// errorcheck -0 -N -m -l // 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. // Test, using compiler diagnostic flags, that the escape analysis is working. // Compiles but does not run. Inlining is disabled. // Registerization is disabled too (-N), which should // have no effect on escape analysis. package foo import ( "fmt" "unsafe" ) var gxx *int func foo1(x int) { // ERROR "moved to heap: x" gxx = &x // ERROR "&x escapes to heap" } func foo2(yy *int) { // ERROR "leaking param: yy" gxx = yy } func foo3(x int) *int { // ERROR "moved to heap: x" return &x // ERROR "&x escapes to heap" } type T *T func foo3b(t T) { // ERROR "leaking param: t" *t = t } // xx isn't going anywhere, so use of yy is ok func foo4(xx, yy *int) { // ERROR "xx does not escape" "yy does not escape" xx = yy } // xx isn't going anywhere, so taking address of yy is ok func foo5(xx **int, yy *int) { // ERROR "xx does not escape" "yy does not escape" xx = &yy // ERROR "&yy does not escape" } func foo6(xx **int, yy *int) { // ERROR "xx does not escape" "leaking param: yy" *xx = yy } func foo7(xx **int, yy *int) { // ERROR "xx does not escape" "yy does not escape" **xx = *yy } func foo8(xx, yy *int) int { // ERROR "xx does not escape" "yy does not escape" xx = yy return *xx } func foo9(xx, yy *int) *int { // ERROR "leaking param: xx" "leaking param: yy" xx = yy return xx } func foo10(xx, yy *int) { // ERROR "xx does not escape" "yy does not escape" *xx = *yy } func foo11() int { x, y := 0, 42 xx := &x // ERROR "&x does not escape" yy := &y // ERROR "&y does not escape" *xx = *yy return x } var xxx **int func foo12(yyy **int) { // ERROR "leaking param: yyy" xxx = yyy } // Must treat yyy as leaking because *yyy leaks, and the escape analysis // summaries in exported metadata do not distinguish these two cases. func foo13(yyy **int) { // ERROR "leaking param: yyy" *xxx = *yyy } func foo14(yyy **int) { // ERROR "yyy does not escape" **xxx = **yyy } func foo15(yy *int) { // ERROR "moved to heap: yy" xxx = &yy // ERROR "&yy escapes to heap" } func foo16(yy *int) { // ERROR "leaking param: yy" *xxx = yy } func foo17(yy *int) { // ERROR "yy does not escape" **xxx = *yy } func foo18(y int) { // ERROR "moved to heap: "y" *xxx = &y // ERROR "&y escapes to heap" } func foo19(y int) { **xxx = y } type Bar struct { i int ii *int } func NewBar() *Bar { return &Bar{42, nil} // ERROR "&Bar literal escapes to heap" } func NewBarp(x *int) *Bar { // ERROR "leaking param: x" return &Bar{42, x} // ERROR "&Bar literal escapes to heap" } func NewBarp2(x *int) *Bar { // ERROR "x does not escape" return &Bar{*x, nil} // ERROR "&Bar literal escapes to heap" } func (b *Bar) NoLeak() int { // ERROR "b does not escape" return *(b.ii) } func (b *Bar) Leak() *int { // ERROR "leaking param: b" return &b.i // ERROR "&b.i escapes to heap" } func (b *Bar) AlsoNoLeak() *int { // ERROR "leaking param b content to result ~r0" return b.ii } func (b Bar) AlsoLeak() *int { // ERROR "leaking param: b" return b.ii } func (b Bar) LeaksToo() *int { // ERROR "leaking param: b" v := 0 // ERROR "moved to heap: v" b.ii = &v // ERROR "&v escapes" return b.ii } func (b *Bar) LeaksABit() *int { // ERROR "leaking param b content to result ~r0" v := 0 // ERROR "moved to heap: v" b.ii = &v // ERROR "&v escapes" return b.ii } func (b Bar) StillNoLeak() int { // ERROR "b does not escape" v := 0 b.ii = &v // ERROR "&v does not escape" return b.i } func goLeak(b *Bar) { // ERROR "leaking param: b" go b.NoLeak() } type Bar2 struct { i [12]int ii []int } func NewBar2() *Bar2 { return &Bar2{[12]int{42}, nil} // ERROR "&Bar2 literal escapes to heap" } func (b *Bar2) NoLeak() int { // ERROR "b does not escape" return b.i[0] } func (b *Bar2) Leak() []int { // ERROR "leaking param: b" return b.i[:] // ERROR "b.i escapes to heap" } func (b *Bar2) AlsoNoLeak() []int { // ERROR "leaking param b content to result ~r0" return b.ii[0:1] } func (b Bar2) AgainNoLeak() [12]int { // ERROR "b does not escape" return b.i } func (b *Bar2) LeakSelf() { // ERROR "leaking param: b" b.ii = b.i[0:4] // ERROR "b.i escapes to heap" } func (b *Bar2) LeakSelf2() { // ERROR "leaking param: b" var buf []int buf = b.i[0:] // ERROR "b.i escapes to heap" b.ii = buf } func foo21() func() int { x := 42 // ERROR "moved to heap: x" return func() int { // ERROR "func literal escapes to heap" return x // ERROR "&x escapes to heap" } } func foo22() int { x := 42 return func() int { // ERROR "func literal does not escape" return x }() } func foo23(x int) func() int { // ERROR "moved to heap: x" return func() int { // ERROR "func literal escapes to heap" return x // ERROR "&x escapes to heap" } } func foo23a(x int) func() int { // ERROR "moved to heap: x" f := func() int { // ERROR "func literal escapes to heap" return x // ERROR "&x escapes to heap" } return f } func foo23b(x int) *(func() int) { // ERROR "moved to heap: x" f := func() int { return x } // ERROR "moved to heap: f" "func literal escapes to heap" "&x escapes to heap" return &f // ERROR "&f escapes to heap" } func foo24(x int) int { return func() int { // ERROR "func literal does not escape" return x }() } var x *int func fooleak(xx *int) int { // ERROR "leaking param: xx" x = xx return *x } func foonoleak(xx *int) int { // ERROR "xx does not escape" return *x + *xx } func foo31(x int) int { // ERROR "moved to heap: x" return fooleak(&x) // ERROR "&x escapes to heap" } func foo32(x int) int { return foonoleak(&x) // ERROR "&x does not escape" } type Foo struct { xx *int x int } var F Foo var pf *Foo func (f *Foo) fooleak() { // ERROR "leaking param: f" pf = f } func (f *Foo) foonoleak() { // ERROR "f does not escape" F.x = f.x } func (f *Foo) Leak() { // ERROR "leaking param: f" f.fooleak() } func (f *Foo) NoLeak() { // ERROR "f does not escape" f.foonoleak() } func foo41(x int) { // ERROR "moved to heap: x" F.xx = &x // ERROR "&x escapes to heap" } func (f *Foo) foo42(x int) { // ERROR "f does not escape" "moved to heap: x" f.xx = &x // ERROR "&x escapes to heap" } func foo43(f *Foo, x int) { // ERROR "f does not escape" "moved to heap: x" f.xx = &x // ERROR "&x escapes to heap" } func foo44(yy *int) { // ERROR "leaking param: yy" F.xx = yy } func (f *Foo) foo45() { // ERROR "f does not escape" F.x = f.x } // See foo13 above for explanation of why f leaks. func (f *Foo) foo46() { // ERROR "leaking param: f" F.xx = f.xx } func (f *Foo) foo47() { // ERROR "leaking param: f" f.xx = &f.x // ERROR "&f.x escapes to heap" } var ptrSlice []*int func foo50(i *int) { // ERROR "leaking param: i" ptrSlice[0] = i } var ptrMap map[*int]*int func foo51(i *int) { // ERROR "leaking param: i" ptrMap[i] = i } func indaddr1(x int) *int { // ERROR "moved to heap: x" return &x // ERROR "&x escapes to heap" } func indaddr2(x *int) *int { // ERROR "leaking param: x" return *&x // ERROR "&x does not escape" } func indaddr3(x *int32) *int { // ERROR "leaking param: x" return *(**int)(unsafe.Pointer(&x)) // ERROR "&x does not escape" } // From package math: func Float32bits(f float32) uint32 { return *(*uint32)(unsafe.Pointer(&f)) // ERROR "&f does not escape" } func Float32frombits(b uint32) float32 { return *(*float32)(unsafe.Pointer(&b)) // ERROR "&b does not escape" } func Float64bits(f float64) uint64 { return *(*uint64)(unsafe.Pointer(&f)) // ERROR "&f does not escape" } func Float64frombits(b uint64) float64 { return *(*float64)(unsafe.Pointer(&b)) // ERROR "&b does not escape" } // contrast with func float64bitsptr(f float64) *uint64 { // ERROR "moved to heap: f" return (*uint64)(unsafe.Pointer(&f)) // ERROR "&f escapes to heap" } func float64ptrbitsptr(f *float64) *uint64 { // ERROR "leaking param: f" return (*uint64)(unsafe.Pointer(f)) } func typesw(i interface{}) *int { // ERROR "leaking param: i" switch val := i.(type) { case *int: return val case *int8: v := int(*val) // ERROR "moved to heap: v" return &v // ERROR "&v escapes to heap" } return nil } func exprsw(i *int) *int { // ERROR "leaking param: 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: i" var a [12]*int a[0] = i return a[1] } func foo60a(i *int) *int { // ERROR "i does not escape" 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: i" type S struct { a, b *int } var s S s.a = i return s.b } func foo61a(i *int) *int { // ERROR "i does not escape" 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: i" type S struct { a, b *int } s := new(S) // ERROR "new[(]S[)] does not escape" s.a = i return nil // s.b } type M interface { M() } func foo63(m M) { // ERROR "m does not escape" } func foo64(m M) { // ERROR "leaking param: m" m.M() } func foo64b(m M) { // ERROR "leaking param: m" defer m.M() } type MV int func (MV) M() {} func foo65() { var mv MV foo63(&mv) // ERROR "&mv does not escape" } func foo66() { var mv MV // ERROR "moved to heap: mv" foo64(&mv) // ERROR "&mv escapes to heap" } 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: m" foo64(m) } func foo70(mv1 *MV, m M) { // ERROR "leaking param: mv1" "leaking param: m" m = mv1 foo64(m) } func foo71(x *int) []*int { // ERROR "leaking param: x" var y []*int y = append(y, x) return y } func foo71a(x int) []*int { // ERROR "moved to heap: x" var y []*int y = append(y, &x) // ERROR "&x escapes to heap" return y } func foo72() { var x int var y [1]*int y[0] = &x // ERROR "&x does not escape" } func foo72aa() [10]*int { var x int // ERROR "moved to heap: x" var y [10]*int y[0] = &x // ERROR "&x escapes to heap" return y } func foo72a() { var y [10]*int for i := 0; i < 10; i++ { // escapes its scope x := i // ERROR "moved to heap: x" y[i] = &x // ERROR "&x escapes to heap" } return } func foo72b() [10]*int { var y [10]*int for i := 0; i < 10; i++ { x := i // ERROR "moved to heap: x" y[i] = &x // ERROR "&x escapes to heap" } return y } // issue 2145 func foo73() { s := []int{3, 2, 1} // ERROR "\[\]int literal does not escape" for _, v := range s { vv := v // ERROR "moved to heap: vv" // actually just escapes its scope defer func() { // ERROR "func literal escapes to heap" println(vv) // ERROR "&vv escapes to heap" }() } } func foo74() { s := []int{3, 2, 1} // ERROR "\[\]int literal does not escape" for _, v := range s { vv := v // ERROR "moved to heap: vv" // actually just escapes its scope fn := func() { // ERROR "func literal escapes to heap" println(vv) // ERROR "&vv escapes to heap" } defer fn() } } // issue 3975 func foo74b() { var array [3]func() s := []int{3, 2, 1} // ERROR "\[\]int literal does not escape" for i, v := range s { vv := v // ERROR "moved to heap: vv" // actually just escapes its scope array[i] = func() { // ERROR "func literal escapes to heap" println(vv) // ERROR "&vv escapes to heap" } } } func myprint(y *int, x ...interface{}) *int { // ERROR "x does not escape" "leaking param: y" return y } func myprint1(y *int, x ...interface{}) *interface{} { // ERROR "y does not escape" "leaking param: x" return &x[0] // ERROR "&x.0. escapes to heap" } func foo75(z *int) { // ERROR "z does not escape" myprint(z, 1, 2, 3) // ERROR "[.][.][.] argument does not escape" } func foo75a(z *int) { // ERROR "z does not escape" myprint1(z, 1, 2, 3) // ERROR "[.][.][.] argument does not escape" } func foo75esc(z *int) { // ERROR "leaking param: z" gxx = myprint(z, 1, 2, 3) // ERROR "[.][.][.] argument does not escape" } func foo75aesc(z *int) { // ERROR "z does not escape" var ppi **interface{} // assignments to pointer dereferences lose track *ppi = myprint1(z, 1, 2, 3) // ERROR "[.][.][.] argument escapes to heap" } func foo76(z *int) { // ERROR "leaking param: z" myprint(nil, z) // ERROR "[.][.][.] argument does not escape" } func foo76a(z *int) { // ERROR "leaking param: z" myprint1(nil, z) // ERROR "[.][.][.] argument does not escape" } func foo76b() { myprint(nil, 1, 2, 3) // ERROR "[.][.][.] argument does not escape" } func foo76c() { myprint1(nil, 1, 2, 3) // ERROR "[.][.][.] argument does not escape" } func foo76d() { defer myprint(nil, 1, 2, 3) // ERROR "[.][.][.] argument does not escape" } func foo76e() { defer myprint1(nil, 1, 2, 3) // ERROR "[.][.][.] argument does not escape" } func foo76f() { for { // TODO: This one really only escapes its scope, but we don't distinguish yet. defer myprint(nil, 1, 2, 3) // ERROR "[.][.][.] argument escapes to heap" } } func foo76g() { for { defer myprint1(nil, 1, 2, 3) // ERROR "[.][.][.] argument escapes to heap" } } func foo77(z []interface{}) { // ERROR "z does not escape" myprint(nil, z...) // z does not escape } func foo77a(z []interface{}) { // ERROR "z does not escape" myprint1(nil, z...) } func foo77b(z []interface{}) { // ERROR "leaking param: z" var ppi **interface{} *ppi = myprint1(nil, z...) } func foo78(z int) *int { // ERROR "moved to heap: z" return &z // ERROR "&z escapes to heap" } func foo78a(z int) *int { // ERROR "moved to heap: z" y := &z // ERROR "&z escapes to heap" x := &y // ERROR "&y does not escape" return *x // really return y } func foo79() *int { return new(int) // ERROR "new[(]int[)] escapes to heap" } func foo80() *int { var z *int for { // Really just escapes its scope but we don't distinguish z = new(int) // ERROR "new[(]int[)] escapes to heap" } _ = z return nil } func foo81() *int { for { z := new(int) // ERROR "new[(]int[)] does not escape" _ = z } return nil } func tee(p *int) (x, y *int) { return p, p } // ERROR "leaking param" func noop(x, y *int) {} // ERROR "does not escape" func foo82() { var x, y, z int // ERROR "moved to heap" go noop(tee(&z)) // ERROR "&z escapes to heap" go noop(&x, &y) // ERROR "escapes to heap" for { var u, v, w int // ERROR "moved to heap" defer noop(tee(&u)) // ERROR "&u escapes to heap" defer noop(&v, &w) // ERROR "escapes to heap" } } type Fooer interface { Foo() } type LimitedFooer struct { Fooer N int64 } func LimitFooer(r Fooer, n int64) Fooer { // ERROR "leaking param: r" return &LimitedFooer{r, n} // ERROR "&LimitedFooer literal escapes to heap" } func foo90(x *int) map[*int]*int { // ERROR "leaking param: x" return map[*int]*int{nil: x} // ERROR "map\[\*int\]\*int literal escapes to heap" } func foo91(x *int) map[*int]*int { // ERROR "leaking param: x" return map[*int]*int{x: nil} // ERROR "map\[\*int\]\*int literal escapes to heap" } func foo92(x *int) [2]*int { // ERROR "leaking param: x" return [2]*int{x, nil} } // does not leak c func foo93(c chan *int) *int { // ERROR "c does not escape" for v := range c { return v } return nil } // does not leak m func foo94(m map[*int]*int, b bool) *int { // ERROR "m does not escape" 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 "m does not escape" "leaking param: x" m[x] = x } // does not leak m func foo96(m []*int) *int { // ERROR "m does not escape" return m[0] } // does leak m func foo97(m [1]*int) *int { // ERROR "leaking param: m" return m[0] } // does not leak m func foo98(m map[int]*int) *int { // ERROR "m does not escape" return m[0] } // does leak m func foo99(m *[1]*int) []*int { // ERROR "leaking param: m" return m[:] } // does not leak m func foo100(m []*int) *int { // ERROR "m does not escape" for _, v := range m { return v } return nil } // does leak m func foo101(m [1]*int) *int { // ERROR "leaking param: m" for _, v := range m { return v } return nil } // does not leak m func foo101a(m [1]*int) *int { // ERROR "m does not escape" for i := range m { // ERROR "moved to heap: i" return &i // ERROR "&i escapes to heap" } return nil } // does leak x func foo102(m []*int, x *int) { // ERROR "m does not escape" "leaking param: x" m[0] = x } // does not leak x func foo103(m [1]*int, x *int) { // ERROR "m does not escape" "x does not escape" m[0] = x } var y []*int // does not leak x func foo104(x []*int) { // ERROR "x does not escape" copy(y, x) } // does not leak x func foo105(x []*int) { // ERROR "x does not escape" _ = append(y, x...) } // does leak x func foo106(x *int) { // ERROR "leaking param: x" _ = append(y, x) } func foo107(x *int) map[*int]*int { // ERROR "leaking param: x" return map[*int]*int{x: nil} // ERROR "map.* literal escapes to heap" } func foo108(x *int) map[*int]*int { // ERROR "leaking param: x" return map[*int]*int{nil: x} // ERROR "map.* literal escapes to heap" } func foo109(x *int) *int { // ERROR "leaking param: x" m := map[*int]*int{x: nil} // ERROR "map.* literal does not escape" for k, _ := range m { return k } return nil } func foo110(x *int) *int { // ERROR "leaking param: x" m := map[*int]*int{nil: x} // ERROR "map.* literal does not escape" return m[nil] } func foo111(x *int) *int { // ERROR "leaking param: x" m := []*int{x} // ERROR "\[\]\*int literal does not escape" return m[0] } func foo112(x *int) *int { // ERROR "leaking param: x" m := [1]*int{x} return m[0] } func foo113(x *int) *int { // ERROR "leaking param: x" m := Bar{ii: x} return m.ii } func foo114(x *int) *int { // ERROR "leaking param: x" m := &Bar{ii: x} // ERROR "&Bar literal does not escape" return m.ii } func foo115(x *int) *int { // ERROR "leaking param: x" return (*int)(unsafe.Pointer(uintptr(unsafe.Pointer(x)) + 1)) } func foo116(b bool) *int { if b { x := 1 // ERROR "moved to heap: x" return &x // ERROR "&x escapes to heap" } else { y := 1 // ERROR "moved to heap: y" return &y // ERROR "&y escapes to heap" } return nil } func foo117(unknown func(interface{})) { // ERROR "unknown does not escape" x := 1 // ERROR "moved to heap: x" unknown(&x) // ERROR "&x escapes to heap" } func foo118(unknown func(*int)) { // ERROR "unknown does not escape" x := 1 // ERROR "moved to heap: x" unknown(&x) // ERROR "&x escapes to heap" } func external(*int) func foo119(x *int) { // ERROR "leaking param: x" external(x) } func foo120() { // formerly exponential time analysis L1: L2: L3: L4: L5: L6: L7: L8: L9: L10: L11: L12: L13: L14: L15: L16: L17: L18: L19: L20: L21: L22: L23: L24: L25: L26: L27: L28: L29: L30: L31: L32: L33: L34: L35: L36: L37: L38: L39: L40: L41: L42: L43: L44: L45: L46: L47: L48: L49: L50: L51: L52: L53: L54: L55: L56: L57: L58: L59: L60: L61: L62: L63: L64: L65: L66: L67: L68: L69: L70: L71: L72: L73: L74: L75: L76: L77: L78: L79: L80: L81: L82: L83: L84: L85: L86: L87: L88: L89: L90: L91: L92: L93: L94: L95: L96: L97: L98: L99: L100: // use the labels to silence compiler errors goto L1 goto L2 goto L3 goto L4 goto L5 goto L6 goto L7 goto L8 goto L9 goto L10 goto L11 goto L12 goto L13 goto L14 goto L15 goto L16 goto L17 goto L18 goto L19 goto L20 goto L21 goto L22 goto L23 goto L24 goto L25 goto L26 goto L27 goto L28 goto L29 goto L30 goto L31 goto L32 goto L33 goto L34 goto L35 goto L36 goto L37 goto L38 goto L39 goto L40 goto L41 goto L42 goto L43 goto L44 goto L45 goto L46 goto L47 goto L48 goto L49 goto L50 goto L51 goto L52 goto L53 goto L54 goto L55 goto L56 goto L57 goto L58 goto L59 goto L60 goto L61 goto L62 goto L63 goto L64 goto L65 goto L66 goto L67 goto L68 goto L69 goto L70 goto L71 goto L72 goto L73 goto L74 goto L75 goto L76 goto L77 goto L78 goto L79 goto L80 goto L81 goto L82 goto L83 goto L84 goto L85 goto L86 goto L87 goto L88 goto L89 goto L90 goto L91 goto L92 goto L93 goto L94 goto L95 goto L96 goto L97 goto L98 goto L99 goto L100 } func foo121() { for i := 0; i < 10; i++ { defer myprint(nil, i) // ERROR "[.][.][.] argument escapes to heap" go myprint(nil, i) // ERROR "[.][.][.] argument escapes to heap" } } // same as foo121 but check across import func foo121b() { for i := 0; i < 10; i++ { defer fmt.Printf("%d", i) // ERROR "[.][.][.] argument escapes to heap" go fmt.Printf("%d", i) // ERROR "[.][.][.] argument escapes to heap" } } // a harmless forward jump func foo122() { var i *int goto L1 L1: i = new(int) // ERROR "new.int. does not escape" _ = i } // a backward jump, increases loopdepth func foo123() { var i *int L1: i = new(int) // ERROR "new.int. escapes to heap" goto L1 _ = i } func foo124(x **int) { // ERROR "x does not escape" var i int // ERROR "moved to heap: i" p := &i // ERROR "&i escapes" func() { // ERROR "func literal does not escape" *x = p // ERROR "leaking closure reference p" }() } func foo125(ch chan *int) { // ERROR "does not escape" var i int // ERROR "moved to heap" p := &i // ERROR "&i escapes to heap" func() { // ERROR "func literal does not escape" ch <- p // ERROR "leaking closure reference p" }() } func foo126() { var px *int // loopdepth 0 for { // loopdepth 1 var i int // ERROR "moved to heap" func() { // ERROR "func literal does not escape" px = &i // ERROR "&i escapes" }() } _ = px } var px *int func foo127() { var i int // ERROR "moved to heap: i" p := &i // ERROR "&i escapes to heap" q := p px = q } func foo128() { var i int p := &i // ERROR "&i does not escape" q := p _ = q } func foo129() { var i int // ERROR "moved to heap: i" p := &i // ERROR "&i escapes to heap" func() { // ERROR "func literal does not escape" q := p // ERROR "leaking closure reference p" func() { // ERROR "func literal does not escape" r := q // ERROR "leaking closure reference q" px = r }() }() } func foo130() { for { var i int // ERROR "moved to heap" func() { // ERROR "func literal does not escape" px = &i // ERROR "&i escapes" "leaking closure reference i" }() } } func foo131() { var i int // ERROR "moved to heap" func() { // ERROR "func literal does not escape" px = &i // ERROR "&i escapes" "leaking closure reference i" }() } func foo132() { var i int // ERROR "moved to heap" go func() { // ERROR "func literal escapes to heap" px = &i // ERROR "&i escapes" "leaking closure reference i" }() } func foo133() { var i int // ERROR "moved to heap" defer func() { // ERROR "func literal does not escape" px = &i // ERROR "&i escapes" "leaking closure reference i" }() } func foo134() { var i int p := &i // ERROR "&i does not escape" func() { // ERROR "func literal does not escape" q := p func() { // ERROR "func literal does not escape" r := q _ = r }() }() } func foo135() { var i int // ERROR "moved to heap: i" p := &i // ERROR "&i escapes to heap" "moved to heap: p" go func() { // ERROR "func literal escapes to heap" q := p // ERROR "&p escapes to heap" func() { // ERROR "func literal does not escape" r := q _ = r }() }() } func foo136() { var i int // ERROR "moved to heap: i" p := &i // ERROR "&i escapes to heap" "moved to heap: p" go func() { // ERROR "func literal escapes to heap" q := p // ERROR "&p escapes to heap" "leaking closure reference p" func() { // ERROR "func literal does not escape" r := q // ERROR "leaking closure reference q" px = r }() }() } func foo137() { var i int // ERROR "moved to heap: i" p := &i // ERROR "&i escapes to heap" func() { // ERROR "func literal does not escape" q := p // ERROR "leaking closure reference p" "moved to heap: q" go func() { // ERROR "func literal escapes to heap" r := q // ERROR "&q escapes to heap" _ = r }() }() } func foo138() *byte { type T struct { x [1]byte } t := new(T) // ERROR "new.T. escapes to heap" return &t.x[0] // ERROR "&t.x.0. escapes to heap" } func foo139() *byte { type T struct { x struct { y byte } } t := new(T) // ERROR "new.T. escapes to heap" return &t.x.y // ERROR "&t.x.y escapes to heap" } // issue 4751 func foo140() interface{} { type T struct { X string } type U struct { X string T *T } t := &T{} // ERROR "&T literal escapes to heap" return U{ X: t.X, T: t, } } //go:noescape func F1([]byte) func F2([]byte) //go:noescape func F3(x []byte) // ERROR "F3 x does not escape" func F4(x []byte) func G() { var buf1 [10]byte F1(buf1[:]) // ERROR "buf1 does not escape" var buf2 [10]byte // ERROR "moved to heap: buf2" F2(buf2[:]) // ERROR "buf2 escapes to heap" var buf3 [10]byte F3(buf3[:]) // ERROR "buf3 does not escape" var buf4 [10]byte // ERROR "moved to heap: buf4" F4(buf4[:]) // ERROR "buf4 escapes to heap" } type Tm struct { x int } func (t *Tm) M() { // ERROR "t does not escape" } func foo141() { var f func() t := new(Tm) // ERROR "escapes to heap" f = t.M // ERROR "t.M does not escape" _ = f } var gf func() func foo142() { t := new(Tm) // ERROR "escapes to heap" gf = t.M // ERROR "t.M escapes to heap" } // issue 3888. func foo143() { for i := 0; i < 1000; i++ { func() { // ERROR "func literal does not escape" for i := 0; i < 1; i++ { var t Tm t.M() // ERROR "t does not escape" } }() } } // issue 5773 // Check that annotations take effect regardless of whether they // are before or after the use in the source code. //go:noescape func foo144a(*int) func foo144() { var x int foo144a(&x) // ERROR "&x does not escape" var y int foo144b(&y) // ERROR "&y does not escape" } //go:noescape func foo144b(*int) // issue 7313: for loop init should not be treated as "in loop" type List struct { Next *List } func foo145(l List) { // ERROR "l does not escape" var p *List for p = &l; p.Next != nil; p = p.Next { // ERROR "&l does not escape" } } func foo146(l List) { // ERROR "l does not escape" var p *List p = &l // ERROR "&l does not escape" for ; p.Next != nil; p = p.Next { } } func foo147(l List) { // ERROR "l does not escape" var p *List p = &l // ERROR "&l does not escape" for p.Next != nil { p = p.Next } } func foo148(l List) { // ERROR " l does not escape" for p := &l; p.Next != nil; p = p.Next { // ERROR "&l does not escape" } } // related: address of variable should have depth of variable, not of loop func foo149(l List) { // ERROR " l does not escape" var p *List for { for p = &l; p.Next != nil; p = p.Next { // ERROR "&l does not escape" } } } // issue 7934: missed ... if element type had no pointers var save150 []byte func foo150(x ...byte) { // ERROR "leaking param: x" save150 = x } func bar150() { foo150(1, 2, 3) // ERROR "[.][.][.] argument escapes to heap" } // issue 7931: bad handling of slice of array var save151 *int func foo151(x *int) { // ERROR "leaking param: x" save151 = x } func bar151() { var a [64]int // ERROR "moved to heap: a" a[4] = 101 foo151(&(&a)[4:8][0]) // ERROR "&\(&a\)\[4:8\]\[0\] escapes to heap" "&a escapes to heap" } func bar151b() { var a [10]int // ERROR "moved to heap: a" b := a[:] // ERROR "a escapes to heap" foo151(&b[4:8][0]) // ERROR "&b\[4:8\]\[0\] escapes to heap" } func bar151c() { var a [64]int // ERROR "moved to heap: a" a[4] = 101 foo151(&(&a)[4:8:8][0]) // ERROR "&\(&a\)\[4:8:8\]\[0\] escapes to heap" "&a escapes to heap" } func bar151d() { var a [10]int // ERROR "moved to heap: a" b := a[:] // ERROR "a escapes to heap" foo151(&b[4:8:8][0]) // ERROR "&b\[4:8:8\]\[0\] escapes to heap" } // issue 8120 type U struct { s *string } func (u *U) String() *string { // ERROR "leaking param u content to result ~r0" return u.s } type V struct { s *string } func NewV(u U) *V { // ERROR "leaking param: u" return &V{u.String()} // ERROR "&V literal escapes to heap" "u does not escape" } func foo152() { a := "a" // ERROR "moved to heap: a" u := U{&a} // ERROR "&a escapes to heap" v := NewV(u) println(v) } // issue 8176 - &x in type switch body not marked as escaping func foo153(v interface{}) *int { // ERROR "leaking param: v" switch x := v.(type) { case int: // ERROR "moved to heap: x" return &x // ERROR "&x escapes to heap" } panic(0) } // issue 8185 - &result escaping into result func f() (x int, y *int) { // ERROR "moved to heap: x" y = &x // ERROR "&x escapes to heap" return } func g() (x interface{}) { // ERROR "moved to heap: x" x = &x // ERROR "&x escapes to heap" return } var sink interface{} type Lit struct { p *int } func ptrlitNoescape() { // Both literal and element do not escape. i := 0 x := &Lit{&i} // ERROR "&Lit literal does not escape" "&i does not escape" _ = x } func ptrlitNoEscape2() { // Literal does not escape, but element does. i := 0 // ERROR "moved to heap: i" x := &Lit{&i} // ERROR "&Lit literal does not escape" "&i escapes to heap" sink = *x } func ptrlitEscape() { // Both literal and element escape. i := 0 // ERROR "moved to heap: i" x := &Lit{&i} // ERROR "&Lit literal escapes to heap" "&i escapes to heap" sink = x } // self-assignments type Buffer struct { arr [64]byte buf1 []byte buf2 []byte str1 string str2 string } func (b *Buffer) foo() { // ERROR "b does not escape" b.buf1 = b.buf1[1:2] // ERROR "ignoring self-assignment to b.buf1" b.buf1 = b.buf1[1:2:3] // ERROR "ignoring self-assignment to b.buf1" b.buf1 = b.buf2[1:2] // ERROR "ignoring self-assignment to b.buf1" b.buf1 = b.buf2[1:2:3] // ERROR "ignoring self-assignment to b.buf1" } func (b *Buffer) bar() { // ERROR "leaking param: b" b.buf1 = b.arr[1:2] // ERROR "b.arr escapes to heap" } func (b *Buffer) baz() { // ERROR "b does not escape" b.str1 = b.str1[1:2] // ERROR "ignoring self-assignment to b.str1" b.str1 = b.str2[1:2] // ERROR "ignoring self-assignment to b.str1" } func (b *Buffer) bat() { // ERROR "leaking param: b" o := new(Buffer) // ERROR "new\(Buffer\) escapes to heap" o.buf1 = b.buf1[1:2] sink = o } func quux(sp *string, bp *[]byte) { // ERROR "sp does not escape" "bp does not escape" *sp = (*sp)[1:2] // ERROR "quux ignoring self-assignment to \*sp" *bp = (*bp)[1:2] // ERROR "quux ignoring self-assignment to \*bp" } type StructWithString struct { p *int s string } // This is escape analysis false negative. // We assign the pointer to x.p but leak x.s. Escape analysis coarsens flows // to just x, and thus &i looks escaping. func fieldFlowTracking() { var x StructWithString i := 0 // ERROR "moved to heap: i" x.p = &i // ERROR "&i escapes to heap" sink = x.s } // String operations. func slicebytetostring0() { b := make([]byte, 20) // ERROR "does not escape" s := string(b) // ERROR "string\(b\) does not escape" _ = s } func slicebytetostring1() { b := make([]byte, 20) // ERROR "does not escape" s := string(b) // ERROR "string\(b\) does not escape" s1 := s[0:1] _ = s1 } func slicebytetostring2() { b := make([]byte, 20) // ERROR "does not escape" s := string(b) // ERROR "string\(b\) escapes to heap" s1 := s[0:1] // ERROR "moved to heap: s1" sink = &s1 // ERROR "&s1 escapes to heap" } func slicebytetostring3() { b := make([]byte, 20) // ERROR "does not escape" s := string(b) // ERROR "string\(b\) escapes to heap" s1 := s[0:1] sink = s1 } func addstr0() { s0 := "a" s1 := "b" s := s0 + s1 // ERROR "s0 \+ s1 does not escape" _ = s } func addstr1() { s0 := "a" s1 := "b" s := "c" s += s0 + s1 // ERROR "s0 \+ s1 does not escape" _ = s } func addstr2() { b := make([]byte, 20) // ERROR "does not escape" s0 := "a" s := string(b) + s0 // ERROR "string\(b\) does not escape" "string\(b\) \+ s0 does not escape" _ = s } func addstr3() { s0 := "a" s1 := "b" s := s0 + s1 // ERROR "s0 \+ s1 escapes to heap" s2 := s[0:1] sink = s2 } func intstring0() bool { // string does not escape x := '0' s := string(x) // ERROR "string\(x\) does not escape" return s == "0" } func intstring1() string { // string does not escape, but the buffer does x := '0' s := string(x) // ERROR "string\(x\) escapes to heap" return s } func intstring2() { // string escapes to heap x := '0' s := string(x) // ERROR "string\(x\) escapes to heap" "moved to heap: s" sink = &s // ERROR "&s escapes to heap" }