// spec: "For a variable x of array type: unsafe.Alignof(x)
		// is the same as unsafe.Alignof(x[0]), but at least 1."
		return s.Alignof(t.elem)

}

// stdSizes is used if Config.Sizes == nil.
var stdSizes = SizesFor("gc", "amd64")

func (conf *Config) alignof(T Type) int64 {
	f := stdSizes.Alignof
	if conf.Sizes != nil {
		f = conf.Sizes.Alignof
	}
	if a := f(T); a >= 1 {
		return a
	}
	panic("implementation of alignof returned an alignment < 1")
}

func (conf *Config) offsetsof(T *Struct) []int64 {
	var offsets []int64

// Their contents must be kept in sync with their definitions.
// Because the host and target type sizes can differ, the compiler and
// linker cannot use the host information that they might get from
// either unsafe.Sizeof and Alignof, nor runtime, reflect, or reflectlite.

// CommonSize returns sizeof(Type) for a compilation target with a given ptrSize
func CommonSize(ptrSize int) int { return 4*ptrSize + 8 + 8 }

	{"Add", `_ = unsafe.Add(nil, 0)`, `func(unsafe.Pointer, int) unsafe.Pointer`},

	{"Alignof", `_ = unsafe.Alignof(0)`, `invalid type`},                 // constant
	{"Alignof", `var x struct{}; _ = unsafe.Alignof(x)`, `invalid type`}, // constant
	{"Alignof", `var x P; _ = unsafe.Alignof(x)`, `func(P) uintptr`},

	{"Offsetof", `var x struct{f bool}; _ = unsafe.Offsetof(x.f)`, `invalid type`},           // constant

	{"Add", `_ = unsafe.Add(nil, 0)`, `func(unsafe.Pointer, int) unsafe.Pointer`},

	{"Alignof", `_ = unsafe.Alignof(0)`, `invalid type`},                 // constant
	{"Alignof", `var x struct{}; _ = unsafe.Alignof(x)`, `invalid type`}, // constant
	{"Alignof", `var x P; _ = unsafe.Alignof(x)`, `func(P) uintptr`},

	{"Offsetof", `var x struct{f bool}; _ = unsafe.Offsetof(x.f)`, `invalid type`},           // constant

	}

	if tab.baseList[0] != nil || tab.indexMap[nil] != 0 {
		t.Errorf("nil base not at index 0")
	}
}

func TestSize(t *testing.T) {
	var p XPos
	if unsafe.Alignof(p) != 4 {
		t.Errorf("alignment = %v; want 4", unsafe.Alignof(p))
	}
	if unsafe.Sizeof(p) != 8 {
		t.Errorf("size = %v; want 8", unsafe.Sizeof(p))
	}
}

func TestSetBase(t *testing.T) {
	var tab PosTable
	b1 := NewFileBase("b1", "b1")

package main

import "unsafe"

func F[G int](g G) (uintptr, uintptr, uintptr) {
	var c chan func() int
	type s struct {
		g G
		x []int
	}
	return unsafe.Sizeof(s{g, make([]int, (<-c)())}),
		unsafe.Alignof(s{g, make([]int, (<-c)())}),
		unsafe.Offsetof(s{g, make([]int, (<-c)())}.x)
}

func main() {
	F(0)