Initial commit: Go 1.23 release state

test/nilptr3.go

@@ -0,0 +1,256 @@
+// errorcheck -0 -d=nil
+
+//go:build !wasm && !aix
+
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Test that nil checks are removed.
+// Optimization is enabled.
+
+package p
+
+type Struct struct {
+	X int
+	Y float64
+}
+
+type BigStruct struct {
+	X int
+	Y float64
+	A [1 << 20]int
+	Z string
+}
+
+type Empty struct {
+}
+
+type Empty1 struct {
+	Empty
+}
+
+var (
+	intp       *int
+	arrayp     *[10]int
+	array0p    *[0]int
+	bigarrayp  *[1 << 26]int
+	structp    *Struct
+	bigstructp *BigStruct
+	emptyp     *Empty
+	empty1p    *Empty1
+)
+
+func f1() {
+	_ = *intp // ERROR "generated nil check"
+
+	// This one should be removed but the block copy needs
+	// to be turned into its own pseudo-op in order to see
+	// the indirect.
+	_ = *arrayp // ERROR "generated nil check"
+
+	// 0-byte indirect doesn't suffice.
+	// we don't registerize globals, so there are no removed.* nil checks.
+	_ = *array0p // ERROR "generated nil check"
+	_ = *array0p // ERROR "removed nil check"
+
+	_ = *intp    // ERROR "removed nil check"
+	_ = *arrayp  // ERROR "removed nil check"
+	_ = *structp // ERROR "generated nil check"
+	_ = *emptyp  // ERROR "generated nil check"
+	_ = *arrayp  // ERROR "removed nil check"
+}
+
+func f2() {
+	var (
+		intp       *int
+		arrayp     *[10]int
+		array0p    *[0]int
+		bigarrayp  *[1 << 20]int
+		structp    *Struct
+		bigstructp *BigStruct
+		emptyp     *Empty
+		empty1p    *Empty1
+	)
+
+	_ = *intp       // ERROR "generated nil check"
+	_ = *arrayp     // ERROR "generated nil check"
+	_ = *array0p    // ERROR "generated nil check"
+	_ = *array0p    // ERROR "removed.* nil check"
+	_ = *intp       // ERROR "removed.* nil check"
+	_ = *arrayp     // ERROR "removed.* nil check"
+	_ = *structp    // ERROR "generated nil check"
+	_ = *emptyp     // ERROR "generated nil check"
+	_ = *arrayp     // ERROR "removed.* nil check"
+	_ = *bigarrayp  // ERROR "generated nil check" ARM removed nil check before indirect!!
+	_ = *bigstructp // ERROR "generated nil check"
+	_ = *empty1p    // ERROR "generated nil check"
+}
+
+func fx10k() *[10000]int
+
+var b bool
+
+func f3(x *[10000]int) {
+	// Using a huge type and huge offsets so the compiler
+	// does not expect the memory hardware to fault.
+	_ = x[9999] // ERROR "generated nil check"
+
+	for {
+		if x[9999] != 0 { // ERROR "removed nil check"
+			break
+		}
+	}
+
+	x = fx10k()
+	_ = x[9999] // ERROR "generated nil check"
+	if b {
+		_ = x[9999] // ERROR "removed.* nil check"
+	} else {
+		_ = x[9999] // ERROR "removed.* nil check"
+	}
+	_ = x[9999] // ERROR "removed nil check"
+
+	x = fx10k()
+	if b {
+		_ = x[9999] // ERROR "generated nil check"
+	} else {
+		_ = x[9999] // ERROR "generated nil check"
+	}
+	_ = x[9999] // ERROR "generated nil check"
+
+	fx10k()
+	// This one is a bit redundant, if we figured out that
+	// x wasn't going to change across the function call.
+	// But it's a little complex to do and in practice doesn't
+	// matter enough.
+	_ = x[9999] // ERROR "removed nil check"
+}
+
+func f3a() {
+	x := fx10k()
+	y := fx10k()
+	z := fx10k()
+	_ = &x[9] // ERROR "generated nil check"
+	y = z
+	_ = &x[9] // ERROR "removed.* nil check"
+	x = y
+	_ = &x[9] // ERROR "generated nil check"
+}
+
+func f3b() {
+	x := fx10k()
+	y := fx10k()
+	_ = &x[9] // ERROR "generated nil check"
+	y = x
+	_ = &x[9] // ERROR "removed.* nil check"
+	x = y
+	_ = &x[9] // ERROR "removed.* nil check"
+}
+
+func fx10() *[10]int
+
+func f4(x *[10]int) {
+	// Most of these have no checks because a real memory reference follows,
+	// and the offset is small enough that if x is nil, the address will still be
+	// in the first unmapped page of memory.
+
+	_ = x[9] // ERROR "generated nil check" // bug: would like to remove this check (but nilcheck and load are in different blocks)
+
+	for {
+		if x[9] != 0 { // ERROR "removed nil check"
+			break
+		}
+	}
+
+	x = fx10()
+	_ = x[9] // ERROR "generated nil check" // bug would like to remove before indirect
+	if b {
+		_ = x[9] // ERROR "removed nil check"
+	} else {
+		_ = x[9] // ERROR "removed nil check"
+	}
+	_ = x[9] // ERROR "removed nil check"
+
+	x = fx10()
+	if b {
+		_ = x[9] // ERROR "generated nil check"  // bug would like to remove before indirect
+	} else {
+		_ = &x[9] // ERROR "generated nil check"
+	}
+	_ = x[9] // ERROR "generated nil check"  // bug would like to remove before indirect
+
+	fx10()
+	_ = x[9] // ERROR "removed nil check"
+
+	x = fx10()
+	y := fx10()
+	_ = &x[9] // ERROR "generated nil check"
+	y = x
+	_ = &x[9] // ERROR "removed[a-z ]* nil check"
+	x = y
+	_ = &x[9] // ERROR "removed[a-z ]* nil check"
+}
+
+func m1(m map[int][80]byte) byte {
+	v := m[3] // ERROR "removed nil check"
+	return v[5]
+}
+func m2(m map[int][800]byte) byte {
+	v := m[3] // ERROR "removed nil check"
+	return v[5]
+}
+func m3(m map[int][80]byte) (byte, bool) {
+	v, ok := m[3] // ERROR "removed nil check"
+	return v[5], ok
+}
+func m4(m map[int][800]byte) (byte, bool) {
+	v, ok := m[3] // ERROR "removed nil check"
+	return v[5], ok
+}
+func p1() byte {
+	p := new([100]byte)
+	return p[5] // ERROR "removed nil check"
+}
+
+type SS struct {
+	x byte
+}
+
+type TT struct {
+	SS
+}
+
+func f(t *TT) *byte {
+	// See issue 17242.
+	s := &t.SS  // ERROR "generated nil check"
+	return &s.x // ERROR "removed nil check"
+}
+
+// make sure not to do nil check for newobject
+func f7() (*Struct, float64) {
+	t := new(Struct)
+	p := &t.Y    // ERROR "removed nil check"
+	return t, *p // ERROR "removed nil check"
+}
+
+func f9() []int {
+	x := new([1]int)
+	x[0] = 1  // ERROR "removed nil check"
+	y := x[:] // ERROR "removed nil check"
+	return y
+}
+
+// See issue 42673.
+func f10(p **int) int {
+	return * // ERROR "removed nil check"
+	/* */
+	*p // ERROR "removed nil check"
+}
+
+func f11(x []byte) {
+	p := (*[0]byte)(x)
+	_ = *p // ERROR "generated nil check"
+	q := (*[4]byte)(x)
+	_ = *q // ERROR "removed nil check"
+}