gcc/testsuite/go.test/test/nilcheck.go

   1 // errorcheck -0 -N -d=nil
   2
   3 // Copyright 2013 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 that nil checks are inserted.
   8 // Optimization is disabled, so redundant checks are not removed.
   9
  10 package p
  11
  12 type Struct struct {
  13         X int
  14         Y float64
  15 }
  16
  17 type BigStruct struct {
  18         X int
  19         Y float64
  20         A [1<<20]int
  21         Z string
  22 }
  23
  24 type Empty struct {
  25 }
  26
  27 type Empty1 struct {
  28         Empty
  29 }
  30
  31 var (
  32         intp *int
  33         arrayp *[10]int
  34         array0p *[0]int
  35         bigarrayp *[1<<26]int
  36         structp *Struct
  37         bigstructp *BigStruct
  38         emptyp *Empty
  39         empty1p *Empty1
  40 )
  41
  42 func f1() {
  43         _ = *intp // ERROR "nil check"
  44         _ = *arrayp // ERROR "nil check"
  45         _ = *array0p // ERROR "nil check"
  46         _ = *array0p // ERROR "nil check"
  47         _ = *intp // ERROR "nil check"
  48         _ = *arrayp // ERROR "nil check"
  49         _ = *structp // ERROR "nil check"
  50         _ = *emptyp // ERROR "nil check"
  51         _ = *arrayp // ERROR "nil check"
  52 }
  53
  54 func f2() {
  55         var (
  56                 intp *int
  57                 arrayp *[10]int
  58                 array0p *[0]int
  59                 bigarrayp *[1<<20]int
  60                 structp *Struct
  61                 bigstructp *BigStruct
  62                 emptyp *Empty
  63                 empty1p *Empty1
  64         )
  65
  66         _ = *intp // ERROR "nil check"
  67         _ = *arrayp // ERROR "nil check"
  68         _ = *array0p // ERROR "nil check"
  69         _ = *array0p // ERROR "nil check"
  70         _ = *intp // ERROR "nil check"
  71         _ = *arrayp // ERROR "nil check"
  72         _ = *structp // ERROR "nil check"
  73         _ = *emptyp // ERROR "nil check"
  74         _ = *arrayp // ERROR "nil check"
  75         _ = *bigarrayp // ERROR "nil check"
  76         _ = *bigstructp // ERROR "nil check"
  77         _ = *empty1p // ERROR "nil check"
  78 }
  79
  80 func fx10k() *[10000]int
  81 var b bool
  82
  83
  84 func f3(x *[10000]int) {
  85         // Using a huge type and huge offsets so the compiler
  86         // does not expect the memory hardware to fault.
  87         _ = x[9999] // ERROR "nil check"
  88
  89         for {
  90                 if x[9999] != 0 { // ERROR "nil check"
  91                         break
  92                 }
  93         }
  94
  95         x = fx10k()
  96         _ = x[9999] // ERROR "nil check"
  97         if b {
  98                 _ = x[9999] // ERROR "nil check"
  99         } else {
 100                 _ = x[9999] // ERROR "nil check"
 101         }
 102         _ = x[9999] // ERROR "nil check"
 103
 104         x = fx10k()
 105         if b {
 106                 _ = x[9999] // ERROR "nil check"
 107         } else {
 108                 _ = x[9999] // ERROR "nil check"
 109         }
 110         _ = x[9999] // ERROR "nil check"
 111
 112         fx10k()
 113         // This one is a bit redundant, if we figured out that
 114         // x wasn't going to change across the function call.
 115         // But it's a little complex to do and in practice doesn't
 116         // matter enough.
 117         _ = x[9999] // ERROR "nil check"
 118 }
 119
 120 func f3a() {
 121         x := fx10k()
 122         y := fx10k()
 123         z := fx10k()
 124         _ = &x[9] // ERROR "nil check"
 125         y = z
 126         _ = &x[9] // ERROR "nil check"
 127         x = y
 128         _ = &x[9] // ERROR "nil check"
 129 }
 130
 131 func f3b() {
 132         x := fx10k()
 133         y := fx10k()
 134         _ = &x[9] // ERROR "nil check"
 135         y = x
 136         _ = &x[9] // ERROR "nil check"
 137         x = y
 138         _ = &x[9] // ERROR "nil check"
 139 }
 140
 141 func fx10() *[10]int
 142
 143 func f4(x *[10]int) {
 144         // Most of these have no checks because a real memory reference follows,
 145         // and the offset is small enough that if x is nil, the address will still be
 146         // in the first unmapped page of memory.
 147
 148         _ = x[9] // ERROR "nil check"
 149
 150         for {
 151                 if x[9] != 0 { // ERROR "nil check"
 152                         break
 153                 }
 154         }
 155
 156         x = fx10()
 157         _ = x[9] // ERROR "nil check"
 158         if b {
 159                 _ = x[9] // ERROR "nil check"
 160         } else {
 161                 _ = x[9] // ERROR "nil check"
 162         }
 163         _ = x[9] // ERROR "nil check"
 164
 165         x = fx10()
 166         if b {
 167                 _ = x[9] // ERROR "nil check"
 168         } else {
 169                 _ = &x[9] // ERROR "nil check"
 170         }
 171         _ = x[9] // ERROR "nil check"
 172
 173         fx10()
 174         _ = x[9] // ERROR "nil check"
 175
 176         x = fx10()
 177         y := fx10()
 178         _ = &x[9] // ERROR "nil check"
 179         y = x
 180         _ = &x[9] // ERROR "nil check"
 181         x = y
 182         _ = &x[9] // ERROR "nil check"
 183 }
 184