| // Copyright 2013 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| package interp |
| |
| import ( |
| "bytes" |
| "fmt" |
| exact "go/constant" |
| "go/token" |
| "go/types" |
| "strings" |
| "sync" |
| "unsafe" |
| |
| "golang.org/x/tools/go/ssa" |
| ) |
| |
| // If the target program panics, the interpreter panics with this type. |
| type targetPanic struct { |
| v value |
| } |
| |
| func (p targetPanic) String() string { |
| return toString(p.v) |
| } |
| |
| // If the target program calls exit, the interpreter panics with this type. |
| type exitPanic int |
| |
| // constValue returns the value of the constant with the |
| // dynamic type tag appropriate for c.Type(). |
| func constValue(c *ssa.Const) value { |
| if c.IsNil() { |
| return zero(c.Type()) // typed nil |
| } |
| |
| if t, ok := c.Type().Underlying().(*types.Basic); ok { |
| // TODO(adonovan): eliminate untyped constants from SSA form. |
| switch t.Kind() { |
| case types.Bool, types.UntypedBool: |
| return exact.BoolVal(c.Value) |
| case types.Int, types.UntypedInt: |
| // Assume sizeof(int) is same on host and target. |
| return int(c.Int64()) |
| case types.Int8: |
| return int8(c.Int64()) |
| case types.Int16: |
| return int16(c.Int64()) |
| case types.Int32, types.UntypedRune: |
| return int32(c.Int64()) |
| case types.Int64: |
| return c.Int64() |
| case types.Uint: |
| // Assume sizeof(uint) is same on host and target. |
| return uint(c.Uint64()) |
| case types.Uint8: |
| return uint8(c.Uint64()) |
| case types.Uint16: |
| return uint16(c.Uint64()) |
| case types.Uint32: |
| return uint32(c.Uint64()) |
| case types.Uint64: |
| return c.Uint64() |
| case types.Uintptr: |
| // Assume sizeof(uintptr) is same on host and target. |
| return uintptr(c.Uint64()) |
| case types.Float32: |
| return float32(c.Float64()) |
| case types.Float64, types.UntypedFloat: |
| return c.Float64() |
| case types.Complex64: |
| return complex64(c.Complex128()) |
| case types.Complex128, types.UntypedComplex: |
| return c.Complex128() |
| case types.String, types.UntypedString: |
| if c.Value.Kind() == exact.String { |
| return exact.StringVal(c.Value) |
| } |
| return string(rune(c.Int64())) |
| } |
| } |
| |
| panic(fmt.Sprintf("constValue: %s", c)) |
| } |
| |
| // asInt converts x, which must be an integer, to an int suitable for |
| // use as a slice or array index or operand to make(). |
| func asInt(x value) int { |
| switch x := x.(type) { |
| case int: |
| return x |
| case int8: |
| return int(x) |
| case int16: |
| return int(x) |
| case int32: |
| return int(x) |
| case int64: |
| return int(x) |
| case uint: |
| return int(x) |
| case uint8: |
| return int(x) |
| case uint16: |
| return int(x) |
| case uint32: |
| return int(x) |
| case uint64: |
| return int(x) |
| case uintptr: |
| return int(x) |
| } |
| panic(fmt.Sprintf("cannot convert %T to int", x)) |
| } |
| |
| // asUint64 converts x, which must be an unsigned integer, to a uint64 |
| // suitable for use as a bitwise shift count. |
| func asUint64(x value) uint64 { |
| switch x := x.(type) { |
| case uint: |
| return uint64(x) |
| case uint8: |
| return uint64(x) |
| case uint16: |
| return uint64(x) |
| case uint32: |
| return uint64(x) |
| case uint64: |
| return x |
| case uintptr: |
| return uint64(x) |
| } |
| panic(fmt.Sprintf("cannot convert %T to uint64", x)) |
| } |
| |
| // zero returns a new "zero" value of the specified type. |
| func zero(t types.Type) value { |
| switch t := t.(type) { |
| case *types.Basic: |
| if t.Kind() == types.UntypedNil { |
| panic("untyped nil has no zero value") |
| } |
| if t.Info()&types.IsUntyped != 0 { |
| // TODO(adonovan): make it an invariant that |
| // this is unreachable. Currently some |
| // constants have 'untyped' types when they |
| // should be defaulted by the typechecker. |
| t = ssa.DefaultType(t).(*types.Basic) |
| } |
| switch t.Kind() { |
| case types.Bool: |
| return false |
| case types.Int: |
| return int(0) |
| case types.Int8: |
| return int8(0) |
| case types.Int16: |
| return int16(0) |
| case types.Int32: |
| return int32(0) |
| case types.Int64: |
| return int64(0) |
| case types.Uint: |
| return uint(0) |
| case types.Uint8: |
| return uint8(0) |
| case types.Uint16: |
| return uint16(0) |
| case types.Uint32: |
| return uint32(0) |
| case types.Uint64: |
| return uint64(0) |
| case types.Uintptr: |
| return uintptr(0) |
| case types.Float32: |
| return float32(0) |
| case types.Float64: |
| return float64(0) |
| case types.Complex64: |
| return complex64(0) |
| case types.Complex128: |
| return complex128(0) |
| case types.String: |
| return "" |
| case types.UnsafePointer: |
| return unsafe.Pointer(nil) |
| default: |
| panic(fmt.Sprint("zero for unexpected type:", t)) |
| } |
| case *types.Pointer: |
| return (*value)(nil) |
| case *types.Array: |
| a := make(array, t.Len()) |
| for i := range a { |
| a[i] = zero(t.Elem()) |
| } |
| return a |
| case *types.Named: |
| return zero(t.Underlying()) |
| case *types.Interface: |
| return iface{} // nil type, methodset and value |
| case *types.Slice: |
| return []value(nil) |
| case *types.Struct: |
| s := make(structure, t.NumFields()) |
| for i := range s { |
| s[i] = zero(t.Field(i).Type()) |
| } |
| return s |
| case *types.Tuple: |
| if t.Len() == 1 { |
| return zero(t.At(0).Type()) |
| } |
| s := make(tuple, t.Len()) |
| for i := range s { |
| s[i] = zero(t.At(i).Type()) |
| } |
| return s |
| case *types.Chan: |
| return chan value(nil) |
| case *types.Map: |
| if usesBuiltinMap(t.Key()) { |
| return map[value]value(nil) |
| } |
| return (*hashmap)(nil) |
| case *types.Signature: |
| return (*ssa.Function)(nil) |
| } |
| panic(fmt.Sprint("zero: unexpected ", t)) |
| } |
| |
| // slice returns x[lo:hi:max]. Any of lo, hi and max may be nil. |
| func slice(x, lo, hi, max value) value { |
| var Len, Cap int |
| switch x := x.(type) { |
| case string: |
| Len = len(x) |
| case []value: |
| Len = len(x) |
| Cap = cap(x) |
| case *value: // *array |
| a := (*x).(array) |
| Len = len(a) |
| Cap = cap(a) |
| } |
| |
| l := 0 |
| if lo != nil { |
| l = asInt(lo) |
| } |
| |
| h := Len |
| if hi != nil { |
| h = asInt(hi) |
| } |
| |
| m := Cap |
| if max != nil { |
| m = asInt(max) |
| } |
| |
| switch x := x.(type) { |
| case string: |
| return x[l:h] |
| case []value: |
| return x[l:h:m] |
| case *value: // *array |
| a := (*x).(array) |
| return []value(a)[l:h:m] |
| } |
| panic(fmt.Sprintf("slice: unexpected X type: %T", x)) |
| } |
| |
| // lookup returns x[idx] where x is a map or string. |
| func lookup(instr *ssa.Lookup, x, idx value) value { |
| switch x := x.(type) { // map or string |
| case map[value]value, *hashmap: |
| var v value |
| var ok bool |
| switch x := x.(type) { |
| case map[value]value: |
| v, ok = x[idx] |
| case *hashmap: |
| v = x.lookup(idx.(hashable)) |
| ok = v != nil |
| } |
| if !ok { |
| v = zero(instr.X.Type().Underlying().(*types.Map).Elem()) |
| } |
| if instr.CommaOk { |
| v = tuple{v, ok} |
| } |
| return v |
| case string: |
| return x[asInt(idx)] |
| } |
| panic(fmt.Sprintf("unexpected x type in Lookup: %T", x)) |
| } |
| |
| // binop implements all arithmetic and logical binary operators for |
| // numeric datatypes and strings. Both operands must have identical |
| // dynamic type. |
| // |
| func binop(op token.Token, t types.Type, x, y value) value { |
| switch op { |
| case token.ADD: |
| switch x.(type) { |
| case int: |
| return x.(int) + y.(int) |
| case int8: |
| return x.(int8) + y.(int8) |
| case int16: |
| return x.(int16) + y.(int16) |
| case int32: |
| return x.(int32) + y.(int32) |
| case int64: |
| return x.(int64) + y.(int64) |
| case uint: |
| return x.(uint) + y.(uint) |
| case uint8: |
| return x.(uint8) + y.(uint8) |
| case uint16: |
| return x.(uint16) + y.(uint16) |
| case uint32: |
| return x.(uint32) + y.(uint32) |
| case uint64: |
| return x.(uint64) + y.(uint64) |
| case uintptr: |
| return x.(uintptr) + y.(uintptr) |
| case float32: |
| return x.(float32) + y.(float32) |
| case float64: |
| return x.(float64) + y.(float64) |
| case complex64: |
| return x.(complex64) + y.(complex64) |
| case complex128: |
| return x.(complex128) + y.(complex128) |
| case string: |
| return x.(string) + y.(string) |
| } |
| |
| case token.SUB: |
| switch x.(type) { |
| case int: |
| return x.(int) - y.(int) |
| case int8: |
| return x.(int8) - y.(int8) |
| case int16: |
| return x.(int16) - y.(int16) |
| case int32: |
| return x.(int32) - y.(int32) |
| case int64: |
| return x.(int64) - y.(int64) |
| case uint: |
| return x.(uint) - y.(uint) |
| case uint8: |
| return x.(uint8) - y.(uint8) |
| case uint16: |
| return x.(uint16) - y.(uint16) |
| case uint32: |
| return x.(uint32) - y.(uint32) |
| case uint64: |
| return x.(uint64) - y.(uint64) |
| case uintptr: |
| return x.(uintptr) - y.(uintptr) |
| case float32: |
| return x.(float32) - y.(float32) |
| case float64: |
| return x.(float64) - y.(float64) |
| case complex64: |
| return x.(complex64) - y.(complex64) |
| case complex128: |
| return x.(complex128) - y.(complex128) |
| } |
| |
| case token.MUL: |
| switch x.(type) { |
| case int: |
| return x.(int) * y.(int) |
| case int8: |
| return x.(int8) * y.(int8) |
| case int16: |
| return x.(int16) * y.(int16) |
| case int32: |
| return x.(int32) * y.(int32) |
| case int64: |
| return x.(int64) * y.(int64) |
| case uint: |
| return x.(uint) * y.(uint) |
| case uint8: |
| return x.(uint8) * y.(uint8) |
| case uint16: |
| return x.(uint16) * y.(uint16) |
| case uint32: |
| return x.(uint32) * y.(uint32) |
| case uint64: |
| return x.(uint64) * y.(uint64) |
| case uintptr: |
| return x.(uintptr) * y.(uintptr) |
| case float32: |
| return x.(float32) * y.(float32) |
| case float64: |
| return x.(float64) * y.(float64) |
| case complex64: |
| return x.(complex64) * y.(complex64) |
| case complex128: |
| return x.(complex128) * y.(complex128) |
| } |
| |
| case token.QUO: |
| switch x.(type) { |
| case int: |
| return x.(int) / y.(int) |
| case int8: |
| return x.(int8) / y.(int8) |
| case int16: |
| return x.(int16) / y.(int16) |
| case int32: |
| return x.(int32) / y.(int32) |
| case int64: |
| return x.(int64) / y.(int64) |
| case uint: |
| return x.(uint) / y.(uint) |
| case uint8: |
| return x.(uint8) / y.(uint8) |
| case uint16: |
| return x.(uint16) / y.(uint16) |
| case uint32: |
| return x.(uint32) / y.(uint32) |
| case uint64: |
| return x.(uint64) / y.(uint64) |
| case uintptr: |
| return x.(uintptr) / y.(uintptr) |
| case float32: |
| return x.(float32) / y.(float32) |
| case float64: |
| return x.(float64) / y.(float64) |
| case complex64: |
| return x.(complex64) / y.(complex64) |
| case complex128: |
| return x.(complex128) / y.(complex128) |
| } |
| |
| case token.REM: |
| switch x.(type) { |
| case int: |
| return x.(int) % y.(int) |
| case int8: |
| return x.(int8) % y.(int8) |
| case int16: |
| return x.(int16) % y.(int16) |
| case int32: |
| return x.(int32) % y.(int32) |
| case int64: |
| return x.(int64) % y.(int64) |
| case uint: |
| return x.(uint) % y.(uint) |
| case uint8: |
| return x.(uint8) % y.(uint8) |
| case uint16: |
| return x.(uint16) % y.(uint16) |
| case uint32: |
| return x.(uint32) % y.(uint32) |
| case uint64: |
| return x.(uint64) % y.(uint64) |
| case uintptr: |
| return x.(uintptr) % y.(uintptr) |
| } |
| |
| case token.AND: |
| switch x.(type) { |
| case int: |
| return x.(int) & y.(int) |
| case int8: |
| return x.(int8) & y.(int8) |
| case int16: |
| return x.(int16) & y.(int16) |
| case int32: |
| return x.(int32) & y.(int32) |
| case int64: |
| return x.(int64) & y.(int64) |
| case uint: |
| return x.(uint) & y.(uint) |
| case uint8: |
| return x.(uint8) & y.(uint8) |
| case uint16: |
| return x.(uint16) & y.(uint16) |
| case uint32: |
| return x.(uint32) & y.(uint32) |
| case uint64: |
| return x.(uint64) & y.(uint64) |
| case uintptr: |
| return x.(uintptr) & y.(uintptr) |
| } |
| |
| case token.OR: |
| switch x.(type) { |
| case int: |
| return x.(int) | y.(int) |
| case int8: |
| return x.(int8) | y.(int8) |
| case int16: |
| return x.(int16) | y.(int16) |
| case int32: |
| return x.(int32) | y.(int32) |
| case int64: |
| return x.(int64) | y.(int64) |
| case uint: |
| return x.(uint) | y.(uint) |
| case uint8: |
| return x.(uint8) | y.(uint8) |
| case uint16: |
| return x.(uint16) | y.(uint16) |
| case uint32: |
| return x.(uint32) | y.(uint32) |
| case uint64: |
| return x.(uint64) | y.(uint64) |
| case uintptr: |
| return x.(uintptr) | y.(uintptr) |
| } |
| |
| case token.XOR: |
| switch x.(type) { |
| case int: |
| return x.(int) ^ y.(int) |
| case int8: |
| return x.(int8) ^ y.(int8) |
| case int16: |
| return x.(int16) ^ y.(int16) |
| case int32: |
| return x.(int32) ^ y.(int32) |
| case int64: |
| return x.(int64) ^ y.(int64) |
| case uint: |
| return x.(uint) ^ y.(uint) |
| case uint8: |
| return x.(uint8) ^ y.(uint8) |
| case uint16: |
| return x.(uint16) ^ y.(uint16) |
| case uint32: |
| return x.(uint32) ^ y.(uint32) |
| case uint64: |
| return x.(uint64) ^ y.(uint64) |
| case uintptr: |
| return x.(uintptr) ^ y.(uintptr) |
| } |
| |
| case token.AND_NOT: |
| switch x.(type) { |
| case int: |
| return x.(int) &^ y.(int) |
| case int8: |
| return x.(int8) &^ y.(int8) |
| case int16: |
| return x.(int16) &^ y.(int16) |
| case int32: |
| return x.(int32) &^ y.(int32) |
| case int64: |
| return x.(int64) &^ y.(int64) |
| case uint: |
| return x.(uint) &^ y.(uint) |
| case uint8: |
| return x.(uint8) &^ y.(uint8) |
| case uint16: |
| return x.(uint16) &^ y.(uint16) |
| case uint32: |
| return x.(uint32) &^ y.(uint32) |
| case uint64: |
| return x.(uint64) &^ y.(uint64) |
| case uintptr: |
| return x.(uintptr) &^ y.(uintptr) |
| } |
| |
| case token.SHL: |
| y := asUint64(y) |
| switch x.(type) { |
| case int: |
| return x.(int) << y |
| case int8: |
| return x.(int8) << y |
| case int16: |
| return x.(int16) << y |
| case int32: |
| return x.(int32) << y |
| case int64: |
| return x.(int64) << y |
| case uint: |
| return x.(uint) << y |
| case uint8: |
| return x.(uint8) << y |
| case uint16: |
| return x.(uint16) << y |
| case uint32: |
| return x.(uint32) << y |
| case uint64: |
| return x.(uint64) << y |
| case uintptr: |
| return x.(uintptr) << y |
| } |
| |
| case token.SHR: |
| y := asUint64(y) |
| switch x.(type) { |
| case int: |
| return x.(int) >> y |
| case int8: |
| return x.(int8) >> y |
| case int16: |
| return x.(int16) >> y |
| case int32: |
| return x.(int32) >> y |
| case int64: |
| return x.(int64) >> y |
| case uint: |
| return x.(uint) >> y |
| case uint8: |
| return x.(uint8) >> y |
| case uint16: |
| return x.(uint16) >> y |
| case uint32: |
| return x.(uint32) >> y |
| case uint64: |
| return x.(uint64) >> y |
| case uintptr: |
| return x.(uintptr) >> y |
| } |
| |
| case token.LSS: |
| switch x.(type) { |
| case int: |
| return x.(int) < y.(int) |
| case int8: |
| return x.(int8) < y.(int8) |
| case int16: |
| return x.(int16) < y.(int16) |
| case int32: |
| return x.(int32) < y.(int32) |
| case int64: |
| return x.(int64) < y.(int64) |
| case uint: |
| return x.(uint) < y.(uint) |
| case uint8: |
| return x.(uint8) < y.(uint8) |
| case uint16: |
| return x.(uint16) < y.(uint16) |
| case uint32: |
| return x.(uint32) < y.(uint32) |
| case uint64: |
| return x.(uint64) < y.(uint64) |
| case uintptr: |
| return x.(uintptr) < y.(uintptr) |
| case float32: |
| return x.(float32) < y.(float32) |
| case float64: |
| return x.(float64) < y.(float64) |
| case string: |
| return x.(string) < y.(string) |
| } |
| |
| case token.LEQ: |
| switch x.(type) { |
| case int: |
| return x.(int) <= y.(int) |
| case int8: |
| return x.(int8) <= y.(int8) |
| case int16: |
| return x.(int16) <= y.(int16) |
| case int32: |
| return x.(int32) <= y.(int32) |
| case int64: |
| return x.(int64) <= y.(int64) |
| case uint: |
| return x.(uint) <= y.(uint) |
| case uint8: |
| return x.(uint8) <= y.(uint8) |
| case uint16: |
| return x.(uint16) <= y.(uint16) |
| case uint32: |
| return x.(uint32) <= y.(uint32) |
| case uint64: |
| return x.(uint64) <= y.(uint64) |
| case uintptr: |
| return x.(uintptr) <= y.(uintptr) |
| case float32: |
| return x.(float32) <= y.(float32) |
| case float64: |
| return x.(float64) <= y.(float64) |
| case string: |
| return x.(string) <= y.(string) |
| } |
| |
| case token.EQL: |
| return eqnil(t, x, y) |
| |
| case token.NEQ: |
| return !eqnil(t, x, y) |
| |
| case token.GTR: |
| switch x.(type) { |
| case int: |
| return x.(int) > y.(int) |
| case int8: |
| return x.(int8) > y.(int8) |
| case int16: |
| return x.(int16) > y.(int16) |
| case int32: |
| return x.(int32) > y.(int32) |
| case int64: |
| return x.(int64) > y.(int64) |
| case uint: |
| return x.(uint) > y.(uint) |
| case uint8: |
| return x.(uint8) > y.(uint8) |
| case uint16: |
| return x.(uint16) > y.(uint16) |
| case uint32: |
| return x.(uint32) > y.(uint32) |
| case uint64: |
| return x.(uint64) > y.(uint64) |
| case uintptr: |
| return x.(uintptr) > y.(uintptr) |
| case float32: |
| return x.(float32) > y.(float32) |
| case float64: |
| return x.(float64) > y.(float64) |
| case string: |
| return x.(string) > y.(string) |
| } |
| |
| case token.GEQ: |
| switch x.(type) { |
| case int: |
| return x.(int) >= y.(int) |
| case int8: |
| return x.(int8) >= y.(int8) |
| case int16: |
| return x.(int16) >= y.(int16) |
| case int32: |
| return x.(int32) >= y.(int32) |
| case int64: |
| return x.(int64) >= y.(int64) |
| case uint: |
| return x.(uint) >= y.(uint) |
| case uint8: |
| return x.(uint8) >= y.(uint8) |
| case uint16: |
| return x.(uint16) >= y.(uint16) |
| case uint32: |
| return x.(uint32) >= y.(uint32) |
| case uint64: |
| return x.(uint64) >= y.(uint64) |
| case uintptr: |
| return x.(uintptr) >= y.(uintptr) |
| case float32: |
| return x.(float32) >= y.(float32) |
| case float64: |
| return x.(float64) >= y.(float64) |
| case string: |
| return x.(string) >= y.(string) |
| } |
| } |
| panic(fmt.Sprintf("invalid binary op: %T %s %T", x, op, y)) |
| } |
| |
| // eqnil returns the comparison x == y using the equivalence relation |
| // appropriate for type t. |
| // If t is a reference type, at most one of x or y may be a nil value |
| // of that type. |
| // |
| func eqnil(t types.Type, x, y value) bool { |
| switch t.Underlying().(type) { |
| case *types.Map, *types.Signature, *types.Slice: |
| // Since these types don't support comparison, |
| // one of the operands must be a literal nil. |
| switch x := x.(type) { |
| case *hashmap: |
| return (x != nil) == (y.(*hashmap) != nil) |
| case map[value]value: |
| return (x != nil) == (y.(map[value]value) != nil) |
| case *ssa.Function: |
| switch y := y.(type) { |
| case *ssa.Function: |
| return (x != nil) == (y != nil) |
| case *closure: |
| return true |
| } |
| case *closure: |
| return (x != nil) == (y.(*ssa.Function) != nil) |
| case []value: |
| return (x != nil) == (y.([]value) != nil) |
| } |
| panic(fmt.Sprintf("eqnil(%s): illegal dynamic type: %T", t, x)) |
| } |
| |
| return equals(t, x, y) |
| } |
| |
| func unop(instr *ssa.UnOp, x value) value { |
| switch instr.Op { |
| case token.ARROW: // receive |
| v, ok := <-x.(chan value) |
| if !ok { |
| v = zero(instr.X.Type().Underlying().(*types.Chan).Elem()) |
| } |
| if instr.CommaOk { |
| v = tuple{v, ok} |
| } |
| return v |
| case token.SUB: |
| switch x := x.(type) { |
| case int: |
| return -x |
| case int8: |
| return -x |
| case int16: |
| return -x |
| case int32: |
| return -x |
| case int64: |
| return -x |
| case uint: |
| return -x |
| case uint8: |
| return -x |
| case uint16: |
| return -x |
| case uint32: |
| return -x |
| case uint64: |
| return -x |
| case uintptr: |
| return -x |
| case float32: |
| return -x |
| case float64: |
| return -x |
| case complex64: |
| return -x |
| case complex128: |
| return -x |
| } |
| case token.MUL: |
| return load(deref(instr.X.Type()), x.(*value)) |
| case token.NOT: |
| return !x.(bool) |
| case token.XOR: |
| switch x := x.(type) { |
| case int: |
| return ^x |
| case int8: |
| return ^x |
| case int16: |
| return ^x |
| case int32: |
| return ^x |
| case int64: |
| return ^x |
| case uint: |
| return ^x |
| case uint8: |
| return ^x |
| case uint16: |
| return ^x |
| case uint32: |
| return ^x |
| case uint64: |
| return ^x |
| case uintptr: |
| return ^x |
| } |
| } |
| panic(fmt.Sprintf("invalid unary op %s %T", instr.Op, x)) |
| } |
| |
| // typeAssert checks whether dynamic type of itf is instr.AssertedType. |
| // It returns the extracted value on success, and panics on failure, |
| // unless instr.CommaOk, in which case it always returns a "value,ok" tuple. |
| // |
| func typeAssert(i *interpreter, instr *ssa.TypeAssert, itf iface) value { |
| var v value |
| err := "" |
| if itf.t == nil { |
| err = fmt.Sprintf("interface conversion: interface is nil, not %s", instr.AssertedType) |
| |
| } else if idst, ok := instr.AssertedType.Underlying().(*types.Interface); ok { |
| v = itf |
| err = checkInterface(i, idst, itf) |
| |
| } else if types.Identical(itf.t, instr.AssertedType) { |
| v = itf.v // extract value |
| |
| } else { |
| err = fmt.Sprintf("interface conversion: interface is %s, not %s", itf.t, instr.AssertedType) |
| } |
| |
| if err != "" { |
| if !instr.CommaOk { |
| panic(err) |
| } |
| return tuple{zero(instr.AssertedType), false} |
| } |
| if instr.CommaOk { |
| return tuple{v, true} |
| } |
| return v |
| } |
| |
| // If CapturedOutput is non-nil, all writes by the interpreted program |
| // to file descriptors 1 and 2 will also be written to CapturedOutput. |
| // |
| // (The $GOROOT/test system requires that the test be considered a |
| // failure if "BUG" appears in the combined stdout/stderr output, even |
| // if it exits zero. This is a global variable shared by all |
| // interpreters in the same process.) |
| // |
| var CapturedOutput *bytes.Buffer |
| var capturedOutputMu sync.Mutex |
| |
| // write writes bytes b to the target program's file descriptor fd. |
| // The print/println built-ins and the write() system call funnel |
| // through here so they can be captured by the test driver. |
| func write(fd int, b []byte) (int, error) { |
| // TODO(adonovan): fix: on Windows, std{out,err} are not 1, 2. |
| if CapturedOutput != nil && (fd == 1 || fd == 2) { |
| capturedOutputMu.Lock() |
| CapturedOutput.Write(b) // ignore errors |
| capturedOutputMu.Unlock() |
| } |
| return syswrite(fd, b) |
| } |
| |
| var syswrite func(int, []byte) (int, error) // set on darwin/linux only |
| |
| // callBuiltin interprets a call to builtin fn with arguments args, |
| // returning its result. |
| func callBuiltin(caller *frame, callpos token.Pos, fn *ssa.Builtin, args []value) value { |
| switch fn.Name() { |
| case "append": |
| if len(args) == 1 { |
| return args[0] |
| } |
| if s, ok := args[1].(string); ok { |
| // append([]byte, ...string) []byte |
| arg0 := args[0].([]value) |
| for i := 0; i < len(s); i++ { |
| arg0 = append(arg0, s[i]) |
| } |
| return arg0 |
| } |
| // append([]T, ...[]T) []T |
| return append(args[0].([]value), args[1].([]value)...) |
| |
| case "copy": // copy([]T, []T) int or copy([]byte, string) int |
| src := args[1] |
| if _, ok := src.(string); ok { |
| params := fn.Type().(*types.Signature).Params() |
| src = conv(params.At(0).Type(), params.At(1).Type(), src) |
| } |
| return copy(args[0].([]value), src.([]value)) |
| |
| case "close": // close(chan T) |
| close(args[0].(chan value)) |
| return nil |
| |
| case "delete": // delete(map[K]value, K) |
| switch m := args[0].(type) { |
| case map[value]value: |
| delete(m, args[1]) |
| case *hashmap: |
| m.delete(args[1].(hashable)) |
| default: |
| panic(fmt.Sprintf("illegal map type: %T", m)) |
| } |
| return nil |
| |
| case "print", "println": // print(any, ...) |
| ln := fn.Name() == "println" |
| var buf bytes.Buffer |
| for i, arg := range args { |
| if i > 0 && ln { |
| buf.WriteRune(' ') |
| } |
| buf.WriteString(toString(arg)) |
| } |
| if ln { |
| buf.WriteRune('\n') |
| } |
| write(1, buf.Bytes()) |
| return nil |
| |
| case "len": |
| switch x := args[0].(type) { |
| case string: |
| return len(x) |
| case array: |
| return len(x) |
| case *value: |
| return len((*x).(array)) |
| case []value: |
| return len(x) |
| case map[value]value: |
| return len(x) |
| case *hashmap: |
| return x.len() |
| case chan value: |
| return len(x) |
| default: |
| panic(fmt.Sprintf("len: illegal operand: %T", x)) |
| } |
| |
| case "cap": |
| switch x := args[0].(type) { |
| case array: |
| return cap(x) |
| case *value: |
| return cap((*x).(array)) |
| case []value: |
| return cap(x) |
| case chan value: |
| return cap(x) |
| default: |
| panic(fmt.Sprintf("cap: illegal operand: %T", x)) |
| } |
| |
| case "real": |
| switch c := args[0].(type) { |
| case complex64: |
| return real(c) |
| case complex128: |
| return real(c) |
| default: |
| panic(fmt.Sprintf("real: illegal operand: %T", c)) |
| } |
| |
| case "imag": |
| switch c := args[0].(type) { |
| case complex64: |
| return imag(c) |
| case complex128: |
| return imag(c) |
| default: |
| panic(fmt.Sprintf("imag: illegal operand: %T", c)) |
| } |
| |
| case "complex": |
| switch f := args[0].(type) { |
| case float32: |
| return complex(f, args[1].(float32)) |
| case float64: |
| return complex(f, args[1].(float64)) |
| default: |
| panic(fmt.Sprintf("complex: illegal operand: %T", f)) |
| } |
| |
| case "panic": |
| // ssa.Panic handles most cases; this is only for "go |
| // panic" or "defer panic". |
| panic(targetPanic{args[0]}) |
| |
| case "recover": |
| return doRecover(caller) |
| |
| case "ssa:wrapnilchk": |
| recv := args[0] |
| if recv.(*value) == nil { |
| recvType := args[1] |
| methodName := args[2] |
| panic(fmt.Sprintf("value method (%s).%s called using nil *%s pointer", |
| recvType, methodName, recvType)) |
| } |
| return recv |
| } |
| |
| panic("unknown built-in: " + fn.Name()) |
| } |
| |
| func rangeIter(x value, t types.Type) iter { |
| switch x := x.(type) { |
| case map[value]value: |
| // TODO(adonovan): fix: leaks goroutines and channels |
| // on each incomplete map iteration. We need to open |
| // up an iteration interface using the |
| // reflect.(Value).MapKeys machinery. |
| it := make(mapIter) |
| go func() { |
| for k, v := range x { |
| it <- [2]value{k, v} |
| } |
| close(it) |
| }() |
| return it |
| case *hashmap: |
| // TODO(adonovan): fix: leaks goroutines and channels |
| // on each incomplete map iteration. We need to open |
| // up an iteration interface using the |
| // reflect.(Value).MapKeys machinery. |
| it := make(mapIter) |
| go func() { |
| for _, e := range x.entries() { |
| for e != nil { |
| it <- [2]value{e.key, e.value} |
| e = e.next |
| } |
| } |
| close(it) |
| }() |
| return it |
| case string: |
| return &stringIter{Reader: strings.NewReader(x)} |
| } |
| panic(fmt.Sprintf("cannot range over %T", x)) |
| } |
| |
| // widen widens a basic typed value x to the widest type of its |
| // category, one of: |
| // bool, int64, uint64, float64, complex128, string. |
| // This is inefficient but reduces the size of the cross-product of |
| // cases we have to consider. |
| // |
| func widen(x value) value { |
| switch y := x.(type) { |
| case bool, int64, uint64, float64, complex128, string, unsafe.Pointer: |
| return x |
| case int: |
| return int64(y) |
| case int8: |
| return int64(y) |
| case int16: |
| return int64(y) |
| case int32: |
| return int64(y) |
| case uint: |
| return uint64(y) |
| case uint8: |
| return uint64(y) |
| case uint16: |
| return uint64(y) |
| case uint32: |
| return uint64(y) |
| case uintptr: |
| return uint64(y) |
| case float32: |
| return float64(y) |
| case complex64: |
| return complex128(y) |
| } |
| panic(fmt.Sprintf("cannot widen %T", x)) |
| } |
| |
| // conv converts the value x of type t_src to type t_dst and returns |
| // the result. |
| // Possible cases are described with the ssa.Convert operator. |
| // |
| func conv(t_dst, t_src types.Type, x value) value { |
| ut_src := t_src.Underlying() |
| ut_dst := t_dst.Underlying() |
| |
| // Destination type is not an "untyped" type. |
| if b, ok := ut_dst.(*types.Basic); ok && b.Info()&types.IsUntyped != 0 { |
| panic("oops: conversion to 'untyped' type: " + b.String()) |
| } |
| |
| // Nor is it an interface type. |
| if _, ok := ut_dst.(*types.Interface); ok { |
| if _, ok := ut_src.(*types.Interface); ok { |
| panic("oops: Convert should be ChangeInterface") |
| } else { |
| panic("oops: Convert should be MakeInterface") |
| } |
| } |
| |
| // Remaining conversions: |
| // + untyped string/number/bool constant to a specific |
| // representation. |
| // + conversions between non-complex numeric types. |
| // + conversions between complex numeric types. |
| // + integer/[]byte/[]rune -> string. |
| // + string -> []byte/[]rune. |
| // |
| // All are treated the same: first we extract the value to the |
| // widest representation (int64, uint64, float64, complex128, |
| // or string), then we convert it to the desired type. |
| |
| switch ut_src := ut_src.(type) { |
| case *types.Pointer: |
| switch ut_dst := ut_dst.(type) { |
| case *types.Basic: |
| // *value to unsafe.Pointer? |
| if ut_dst.Kind() == types.UnsafePointer { |
| return unsafe.Pointer(x.(*value)) |
| } |
| } |
| |
| case *types.Slice: |
| // []byte or []rune -> string |
| // TODO(adonovan): fix: type B byte; conv([]B -> string). |
| switch ut_src.Elem().(*types.Basic).Kind() { |
| case types.Byte: |
| x := x.([]value) |
| b := make([]byte, 0, len(x)) |
| for i := range x { |
| b = append(b, x[i].(byte)) |
| } |
| return string(b) |
| |
| case types.Rune: |
| x := x.([]value) |
| r := make([]rune, 0, len(x)) |
| for i := range x { |
| r = append(r, x[i].(rune)) |
| } |
| return string(r) |
| } |
| |
| case *types.Basic: |
| x = widen(x) |
| |
| // integer -> string? |
| // TODO(adonovan): fix: test integer -> named alias of string. |
| if ut_src.Info()&types.IsInteger != 0 { |
| if ut_dst, ok := ut_dst.(*types.Basic); ok && ut_dst.Kind() == types.String { |
| return string(asInt(x)) |
| } |
| } |
| |
| // string -> []rune, []byte or string? |
| if s, ok := x.(string); ok { |
| switch ut_dst := ut_dst.(type) { |
| case *types.Slice: |
| var res []value |
| // TODO(adonovan): fix: test named alias of rune, byte. |
| switch ut_dst.Elem().(*types.Basic).Kind() { |
| case types.Rune: |
| for _, r := range []rune(s) { |
| res = append(res, r) |
| } |
| return res |
| case types.Byte: |
| for _, b := range []byte(s) { |
| res = append(res, b) |
| } |
| return res |
| } |
| case *types.Basic: |
| if ut_dst.Kind() == types.String { |
| return x.(string) |
| } |
| } |
| break // fail: no other conversions for string |
| } |
| |
| // unsafe.Pointer -> *value |
| if ut_src.Kind() == types.UnsafePointer { |
| // TODO(adonovan): this is wrong and cannot |
| // really be fixed with the current design. |
| // |
| // return (*value)(x.(unsafe.Pointer)) |
| // creates a new pointer of a different |
| // type but the underlying interface value |
| // knows its "true" type and so cannot be |
| // meaningfully used through the new pointer. |
| // |
| // To make this work, the interpreter needs to |
| // simulate the memory layout of a real |
| // compiled implementation. |
| // |
| // To at least preserve type-safety, we'll |
| // just return the zero value of the |
| // destination type. |
| return zero(t_dst) |
| } |
| |
| // Conversions between complex numeric types? |
| if ut_src.Info()&types.IsComplex != 0 { |
| switch ut_dst.(*types.Basic).Kind() { |
| case types.Complex64: |
| return complex64(x.(complex128)) |
| case types.Complex128: |
| return x.(complex128) |
| } |
| break // fail: no other conversions for complex |
| } |
| |
| // Conversions between non-complex numeric types? |
| if ut_src.Info()&types.IsNumeric != 0 { |
| kind := ut_dst.(*types.Basic).Kind() |
| switch x := x.(type) { |
| case int64: // signed integer -> numeric? |
| switch kind { |
| case types.Int: |
| return int(x) |
| case types.Int8: |
| return int8(x) |
| case types.Int16: |
| return int16(x) |
| case types.Int32: |
| return int32(x) |
| case types.Int64: |
| return int64(x) |
| case types.Uint: |
| return uint(x) |
| case types.Uint8: |
| return uint8(x) |
| case types.Uint16: |
| return uint16(x) |
| case types.Uint32: |
| return uint32(x) |
| case types.Uint64: |
| return uint64(x) |
| case types.Uintptr: |
| return uintptr(x) |
| case types.Float32: |
| return float32(x) |
| case types.Float64: |
| return float64(x) |
| } |
| |
| case uint64: // unsigned integer -> numeric? |
| switch kind { |
| case types.Int: |
| return int(x) |
| case types.Int8: |
| return int8(x) |
| case types.Int16: |
| return int16(x) |
| case types.Int32: |
| return int32(x) |
| case types.Int64: |
| return int64(x) |
| case types.Uint: |
| return uint(x) |
| case types.Uint8: |
| return uint8(x) |
| case types.Uint16: |
| return uint16(x) |
| case types.Uint32: |
| return uint32(x) |
| case types.Uint64: |
| return uint64(x) |
| case types.Uintptr: |
| return uintptr(x) |
| case types.Float32: |
| return float32(x) |
| case types.Float64: |
| return float64(x) |
| } |
| |
| case float64: // floating point -> numeric? |
| switch kind { |
| case types.Int: |
| return int(x) |
| case types.Int8: |
| return int8(x) |
| case types.Int16: |
| return int16(x) |
| case types.Int32: |
| return int32(x) |
| case types.Int64: |
| return int64(x) |
| case types.Uint: |
| return uint(x) |
| case types.Uint8: |
| return uint8(x) |
| case types.Uint16: |
| return uint16(x) |
| case types.Uint32: |
| return uint32(x) |
| case types.Uint64: |
| return uint64(x) |
| case types.Uintptr: |
| return uintptr(x) |
| case types.Float32: |
| return float32(x) |
| case types.Float64: |
| return float64(x) |
| } |
| } |
| } |
| } |
| |
| panic(fmt.Sprintf("unsupported conversion: %s -> %s, dynamic type %T", t_src, t_dst, x)) |
| } |
| |
| // checkInterface checks that the method set of x implements the |
| // interface itype. |
| // On success it returns "", on failure, an error message. |
| // |
| func checkInterface(i *interpreter, itype *types.Interface, x iface) string { |
| if meth, _ := types.MissingMethod(x.t, itype, true); meth != nil { |
| return fmt.Sprintf("interface conversion: %v is not %v: missing method %s", |
| x.t, itype, meth.Name()) |
| } |
| return "" // ok |
| } |
