| 1 | // This interpreter test is designed to run very quickly yet provide |
|---|---|
| 2 | // some coverage of a broad selection of constructs. |
| 3 | // |
| 4 | // Validate this file with 'go run' after editing. |
| 5 | // TODO(adonovan): break this into small files organized by theme. |
| 6 | |
| 7 | package main |
| 8 | |
| 9 | import ( |
| 10 | "fmt" |
| 11 | "reflect" |
| 12 | "strings" |
| 13 | ) |
| 14 | |
| 15 | func init() { |
| 16 | // Call of variadic function with (implicit) empty slice. |
| 17 | if x := fmt.Sprint(); x != "" { |
| 18 | panic(x) |
| 19 | } |
| 20 | } |
| 21 | |
| 22 | type empty interface{} |
| 23 | |
| 24 | type I interface { |
| 25 | f() int |
| 26 | } |
| 27 | |
| 28 | type T struct{ z int } |
| 29 | |
| 30 | func (t T) f() int { return t.z } |
| 31 | |
| 32 | func use(interface{}) {} |
| 33 | |
| 34 | var counter = 2 |
| 35 | |
| 36 | // Test initialization, including init blocks containing 'return'. |
| 37 | // Assertion is in main. |
| 38 | func init() { |
| 39 | counter *= 3 |
| 40 | return |
| 41 | counter *= 3 |
| 42 | } |
| 43 | |
| 44 | func init() { |
| 45 | counter *= 5 |
| 46 | return |
| 47 | counter *= 5 |
| 48 | } |
| 49 | |
| 50 | // Recursion. |
| 51 | func fib(x int) int { |
| 52 | if x < 2 { |
| 53 | return x |
| 54 | } |
| 55 | return fib(x-1) + fib(x-2) |
| 56 | } |
| 57 | |
| 58 | func fibgen(ch chan int) { |
| 59 | for x := 0; x < 10; x++ { |
| 60 | ch <- fib(x) |
| 61 | } |
| 62 | close(ch) |
| 63 | } |
| 64 | |
| 65 | // Goroutines and channels. |
| 66 | func init() { |
| 67 | ch := make(chan int) |
| 68 | go fibgen(ch) |
| 69 | var fibs []int |
| 70 | for v := range ch { |
| 71 | fibs = append(fibs, v) |
| 72 | if len(fibs) == 10 { |
| 73 | break |
| 74 | } |
| 75 | } |
| 76 | if x := fmt.Sprint(fibs); x != "[0 1 1 2 3 5 8 13 21 34]" { |
| 77 | panic(x) |
| 78 | } |
| 79 | } |
| 80 | |
| 81 | // Test of aliasing. |
| 82 | func init() { |
| 83 | type S struct { |
| 84 | a, b string |
| 85 | } |
| 86 | |
| 87 | s1 := []string{"foo", "bar"} |
| 88 | s2 := s1 // creates an alias |
| 89 | s2[0] = "wiz" |
| 90 | if x := fmt.Sprint(s1, s2); x != "[wiz bar] [wiz bar]" { |
| 91 | panic(x) |
| 92 | } |
| 93 | |
| 94 | pa1 := &[2]string{"foo", "bar"} |
| 95 | pa2 := pa1 // creates an alias |
| 96 | pa2[0] = "wiz" |
| 97 | if x := fmt.Sprint(*pa1, *pa2); x != "[wiz bar] [wiz bar]" { |
| 98 | panic(x) |
| 99 | } |
| 100 | |
| 101 | a1 := [2]string{"foo", "bar"} |
| 102 | a2 := a1 // creates a copy |
| 103 | a2[0] = "wiz" |
| 104 | if x := fmt.Sprint(a1, a2); x != "[foo bar] [wiz bar]" { |
| 105 | panic(x) |
| 106 | } |
| 107 | |
| 108 | t1 := S{"foo", "bar"} |
| 109 | t2 := t1 // copy |
| 110 | t2.a = "wiz" |
| 111 | if x := fmt.Sprint(t1, t2); x != "{foo bar} {wiz bar}" { |
| 112 | panic(x) |
| 113 | } |
| 114 | } |
| 115 | |
| 116 | func main() { |
| 117 | print() // legal |
| 118 | |
| 119 | if counter != 2*3*5 { |
| 120 | panic(counter) |
| 121 | } |
| 122 | |
| 123 | // Test builtins (e.g. complex) preserve named argument types. |
| 124 | type N complex128 |
| 125 | var n N |
| 126 | n = complex(1.0, 2.0) |
| 127 | if n != complex(1.0, 2.0) { |
| 128 | panic(n) |
| 129 | } |
| 130 | if x := reflect.TypeOf(n).String(); x != "main.N" { |
| 131 | panic(x) |
| 132 | } |
| 133 | if real(n) != 1.0 || imag(n) != 2.0 { |
| 134 | panic(n) |
| 135 | } |
| 136 | |
| 137 | // Channel + select. |
| 138 | ch := make(chan int, 1) |
| 139 | select { |
| 140 | case ch <- 1: |
| 141 | // ok |
| 142 | default: |
| 143 | panic("couldn't send") |
| 144 | } |
| 145 | if <-ch != 1 { |
| 146 | panic("couldn't receive") |
| 147 | } |
| 148 | // A "receive" select-case that doesn't declare its vars. (regression test) |
| 149 | anint := 0 |
| 150 | ok := false |
| 151 | select { |
| 152 | case anint, ok = <-ch: |
| 153 | case anint = <-ch: |
| 154 | default: |
| 155 | } |
| 156 | _ = anint |
| 157 | _ = ok |
| 158 | |
| 159 | // Anon structs with methods. |
| 160 | anon := struct{ T }{T: T{z: 1}} |
| 161 | if x := anon.f(); x != 1 { |
| 162 | panic(x) |
| 163 | } |
| 164 | var i I = anon |
| 165 | if x := i.f(); x != 1 { |
| 166 | panic(x) |
| 167 | } |
| 168 | // NB. precise output of reflect.Type.String is undefined. |
| 169 | if x := reflect.TypeOf(i).String(); x != "struct { main.T }" && x != "struct{main.T}" { |
| 170 | panic(x) |
| 171 | } |
| 172 | |
| 173 | // fmt. |
| 174 | const message = "Hello, World!" |
| 175 | if fmt.Sprint("Hello", ", ", "World", "!") != message { |
| 176 | panic("oops") |
| 177 | } |
| 178 | |
| 179 | // Type assertion. |
| 180 | type S struct { |
| 181 | f int |
| 182 | } |
| 183 | var e empty = S{f: 42} |
| 184 | switch v := e.(type) { |
| 185 | case S: |
| 186 | if v.f != 42 { |
| 187 | panic(v.f) |
| 188 | } |
| 189 | default: |
| 190 | panic(reflect.TypeOf(v)) |
| 191 | } |
| 192 | if i, ok := e.(I); ok { |
| 193 | panic(i) |
| 194 | } |
| 195 | |
| 196 | // Switch. |
| 197 | var x int |
| 198 | switch x { |
| 199 | case 1: |
| 200 | panic(x) |
| 201 | fallthrough |
| 202 | case 2, 3: |
| 203 | panic(x) |
| 204 | default: |
| 205 | // ok |
| 206 | } |
| 207 | // empty switch |
| 208 | switch { |
| 209 | } |
| 210 | // empty switch |
| 211 | switch { |
| 212 | default: |
| 213 | } |
| 214 | // empty switch |
| 215 | switch { |
| 216 | default: |
| 217 | fallthrough |
| 218 | case false: |
| 219 | } |
| 220 | |
| 221 | // string -> []rune conversion. |
| 222 | use([]rune("foo")) |
| 223 | |
| 224 | // Calls of form x.f(). |
| 225 | type S2 struct { |
| 226 | f func() int |
| 227 | } |
| 228 | S2{f: func() int { return 1 }}.f() // field is a func value |
| 229 | T{}.f() // method call |
| 230 | i.f() // interface method invocation |
| 231 | (interface { |
| 232 | f() int |
| 233 | }(T{})).f() // anon interface method invocation |
| 234 | |
| 235 | // Map lookup. |
| 236 | if v, ok := map[string]string{}["foo5"]; v != "" || ok { |
| 237 | panic("oops") |
| 238 | } |
| 239 | |
| 240 | // Regression test: implicit address-taken struct literal |
| 241 | // inside literal map element. |
| 242 | _ = map[int]*struct{}{0: {}} |
| 243 | } |
| 244 | |
| 245 | type mybool bool |
| 246 | |
| 247 | func (mybool) f() {} |
| 248 | |
| 249 | func init() { |
| 250 | type mybool bool |
| 251 | var b mybool |
| 252 | var i interface{} = b || b // result preserves types of operands |
| 253 | _ = i.(mybool) |
| 254 | |
| 255 | i = false && b // result preserves type of "typed" operand |
| 256 | _ = i.(mybool) |
| 257 | |
| 258 | i = b || true // result preserves type of "typed" operand |
| 259 | _ = i.(mybool) |
| 260 | } |
| 261 | |
| 262 | func init() { |
| 263 | var x, y int |
| 264 | var b mybool = x == y // x==y is an untyped bool |
| 265 | b.f() |
| 266 | } |
| 267 | |
| 268 | // Simple closures. |
| 269 | func init() { |
| 270 | b := 3 |
| 271 | f := func(a int) int { |
| 272 | return a + b |
| 273 | } |
| 274 | b++ |
| 275 | if x := f(1); x != 5 { // 1+4 == 5 |
| 276 | panic(x) |
| 277 | } |
| 278 | b++ |
| 279 | if x := f(2); x != 7 { // 2+5 == 7 |
| 280 | panic(x) |
| 281 | } |
| 282 | if b := f(1) < 16 || f(2) < 17; !b { |
| 283 | panic("oops") |
| 284 | } |
| 285 | } |
| 286 | |
| 287 | // Shifts. |
| 288 | func init() { |
| 289 | var i int64 = 1 |
| 290 | var u uint64 = 1 << 32 |
| 291 | if x := i << uint32(u); x != 1 { |
| 292 | panic(x) |
| 293 | } |
| 294 | if x := i << uint64(u); x != 0 { |
| 295 | panic(x) |
| 296 | } |
| 297 | } |
| 298 | |
| 299 | // Implicit conversion of delete() key operand. |
| 300 | func init() { |
| 301 | type I interface{} |
| 302 | m := make(map[I]bool) |
| 303 | m[1] = true |
| 304 | m[I(2)] = true |
| 305 | if len(m) != 2 { |
| 306 | panic(m) |
| 307 | } |
| 308 | delete(m, I(1)) |
| 309 | delete(m, 2) |
| 310 | if len(m) != 0 { |
| 311 | panic(m) |
| 312 | } |
| 313 | } |
| 314 | |
| 315 | // An I->I conversion always succeeds. |
| 316 | func init() { |
| 317 | var x I |
| 318 | if I(x) != I(nil) { |
| 319 | panic("I->I conversion failed") |
| 320 | } |
| 321 | } |
| 322 | |
| 323 | // An I->I type-assert fails iff the value is nil. |
| 324 | func init() { |
| 325 | defer func() { |
| 326 | r := fmt.Sprint(recover()) |
| 327 | // Exact error varies by toolchain. |
| 328 | if r != "runtime error: interface conversion: interface is nil, not main.I" && |
| 329 | r != "interface conversion: interface is nil, not main.I" { |
| 330 | panic("I->I type assertion succeeded for nil value") |
| 331 | } |
| 332 | }() |
| 333 | var x I |
| 334 | _ = x.(I) |
| 335 | } |
| 336 | |
| 337 | ////////////////////////////////////////////////////////////////////// |
| 338 | // Variadic bridge methods and interface thunks. |
| 339 | |
| 340 | type VT int |
| 341 | |
| 342 | var vcount = 0 |
| 343 | |
| 344 | func (VT) f(x int, y ...string) { |
| 345 | vcount++ |
| 346 | if x != 1 { |
| 347 | panic(x) |
| 348 | } |
| 349 | if len(y) != 2 || y[0] != "foo" || y[1] != "bar" { |
| 350 | panic(y) |
| 351 | } |
| 352 | } |
| 353 | |
| 354 | type VS struct { |
| 355 | VT |
| 356 | } |
| 357 | |
| 358 | type VI interface { |
| 359 | f(x int, y ...string) |
| 360 | } |
| 361 | |
| 362 | func init() { |
| 363 | foobar := []string{"foo", "bar"} |
| 364 | var s VS |
| 365 | s.f(1, "foo", "bar") |
| 366 | s.f(1, foobar...) |
| 367 | if vcount != 2 { |
| 368 | panic("s.f not called twice") |
| 369 | } |
| 370 | |
| 371 | fn := VI.f |
| 372 | fn(s, 1, "foo", "bar") |
| 373 | fn(s, 1, foobar...) |
| 374 | if vcount != 4 { |
| 375 | panic("I.f not called twice") |
| 376 | } |
| 377 | } |
| 378 | |
| 379 | // Multiple labels on same statement. |
| 380 | func multipleLabels() { |
| 381 | var trace []int |
| 382 | i := 0 |
| 383 | one: |
| 384 | two: |
| 385 | for ; i < 3; i++ { |
| 386 | trace = append(trace, i) |
| 387 | switch i { |
| 388 | case 0: |
| 389 | continue two |
| 390 | case 1: |
| 391 | i++ |
| 392 | goto one |
| 393 | case 2: |
| 394 | break two |
| 395 | } |
| 396 | } |
| 397 | if x := fmt.Sprint(trace); x != "[0 1 2]" { |
| 398 | panic(x) |
| 399 | } |
| 400 | } |
| 401 | |
| 402 | func init() { |
| 403 | multipleLabels() |
| 404 | } |
| 405 | |
| 406 | func init() { |
| 407 | // Struct equivalence ignores blank fields. |
| 408 | type s struct{ x, _, z int } |
| 409 | s1 := s{x: 1, z: 3} |
| 410 | s2 := s{x: 1, z: 3} |
| 411 | if s1 != s2 { |
| 412 | panic("not equal") |
| 413 | } |
| 414 | } |
| 415 | |
| 416 | func init() { |
| 417 | // A slice var can be compared to const []T nil. |
| 418 | var i interface{} = []string{"foo"} |
| 419 | var j interface{} = []string(nil) |
| 420 | if i.([]string) == nil { |
| 421 | panic("expected i non-nil") |
| 422 | } |
| 423 | if j.([]string) != nil { |
| 424 | panic("expected j nil") |
| 425 | } |
| 426 | // But two slices cannot be compared, even if one is nil. |
| 427 | defer func() { |
| 428 | r := fmt.Sprint(recover()) |
| 429 | if !(strings.Contains(r, "compar") && strings.Contains(r, "[]string")) { |
| 430 | panic("want panic from slice comparison, got " + r) |
| 431 | } |
| 432 | }() |
| 433 | _ = i == j // interface comparison recurses on types |
| 434 | } |
| 435 | |
| 436 | func init() { |
| 437 | // Regression test for SSA renaming bug. |
| 438 | var ints []int |
| 439 | for range "foo" { |
| 440 | var x int |
| 441 | x++ |
| 442 | ints = append(ints, x) |
| 443 | } |
| 444 | if fmt.Sprint(ints) != "[1 1 1]" { |
| 445 | panic(ints) |
| 446 | } |
| 447 | } |
| 448 | |
| 449 | // Regression test for issue 6949: |
| 450 | // []byte("foo") is not a constant since it allocates memory. |
| 451 | func init() { |
| 452 | var r string |
| 453 | for i, b := range "ABC" { |
| 454 | x := []byte("abc") |
| 455 | x[i] = byte(b) |
| 456 | r += string(x) |
| 457 | } |
| 458 | if r != "AbcaBcabC" { |
| 459 | panic(r) |
| 460 | } |
| 461 | } |
| 462 | |
| 463 | // Test of 3-operand x[lo:hi:max] slice. |
| 464 | func init() { |
| 465 | s := []int{0, 1, 2, 3} |
| 466 | lenCapLoHi := func(x []int) [4]int { return [4]int{len(x), cap(x), x[0], x[len(x)-1]} } |
| 467 | if got := lenCapLoHi(s[1:3]); got != [4]int{2, 3, 1, 2} { |
| 468 | panic(got) |
| 469 | } |
| 470 | if got := lenCapLoHi(s[1:3:3]); got != [4]int{2, 2, 1, 2} { |
| 471 | panic(got) |
| 472 | } |
| 473 | max := 3 |
| 474 | if "a"[0] == 'a' { |
| 475 | max = 2 // max is non-constant, even in SSA form |
| 476 | } |
| 477 | if got := lenCapLoHi(s[1:2:max]); got != [4]int{1, 1, 1, 1} { |
| 478 | panic(got) |
| 479 | } |
| 480 | } |
| 481 | |
| 482 | var one = 1 // not a constant |
| 483 | |
| 484 | // Test makeslice. |
| 485 | func init() { |
| 486 | check := func(s []string, wantLen, wantCap int) { |
| 487 | if len(s) != wantLen { |
| 488 | panic(len(s)) |
| 489 | } |
| 490 | if cap(s) != wantCap { |
| 491 | panic(cap(s)) |
| 492 | } |
| 493 | } |
| 494 | // SSA form: |
| 495 | check(make([]string, 10), 10, 10) // new([10]string)[:10] |
| 496 | check(make([]string, one), 1, 1) // make([]string, one, one) |
| 497 | check(make([]string, 0, 10), 0, 10) // new([10]string)[:0] |
| 498 | check(make([]string, 0, one), 0, 1) // make([]string, 0, one) |
| 499 | check(make([]string, one, 10), 1, 10) // new([10]string)[:one] |
| 500 | check(make([]string, one, one), 1, 1) // make([]string, one, one) |
| 501 | } |
| 502 | |
| 503 | // Test that a nice error is issued by indirection wrappers. |
| 504 | func init() { |
| 505 | var ptr *T |
| 506 | var i I = ptr |
| 507 | |
| 508 | defer func() { |
| 509 | r := fmt.Sprint(recover()) |
| 510 | // Exact error varies by toolchain: |
| 511 | if r != "runtime error: value method (main.T).f called using nil *main.T pointer" && |
| 512 | r != "value method (main.T).f called using nil *main.T pointer" { |
| 513 | panic("want panic from call with nil receiver, got " + r) |
| 514 | } |
| 515 | }() |
| 516 | i.f() |
| 517 | panic("unreachable") |
| 518 | } |
| 519 | |
| 520 | // Regression test for a subtle bug in which copying values would causes |
| 521 | // subcomponents of aggregate variables to change address, breaking |
| 522 | // aliases. |
| 523 | func init() { |
| 524 | type T struct{ f int } |
| 525 | var x T |
| 526 | p := &x.f |
| 527 | x = T{} |
| 528 | *p = 1 |
| 529 | if x.f != 1 { |
| 530 | panic("lost store") |
| 531 | } |
| 532 | if p != &x.f { |
| 533 | panic("unstable address") |
| 534 | } |
| 535 | } |
| 536 |
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