Initial commit: Go 1.23 release state

test/escape_param.go

@@ -0,0 +1,441 @@
+// errorcheck -0 -m -l
+
+// Copyright 2015 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 escape analysis for function parameters.
+
+// In this test almost everything is BAD except the simplest cases
+// where input directly flows to output.
+
+package escape
+
+func zero() int { return 0 }
+
+var sink interface{}
+
+// in -> out
+func param0(p *int) *int { // ERROR "leaking param: p to result ~r0"
+	return p
+}
+
+func caller0a() {
+	i := 0
+	_ = param0(&i)
+}
+
+func caller0b() {
+	i := 0 // ERROR "moved to heap: i$"
+	sink = param0(&i)
+}
+
+// in, in -> out, out
+func param1(p1, p2 *int) (*int, *int) { // ERROR "leaking param: p1 to result ~r0" "leaking param: p2 to result ~r1"
+	return p1, p2
+}
+
+func caller1() {
+	i := 0 // ERROR "moved to heap: i$"
+	j := 0
+	sink, _ = param1(&i, &j)
+}
+
+// in -> other in
+func param2(p1 *int, p2 **int) { // ERROR "leaking param: p1$" "p2 does not escape$"
+	*p2 = p1
+}
+
+func caller2a() {
+	i := 0 // ERROR "moved to heap: i$"
+	var p *int
+	param2(&i, &p)
+	_ = p
+}
+
+func caller2b() {
+	i := 0 // ERROR "moved to heap: i$"
+	var p *int
+	param2(&i, &p)
+	sink = p
+}
+
+func paramArraySelfAssign(p *PairOfPairs) { // ERROR "p does not escape"
+	p.pairs[0] = p.pairs[1] // ERROR "ignoring self-assignment in p.pairs\[0\] = p.pairs\[1\]"
+}
+
+func paramArraySelfAssignUnsafeIndex(p *PairOfPairs) { // ERROR "leaking param content: p"
+	// Function call inside index disables self-assignment case to trigger.
+	p.pairs[zero()] = p.pairs[1]
+	p.pairs[zero()+1] = p.pairs[1]
+}
+
+type PairOfPairs struct {
+	pairs [2]*Pair
+}
+
+type BoxedPair struct {
+	pair *Pair
+}
+
+type WrappedPair struct {
+	pair Pair
+}
+
+func leakParam(x interface{}) { // ERROR "leaking param: x"
+	sink = x
+}
+
+func sinkAfterSelfAssignment1(box *BoxedPair) { // ERROR "leaking param content: box"
+	box.pair.p1 = box.pair.p2 // ERROR "ignoring self-assignment in box.pair.p1 = box.pair.p2"
+	sink = box.pair.p2
+}
+
+func sinkAfterSelfAssignment2(box *BoxedPair) { // ERROR "leaking param content: box"
+	box.pair.p1 = box.pair.p2 // ERROR "ignoring self-assignment in box.pair.p1 = box.pair.p2"
+	sink = box.pair
+}
+
+func sinkAfterSelfAssignment3(box *BoxedPair) { // ERROR "leaking param content: box"
+	box.pair.p1 = box.pair.p2 // ERROR "ignoring self-assignment in box.pair.p1 = box.pair.p2"
+	leakParam(box.pair.p2)
+}
+
+func sinkAfterSelfAssignment4(box *BoxedPair) { // ERROR "leaking param content: box"
+	box.pair.p1 = box.pair.p2 // ERROR "ignoring self-assignment in box.pair.p1 = box.pair.p2"
+	leakParam(box.pair)
+}
+
+func selfAssignmentAndUnrelated(box1, box2 *BoxedPair) { // ERROR "leaking param content: box2" "box1 does not escape"
+	box1.pair.p1 = box1.pair.p2 // ERROR "ignoring self-assignment in box1.pair.p1 = box1.pair.p2"
+	leakParam(box2.pair.p2)
+}
+
+func notSelfAssignment1(box1, box2 *BoxedPair) { // ERROR "leaking param content: box2" "box1 does not escape"
+	box1.pair.p1 = box2.pair.p1
+}
+
+func notSelfAssignment2(p1, p2 *PairOfPairs) { // ERROR "leaking param content: p2" "p1 does not escape"
+	p1.pairs[0] = p2.pairs[1]
+}
+
+func notSelfAssignment3(p1, p2 *PairOfPairs) { // ERROR "leaking param content: p2" "p1 does not escape"
+	p1.pairs[0].p1 = p2.pairs[1].p1
+}
+
+func boxedPairSelfAssign(box *BoxedPair) { // ERROR "box does not escape"
+	box.pair.p1 = box.pair.p2 // ERROR "ignoring self-assignment in box.pair.p1 = box.pair.p2"
+}
+
+func wrappedPairSelfAssign(w *WrappedPair) { // ERROR "w does not escape"
+	w.pair.p1 = w.pair.p2 // ERROR "ignoring self-assignment in w.pair.p1 = w.pair.p2"
+}
+
+// in -> in
+type Pair struct {
+	p1 *int
+	p2 *int
+}
+
+func param3(p *Pair) { // ERROR "p does not escape"
+	p.p1 = p.p2 // ERROR "param3 ignoring self-assignment in p.p1 = p.p2"
+}
+
+func caller3a() {
+	i := 0
+	j := 0
+	p := Pair{&i, &j}
+	param3(&p)
+	_ = p
+}
+
+func caller3b() {
+	i := 0 // ERROR "moved to heap: i$"
+	j := 0 // ERROR "moved to heap: j$"
+	p := Pair{&i, &j}
+	param3(&p)
+	sink = p // ERROR "p escapes to heap$"
+}
+
+// in -> rcvr
+func (p *Pair) param4(i *int) { // ERROR "p does not escape$" "leaking param: i$"
+	p.p1 = i
+}
+
+func caller4a() {
+	i := 0 // ERROR "moved to heap: i$"
+	p := Pair{}
+	p.param4(&i)
+	_ = p
+}
+
+func caller4b() {
+	i := 0 // ERROR "moved to heap: i$"
+	p := Pair{}
+	p.param4(&i)
+	sink = p // ERROR "p escapes to heap$"
+}
+
+// in -> heap
+func param5(i *int) { // ERROR "leaking param: i$"
+	sink = i
+}
+
+func caller5() {
+	i := 0 // ERROR "moved to heap: i$"
+	param5(&i)
+}
+
+// *in -> heap
+func param6(i ***int) { // ERROR "leaking param content: i$"
+	sink = *i
+}
+
+func caller6a() {
+	i := 0  // ERROR "moved to heap: i$"
+	p := &i // ERROR "moved to heap: p$"
+	p2 := &p
+	param6(&p2)
+}
+
+// **in -> heap
+func param7(i ***int) { // ERROR "leaking param content: i$"
+	sink = **i
+}
+
+func caller7() {
+	i := 0 // ERROR "moved to heap: i$"
+	p := &i
+	p2 := &p
+	param7(&p2)
+}
+
+// **in -> heap
+func param8(i **int) { // ERROR "i does not escape$"
+	sink = **i // ERROR "\*\(\*i\) escapes to heap"
+}
+
+func caller8() {
+	i := 0
+	p := &i
+	param8(&p)
+}
+
+// *in -> out
+func param9(p ***int) **int { // ERROR "leaking param: p to result ~r0 level=1"
+	return *p
+}
+
+func caller9a() {
+	i := 0
+	p := &i
+	p2 := &p
+	_ = param9(&p2)
+}
+
+func caller9b() {
+	i := 0  // ERROR "moved to heap: i$"
+	p := &i // ERROR "moved to heap: p$"
+	p2 := &p
+	sink = param9(&p2)
+}
+
+// **in -> out
+func param10(p ***int) *int { // ERROR "leaking param: p to result ~r0 level=2"
+	return **p
+}
+
+func caller10a() {
+	i := 0
+	p := &i
+	p2 := &p
+	_ = param10(&p2)
+}
+
+func caller10b() {
+	i := 0 // ERROR "moved to heap: i$"
+	p := &i
+	p2 := &p
+	sink = param10(&p2)
+}
+
+// in escapes to heap (address of param taken and returned)
+func param11(i **int) ***int { // ERROR "moved to heap: i$"
+	return &i
+}
+
+func caller11a() {
+	i := 0  // ERROR "moved to heap: i"
+	p := &i // ERROR "moved to heap: p"
+	_ = param11(&p)
+}
+
+func caller11b() {
+	i := 0  // ERROR "moved to heap: i$"
+	p := &i // ERROR "moved to heap: p$"
+	sink = param11(&p)
+}
+
+func caller11c() { // GOOD
+	i := 0  // ERROR "moved to heap: i$"
+	p := &i // ERROR "moved to heap: p"
+	sink = *param11(&p)
+}
+
+func caller11d() {
+	i := 0  // ERROR "moved to heap: i$"
+	p := &i // ERROR "moved to heap: p"
+	p2 := &p
+	sink = param11(p2)
+}
+
+// &in -> rcvr
+type Indir struct {
+	p ***int
+}
+
+func (r *Indir) param12(i **int) { // ERROR "r does not escape$" "moved to heap: i$"
+	r.p = &i
+}
+
+func caller12a() {
+	i := 0  // ERROR "moved to heap: i$"
+	p := &i // ERROR "moved to heap: p$"
+	var r Indir
+	r.param12(&p)
+	_ = r
+}
+
+func caller12b() {
+	i := 0        // ERROR "moved to heap: i$"
+	p := &i       // ERROR "moved to heap: p$"
+	r := &Indir{} // ERROR "&Indir{} does not escape$"
+	r.param12(&p)
+	_ = r
+}
+
+func caller12c() {
+	i := 0  // ERROR "moved to heap: i$"
+	p := &i // ERROR "moved to heap: p$"
+	r := Indir{}
+	r.param12(&p)
+	sink = r
+}
+
+func caller12d() {
+	i := 0  // ERROR "moved to heap: i$"
+	p := &i // ERROR "moved to heap: p$"
+	r := Indir{}
+	r.param12(&p)
+	sink = **r.p
+}
+
+// in -> value rcvr
+type Val struct {
+	p **int
+}
+
+func (v Val) param13(i *int) { // ERROR "v does not escape$" "leaking param: i$"
+	*v.p = i
+}
+
+func caller13a() {
+	i := 0 // ERROR "moved to heap: i$"
+	var p *int
+	var v Val
+	v.p = &p
+	v.param13(&i)
+	_ = v
+}
+
+func caller13b() {
+	i := 0 // ERROR "moved to heap: i$"
+	var p *int
+	v := Val{&p}
+	v.param13(&i)
+	_ = v
+}
+
+func caller13c() {
+	i := 0 // ERROR "moved to heap: i$"
+	var p *int
+	v := &Val{&p} // ERROR "&Val{...} does not escape$"
+	v.param13(&i)
+	_ = v
+}
+
+func caller13d() {
+	i := 0     // ERROR "moved to heap: i$"
+	var p *int // ERROR "moved to heap: p$"
+	var v Val
+	v.p = &p
+	v.param13(&i)
+	sink = v
+}
+
+func caller13e() {
+	i := 0     // ERROR "moved to heap: i$"
+	var p *int // ERROR "moved to heap: p$"
+	v := Val{&p}
+	v.param13(&i)
+	sink = v
+}
+
+func caller13f() {
+	i := 0        // ERROR "moved to heap: i$"
+	var p *int    // ERROR "moved to heap: p$"
+	v := &Val{&p} // ERROR "&Val{...} escapes to heap$"
+	v.param13(&i)
+	sink = v
+}
+
+func caller13g() {
+	i := 0 // ERROR "moved to heap: i$"
+	var p *int
+	v := Val{&p}
+	v.param13(&i)
+	sink = *v.p
+}
+
+func caller13h() {
+	i := 0 // ERROR "moved to heap: i$"
+	var p *int
+	v := &Val{&p} // ERROR "&Val{...} does not escape$"
+	v.param13(&i)
+	sink = **v.p // ERROR "\*\(\*v\.p\) escapes to heap"
+}
+
+type Node struct {
+	p *Node
+}
+
+var Sink *Node
+
+func f(x *Node) { // ERROR "leaking param content: x"
+	Sink = &Node{x.p} // ERROR "&Node{...} escapes to heap"
+}
+
+func g(x *Node) *Node { // ERROR "leaking param content: x"
+	return &Node{x.p} // ERROR "&Node{...} escapes to heap"
+}
+
+func h(x *Node) { // ERROR "leaking param: x"
+	y := &Node{x} // ERROR "&Node{...} does not escape"
+	Sink = g(y)
+	f(y)
+}
+
+// interface(in) -> out
+// See also issue 29353.
+
+// Convert to a non-direct interface, require an allocation and
+// copy x to heap (not to result).
+func param14a(x [4]*int) interface{} { // ERROR "leaking param: x$"
+	return x // ERROR "x escapes to heap"
+}
+
+// Convert to a direct interface, does not need an allocation.
+// So x only leaks to result.
+func param14b(x *int) interface{} { // ERROR "leaking param: x to result ~r0 level=0"
+	return x
+}