| 1 | // Copyright 2013 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 | package interp |
| 6 | |
| 7 | import ( |
| 8 | "bytes" |
| 9 | "fmt" |
| 10 | "go/constant" |
| 11 | "go/token" |
| 12 | "go/types" |
| 13 | "os" |
| 14 | "reflect" |
| 15 | "strings" |
| 16 | "sync" |
| 17 | "unsafe" |
| 18 | |
| 19 | "golang.org/x/tools/go/ssa" |
| 20 | ) |
| 21 | |
| 22 | // If the target program panics, the interpreter panics with this type. |
| 23 | type targetPanic struct { |
| 24 | v value |
| 25 | } |
| 26 | |
| 27 | func (p targetPanic) String() string { |
| 28 | return toString(p.v) |
| 29 | } |
| 30 | |
| 31 | // If the target program calls exit, the interpreter panics with this type. |
| 32 | type exitPanic int |
| 33 | |
| 34 | // constValue returns the value of the constant with the |
| 35 | // dynamic type tag appropriate for c.Type(). |
| 36 | func constValue(c *ssa.Const) value { |
| 37 | if c.Value == nil { |
| 38 | return zero(c.Type()) // typed zero |
| 39 | } |
| 40 | // c is not a type parameter so it's underlying type is basic. |
| 41 | |
| 42 | if t, ok := c.Type().Underlying().(*types.Basic); ok { |
| 43 | // TODO(adonovan): eliminate untyped constants from SSA form. |
| 44 | switch t.Kind() { |
| 45 | case types.Bool, types.UntypedBool: |
| 46 | return constant.BoolVal(c.Value) |
| 47 | case types.Int, types.UntypedInt: |
| 48 | // Assume sizeof(int) is same on host and target. |
| 49 | return int(c.Int64()) |
| 50 | case types.Int8: |
| 51 | return int8(c.Int64()) |
| 52 | case types.Int16: |
| 53 | return int16(c.Int64()) |
| 54 | case types.Int32, types.UntypedRune: |
| 55 | return int32(c.Int64()) |
| 56 | case types.Int64: |
| 57 | return c.Int64() |
| 58 | case types.Uint: |
| 59 | // Assume sizeof(uint) is same on host and target. |
| 60 | return uint(c.Uint64()) |
| 61 | case types.Uint8: |
| 62 | return uint8(c.Uint64()) |
| 63 | case types.Uint16: |
| 64 | return uint16(c.Uint64()) |
| 65 | case types.Uint32: |
| 66 | return uint32(c.Uint64()) |
| 67 | case types.Uint64: |
| 68 | return c.Uint64() |
| 69 | case types.Uintptr: |
| 70 | // Assume sizeof(uintptr) is same on host and target. |
| 71 | return uintptr(c.Uint64()) |
| 72 | case types.Float32: |
| 73 | return float32(c.Float64()) |
| 74 | case types.Float64, types.UntypedFloat: |
| 75 | return c.Float64() |
| 76 | case types.Complex64: |
| 77 | return complex64(c.Complex128()) |
| 78 | case types.Complex128, types.UntypedComplex: |
| 79 | return c.Complex128() |
| 80 | case types.String, types.UntypedString: |
| 81 | if c.Value.Kind() == constant.String { |
| 82 | return constant.StringVal(c.Value) |
| 83 | } |
| 84 | return string(rune(c.Int64())) |
| 85 | } |
| 86 | } |
| 87 | |
| 88 | panic(fmt.Sprintf("constValue: %s", c)) |
| 89 | } |
| 90 | |
| 91 | // fitsInt returns true if x fits in type int according to sizes. |
| 92 | func fitsInt(x int64, sizes types.Sizes) bool { |
| 93 | intSize := sizes.Sizeof(types.Typ[types.Int]) |
| 94 | if intSize < sizes.Sizeof(types.Typ[types.Int64]) { |
| 95 | maxInt := int64(1)<<(intSize-1) - 1 |
| 96 | minInt := -int64(1) << (intSize - 1) |
| 97 | return minInt <= x && x <= maxInt |
| 98 | } |
| 99 | return true |
| 100 | } |
| 101 | |
| 102 | // asInt64 converts x, which must be an integer, to an int64. |
| 103 | // |
| 104 | // Callers that need a value directly usable as an int should combine this with fitsInt(). |
| 105 | func asInt64(x value) int64 { |
| 106 | switch x := x.(type) { |
| 107 | case int: |
| 108 | return int64(x) |
| 109 | case int8: |
| 110 | return int64(x) |
| 111 | case int16: |
| 112 | return int64(x) |
| 113 | case int32: |
| 114 | return int64(x) |
| 115 | case int64: |
| 116 | return x |
| 117 | case uint: |
| 118 | return int64(x) |
| 119 | case uint8: |
| 120 | return int64(x) |
| 121 | case uint16: |
| 122 | return int64(x) |
| 123 | case uint32: |
| 124 | return int64(x) |
| 125 | case uint64: |
| 126 | return int64(x) |
| 127 | case uintptr: |
| 128 | return int64(x) |
| 129 | } |
| 130 | panic(fmt.Sprintf("cannot convert %T to int64", x)) |
| 131 | } |
| 132 | |
| 133 | // asUint64 converts x, which must be an unsigned integer, to a uint64 |
| 134 | // suitable for use as a bitwise shift count. |
| 135 | func asUint64(x value) uint64 { |
| 136 | switch x := x.(type) { |
| 137 | case uint: |
| 138 | return uint64(x) |
| 139 | case uint8: |
| 140 | return uint64(x) |
| 141 | case uint16: |
| 142 | return uint64(x) |
| 143 | case uint32: |
| 144 | return uint64(x) |
| 145 | case uint64: |
| 146 | return x |
| 147 | case uintptr: |
| 148 | return uint64(x) |
| 149 | } |
| 150 | panic(fmt.Sprintf("cannot convert %T to uint64", x)) |
| 151 | } |
| 152 | |
| 153 | // asUnsigned returns the value of x, which must be an integer type, as its equivalent unsigned type, |
| 154 | // and returns true if x is non-negative. |
| 155 | func asUnsigned(x value) (value, bool) { |
| 156 | switch x := x.(type) { |
| 157 | case int: |
| 158 | return uint(x), x >= 0 |
| 159 | case int8: |
| 160 | return uint8(x), x >= 0 |
| 161 | case int16: |
| 162 | return uint16(x), x >= 0 |
| 163 | case int32: |
| 164 | return uint32(x), x >= 0 |
| 165 | case int64: |
| 166 | return uint64(x), x >= 0 |
| 167 | case uint, uint8, uint32, uint64, uintptr: |
| 168 | return x, true |
| 169 | } |
| 170 | panic(fmt.Sprintf("cannot convert %T to unsigned", x)) |
| 171 | } |
| 172 | |
| 173 | // zero returns a new "zero" value of the specified type. |
| 174 | func zero(t types.Type) value { |
| 175 | switch t := t.(type) { |
| 176 | case *types.Basic: |
| 177 | if t.Kind() == types.UntypedNil { |
| 178 | panic("untyped nil has no zero value") |
| 179 | } |
| 180 | if t.Info()&types.IsUntyped != 0 { |
| 181 | // TODO(adonovan): make it an invariant that |
| 182 | // this is unreachable. Currently some |
| 183 | // constants have 'untyped' types when they |
| 184 | // should be defaulted by the typechecker. |
| 185 | t = types.Default(t).(*types.Basic) |
| 186 | } |
| 187 | switch t.Kind() { |
| 188 | case types.Bool: |
| 189 | return false |
| 190 | case types.Int: |
| 191 | return int(0) |
| 192 | case types.Int8: |
| 193 | return int8(0) |
| 194 | case types.Int16: |
| 195 | return int16(0) |
| 196 | case types.Int32: |
| 197 | return int32(0) |
| 198 | case types.Int64: |
| 199 | return int64(0) |
| 200 | case types.Uint: |
| 201 | return uint(0) |
| 202 | case types.Uint8: |
| 203 | return uint8(0) |
| 204 | case types.Uint16: |
| 205 | return uint16(0) |
| 206 | case types.Uint32: |
| 207 | return uint32(0) |
| 208 | case types.Uint64: |
| 209 | return uint64(0) |
| 210 | case types.Uintptr: |
| 211 | return uintptr(0) |
| 212 | case types.Float32: |
| 213 | return float32(0) |
| 214 | case types.Float64: |
| 215 | return float64(0) |
| 216 | case types.Complex64: |
| 217 | return complex64(0) |
| 218 | case types.Complex128: |
| 219 | return complex128(0) |
| 220 | case types.String: |
| 221 | return "" |
| 222 | case types.UnsafePointer: |
| 223 | return unsafe.Pointer(nil) |
| 224 | default: |
| 225 | panic(fmt.Sprint("zero for unexpected type:", t)) |
| 226 | } |
| 227 | case *types.Pointer: |
| 228 | return (*value)(nil) |
| 229 | case *types.Array: |
| 230 | a := make(array, t.Len()) |
| 231 | for i := range a { |
| 232 | a[i] = zero(t.Elem()) |
| 233 | } |
| 234 | return a |
| 235 | case *types.Named: |
| 236 | return zero(t.Underlying()) |
| 237 | case *types.Interface: |
| 238 | return iface{} // nil type, methodset and value |
| 239 | case *types.Slice: |
| 240 | return []value(nil) |
| 241 | case *types.Struct: |
| 242 | s := make(structure, t.NumFields()) |
| 243 | for i := range s { |
| 244 | s[i] = zero(t.Field(i).Type()) |
| 245 | } |
| 246 | return s |
| 247 | case *types.Tuple: |
| 248 | if t.Len() == 1 { |
| 249 | return zero(t.At(0).Type()) |
| 250 | } |
| 251 | s := make(tuple, t.Len()) |
| 252 | for i := range s { |
| 253 | s[i] = zero(t.At(i).Type()) |
| 254 | } |
| 255 | return s |
| 256 | case *types.Chan: |
| 257 | return chan value(nil) |
| 258 | case *types.Map: |
| 259 | if usesBuiltinMap(t.Key()) { |
| 260 | return map[value]value(nil) |
| 261 | } |
| 262 | return (*hashmap)(nil) |
| 263 | case *types.Signature: |
| 264 | return (*ssa.Function)(nil) |
| 265 | } |
| 266 | panic(fmt.Sprint("zero: unexpected ", t)) |
| 267 | } |
| 268 | |
| 269 | // slice returns x[lo:hi:max]. Any of lo, hi and max may be nil. |
| 270 | func slice(x, lo, hi, max value) value { |
| 271 | var Len, Cap int |
| 272 | switch x := x.(type) { |
| 273 | case string: |
| 274 | Len = len(x) |
| 275 | case []value: |
| 276 | Len = len(x) |
| 277 | Cap = cap(x) |
| 278 | case *value: // *array |
| 279 | a := (*x).(array) |
| 280 | Len = len(a) |
| 281 | Cap = cap(a) |
| 282 | } |
| 283 | |
| 284 | l := int64(0) |
| 285 | if lo != nil { |
| 286 | l = asInt64(lo) |
| 287 | } |
| 288 | |
| 289 | h := int64(Len) |
| 290 | if hi != nil { |
| 291 | h = asInt64(hi) |
| 292 | } |
| 293 | |
| 294 | m := int64(Cap) |
| 295 | if max != nil { |
| 296 | m = asInt64(max) |
| 297 | } |
| 298 | |
| 299 | switch x := x.(type) { |
| 300 | case string: |
| 301 | return x[l:h] |
| 302 | case []value: |
| 303 | return x[l:h:m] |
| 304 | case *value: // *array |
| 305 | a := (*x).(array) |
| 306 | return []value(a)[l:h:m] |
| 307 | } |
| 308 | panic(fmt.Sprintf("slice: unexpected X type: %T", x)) |
| 309 | } |
| 310 | |
| 311 | // lookup returns x[idx] where x is a map. |
| 312 | func lookup(instr *ssa.Lookup, x, idx value) value { |
| 313 | switch x := x.(type) { // map or string |
| 314 | case map[value]value, *hashmap: |
| 315 | var v value |
| 316 | var ok bool |
| 317 | switch x := x.(type) { |
| 318 | case map[value]value: |
| 319 | v, ok = x[idx] |
| 320 | case *hashmap: |
| 321 | v = x.lookup(idx.(hashable)) |
| 322 | ok = v != nil |
| 323 | } |
| 324 | if !ok { |
| 325 | v = zero(instr.X.Type().Underlying().(*types.Map).Elem()) |
| 326 | } |
| 327 | if instr.CommaOk { |
| 328 | v = tuple{v, ok} |
| 329 | } |
| 330 | return v |
| 331 | } |
| 332 | panic(fmt.Sprintf("unexpected x type in Lookup: %T", x)) |
| 333 | } |
| 334 | |
| 335 | // binop implements all arithmetic and logical binary operators for |
| 336 | // numeric datatypes and strings. Both operands must have identical |
| 337 | // dynamic type. |
| 338 | func binop(op token.Token, t types.Type, x, y value) value { |
| 339 | switch op { |
| 340 | case token.ADD: |
| 341 | switch x.(type) { |
| 342 | case int: |
| 343 | return x.(int) + y.(int) |
| 344 | case int8: |
| 345 | return x.(int8) + y.(int8) |
| 346 | case int16: |
| 347 | return x.(int16) + y.(int16) |
| 348 | case int32: |
| 349 | return x.(int32) + y.(int32) |
| 350 | case int64: |
| 351 | return x.(int64) + y.(int64) |
| 352 | case uint: |
| 353 | return x.(uint) + y.(uint) |
| 354 | case uint8: |
| 355 | return x.(uint8) + y.(uint8) |
| 356 | case uint16: |
| 357 | return x.(uint16) + y.(uint16) |
| 358 | case uint32: |
| 359 | return x.(uint32) + y.(uint32) |
| 360 | case uint64: |
| 361 | return x.(uint64) + y.(uint64) |
| 362 | case uintptr: |
| 363 | return x.(uintptr) + y.(uintptr) |
| 364 | case float32: |
| 365 | return x.(float32) + y.(float32) |
| 366 | case float64: |
| 367 | return x.(float64) + y.(float64) |
| 368 | case complex64: |
| 369 | return x.(complex64) + y.(complex64) |
| 370 | case complex128: |
| 371 | return x.(complex128) + y.(complex128) |
| 372 | case string: |
| 373 | return x.(string) + y.(string) |
| 374 | } |
| 375 | |
| 376 | case token.SUB: |
| 377 | switch x.(type) { |
| 378 | case int: |
| 379 | return x.(int) - y.(int) |
| 380 | case int8: |
| 381 | return x.(int8) - y.(int8) |
| 382 | case int16: |
| 383 | return x.(int16) - y.(int16) |
| 384 | case int32: |
| 385 | return x.(int32) - y.(int32) |
| 386 | case int64: |
| 387 | return x.(int64) - y.(int64) |
| 388 | case uint: |
| 389 | return x.(uint) - y.(uint) |
| 390 | case uint8: |
| 391 | return x.(uint8) - y.(uint8) |
| 392 | case uint16: |
| 393 | return x.(uint16) - y.(uint16) |
| 394 | case uint32: |
| 395 | return x.(uint32) - y.(uint32) |
| 396 | case uint64: |
| 397 | return x.(uint64) - y.(uint64) |
| 398 | case uintptr: |
| 399 | return x.(uintptr) - y.(uintptr) |
| 400 | case float32: |
| 401 | return x.(float32) - y.(float32) |
| 402 | case float64: |
| 403 | return x.(float64) - y.(float64) |
| 404 | case complex64: |
| 405 | return x.(complex64) - y.(complex64) |
| 406 | case complex128: |
| 407 | return x.(complex128) - y.(complex128) |
| 408 | } |
| 409 | |
| 410 | case token.MUL: |
| 411 | switch x.(type) { |
| 412 | case int: |
| 413 | return x.(int) * y.(int) |
| 414 | case int8: |
| 415 | return x.(int8) * y.(int8) |
| 416 | case int16: |
| 417 | return x.(int16) * y.(int16) |
| 418 | case int32: |
| 419 | return x.(int32) * y.(int32) |
| 420 | case int64: |
| 421 | return x.(int64) * y.(int64) |
| 422 | case uint: |
| 423 | return x.(uint) * y.(uint) |
| 424 | case uint8: |
| 425 | return x.(uint8) * y.(uint8) |
| 426 | case uint16: |
| 427 | return x.(uint16) * y.(uint16) |
| 428 | case uint32: |
| 429 | return x.(uint32) * y.(uint32) |
| 430 | case uint64: |
| 431 | return x.(uint64) * y.(uint64) |
| 432 | case uintptr: |
| 433 | return x.(uintptr) * y.(uintptr) |
| 434 | case float32: |
| 435 | return x.(float32) * y.(float32) |
| 436 | case float64: |
| 437 | return x.(float64) * y.(float64) |
| 438 | case complex64: |
| 439 | return x.(complex64) * y.(complex64) |
| 440 | case complex128: |
| 441 | return x.(complex128) * y.(complex128) |
| 442 | } |
| 443 | |
| 444 | case token.QUO: |
| 445 | switch x.(type) { |
| 446 | case int: |
| 447 | return x.(int) / y.(int) |
| 448 | case int8: |
| 449 | return x.(int8) / y.(int8) |
| 450 | case int16: |
| 451 | return x.(int16) / y.(int16) |
| 452 | case int32: |
| 453 | return x.(int32) / y.(int32) |
| 454 | case int64: |
| 455 | return x.(int64) / y.(int64) |
| 456 | case uint: |
| 457 | return x.(uint) / y.(uint) |
| 458 | case uint8: |
| 459 | return x.(uint8) / y.(uint8) |
| 460 | case uint16: |
| 461 | return x.(uint16) / y.(uint16) |
| 462 | case uint32: |
| 463 | return x.(uint32) / y.(uint32) |
| 464 | case uint64: |
| 465 | return x.(uint64) / y.(uint64) |
| 466 | case uintptr: |
| 467 | return x.(uintptr) / y.(uintptr) |
| 468 | case float32: |
| 469 | return x.(float32) / y.(float32) |
| 470 | case float64: |
| 471 | return x.(float64) / y.(float64) |
| 472 | case complex64: |
| 473 | return x.(complex64) / y.(complex64) |
| 474 | case complex128: |
| 475 | return x.(complex128) / y.(complex128) |
| 476 | } |
| 477 | |
| 478 | case token.REM: |
| 479 | switch x.(type) { |
| 480 | case int: |
| 481 | return x.(int) % y.(int) |
| 482 | case int8: |
| 483 | return x.(int8) % y.(int8) |
| 484 | case int16: |
| 485 | return x.(int16) % y.(int16) |
| 486 | case int32: |
| 487 | return x.(int32) % y.(int32) |
| 488 | case int64: |
| 489 | return x.(int64) % y.(int64) |
| 490 | case uint: |
| 491 | return x.(uint) % y.(uint) |
| 492 | case uint8: |
| 493 | return x.(uint8) % y.(uint8) |
| 494 | case uint16: |
| 495 | return x.(uint16) % y.(uint16) |
| 496 | case uint32: |
| 497 | return x.(uint32) % y.(uint32) |
| 498 | case uint64: |
| 499 | return x.(uint64) % y.(uint64) |
| 500 | case uintptr: |
| 501 | return x.(uintptr) % y.(uintptr) |
| 502 | } |
| 503 | |
| 504 | case token.AND: |
| 505 | switch x.(type) { |
| 506 | case int: |
| 507 | return x.(int) & y.(int) |
| 508 | case int8: |
| 509 | return x.(int8) & y.(int8) |
| 510 | case int16: |
| 511 | return x.(int16) & y.(int16) |
| 512 | case int32: |
| 513 | return x.(int32) & y.(int32) |
| 514 | case int64: |
| 515 | return x.(int64) & y.(int64) |
| 516 | case uint: |
| 517 | return x.(uint) & y.(uint) |
| 518 | case uint8: |
| 519 | return x.(uint8) & y.(uint8) |
| 520 | case uint16: |
| 521 | return x.(uint16) & y.(uint16) |
| 522 | case uint32: |
| 523 | return x.(uint32) & y.(uint32) |
| 524 | case uint64: |
| 525 | return x.(uint64) & y.(uint64) |
| 526 | case uintptr: |
| 527 | return x.(uintptr) & y.(uintptr) |
| 528 | } |
| 529 | |
| 530 | case token.OR: |
| 531 | switch x.(type) { |
| 532 | case int: |
| 533 | return x.(int) | y.(int) |
| 534 | case int8: |
| 535 | return x.(int8) | y.(int8) |
| 536 | case int16: |
| 537 | return x.(int16) | y.(int16) |
| 538 | case int32: |
| 539 | return x.(int32) | y.(int32) |
| 540 | case int64: |
| 541 | return x.(int64) | y.(int64) |
| 542 | case uint: |
| 543 | return x.(uint) | y.(uint) |
| 544 | case uint8: |
| 545 | return x.(uint8) | y.(uint8) |
| 546 | case uint16: |
| 547 | return x.(uint16) | y.(uint16) |
| 548 | case uint32: |
| 549 | return x.(uint32) | y.(uint32) |
| 550 | case uint64: |
| 551 | return x.(uint64) | y.(uint64) |
| 552 | case uintptr: |
| 553 | return x.(uintptr) | y.(uintptr) |
| 554 | } |
| 555 | |
| 556 | case token.XOR: |
| 557 | switch x.(type) { |
| 558 | case int: |
| 559 | return x.(int) ^ y.(int) |
| 560 | case int8: |
| 561 | return x.(int8) ^ y.(int8) |
| 562 | case int16: |
| 563 | return x.(int16) ^ y.(int16) |
| 564 | case int32: |
| 565 | return x.(int32) ^ y.(int32) |
| 566 | case int64: |
| 567 | return x.(int64) ^ y.(int64) |
| 568 | case uint: |
| 569 | return x.(uint) ^ y.(uint) |
| 570 | case uint8: |
| 571 | return x.(uint8) ^ y.(uint8) |
| 572 | case uint16: |
| 573 | return x.(uint16) ^ y.(uint16) |
| 574 | case uint32: |
| 575 | return x.(uint32) ^ y.(uint32) |
| 576 | case uint64: |
| 577 | return x.(uint64) ^ y.(uint64) |
| 578 | case uintptr: |
| 579 | return x.(uintptr) ^ y.(uintptr) |
| 580 | } |
| 581 | |
| 582 | case token.AND_NOT: |
| 583 | switch x.(type) { |
| 584 | case int: |
| 585 | return x.(int) &^ y.(int) |
| 586 | case int8: |
| 587 | return x.(int8) &^ y.(int8) |
| 588 | case int16: |
| 589 | return x.(int16) &^ y.(int16) |
| 590 | case int32: |
| 591 | return x.(int32) &^ y.(int32) |
| 592 | case int64: |
| 593 | return x.(int64) &^ y.(int64) |
| 594 | case uint: |
| 595 | return x.(uint) &^ y.(uint) |
| 596 | case uint8: |
| 597 | return x.(uint8) &^ y.(uint8) |
| 598 | case uint16: |
| 599 | return x.(uint16) &^ y.(uint16) |
| 600 | case uint32: |
| 601 | return x.(uint32) &^ y.(uint32) |
| 602 | case uint64: |
| 603 | return x.(uint64) &^ y.(uint64) |
| 604 | case uintptr: |
| 605 | return x.(uintptr) &^ y.(uintptr) |
| 606 | } |
| 607 | |
| 608 | case token.SHL: |
| 609 | u, ok := asUnsigned(y) |
| 610 | if !ok { |
| 611 | panic("negative shift amount") |
| 612 | } |
| 613 | y := asUint64(u) |
| 614 | switch x.(type) { |
| 615 | case int: |
| 616 | return x.(int) << y |
| 617 | case int8: |
| 618 | return x.(int8) << y |
| 619 | case int16: |
| 620 | return x.(int16) << y |
| 621 | case int32: |
| 622 | return x.(int32) << y |
| 623 | case int64: |
| 624 | return x.(int64) << y |
| 625 | case uint: |
| 626 | return x.(uint) << y |
| 627 | case uint8: |
| 628 | return x.(uint8) << y |
| 629 | case uint16: |
| 630 | return x.(uint16) << y |
| 631 | case uint32: |
| 632 | return x.(uint32) << y |
| 633 | case uint64: |
| 634 | return x.(uint64) << y |
| 635 | case uintptr: |
| 636 | return x.(uintptr) << y |
| 637 | } |
| 638 | |
| 639 | case token.SHR: |
| 640 | u, ok := asUnsigned(y) |
| 641 | if !ok { |
| 642 | panic("negative shift amount") |
| 643 | } |
| 644 | y := asUint64(u) |
| 645 | switch x.(type) { |
| 646 | case int: |
| 647 | return x.(int) >> y |
| 648 | case int8: |
| 649 | return x.(int8) >> y |
| 650 | case int16: |
| 651 | return x.(int16) >> y |
| 652 | case int32: |
| 653 | return x.(int32) >> y |
| 654 | case int64: |
| 655 | return x.(int64) >> y |
| 656 | case uint: |
| 657 | return x.(uint) >> y |
| 658 | case uint8: |
| 659 | return x.(uint8) >> y |
| 660 | case uint16: |
| 661 | return x.(uint16) >> y |
| 662 | case uint32: |
| 663 | return x.(uint32) >> y |
| 664 | case uint64: |
| 665 | return x.(uint64) >> y |
| 666 | case uintptr: |
| 667 | return x.(uintptr) >> y |
| 668 | } |
| 669 | |
| 670 | case token.LSS: |
| 671 | switch x.(type) { |
| 672 | case int: |
| 673 | return x.(int) < y.(int) |
| 674 | case int8: |
| 675 | return x.(int8) < y.(int8) |
| 676 | case int16: |
| 677 | return x.(int16) < y.(int16) |
| 678 | case int32: |
| 679 | return x.(int32) < y.(int32) |
| 680 | case int64: |
| 681 | return x.(int64) < y.(int64) |
| 682 | case uint: |
| 683 | return x.(uint) < y.(uint) |
| 684 | case uint8: |
| 685 | return x.(uint8) < y.(uint8) |
| 686 | case uint16: |
| 687 | return x.(uint16) < y.(uint16) |
| 688 | case uint32: |
| 689 | return x.(uint32) < y.(uint32) |
| 690 | case uint64: |
| 691 | return x.(uint64) < y.(uint64) |
| 692 | case uintptr: |
| 693 | return x.(uintptr) < y.(uintptr) |
| 694 | case float32: |
| 695 | return x.(float32) < y.(float32) |
| 696 | case float64: |
| 697 | return x.(float64) < y.(float64) |
| 698 | case string: |
| 699 | return x.(string) < y.(string) |
| 700 | } |
| 701 | |
| 702 | case token.LEQ: |
| 703 | switch x.(type) { |
| 704 | case int: |
| 705 | return x.(int) <= y.(int) |
| 706 | case int8: |
| 707 | return x.(int8) <= y.(int8) |
| 708 | case int16: |
| 709 | return x.(int16) <= y.(int16) |
| 710 | case int32: |
| 711 | return x.(int32) <= y.(int32) |
| 712 | case int64: |
| 713 | return x.(int64) <= y.(int64) |
| 714 | case uint: |
| 715 | return x.(uint) <= y.(uint) |
| 716 | case uint8: |
| 717 | return x.(uint8) <= y.(uint8) |
| 718 | case uint16: |
| 719 | return x.(uint16) <= y.(uint16) |
| 720 | case uint32: |
| 721 | return x.(uint32) <= y.(uint32) |
| 722 | case uint64: |
| 723 | return x.(uint64) <= y.(uint64) |
| 724 | case uintptr: |
| 725 | return x.(uintptr) <= y.(uintptr) |
| 726 | case float32: |
| 727 | return x.(float32) <= y.(float32) |
| 728 | case float64: |
| 729 | return x.(float64) <= y.(float64) |
| 730 | case string: |
| 731 | return x.(string) <= y.(string) |
| 732 | } |
| 733 | |
| 734 | case token.EQL: |
| 735 | return eqnil(t, x, y) |
| 736 | |
| 737 | case token.NEQ: |
| 738 | return !eqnil(t, x, y) |
| 739 | |
| 740 | case token.GTR: |
| 741 | switch x.(type) { |
| 742 | case int: |
| 743 | return x.(int) > y.(int) |
| 744 | case int8: |
| 745 | return x.(int8) > y.(int8) |
| 746 | case int16: |
| 747 | return x.(int16) > y.(int16) |
| 748 | case int32: |
| 749 | return x.(int32) > y.(int32) |
| 750 | case int64: |
| 751 | return x.(int64) > y.(int64) |
| 752 | case uint: |
| 753 | return x.(uint) > y.(uint) |
| 754 | case uint8: |
| 755 | return x.(uint8) > y.(uint8) |
| 756 | case uint16: |
| 757 | return x.(uint16) > y.(uint16) |
| 758 | case uint32: |
| 759 | return x.(uint32) > y.(uint32) |
| 760 | case uint64: |
| 761 | return x.(uint64) > y.(uint64) |
| 762 | case uintptr: |
| 763 | return x.(uintptr) > y.(uintptr) |
| 764 | case float32: |
| 765 | return x.(float32) > y.(float32) |
| 766 | case float64: |
| 767 | return x.(float64) > y.(float64) |
| 768 | case string: |
| 769 | return x.(string) > y.(string) |
| 770 | } |
| 771 | |
| 772 | case token.GEQ: |
| 773 | switch x.(type) { |
| 774 | case int: |
| 775 | return x.(int) >= y.(int) |
| 776 | case int8: |
| 777 | return x.(int8) >= y.(int8) |
| 778 | case int16: |
| 779 | return x.(int16) >= y.(int16) |
| 780 | case int32: |
| 781 | return x.(int32) >= y.(int32) |
| 782 | case int64: |
| 783 | return x.(int64) >= y.(int64) |
| 784 | case uint: |
| 785 | return x.(uint) >= y.(uint) |
| 786 | case uint8: |
| 787 | return x.(uint8) >= y.(uint8) |
| 788 | case uint16: |
| 789 | return x.(uint16) >= y.(uint16) |
| 790 | case uint32: |
| 791 | return x.(uint32) >= y.(uint32) |
| 792 | case uint64: |
| 793 | return x.(uint64) >= y.(uint64) |
| 794 | case uintptr: |
| 795 | return x.(uintptr) >= y.(uintptr) |
| 796 | case float32: |
| 797 | return x.(float32) >= y.(float32) |
| 798 | case float64: |
| 799 | return x.(float64) >= y.(float64) |
| 800 | case string: |
| 801 | return x.(string) >= y.(string) |
| 802 | } |
| 803 | } |
| 804 | panic(fmt.Sprintf("invalid binary op: %T %s %T", x, op, y)) |
| 805 | } |
| 806 | |
| 807 | // eqnil returns the comparison x == y using the equivalence relation |
| 808 | // appropriate for type t. |
| 809 | // If t is a reference type, at most one of x or y may be a nil value |
| 810 | // of that type. |
| 811 | func eqnil(t types.Type, x, y value) bool { |
| 812 | switch t.Underlying().(type) { |
| 813 | case *types.Map, *types.Signature, *types.Slice: |
| 814 | // Since these types don't support comparison, |
| 815 | // one of the operands must be a literal nil. |
| 816 | switch x := x.(type) { |
| 817 | case *hashmap: |
| 818 | return (x != nil) == (y.(*hashmap) != nil) |
| 819 | case map[value]value: |
| 820 | return (x != nil) == (y.(map[value]value) != nil) |
| 821 | case *ssa.Function: |
| 822 | switch y := y.(type) { |
| 823 | case *ssa.Function: |
| 824 | return (x != nil) == (y != nil) |
| 825 | case *closure: |
| 826 | return true |
| 827 | } |
| 828 | case *closure: |
| 829 | return (x != nil) == (y.(*ssa.Function) != nil) |
| 830 | case []value: |
| 831 | return (x != nil) == (y.([]value) != nil) |
| 832 | } |
| 833 | panic(fmt.Sprintf("eqnil(%s): illegal dynamic type: %T", t, x)) |
| 834 | } |
| 835 | |
| 836 | return equals(t, x, y) |
| 837 | } |
| 838 | |
| 839 | func unop(instr *ssa.UnOp, x value) value { |
| 840 | switch instr.Op { |
| 841 | case token.ARROW: // receive |
| 842 | v, ok := <-x.(chan value) |
| 843 | if !ok { |
| 844 | v = zero(instr.X.Type().Underlying().(*types.Chan).Elem()) |
| 845 | } |
| 846 | if instr.CommaOk { |
| 847 | v = tuple{v, ok} |
| 848 | } |
| 849 | return v |
| 850 | case token.SUB: |
| 851 | switch x := x.(type) { |
| 852 | case int: |
| 853 | return -x |
| 854 | case int8: |
| 855 | return -x |
| 856 | case int16: |
| 857 | return -x |
| 858 | case int32: |
| 859 | return -x |
| 860 | case int64: |
| 861 | return -x |
| 862 | case uint: |
| 863 | return -x |
| 864 | case uint8: |
| 865 | return -x |
| 866 | case uint16: |
| 867 | return -x |
| 868 | case uint32: |
| 869 | return -x |
| 870 | case uint64: |
| 871 | return -x |
| 872 | case uintptr: |
| 873 | return -x |
| 874 | case float32: |
| 875 | return -x |
| 876 | case float64: |
| 877 | return -x |
| 878 | case complex64: |
| 879 | return -x |
| 880 | case complex128: |
| 881 | return -x |
| 882 | } |
| 883 | case token.MUL: |
| 884 | return load(deref(instr.X.Type()), x.(*value)) |
| 885 | case token.NOT: |
| 886 | return !x.(bool) |
| 887 | case token.XOR: |
| 888 | switch x := x.(type) { |
| 889 | case int: |
| 890 | return ^x |
| 891 | case int8: |
| 892 | return ^x |
| 893 | case int16: |
| 894 | return ^x |
| 895 | case int32: |
| 896 | return ^x |
| 897 | case int64: |
| 898 | return ^x |
| 899 | case uint: |
| 900 | return ^x |
| 901 | case uint8: |
| 902 | return ^x |
| 903 | case uint16: |
| 904 | return ^x |
| 905 | case uint32: |
| 906 | return ^x |
| 907 | case uint64: |
| 908 | return ^x |
| 909 | case uintptr: |
| 910 | return ^x |
| 911 | } |
| 912 | } |
| 913 | panic(fmt.Sprintf("invalid unary op %s %T", instr.Op, x)) |
| 914 | } |
| 915 | |
| 916 | // typeAssert checks whether dynamic type of itf is instr.AssertedType. |
| 917 | // It returns the extracted value on success, and panics on failure, |
| 918 | // unless instr.CommaOk, in which case it always returns a "value,ok" tuple. |
| 919 | func typeAssert(i *interpreter, instr *ssa.TypeAssert, itf iface) value { |
| 920 | var v value |
| 921 | err := "" |
| 922 | if itf.t == nil { |
| 923 | err = fmt.Sprintf("interface conversion: interface is nil, not %s", instr.AssertedType) |
| 924 | |
| 925 | } else if idst, ok := instr.AssertedType.Underlying().(*types.Interface); ok { |
| 926 | v = itf |
| 927 | err = checkInterface(i, idst, itf) |
| 928 | |
| 929 | } else if types.Identical(itf.t, instr.AssertedType) { |
| 930 | v = itf.v // extract value |
| 931 | |
| 932 | } else { |
| 933 | err = fmt.Sprintf("interface conversion: interface is %s, not %s", itf.t, instr.AssertedType) |
| 934 | } |
| 935 | |
| 936 | if err != "" { |
| 937 | if !instr.CommaOk { |
| 938 | panic(err) |
| 939 | } |
| 940 | return tuple{zero(instr.AssertedType), false} |
| 941 | } |
| 942 | if instr.CommaOk { |
| 943 | return tuple{v, true} |
| 944 | } |
| 945 | return v |
| 946 | } |
| 947 | |
| 948 | // If CapturedOutput is non-nil, all writes by the interpreted program |
| 949 | // to file descriptors 1 and 2 will also be written to CapturedOutput. |
| 950 | // |
| 951 | // (The $GOROOT/test system requires that the test be considered a |
| 952 | // failure if "BUG" appears in the combined stdout/stderr output, even |
| 953 | // if it exits zero. This is a global variable shared by all |
| 954 | // interpreters in the same process.) |
| 955 | var CapturedOutput *bytes.Buffer |
| 956 | var capturedOutputMu sync.Mutex |
| 957 | |
| 958 | // write writes bytes b to the target program's standard output. |
| 959 | // The print/println built-ins and the write() system call funnel |
| 960 | // through here so they can be captured by the test driver. |
| 961 | func print(b []byte) (int, error) { |
| 962 | if CapturedOutput != nil { |
| 963 | capturedOutputMu.Lock() |
| 964 | CapturedOutput.Write(b) // ignore errors |
| 965 | capturedOutputMu.Unlock() |
| 966 | } |
| 967 | return os.Stdout.Write(b) |
| 968 | } |
| 969 | |
| 970 | // callBuiltin interprets a call to builtin fn with arguments args, |
| 971 | // returning its result. |
| 972 | func callBuiltin(caller *frame, callpos token.Pos, fn *ssa.Builtin, args []value) value { |
| 973 | switch fn.Name() { |
| 974 | case "append": |
| 975 | if len(args) == 1 { |
| 976 | return args[0] |
| 977 | } |
| 978 | if s, ok := args[1].(string); ok { |
| 979 | // append([]byte, ...string) []byte |
| 980 | arg0 := args[0].([]value) |
| 981 | for i := 0; i < len(s); i++ { |
| 982 | arg0 = append(arg0, s[i]) |
| 983 | } |
| 984 | return arg0 |
| 985 | } |
| 986 | // append([]T, ...[]T) []T |
| 987 | return append(args[0].([]value), args[1].([]value)...) |
| 988 | |
| 989 | case "copy": // copy([]T, []T) int or copy([]byte, string) int |
| 990 | src := args[1] |
| 991 | if _, ok := src.(string); ok { |
| 992 | params := fn.Type().(*types.Signature).Params() |
| 993 | src = conv(params.At(0).Type(), params.At(1).Type(), src) |
| 994 | } |
| 995 | return copy(args[0].([]value), src.([]value)) |
| 996 | |
| 997 | case "close": // close(chan T) |
| 998 | close(args[0].(chan value)) |
| 999 | return nil |
| 1000 | |
| 1001 | case "delete": // delete(map[K]value, K) |
| 1002 | switch m := args[0].(type) { |
| 1003 | case map[value]value: |
| 1004 | delete(m, args[1]) |
| 1005 | case *hashmap: |
| 1006 | m.delete(args[1].(hashable)) |
| 1007 | default: |
| 1008 | panic(fmt.Sprintf("illegal map type: %T", m)) |
| 1009 | } |
| 1010 | return nil |
| 1011 | |
| 1012 | case "print", "println": // print(any, ...) |
| 1013 | ln := fn.Name() == "println" |
| 1014 | var buf bytes.Buffer |
| 1015 | for i, arg := range args { |
| 1016 | if i > 0 && ln { |
| 1017 | buf.WriteRune(' ') |
| 1018 | } |
| 1019 | buf.WriteString(toString(arg)) |
| 1020 | } |
| 1021 | if ln { |
| 1022 | buf.WriteRune('\n') |
| 1023 | } |
| 1024 | print(buf.Bytes()) |
| 1025 | return nil |
| 1026 | |
| 1027 | case "len": |
| 1028 | switch x := args[0].(type) { |
| 1029 | case string: |
| 1030 | return len(x) |
| 1031 | case array: |
| 1032 | return len(x) |
| 1033 | case *value: |
| 1034 | return len((*x).(array)) |
| 1035 | case []value: |
| 1036 | return len(x) |
| 1037 | case map[value]value: |
| 1038 | return len(x) |
| 1039 | case *hashmap: |
| 1040 | return x.len() |
| 1041 | case chan value: |
| 1042 | return len(x) |
| 1043 | default: |
| 1044 | panic(fmt.Sprintf("len: illegal operand: %T", x)) |
| 1045 | } |
| 1046 | |
| 1047 | case "cap": |
| 1048 | switch x := args[0].(type) { |
| 1049 | case array: |
| 1050 | return cap(x) |
| 1051 | case *value: |
| 1052 | return cap((*x).(array)) |
| 1053 | case []value: |
| 1054 | return cap(x) |
| 1055 | case chan value: |
| 1056 | return cap(x) |
| 1057 | default: |
| 1058 | panic(fmt.Sprintf("cap: illegal operand: %T", x)) |
| 1059 | } |
| 1060 | |
| 1061 | case "real": |
| 1062 | switch c := args[0].(type) { |
| 1063 | case complex64: |
| 1064 | return real(c) |
| 1065 | case complex128: |
| 1066 | return real(c) |
| 1067 | default: |
| 1068 | panic(fmt.Sprintf("real: illegal operand: %T", c)) |
| 1069 | } |
| 1070 | |
| 1071 | case "imag": |
| 1072 | switch c := args[0].(type) { |
| 1073 | case complex64: |
| 1074 | return imag(c) |
| 1075 | case complex128: |
| 1076 | return imag(c) |
| 1077 | default: |
| 1078 | panic(fmt.Sprintf("imag: illegal operand: %T", c)) |
| 1079 | } |
| 1080 | |
| 1081 | case "complex": |
| 1082 | switch f := args[0].(type) { |
| 1083 | case float32: |
| 1084 | return complex(f, args[1].(float32)) |
| 1085 | case float64: |
| 1086 | return complex(f, args[1].(float64)) |
| 1087 | default: |
| 1088 | panic(fmt.Sprintf("complex: illegal operand: %T", f)) |
| 1089 | } |
| 1090 | |
| 1091 | case "panic": |
| 1092 | // ssa.Panic handles most cases; this is only for "go |
| 1093 | // panic" or "defer panic". |
| 1094 | panic(targetPanic{args[0]}) |
| 1095 | |
| 1096 | case "recover": |
| 1097 | return doRecover(caller) |
| 1098 | |
| 1099 | case "ssa:wrapnilchk": |
| 1100 | recv := args[0] |
| 1101 | if recv.(*value) == nil { |
| 1102 | recvType := args[1] |
| 1103 | methodName := args[2] |
| 1104 | panic(fmt.Sprintf("value method (%s).%s called using nil *%s pointer", |
| 1105 | recvType, methodName, recvType)) |
| 1106 | } |
| 1107 | return recv |
| 1108 | } |
| 1109 | |
| 1110 | panic("unknown built-in: " + fn.Name()) |
| 1111 | } |
| 1112 | |
| 1113 | func rangeIter(x value, t types.Type) iter { |
| 1114 | switch x := x.(type) { |
| 1115 | case map[value]value: |
| 1116 | return &mapIter{iter: reflect.ValueOf(x).MapRange()} |
| 1117 | case *hashmap: |
| 1118 | return &hashmapIter{iter: reflect.ValueOf(x.entries()).MapRange()} |
| 1119 | case string: |
| 1120 | return &stringIter{Reader: strings.NewReader(x)} |
| 1121 | } |
| 1122 | panic(fmt.Sprintf("cannot range over %T", x)) |
| 1123 | } |
| 1124 | |
| 1125 | // widen widens a basic typed value x to the widest type of its |
| 1126 | // category, one of: |
| 1127 | // |
| 1128 | // bool, int64, uint64, float64, complex128, string. |
| 1129 | // |
| 1130 | // This is inefficient but reduces the size of the cross-product of |
| 1131 | // cases we have to consider. |
| 1132 | func widen(x value) value { |
| 1133 | switch y := x.(type) { |
| 1134 | case bool, int64, uint64, float64, complex128, string, unsafe.Pointer: |
| 1135 | return x |
| 1136 | case int: |
| 1137 | return int64(y) |
| 1138 | case int8: |
| 1139 | return int64(y) |
| 1140 | case int16: |
| 1141 | return int64(y) |
| 1142 | case int32: |
| 1143 | return int64(y) |
| 1144 | case uint: |
| 1145 | return uint64(y) |
| 1146 | case uint8: |
| 1147 | return uint64(y) |
| 1148 | case uint16: |
| 1149 | return uint64(y) |
| 1150 | case uint32: |
| 1151 | return uint64(y) |
| 1152 | case uintptr: |
| 1153 | return uint64(y) |
| 1154 | case float32: |
| 1155 | return float64(y) |
| 1156 | case complex64: |
| 1157 | return complex128(y) |
| 1158 | } |
| 1159 | panic(fmt.Sprintf("cannot widen %T", x)) |
| 1160 | } |
| 1161 | |
| 1162 | // conv converts the value x of type t_src to type t_dst and returns |
| 1163 | // the result. |
| 1164 | // Possible cases are described with the ssa.Convert operator. |
| 1165 | func conv(t_dst, t_src types.Type, x value) value { |
| 1166 | ut_src := t_src.Underlying() |
| 1167 | ut_dst := t_dst.Underlying() |
| 1168 | |
| 1169 | // Destination type is not an "untyped" type. |
| 1170 | if b, ok := ut_dst.(*types.Basic); ok && b.Info()&types.IsUntyped != 0 { |
| 1171 | panic("oops: conversion to 'untyped' type: " + b.String()) |
| 1172 | } |
| 1173 | |
| 1174 | // Nor is it an interface type. |
| 1175 | if _, ok := ut_dst.(*types.Interface); ok { |
| 1176 | if _, ok := ut_src.(*types.Interface); ok { |
| 1177 | panic("oops: Convert should be ChangeInterface") |
| 1178 | } else { |
| 1179 | panic("oops: Convert should be MakeInterface") |
| 1180 | } |
| 1181 | } |
| 1182 | |
| 1183 | // Remaining conversions: |
| 1184 | // + untyped string/number/bool constant to a specific |
| 1185 | // representation. |
| 1186 | // + conversions between non-complex numeric types. |
| 1187 | // + conversions between complex numeric types. |
| 1188 | // + integer/[]byte/[]rune -> string. |
| 1189 | // + string -> []byte/[]rune. |
| 1190 | // |
| 1191 | // All are treated the same: first we extract the value to the |
| 1192 | // widest representation (int64, uint64, float64, complex128, |
| 1193 | // or string), then we convert it to the desired type. |
| 1194 | |
| 1195 | switch ut_src := ut_src.(type) { |
| 1196 | case *types.Pointer: |
| 1197 | switch ut_dst := ut_dst.(type) { |
| 1198 | case *types.Basic: |
| 1199 | // *value to unsafe.Pointer? |
| 1200 | if ut_dst.Kind() == types.UnsafePointer { |
| 1201 | return unsafe.Pointer(x.(*value)) |
| 1202 | } |
| 1203 | } |
| 1204 | |
| 1205 | case *types.Slice: |
| 1206 | // []byte or []rune -> string |
| 1207 | // TODO(adonovan): fix: type B byte; conv([]B -> string). |
| 1208 | switch ut_src.Elem().(*types.Basic).Kind() { |
| 1209 | case types.Byte: |
| 1210 | x := x.([]value) |
| 1211 | b := make([]byte, 0, len(x)) |
| 1212 | for i := range x { |
| 1213 | b = append(b, x[i].(byte)) |
| 1214 | } |
| 1215 | return string(b) |
| 1216 | |
| 1217 | case types.Rune: |
| 1218 | x := x.([]value) |
| 1219 | r := make([]rune, 0, len(x)) |
| 1220 | for i := range x { |
| 1221 | r = append(r, x[i].(rune)) |
| 1222 | } |
| 1223 | return string(r) |
| 1224 | } |
| 1225 | |
| 1226 | case *types.Basic: |
| 1227 | x = widen(x) |
| 1228 | |
| 1229 | // integer -> string? |
| 1230 | // TODO(adonovan): fix: test integer -> named alias of string. |
| 1231 | if ut_src.Info()&types.IsInteger != 0 { |
| 1232 | if ut_dst, ok := ut_dst.(*types.Basic); ok && ut_dst.Kind() == types.String { |
| 1233 | return fmt.Sprintf("%c", x) |
| 1234 | } |
| 1235 | } |
| 1236 | |
| 1237 | // string -> []rune, []byte or string? |
| 1238 | if s, ok := x.(string); ok { |
| 1239 | switch ut_dst := ut_dst.(type) { |
| 1240 | case *types.Slice: |
| 1241 | var res []value |
| 1242 | // TODO(adonovan): fix: test named alias of rune, byte. |
| 1243 | switch ut_dst.Elem().(*types.Basic).Kind() { |
| 1244 | case types.Rune: |
| 1245 | for _, r := range []rune(s) { |
| 1246 | res = append(res, r) |
| 1247 | } |
| 1248 | return res |
| 1249 | case types.Byte: |
| 1250 | for _, b := range []byte(s) { |
| 1251 | res = append(res, b) |
| 1252 | } |
| 1253 | return res |
| 1254 | } |
| 1255 | case *types.Basic: |
| 1256 | if ut_dst.Kind() == types.String { |
| 1257 | return x.(string) |
| 1258 | } |
| 1259 | } |
| 1260 | break // fail: no other conversions for string |
| 1261 | } |
| 1262 | |
| 1263 | // unsafe.Pointer -> *value |
| 1264 | if ut_src.Kind() == types.UnsafePointer { |
| 1265 | // TODO(adonovan): this is wrong and cannot |
| 1266 | // really be fixed with the current design. |
| 1267 | // |
| 1268 | // return (*value)(x.(unsafe.Pointer)) |
| 1269 | // creates a new pointer of a different |
| 1270 | // type but the underlying interface value |
| 1271 | // knows its "true" type and so cannot be |
| 1272 | // meaningfully used through the new pointer. |
| 1273 | // |
| 1274 | // To make this work, the interpreter needs to |
| 1275 | // simulate the memory layout of a real |
| 1276 | // compiled implementation. |
| 1277 | // |
| 1278 | // To at least preserve type-safety, we'll |
| 1279 | // just return the zero value of the |
| 1280 | // destination type. |
| 1281 | return zero(t_dst) |
| 1282 | } |
| 1283 | |
| 1284 | // Conversions between complex numeric types? |
| 1285 | if ut_src.Info()&types.IsComplex != 0 { |
| 1286 | switch ut_dst.(*types.Basic).Kind() { |
| 1287 | case types.Complex64: |
| 1288 | return complex64(x.(complex128)) |
| 1289 | case types.Complex128: |
| 1290 | return x.(complex128) |
| 1291 | } |
| 1292 | break // fail: no other conversions for complex |
| 1293 | } |
| 1294 | |
| 1295 | // Conversions between non-complex numeric types? |
| 1296 | if ut_src.Info()&types.IsNumeric != 0 { |
| 1297 | kind := ut_dst.(*types.Basic).Kind() |
| 1298 | switch x := x.(type) { |
| 1299 | case int64: // signed integer -> numeric? |
| 1300 | switch kind { |
| 1301 | case types.Int: |
| 1302 | return int(x) |
| 1303 | case types.Int8: |
| 1304 | return int8(x) |
| 1305 | case types.Int16: |
| 1306 | return int16(x) |
| 1307 | case types.Int32: |
| 1308 | return int32(x) |
| 1309 | case types.Int64: |
| 1310 | return int64(x) |
| 1311 | case types.Uint: |
| 1312 | return uint(x) |
| 1313 | case types.Uint8: |
| 1314 | return uint8(x) |
| 1315 | case types.Uint16: |
| 1316 | return uint16(x) |
| 1317 | case types.Uint32: |
| 1318 | return uint32(x) |
| 1319 | case types.Uint64: |
| 1320 | return uint64(x) |
| 1321 | case types.Uintptr: |
| 1322 | return uintptr(x) |
| 1323 | case types.Float32: |
| 1324 | return float32(x) |
| 1325 | case types.Float64: |
| 1326 | return float64(x) |
| 1327 | } |
| 1328 | |
| 1329 | case uint64: // unsigned integer -> numeric? |
| 1330 | switch kind { |
| 1331 | case types.Int: |
| 1332 | return int(x) |
| 1333 | case types.Int8: |
| 1334 | return int8(x) |
| 1335 | case types.Int16: |
| 1336 | return int16(x) |
| 1337 | case types.Int32: |
| 1338 | return int32(x) |
| 1339 | case types.Int64: |
| 1340 | return int64(x) |
| 1341 | case types.Uint: |
| 1342 | return uint(x) |
| 1343 | case types.Uint8: |
| 1344 | return uint8(x) |
| 1345 | case types.Uint16: |
| 1346 | return uint16(x) |
| 1347 | case types.Uint32: |
| 1348 | return uint32(x) |
| 1349 | case types.Uint64: |
| 1350 | return uint64(x) |
| 1351 | case types.Uintptr: |
| 1352 | return uintptr(x) |
| 1353 | case types.Float32: |
| 1354 | return float32(x) |
| 1355 | case types.Float64: |
| 1356 | return float64(x) |
| 1357 | } |
| 1358 | |
| 1359 | case float64: // floating point -> numeric? |
| 1360 | switch kind { |
| 1361 | case types.Int: |
| 1362 | return int(x) |
| 1363 | case types.Int8: |
| 1364 | return int8(x) |
| 1365 | case types.Int16: |
| 1366 | return int16(x) |
| 1367 | case types.Int32: |
| 1368 | return int32(x) |
| 1369 | case types.Int64: |
| 1370 | return int64(x) |
| 1371 | case types.Uint: |
| 1372 | return uint(x) |
| 1373 | case types.Uint8: |
| 1374 | return uint8(x) |
| 1375 | case types.Uint16: |
| 1376 | return uint16(x) |
| 1377 | case types.Uint32: |
| 1378 | return uint32(x) |
| 1379 | case types.Uint64: |
| 1380 | return uint64(x) |
| 1381 | case types.Uintptr: |
| 1382 | return uintptr(x) |
| 1383 | case types.Float32: |
| 1384 | return float32(x) |
| 1385 | case types.Float64: |
| 1386 | return float64(x) |
| 1387 | } |
| 1388 | } |
| 1389 | } |
| 1390 | } |
| 1391 | |
| 1392 | panic(fmt.Sprintf("unsupported conversion: %s -> %s, dynamic type %T", t_src, t_dst, x)) |
| 1393 | } |
| 1394 | |
| 1395 | // sliceToArrayPointer converts the value x of type slice to type t_dst |
| 1396 | // a pointer to array and returns the result. |
| 1397 | func sliceToArrayPointer(t_dst, t_src types.Type, x value) value { |
| 1398 | if _, ok := t_src.Underlying().(*types.Slice); ok { |
| 1399 | if ptr, ok := t_dst.Underlying().(*types.Pointer); ok { |
| 1400 | if arr, ok := ptr.Elem().Underlying().(*types.Array); ok { |
| 1401 | x := x.([]value) |
| 1402 | if arr.Len() > int64(len(x)) { |
| 1403 | panic("array length is greater than slice length") |
| 1404 | } |
| 1405 | if x == nil { |
| 1406 | return zero(t_dst) |
| 1407 | } |
| 1408 | v := value(array(x[:arr.Len()])) |
| 1409 | return &v |
| 1410 | } |
| 1411 | } |
| 1412 | } |
| 1413 | |
| 1414 | panic(fmt.Sprintf("unsupported conversion: %s -> %s, dynamic type %T", t_src, t_dst, x)) |
| 1415 | } |
| 1416 | |
| 1417 | // checkInterface checks that the method set of x implements the |
| 1418 | // interface itype. |
| 1419 | // On success it returns "", on failure, an error message. |
| 1420 | func checkInterface(i *interpreter, itype *types.Interface, x iface) string { |
| 1421 | if meth, _ := types.MissingMethod(x.t, itype, true); meth != nil { |
| 1422 | return fmt.Sprintf("interface conversion: %v is not %v: missing method %s", |
| 1423 | x.t, itype, meth.Name()) |
| 1424 | } |
| 1425 | return "" // ok |
| 1426 | } |
| 1427 |
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