// 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 // ERROR "m escapes to heap" } 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} // ERROR "&i does not escape" var x M = v // ERROR "v does not escape" _ = x } { i := 0 // ERROR "moved to heap: i" v := M0{&i} // ERROR "&i escapes to heap" var x M = v // ERROR "v escapes to heap" sink = x // ERROR "x escapes to heap" } { i := 0 v := M0{&i} // ERROR "&i does not escape" var x M = v // ERROR "v does not escape" v1 := x.(M0) _ = v1 } { i := 0 // ERROR "moved to heap: i" v := M0{&i} // ERROR "&i escapes to heap" // BAD: v does not escape to heap here var x M = v // ERROR "v escapes to heap" v1 := x.(M0) sink = v1 // ERROR "v1 escapes to heap" } { i := 0 // ERROR "moved to heap: i" v := M0{&i} // ERROR "&i escapes to heap" // BAD: v does not escape to heap here var x M = v // ERROR "v escapes to heap" x.M() } { i := 0 // ERROR "moved to heap: i" v := M0{&i} // ERROR "&i escapes to heap" var x M = v // ERROR "v escapes to heap" mescapes(x) } { i := 0 v := M0{&i} // ERROR "&i does not escape" var x M = v // ERROR "v does not escape" 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} // ERROR "&i does not escape" var x M = v // ERROR "v does not escape" _ = x } { i := 0 // ERROR "moved to heap: i" v := M1{&i, 0} // ERROR "&i escapes to heap" var x M = v // ERROR "v escapes to heap" sink = x // ERROR "x escapes to heap" } { i := 0 v := M1{&i, 0} // ERROR "&i does not escape" var x M = v // ERROR "v does not escape" v1 := x.(M1) _ = v1 } { i := 0 // ERROR "moved to heap: i" v := M1{&i, 0} // ERROR "&i escapes to heap" // BAD: v does not escape to heap here var x M = v // ERROR "v escapes to heap" v1 := x.(M1) sink = v1 // ERROR "v1 escapes to heap" } { i := 0 // ERROR "moved to heap: i" v := M1{&i, 0} // ERROR "&i escapes to heap" // BAD: v does not escape to heap here var x M = v // ERROR "v escapes to heap" x.M() } { i := 0 // ERROR "moved to heap: i" v := M1{&i, 0} // ERROR "&i escapes to heap" var x M = v // ERROR "v escapes to heap" mescapes(x) } { i := 0 v := M1{&i, 0} // ERROR "&i does not escape" 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 "&i does not escape" "&M2 literal does not escape" var x M = v // ERROR "v does not escape" _ = x } { i := 0 // ERROR "moved to heap: i" v := &M2{&i} // ERROR "&i escapes to heap" "&M2 literal escapes to heap" var x M = v // ERROR "v escapes to heap" sink = x // ERROR "x escapes to heap" } { i := 0 v := &M2{&i} // ERROR "&i does not escape" "&M2 literal does not escape" var x M = v // ERROR "v does not escape" v1 := x.(*M2) _ = v1 } { i := 0 // ERROR "moved to heap: i" v := &M2{&i} // ERROR "&i escapes to heap" "&M2 literal escapes to heap" // BAD: v does not escape to heap here var x M = v // ERROR "v escapes to heap" v1 := x.(*M2) sink = v1 // ERROR "v1 escapes to heap" } { i := 0 // ERROR "moved to heap: i" v := &M2{&i} // ERROR "&i escapes to heap" "&M2 literal does not escape" // BAD: v does not escape to heap here var x M = v // ERROR "v does not escape" v1 := x.(*M2) sink = *v1 // ERROR "v1 escapes to heap" } { i := 0 // ERROR "moved to heap: i" v := &M2{&i} // ERROR "&i escapes to heap" "&M2 literal does not escape" // BAD: v does not escape to heap here var x M = v // ERROR "v does not escape" v1, ok := x.(*M2) sink = *v1 // ERROR "v1 escapes to heap" _ = ok } { i := 0 // ERROR "moved to heap: i" v := &M2{&i} // ERROR "&i escapes to heap" "&M2 literal escapes to heap" // BAD: v does not escape to heap here var x M = v // ERROR "v escapes to heap" x.M() } { i := 0 // ERROR "moved to heap: i" v := &M2{&i} // ERROR "&i escapes to heap" "&M2 literal escapes to heap" var x M = v // ERROR "v escapes to heap" mescapes(x) } { i := 0 v := &M2{&i} // ERROR "&i does not escape" "&M2 literal does not escape" var x M = v // ERROR "v does not escape" mdoesnotescape(x) } }