Initial commit: Go 1.23 release state

test/escape_iface.go

@@ -0,0 +1,265 @@
+// 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 interface conversions.
+
+package escape
+
+var sink interface{}
+
+type M interface {
+	M()
+}
+
+func mescapes(m M) { // ERROR "leaking param: m"
+	sink = m
+}
+
+func mdoesnotescape(m M) { // ERROR "m does not escape"
+}
+
+// Tests for type stored directly in iface and with value receiver method.
+type M0 struct {
+	p *int
+}
+
+func (M0) M() {
+}
+
+func efaceEscape0() {
+	{
+		i := 0
+		v := M0{&i}
+		var x M = v
+		_ = x
+	}
+	{
+		i := 0 // ERROR "moved to heap: i"
+		v := M0{&i}
+		var x M = v
+		sink = x
+	}
+	{
+		i := 0
+		v := M0{&i}
+		var x M = v
+		v1 := x.(M0)
+		_ = v1
+	}
+	{
+		i := 0 // ERROR "moved to heap: i"
+		v := M0{&i}
+		// BAD: v does not escape to heap here
+		var x M = v
+		v1 := x.(M0)
+		sink = v1
+	}
+	{
+		i := 0
+		v := M0{&i}
+		var x M = v
+		x.M() // ERROR "devirtualizing x.M"
+	}
+	{
+		i := 0 // ERROR "moved to heap: i"
+		v := M0{&i}
+		var x M = v
+		mescapes(x)
+	}
+	{
+		i := 0
+		v := M0{&i}
+		var x M = v
+		mdoesnotescape(x)
+	}
+}
+
+// Tests for type stored indirectly in iface and with value receiver method.
+type M1 struct {
+	p *int
+	x int
+}
+
+func (M1) M() {
+}
+
+func efaceEscape1() {
+	{
+		i := 0
+		v := M1{&i, 0}
+		var x M = v // ERROR "v does not escape"
+		_ = x
+	}
+	{
+		i := 0 // ERROR "moved to heap: i"
+		v := M1{&i, 0}
+		var x M = v // ERROR "v escapes to heap"
+		sink = x
+	}
+	{
+		i := 0
+		v := M1{&i, 0}
+		var x M = v // ERROR "v does not escape"
+		v1 := x.(M1)
+		_ = v1
+	}
+	{
+		i := 0 // ERROR "moved to heap: i"
+		v := M1{&i, 0}
+		var x M = v // ERROR "v does not escape"
+		v1 := x.(M1)
+		sink = v1 // ERROR "v1 escapes to heap"
+	}
+	{
+		i := 0
+		v := M1{&i, 0}
+		var x M = v // ERROR "v does not escape"
+		x.M()       // ERROR "devirtualizing x.M"
+	}
+	{
+		i := 0 // ERROR "moved to heap: i"
+		v := M1{&i, 0}
+		var x M = v // ERROR "v escapes to heap"
+		mescapes(x)
+	}
+	{
+		i := 0
+		v := M1{&i, 0}
+		var x M = v // ERROR "v does not escape"
+		mdoesnotescape(x)
+	}
+}
+
+// Tests for type stored directly in iface and with pointer receiver method.
+type M2 struct {
+	p *int
+}
+
+func (*M2) M() {
+}
+
+func efaceEscape2() {
+	{
+		i := 0
+		v := &M2{&i} // ERROR "&M2{...} does not escape"
+		var x M = v
+		_ = x
+	}
+	{
+		i := 0       // ERROR "moved to heap: i"
+		v := &M2{&i} // ERROR "&M2{...} escapes to heap"
+		var x M = v
+		sink = x
+	}
+	{
+		i := 0
+		v := &M2{&i} // ERROR "&M2{...} does not escape"
+		var x M = v
+		v1 := x.(*M2)
+		_ = v1
+	}
+	{
+		i := 0       // ERROR "moved to heap: i"
+		v := &M2{&i} // ERROR "&M2{...} escapes to heap"
+		// BAD: v does not escape to heap here
+		var x M = v
+		v1 := x.(*M2)
+		sink = v1
+	}
+	{
+		i := 0       // ERROR "moved to heap: i"
+		v := &M2{&i} // ERROR "&M2{...} does not escape"
+		// BAD: v does not escape to heap here
+		var x M = v
+		v1 := x.(*M2)
+		sink = *v1
+	}
+	{
+		i := 0       // ERROR "moved to heap: i"
+		v := &M2{&i} // ERROR "&M2{...} does not escape"
+		// BAD: v does not escape to heap here
+		var x M = v
+		v1, ok := x.(*M2)
+		sink = *v1
+		_ = ok
+	}
+	{
+		i := 0
+		v := &M2{&i} // ERROR "&M2{...} does not escape"
+		var x M = v
+		x.M() // ERROR "devirtualizing x.M"
+	}
+	{
+		i := 0       // ERROR "moved to heap: i"
+		v := &M2{&i} // ERROR "&M2{...} escapes to heap"
+		var x M = v
+		mescapes(x)
+	}
+	{
+		i := 0
+		v := &M2{&i} // ERROR "&M2{...} does not escape"
+		var x M = v
+		mdoesnotescape(x)
+	}
+}
+
+type T1 struct {
+	p *int
+}
+
+type T2 struct {
+	T1 T1
+}
+
+func dotTypeEscape() *T2 { // #11931
+	var x interface{}
+	x = &T1{p: new(int)} // ERROR "new\(int\) escapes to heap" "&T1{...} does not escape"
+	return &T2{          // ERROR "&T2{...} escapes to heap"
+		T1: *(x.(*T1)),
+	}
+}
+
+func dotTypeEscape2() { // #13805, #15796
+	{
+		i := 0
+		j := 0
+		var v int
+		var ok bool
+		var x interface{} = i // ERROR "i does not escape"
+		var y interface{} = j // ERROR "j does not escape"
+
+		*(&v) = x.(int)
+		*(&v), *(&ok) = y.(int)
+	}
+	{ // #13805, #15796
+		i := 0
+		j := 0
+		var ok bool
+		var x interface{} = i // ERROR "i does not escape"
+		var y interface{} = j // ERROR "j does not escape"
+
+		sink = x.(int)         // ERROR "x.\(int\) escapes to heap"
+		sink, *(&ok) = y.(int) // ERROR "autotmp_.* escapes to heap"
+	}
+	{
+		i := 0 // ERROR "moved to heap: i"
+		j := 0 // ERROR "moved to heap: j"
+		var ok bool
+		var x interface{} = &i
+		var y interface{} = &j
+
+		sink = x.(*int)
+		sink, *(&ok) = y.(*int)
+	}
+}
+
+func issue42279() {
+	type I interface{ M() }
+	type T struct{ I }
+
+	var i I = T{} // ERROR "T\{\} does not escape"
+	i.M()         // ERROR "partially devirtualizing i.M to T"
+}