Source file test/nilptr3.go
Documentation: test
1 // errorcheck -0 -d=nil 2 3 // +build !wasm 4 // +build !aix 5 6 // Copyright 2013 The Go Authors. All rights reserved. 7 // Use of this source code is governed by a BSD-style 8 // license that can be found in the LICENSE file. 9 10 // Test that nil checks are removed. 11 // Optimization is enabled. 12 13 package p 14 15 type Struct struct { 16 X int 17 Y float64 18 } 19 20 type BigStruct struct { 21 X int 22 Y float64 23 A [1 << 20]int 24 Z string 25 } 26 27 type Empty struct { 28 } 29 30 type Empty1 struct { 31 Empty 32 } 33 34 var ( 35 intp *int 36 arrayp *[10]int 37 array0p *[0]int 38 bigarrayp *[1 << 26]int 39 structp *Struct 40 bigstructp *BigStruct 41 emptyp *Empty 42 empty1p *Empty1 43 ) 44 45 func f1() { 46 _ = *intp // ERROR "generated nil check" 47 48 // This one should be removed but the block copy needs 49 // to be turned into its own pseudo-op in order to see 50 // the indirect. 51 _ = *arrayp // ERROR "generated nil check" 52 53 // 0-byte indirect doesn't suffice. 54 // we don't registerize globals, so there are no removed.* nil checks. 55 _ = *array0p // ERROR "generated nil check" 56 _ = *array0p // ERROR "removed nil check" 57 58 _ = *intp // ERROR "removed nil check" 59 _ = *arrayp // ERROR "removed nil check" 60 _ = *structp // ERROR "generated nil check" 61 _ = *emptyp // ERROR "generated nil check" 62 _ = *arrayp // ERROR "removed nil check" 63 } 64 65 func f2() { 66 var ( 67 intp *int 68 arrayp *[10]int 69 array0p *[0]int 70 bigarrayp *[1 << 20]int 71 structp *Struct 72 bigstructp *BigStruct 73 emptyp *Empty 74 empty1p *Empty1 75 ) 76 77 _ = *intp // ERROR "generated nil check" 78 _ = *arrayp // ERROR "generated nil check" 79 _ = *array0p // ERROR "generated nil check" 80 _ = *array0p // ERROR "removed.* nil check" 81 _ = *intp // ERROR "removed.* nil check" 82 _ = *arrayp // ERROR "removed.* nil check" 83 _ = *structp // ERROR "generated nil check" 84 _ = *emptyp // ERROR "generated nil check" 85 _ = *arrayp // ERROR "removed.* nil check" 86 _ = *bigarrayp // ERROR "generated nil check" ARM removed nil check before indirect!! 87 _ = *bigstructp // ERROR "generated nil check" 88 _ = *empty1p // ERROR "generated nil check" 89 } 90 91 func fx10k() *[10000]int 92 93 var b bool 94 95 func f3(x *[10000]int) { 96 // Using a huge type and huge offsets so the compiler 97 // does not expect the memory hardware to fault. 98 _ = x[9999] // ERROR "generated nil check" 99 100 for { 101 if x[9999] != 0 { // ERROR "removed nil check" 102 break 103 } 104 } 105 106 x = fx10k() 107 _ = x[9999] // ERROR "generated nil check" 108 if b { 109 _ = x[9999] // ERROR "removed.* nil check" 110 } else { 111 _ = x[9999] // ERROR "removed.* nil check" 112 } 113 _ = x[9999] // ERROR "removed nil check" 114 115 x = fx10k() 116 if b { 117 _ = x[9999] // ERROR "generated nil check" 118 } else { 119 _ = x[9999] // ERROR "generated nil check" 120 } 121 _ = x[9999] // ERROR "generated nil check" 122 123 fx10k() 124 // This one is a bit redundant, if we figured out that 125 // x wasn't going to change across the function call. 126 // But it's a little complex to do and in practice doesn't 127 // matter enough. 128 _ = x[9999] // ERROR "removed nil check" 129 } 130 131 func f3a() { 132 x := fx10k() 133 y := fx10k() 134 z := fx10k() 135 _ = &x[9] // ERROR "generated nil check" 136 y = z 137 _ = &x[9] // ERROR "removed.* nil check" 138 x = y 139 _ = &x[9] // ERROR "generated nil check" 140 } 141 142 func f3b() { 143 x := fx10k() 144 y := fx10k() 145 _ = &x[9] // ERROR "generated nil check" 146 y = x 147 _ = &x[9] // ERROR "removed.* nil check" 148 x = y 149 _ = &x[9] // ERROR "removed.* nil check" 150 } 151 152 func fx10() *[10]int 153 154 func f4(x *[10]int) { 155 // Most of these have no checks because a real memory reference follows, 156 // and the offset is small enough that if x is nil, the address will still be 157 // in the first unmapped page of memory. 158 159 _ = x[9] // ERROR "generated nil check" // bug: would like to remove this check (but nilcheck and load are in different blocks) 160 161 for { 162 if x[9] != 0 { // ERROR "removed nil check" 163 break 164 } 165 } 166 167 x = fx10() 168 _ = x[9] // ERROR "generated nil check" // bug would like to remove before indirect 169 if b { 170 _ = x[9] // ERROR "removed nil check" 171 } else { 172 _ = x[9] // ERROR "removed nil check" 173 } 174 _ = x[9] // ERROR "removed nil check" 175 176 x = fx10() 177 if b { 178 _ = x[9] // ERROR "generated nil check" // bug would like to remove before indirect 179 } else { 180 _ = &x[9] // ERROR "generated nil check" 181 } 182 _ = x[9] // ERROR "generated nil check" // bug would like to remove before indirect 183 184 fx10() 185 _ = x[9] // ERROR "removed nil check" 186 187 x = fx10() 188 y := fx10() 189 _ = &x[9] // ERROR "generated nil check" 190 y = x 191 _ = &x[9] // ERROR "removed[a-z ]* nil check" 192 x = y 193 _ = &x[9] // ERROR "removed[a-z ]* nil check" 194 } 195 196 func m1(m map[int][80]byte) byte { 197 v := m[3] // ERROR "removed nil check" 198 return v[5] 199 } 200 func m2(m map[int][800]byte) byte { 201 v := m[3] // ERROR "removed nil check" 202 return v[5] 203 } 204 func m3(m map[int][80]byte) (byte, bool) { 205 v, ok := m[3] // ERROR "removed nil check" 206 return v[5], ok 207 } 208 func m4(m map[int][800]byte) (byte, bool) { 209 v, ok := m[3] // ERROR "removed nil check" 210 return v[5], ok 211 } 212 func p1() byte { 213 p := new([100]byte) 214 return p[5] // ERROR "removed nil check" 215 } 216 217 type SS struct { 218 x byte 219 } 220 221 type TT struct { 222 SS 223 } 224 225 func f(t *TT) *byte { 226 // See issue 17242. 227 s := &t.SS // ERROR "generated nil check" 228 return &s.x // ERROR "removed nil check" 229 } 230 231 // make sure not to do nil check for newobject 232 func f7() (*Struct, float64) { 233 t := new(Struct) 234 p := &t.Y // ERROR "removed nil check" 235 return t, *p // ERROR "removed nil check" 236 } 237 238 func f9() []int { 239 x := new([1]int) 240 x[0] = 1 // ERROR "removed nil check" 241 y := x[:] // ERROR "removed nil check" 242 return y 243 } 244