// errchk -0 $G -sm $D/$F.go // Copyright 2010 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. package foo import "unsafe" var gxx *int func foo1(x int) { // ERROR "moved to heap: NAME-x" gxx = &x } func foo2(yy *int) { // ERROR "leaking param: NAME-yy" gxx = yy } func foo3(x int) *int { // ERROR "moved to heap: NAME-x" return &x } type T *T func foo3b(t T) { // ERROR "leaking param: NAME-t" *t = t } // xx isn't going anywhere, so use of yy is ok func foo4(xx, yy *int) { xx = yy } // xx isn't going anywhere, so taking address of yy is ok func foo5(xx **int, yy *int) { xx = &yy } func foo6(xx **int, yy *int) { // ERROR "leaking param: NAME-yy" *xx = yy } func foo7(xx **int, yy *int) { **xx = *yy } func foo8(xx, yy *int) int { xx = yy return *xx } func foo9(xx, yy *int) *int { // ERROR "leaking param: NAME-xx" "leaking param: NAME-yy" xx = yy return xx } func foo10(xx, yy *int) { *xx = *yy } func foo11() int { x, y := 0, 42 xx := &x yy := &y *xx = *yy return x } var xxx **int func foo12(yyy **int) { // ERROR "leaking param: NAME-yyy" xxx = yyy } func foo13(yyy **int) { *xxx = *yyy } func foo14(yyy **int) { **xxx = **yyy } func foo15(yy *int) { // ERROR "moved to heap: NAME-yy" xxx = &yy } func foo16(yy *int) { // ERROR "leaking param: NAME-yy" *xxx = yy } func foo17(yy *int) { **xxx = *yy } func foo18(y int) { // ERROR "moved to heap: "NAME-y" *xxx = &y } func foo19(y int) { **xxx = y } type Bar struct { i int ii *int } func NewBar() *Bar { return &Bar{ 42, nil } } func NewBarp(x *int) *Bar { // ERROR "leaking param: NAME-x" return &Bar{ 42, x } } func NewBarp2(x *int) *Bar { return &Bar{ *x, nil } } func (b *Bar) NoLeak() int { return *(b.ii) } func (b *Bar) AlsoNoLeak() *int { return b.ii } type Bar2 struct { i [12]int ii []int } func NewBar2() *Bar2 { return &Bar2{ [12]int{ 42 }, nil } } func (b *Bar2) NoLeak() int { return b.i[0] } func (b *Bar2) Leak() []int { // ERROR "leaking param: NAME-b" return b.i[:] } func (b *Bar2) AlsoNoLeak() []int { return b.ii[0:1] } func (b *Bar2) LeakSelf() { // ERROR "leaking param: NAME-b" b.ii = b.i[0:4] } func (b *Bar2) LeakSelf2() { // ERROR "leaking param: NAME-b" var buf []int buf = b.i[0:] b.ii = buf } func foo21() func() int { x := 42 // ERROR "moved to heap: NAME-x" return func() int { return x } } func foo22() int { x := 42 return func() int { return x }() } func foo23(x int) func() int { // ERROR "moved to heap: NAME-x" return func() int { return x } } func foo23a(x int) (func() int) { // ERROR "moved to heap: NAME-x" f := func() int { return x } return f } func foo23b(x int) *(func() int) { // ERROR "moved to heap: NAME-x" f := func() int { return x } // ERROR "moved to heap: NAME-f" return &f } func foo24(x int) int { return func() int { return x }() } var x *int func fooleak(xx *int) int { // ERROR "leaking param: NAME-xx" x = xx return *x } func foonoleak(xx *int) int { return *x + *xx } func foo31(x int) int { // ERROR "moved to heap: NAME-x" return fooleak(&x) } func foo32(x int) int { return foonoleak(&x) } type Foo struct { xx *int x int } var F Foo var pf *Foo func (f *Foo) fooleak() { // ERROR "leaking param: NAME-f" pf = f } func (f *Foo) foonoleak() { F.x = f.x } func (f *Foo) Leak() { // ERROR "leaking param: NAME-f" f.fooleak() } func (f *Foo) NoLeak() { f.foonoleak() } func foo41(x int) { // ERROR "moved to heap: NAME-x" F.xx = &x } func (f *Foo) foo42(x int) { // ERROR "moved to heap: NAME-x" f.xx = &x } func foo43(f *Foo, x int) { // ERROR "moved to heap: NAME-x" f.xx = &x } func foo44(yy *int) { // ERROR "leaking param: NAME-yy" F.xx = yy } func (f *Foo) foo45() { F.x = f.x } func (f *Foo) foo46() { F.xx = f.xx } func (f *Foo) foo47() { // ERROR "leaking param: NAME-f" f.xx = &f.x } var ptrSlice []*int func foo50(i *int) { // ERROR "leaking param: NAME-i" ptrSlice[0] = i } var ptrMap map[*int]*int func foo51(i *int) { // ERROR "leaking param: NAME-i" ptrMap[i] = i } func indaddr1(x int) *int { // ERROR "moved to heap: NAME-x" return &x } func indaddr2(x *int) *int { // ERROR "leaking param: NAME-x" return *&x } func indaddr3(x *int32) *int { // ERROR "leaking param: NAME-x" return *(**int)(unsafe.Pointer(&x)) } // From package math: func Float32bits(f float32) uint32 { return *(*uint32)(unsafe.Pointer(&f)) } func Float32frombits(b uint32) float32 { return *(*float32)(unsafe.Pointer(&b)) } func Float64bits(f float64) uint64 { return *(*uint64)(unsafe.Pointer(&f)) } func Float64frombits(b uint64) float64 { return *(*float64)(unsafe.Pointer(&b)) } // contrast with func float64bitsptr(f float64) *uint64 { // ERROR "moved to heap: NAME-f" return (*uint64)(unsafe.Pointer(&f)) } func float64ptrbitsptr(f *float64) *uint64 { // ERROR "leaking param: NAME-f" return (*uint64)(unsafe.Pointer(f)) } func typesw(i interface{}) *int { // ERROR "leaking param: NAME-i" switch val := i.(type) { case *int: return val case *int8: v := int(*val) // ERROR "moved to heap: NAME-v" return &v } return nil } func exprsw(i *int) *int { // ERROR "leaking param: NAME-i" switch j := i; *j + 110 { case 12: return j case 42: return nil } return nil } // assigning to an array element is like assigning to the array func foo60(i *int) *int { // ERROR "leaking param: NAME-i" var a [12]*int a[0] = i return a[1] } func foo60a(i *int) *int { var a [12]*int a[0] = i return nil } // assigning to a struct field is like assigning to the struct func foo61(i *int) *int { // ERROR "leaking param: NAME-i" type S struct { a,b *int } var s S s.a = i return s.b } func foo61a(i *int) *int { type S struct { a,b *int } var s S s.a = i return nil } // assigning to a struct field is like assigning to the struct but // here this subtlety is lost, since s.a counts as an assignment to a // track-losing dereference. func foo62(i *int) *int { // ERROR "leaking param: NAME-i" type S struct { a,b *int } s := new(S) s.a = i return nil // s.b } type M interface { M() } func foo63(m M) { } func foo64(m M) { // ERROR "leaking param: NAME-m" m.M() } type MV int func (MV) M() {} func foo65() { var mv MV foo63(&mv) } func foo66() { var mv MV // ERROR "moved to heap: NAME-mv" foo64(&mv) } func foo67() { var mv MV foo63(mv) } func foo68() { var mv MV foo64(mv) // escapes but it's an int so irrelevant } func foo69(m M) { // ERROR "leaking param: NAME-m" foo64(m) } func foo70(mv1 *MV, m M) { // ERROR "leaking param: NAME-mv1" "leaking param: NAME-m" m = mv1 foo64(m) } func foo71(x *int) []*int { // ERROR "leaking param: NAME-x" var y []*int y = append(y, x) return y } func foo71a(x int) []*int { // ERROR "moved to heap: NAME-x" var y []*int y = append(y, &x) return y } func foo72() { var x int var y [1]*int y[0] = &x } func foo72aa() [10]*int { var x int // ERROR "moved to heap: NAME-x" var y [10]*int y[0] = &x return y } func foo72a() { var y [10]*int for i := 0; i < 10; i++ { x := i // not moved to heap b/c y goes nowhere y[i] = &x } return } func foo72b() [10]*int { var y [10]*int for i := 0; i < 10; i++ { x := i // ERROR "moved to heap: NAME-x" y[i] = &x } return y } // issue 2145 func foo73() { s := []int{3,2,1} for _, v := range s { vv := v // ERROR "moved to heap: NAME-vv" defer func() { // "func literal escapes its scope" "&vv escapes its scope" println(vv) }() } } func foo74() { s := []int{3,2,1} for _, v := range s { vv := v // ERROR "moved to heap: NAME-vv" fn := func() { // "func literal escapes its scope" "&vv escapes its scope" println(vv) } defer fn() } } func myprint(y *int, x ...interface{}) *int { // ERROR "leaking param: NAME-y" return y } func myprint1(y *int, x ...interface{}) *interface{} { // ERROR "leaking param: NAME-x" return &x[0] } func foo75(z *int) { // ERROR "leaking param: NAME-z" myprint(z, 1, 2, 3) } func foo75a(z *int) { myprint1(z, 1, 2, 3) // "[.][.][.] argument escapes to heap" } func foo76(z *int) { myprint(nil, z) } func foo76a(z *int) { // ERROR "leaking param: NAME-z" myprint1(nil, z) // "[.][.][.] argument escapes to heap" } func foo76b() { myprint(nil, 1, 2, 3) } func foo76c() { myprint1(nil, 1, 2, 3) // "[.][.][.] argument escapes to heap" } func foo76d() { defer myprint(nil, 1, 2, 3) } func foo76e() { defer myprint1(nil, 1, 2, 3) // "[.][.][.] argument escapes to heap" } func foo76f() { for { defer myprint(nil, 1, 2, 3) // "[.][.][.] argument escapes its scope" } } func foo76g() { for { defer myprint1(nil, 1, 2, 3) // "[.][.][.] argument escapes to heap" } } func foo77(z []interface{}) { myprint(nil, z...) // z does not escape } func foo77a(z []interface{}) { // ERROR "leaking param: NAME-z" myprint1(nil, z...) } func foo78(z int) *int { // ERROR "moved to heap: NAME-z" return &z // "&z escapes" } func foo78a(z int) *int { // ERROR "moved to heap: NAME-z" y := &z x := &y return *x // really return y } func foo79() *int { return new(int) // "moved to heap: new[(]int[)]" } func foo80() *int { var z *int for { z = new(int) // "new[(]int[)] escapes its scope" } _ = z return nil } func foo81() *int { for { z := new(int) _ = z } return nil } type Fooer interface { Foo() } type LimitedFooer struct { Fooer N int64 } func LimitFooer(r Fooer, n int64) Fooer { // ERROR "leaking param: NAME-r" return &LimitedFooer{r, n} } func foo90(x *int) map[*int]*int { // ERROR "leaking param: NAME-x" return map[*int]*int{ nil: x } } func foo91(x *int) map[*int]*int { // ERROR "leaking param: NAME-x" return map[*int]*int{ x:nil } } func foo92(x *int) [2]*int { // ERROR "leaking param: NAME-x" return [2]*int{ x, nil } } // does not leak c func foo93(c chan *int) *int { for v := range c { return v } return nil } // does not leak m func foo94(m map[*int]*int, b bool) *int { for k, v := range m { if b { return k } return v } return nil } // does leak x func foo95(m map[*int]*int, x *int) { // ERROR "leaking param: NAME-x" m[x] = x } // does not leak m func foo96(m []*int) *int { return m[0] } // does leak m func foo97(m [1]*int) *int { // ERROR "leaking param: NAME-m" return m[0] } // does not leak m func foo98(m map[int]*int) *int { return m[0] } // does leak m func foo99(m *[1]*int) []*int { // ERROR "leaking param: NAME-m" return m[:] } // does not leak m func foo100(m []*int) *int { for _, v := range m { return v } return nil } // does leak m func foo101(m [1]*int) *int { // ERROR "leaking param: NAME-m" for _, v := range m { return v } return nil } // does leak x func foo102(m []*int, x *int) { // ERROR "leaking param: NAME-x" m[0] = x } // does not leak x func foo103(m [1]*int, x *int) { m[0] = x } var y []*int // does not leak x func foo104(x []*int) { copy(y, x) } // does not leak x func foo105(x []*int) { _ = append(y, x...) } // does leak x func foo106(x *int) { // ERROR "leaking param: NAME-x" _ = append(y, x) }