| 1 | // Copyright 2021 The Go Authors. All rights reserved. |
|---|---|
| 2 | // Use of this source code is governed by a BSD-style |
| 3 | // license that can be found in the LICENSE file. |
| 4 | |
| 5 | // go:build ignore |
| 6 | |
| 7 | package testdata |
| 8 | |
| 9 | type I interface { |
| 10 | foo() |
| 11 | } |
| 12 | |
| 13 | type A struct{} |
| 14 | |
| 15 | func (a A) foo() {} |
| 16 | |
| 17 | func recover1() { |
| 18 | print("only this recover should execute") |
| 19 | if r, ok := recover().(I); ok { |
| 20 | r.foo() |
| 21 | } |
| 22 | } |
| 23 | |
| 24 | func recover2() { |
| 25 | recover() |
| 26 | } |
| 27 | |
| 28 | func Baz(a A) { |
| 29 | defer recover1() |
| 30 | defer recover() |
| 31 | panic(a) |
| 32 | } |
| 33 | |
| 34 | // Relevant SSA: |
| 35 | // func recover1(): |
| 36 | // t0 = print("only this recover...":string) |
| 37 | // t1 = recover() |
| 38 | // t2 = typeassert,ok t1.(I) |
| 39 | // t3 = extract t2 #0 |
| 40 | // t4 = extract t2 #1 |
| 41 | // if t4 goto 1 else 2 |
| 42 | // 1: |
| 43 | // t5 = invoke t3.foo() |
| 44 | // jump 2 |
| 45 | // 2: |
| 46 | // return |
| 47 | // |
| 48 | // func recover2(): |
| 49 | // t0 = recover() |
| 50 | // return |
| 51 | // |
| 52 | // func Baz(i I): |
| 53 | // t0 = local A (a) |
| 54 | // *t0 = a |
| 55 | // defer recover1() |
| 56 | // defer recover() |
| 57 | // t1 = *t0 |
| 58 | // t2 = make interface{} <- A (t1) |
| 59 | // panic t2 |
| 60 | |
| 61 | // t2 argument to panic in Baz gets ultimately connected to recover |
| 62 | // registers t1 in recover1() and t0 in recover2(). |
| 63 | |
| 64 | // WANT: |
| 65 | // Panic -> Recover |
| 66 | // Local(t2) -> Panic |
| 67 | // Recover -> Local(t0), Local(t1) |
| 68 |