예제 #1
0
파일: peers.go 프로젝트: tintohill/pythia
// chanOps returns a slice of all the channel operations in the instruction.
// Derived from oracle/peers.go.
func chanOps(instr ssa.Instruction) []chanOp {
	fn := instr.Parent()
	var ops []chanOp
	switch instr := instr.(type) {
	case *ssa.UnOp:
		if instr.Op == token.ARROW {
			// TODO(adonovan): don't assume <-ch; could be 'range ch'.
			ops = append(ops, chanOp{instr.X, "received", instr.Pos(), len("<-"), fn})
		}
	case *ssa.Send:
		ops = append(ops, chanOp{instr.Chan, "sent", instr.Pos(), len("<-"), fn})
	case *ssa.Select:
		for _, st := range instr.States {
			mode := "received"
			if st.Dir == types.SendOnly {
				mode = "sent"
			}
			ops = append(ops, chanOp{st.Chan, mode, st.Pos, len("<-"), fn})
		}
	case ssa.CallInstruction:
		call := instr.Common()
		if blt, ok := call.Value.(*ssa.Builtin); ok && blt.Name() == "close" {
			pos := instr.Common().Pos()
			ops = append(ops, chanOp{call.Args[0], "closed", pos - token.Pos(len("close")), len("close("), fn})
		}
	}
	return ops
}
예제 #2
0
파일: peers.go 프로젝트: tintohill/pythia
// chanOps returns a slice of all the channel operations in the instruction.
func chanOps(instr ssa.Instruction) []chanOp {
	// TODO(adonovan): handle calls to reflect.{Select,Recv,Send,Close} too.
	var ops []chanOp
	switch instr := instr.(type) {
	case *ssa.UnOp:
		if instr.Op == token.ARROW {
			ops = append(ops, chanOp{instr.X, types.RecvOnly, instr.Pos()})
		}
	case *ssa.Send:
		ops = append(ops, chanOp{instr.Chan, types.SendOnly, instr.Pos()})
	case *ssa.Select:
		for _, st := range instr.States {
			ops = append(ops, chanOp{st.Chan, st.Dir, st.Pos})
		}
	case ssa.CallInstruction:
		cc := instr.Common()
		if b, ok := cc.Value.(*ssa.Builtin); ok && b.Name() == "close" {
			ops = append(ops, chanOp{cc.Args[0], types.SendRecv, cc.Pos()})
		}
	}
	return ops
}
예제 #3
0
파일: interp.go 프로젝트: tintohill/pythia
// visitInstr interprets a single ssa.Instruction within the activation
// record frame.  It returns a continuation value indicating where to
// read the next instruction from.
func visitInstr(fr *frame, instr ssa.Instruction) continuation {
	switch instr := instr.(type) {
	case *ssa.DebugRef:
		// no-op

	case *ssa.UnOp:
		fr.env[instr] = unop(instr, fr.get(instr.X))

	case *ssa.BinOp:
		fr.env[instr] = binop(instr.Op, instr.X.Type(), fr.get(instr.X), fr.get(instr.Y))

	case *ssa.Call:
		fn, args := prepareCall(fr, &instr.Call)
		fr.env[instr] = call(fr.i, fr, instr.Pos(), fn, args)

	case *ssa.ChangeInterface:
		fr.env[instr] = fr.get(instr.X)

	case *ssa.ChangeType:
		fr.env[instr] = fr.get(instr.X) // (can't fail)

	case *ssa.Convert:
		fr.env[instr] = conv(instr.Type(), instr.X.Type(), fr.get(instr.X))

	case *ssa.MakeInterface:
		fr.env[instr] = iface{t: instr.X.Type(), v: fr.get(instr.X)}

	case *ssa.Extract:
		fr.env[instr] = fr.get(instr.Tuple).(tuple)[instr.Index]

	case *ssa.Slice:
		fr.env[instr] = slice(fr.get(instr.X), fr.get(instr.Low), fr.get(instr.High), fr.get(instr.Max))

	case *ssa.Return:
		switch len(instr.Results) {
		case 0:
		case 1:
			fr.result = fr.get(instr.Results[0])
		default:
			var res []value
			for _, r := range instr.Results {
				res = append(res, fr.get(r))
			}
			fr.result = tuple(res)
		}
		fr.block = nil
		return kReturn

	case *ssa.RunDefers:
		fr.runDefers()

	case *ssa.Panic:
		panic(targetPanic{fr.get(instr.X)})

	case *ssa.Send:
		fr.get(instr.Chan).(chan value) <- copyVal(fr.get(instr.X))

	case *ssa.Store:
		*fr.get(instr.Addr).(*value) = copyVal(fr.get(instr.Val))

	case *ssa.If:
		succ := 1
		if fr.get(instr.Cond).(bool) {
			succ = 0
		}
		fr.prevBlock, fr.block = fr.block, fr.block.Succs[succ]
		return kJump

	case *ssa.Jump:
		fr.prevBlock, fr.block = fr.block, fr.block.Succs[0]
		return kJump

	case *ssa.Defer:
		fn, args := prepareCall(fr, &instr.Call)
		fr.defers = &deferred{
			fn:    fn,
			args:  args,
			instr: instr,
			tail:  fr.defers,
		}

	case *ssa.Go:
		fn, args := prepareCall(fr, &instr.Call)
		go call(fr.i, nil, instr.Pos(), fn, args)

	case *ssa.MakeChan:
		fr.env[instr] = make(chan value, asInt(fr.get(instr.Size)))

	case *ssa.Alloc:
		var addr *value
		if instr.Heap {
			// new
			addr = new(value)
			fr.env[instr] = addr
		} else {
			// local
			addr = fr.env[instr].(*value)
		}
		*addr = zero(deref(instr.Type()))

	case *ssa.MakeSlice:
		slice := make([]value, asInt(fr.get(instr.Cap)))
		tElt := instr.Type().Underlying().(*types.Slice).Elem()
		for i := range slice {
			slice[i] = zero(tElt)
		}
		fr.env[instr] = slice[:asInt(fr.get(instr.Len))]

	case *ssa.MakeMap:
		reserve := 0
		if instr.Reserve != nil {
			reserve = asInt(fr.get(instr.Reserve))
		}
		fr.env[instr] = makeMap(instr.Type().Underlying().(*types.Map).Key(), reserve)

	case *ssa.Range:
		fr.env[instr] = rangeIter(fr.get(instr.X), instr.X.Type())

	case *ssa.Next:
		fr.env[instr] = fr.get(instr.Iter).(iter).next()

	case *ssa.FieldAddr:
		x := fr.get(instr.X)
		fr.env[instr] = &(*x.(*value)).(structure)[instr.Field]

	case *ssa.Field:
		fr.env[instr] = copyVal(fr.get(instr.X).(structure)[instr.Field])

	case *ssa.IndexAddr:
		x := fr.get(instr.X)
		idx := fr.get(instr.Index)
		switch x := x.(type) {
		case []value:
			fr.env[instr] = &x[asInt(idx)]
		case *value: // *array
			fr.env[instr] = &(*x).(array)[asInt(idx)]
		default:
			panic(fmt.Sprintf("unexpected x type in IndexAddr: %T", x))
		}

	case *ssa.Index:
		fr.env[instr] = copyVal(fr.get(instr.X).(array)[asInt(fr.get(instr.Index))])

	case *ssa.Lookup:
		fr.env[instr] = lookup(instr, fr.get(instr.X), fr.get(instr.Index))

	case *ssa.MapUpdate:
		m := fr.get(instr.Map)
		key := fr.get(instr.Key)
		v := fr.get(instr.Value)
		switch m := m.(type) {
		case map[value]value:
			m[key] = v
		case *hashmap:
			m.insert(key.(hashable), v)
		default:
			panic(fmt.Sprintf("illegal map type: %T", m))
		}

	case *ssa.TypeAssert:
		fr.env[instr] = typeAssert(fr.i, instr, fr.get(instr.X).(iface))

	case *ssa.MakeClosure:
		var bindings []value
		for _, binding := range instr.Bindings {
			bindings = append(bindings, fr.get(binding))
		}
		fr.env[instr] = &closure{instr.Fn.(*ssa.Function), bindings}

	case *ssa.Phi:
		for i, pred := range instr.Block().Preds {
			if fr.prevBlock == pred {
				fr.env[instr] = fr.get(instr.Edges[i])
				break
			}
		}

	case *ssa.Select:
		var cases []reflect.SelectCase
		if !instr.Blocking {
			cases = append(cases, reflect.SelectCase{
				Dir: reflect.SelectDefault,
			})
		}
		for _, state := range instr.States {
			var dir reflect.SelectDir
			if state.Dir == types.RecvOnly {
				dir = reflect.SelectRecv
			} else {
				dir = reflect.SelectSend
			}
			var send reflect.Value
			if state.Send != nil {
				send = reflect.ValueOf(fr.get(state.Send))
			}
			cases = append(cases, reflect.SelectCase{
				Dir:  dir,
				Chan: reflect.ValueOf(fr.get(state.Chan)),
				Send: send,
			})
		}
		chosen, recv, recvOk := reflect.Select(cases)
		if !instr.Blocking {
			chosen-- // default case should have index -1.
		}
		r := tuple{chosen, recvOk}
		for i, st := range instr.States {
			if st.Dir == types.RecvOnly {
				var v value
				if i == chosen && recvOk {
					// No need to copy since send makes an unaliased copy.
					v = recv.Interface().(value)
				} else {
					v = zero(st.Chan.Type().Underlying().(*types.Chan).Elem())
				}
				r = append(r, v)
			}
		}
		fr.env[instr] = r

	default:
		panic(fmt.Sprintf("unexpected instruction: %T", instr))
	}

	// if val, ok := instr.(ssa.Value); ok {
	// 	fmt.Println(toString(fr.env[val])) // debugging
	// }

	return kNext
}