test/recover3.go

   1 // run
   2
   3 // Copyright 2010 The Go Authors. All rights reserved.
   4 // Use of this source code is governed by a BSD-style
   5 // license that can be found in the LICENSE file.
   6
   7 // Test recovering from runtime errors.
   8
   9 package main
  10
  11 import (
  12         "runtime"
  13         "strings"
  14 )
  15
  16 var didbug bool
  17
  18 func bug() {
  19         if didbug {
  20                 return
  21         }
  22         println("BUG")
  23         didbug = true
  24 }
  25
  26 func check(name string, f func(), err string) {
  27         defer func() {
  28                 v := recover()
  29                 if v == nil {
  30                         bug()
  31                         println(name, "did not panic")
  32                         return
  33                 }
  34                 runt, ok := v.(runtime.Error)
  35                 if !ok {
  36                         bug()
  37                         println(name, "panicked but not with runtime.Error")
  38                         return
  39                 }
  40                 s := runt.Error()
  41                 if strings.Index(s, err) < 0 {
  42                         bug()
  43                         println(name, "panicked with", s, "not", err)
  44                         return
  45                 }
  46         }()
  47
  48         f()
  49 }
  50
  51 func main() {
  52         var x int
  53         var x64 int64
  54         var p *[10]int
  55         var q *[10000]int
  56         var i int
  57
  58         check("int-div-zero", func() { println(1 / x) }, "integer divide by zero")
  59         check("int64-div-zero", func() { println(1 / x64) }, "integer divide by zero")
  60
  61         check("nil-deref", func() { println(p[0]) }, "nil pointer dereference")
  62         check("nil-deref-1", func() { println(p[1]) }, "nil pointer dereference")
  63         check("nil-deref-big", func() { println(q[5000]) }, "nil pointer dereference")
  64
  65         i = 99999
  66         var sl []int
  67         p1 := new([10]int)
  68         check("array-bounds", func() { println(p1[i]) }, "index out of range")
  69         check("slice-bounds", func() { println(sl[i]) }, "index out of range")
  70
  71         var inter interface{}
  72         inter = 1
  73         check("type-concrete", func() { println(inter.(string)) }, "int, not string")
  74         check("type-interface", func() { println(inter.(m)) }, "missing method m")
  75
  76         if didbug {
  77                 panic("recover3")
  78         }
  79 }
  80
  81 type m interface {
  82         m()
  83 }