Ejemplo n.º 1
0
// lookupMethod returns the method set for type typ, which may be one
// of the interpreter's fake types.
func lookupMethod(i *interpreter, typ types.Type, meth *types.Func) *ssa.Function {
	switch typ {
	case rtypeType:
		return i.rtypeMethods[meth.Id()]
	case errorType:
		return i.errorMethods[meth.Id()]
	}
	return i.prog.LookupMethod(typ, meth.Pkg(), meth.Name())
}
Ejemplo n.º 2
0
func checkFuncValue(t *testing.T, prog *ssa.Program, obj *types.Func) {
	fn := prog.FuncValue(obj)
	// fmt.Printf("FuncValue(%s) = %s\n", obj, fn) // debugging
	if fn == nil {
		if obj.Name() != "interfaceMethod" {
			t.Errorf("FuncValue(%s) == nil", obj)
		}
		return
	}
	if fnobj := fn.Object(); fnobj != obj {
		t.Errorf("FuncValue(%s).Object() == %s; value was %s",
			obj, fnobj, fn.Name())
		return
	}
	if !types.Identical(fn.Type(), obj.Type()) {
		t.Errorf("FuncValue(%s).Type() == %s", obj, fn.Type())
		return
	}
}
Ejemplo n.º 3
0
// makeBound returns a bound method wrapper (or "bound"), a synthetic
// function that delegates to a concrete or interface method denoted
// by obj.  The resulting function has no receiver, but has one free
// variable which will be used as the method's receiver in the
// tail-call.
//
// Use MakeClosure with such a wrapper to construct a bound method
// closure.  e.g.:
//
//   type T int          or:  type T interface { meth() }
//   func (t T) meth()
//   var t T
//   f := t.meth
//   f() // calls t.meth()
//
// f is a closure of a synthetic wrapper defined as if by:
//
//   f := func() { return t.meth() }
//
// Unlike makeWrapper, makeBound need perform no indirection or field
// selections because that can be done before the closure is
// constructed.
//
// EXCLUSIVE_LOCKS_ACQUIRED(meth.Prog.methodsMu)
//
func makeBound(prog *Program, obj *types.Func) *Function {
	prog.methodsMu.Lock()
	defer prog.methodsMu.Unlock()
	fn, ok := prog.bounds[obj]
	if !ok {
		description := fmt.Sprintf("bound method wrapper for %s", obj)
		if prog.mode&LogSource != 0 {
			defer logStack("%s", description)()
		}
		fn = &Function{
			name:      obj.Name() + "$bound",
			object:    obj,
			Signature: changeRecv(obj.Type().(*types.Signature), nil), // drop receiver
			Synthetic: description,
			Prog:      prog,
			pos:       obj.Pos(),
		}

		fv := &FreeVar{name: "recv", typ: recvType(obj), parent: fn}
		fn.FreeVars = []*FreeVar{fv}
		fn.startBody()
		createParams(fn, 0)
		var c Call

		if !isInterface(recvType(obj)) { // concrete
			c.Call.Value = prog.declaredFunc(obj)
			c.Call.Args = []Value{fv}
		} else {
			c.Call.Value = fv
			c.Call.Method = obj
		}
		for _, arg := range fn.Params {
			c.Call.Args = append(c.Call.Args, arg)
		}
		emitTailCall(fn, &c)
		fn.finishBody()

		prog.bounds[obj] = fn
	}
	return fn
}
Ejemplo n.º 4
0
// Implements displays the "implements" relation as it pertains to the
// selected type.  If the selection is a method, 'implements' displays
// the corresponding methods of the types that would have been reported
// by an implements query on the receiver type.
//
func implements(o *Oracle, qpos *QueryPos) (queryResult, error) {
	// Find the selected type.
	path, action := findInterestingNode(qpos.info, qpos.path)

	var method *types.Func
	var T types.Type // selected type (receiver if method != nil)

	switch action {
	case actionExpr:
		// method?
		if id, ok := path[0].(*ast.Ident); ok {
			if obj, ok := qpos.info.ObjectOf(id).(*types.Func); ok {
				recv := obj.Type().(*types.Signature).Recv()
				if recv == nil {
					return nil, fmt.Errorf("this function is not a method")
				}
				method = obj
				T = recv.Type()
			}
		}
	case actionType:
		T = qpos.info.TypeOf(path[0].(ast.Expr))
	}
	if T == nil {
		return nil, fmt.Errorf("no type or method here")
	}

	// Find all named types, even local types (which can have
	// methods via promotion) and the built-in "error".
	//
	// TODO(adonovan): include all packages in PTA scope too?
	// i.e. don't reduceScope?
	//
	var allNamed []types.Type
	for _, info := range o.typeInfo {
		for _, obj := range info.Defs {
			if obj, ok := obj.(*types.TypeName); ok {
				allNamed = append(allNamed, obj.Type())
			}
		}
	}
	allNamed = append(allNamed, types.Universe.Lookup("error").Type())

	var msets types.MethodSetCache

	// Test each named type.
	var to, from, fromPtr []types.Type
	for _, U := range allNamed {
		if isInterface(T) {
			if msets.MethodSet(T).Len() == 0 {
				continue // empty interface
			}
			if isInterface(U) {
				if msets.MethodSet(U).Len() == 0 {
					continue // empty interface
				}

				// T interface, U interface
				if !types.Identical(T, U) {
					if types.AssignableTo(U, T) {
						to = append(to, U)
					}
					if types.AssignableTo(T, U) {
						from = append(from, U)
					}
				}
			} else {
				// T interface, U concrete
				if types.AssignableTo(U, T) {
					to = append(to, U)
				} else if pU := types.NewPointer(U); types.AssignableTo(pU, T) {
					to = append(to, pU)
				}
			}
		} else if isInterface(U) {
			if msets.MethodSet(U).Len() == 0 {
				continue // empty interface
			}

			// T concrete, U interface
			if types.AssignableTo(T, U) {
				from = append(from, U)
			} else if pT := types.NewPointer(T); types.AssignableTo(pT, U) {
				fromPtr = append(fromPtr, U)
			}
		}
	}

	var pos interface{} = qpos
	if nt, ok := deref(T).(*types.Named); ok {
		pos = nt.Obj()
	}

	// Sort types (arbitrarily) to ensure test determinism.
	sort.Sort(typesByString(to))
	sort.Sort(typesByString(from))
	sort.Sort(typesByString(fromPtr))

	var toMethod, fromMethod, fromPtrMethod []*types.Selection // contain nils
	if method != nil {
		for _, t := range to {
			toMethod = append(toMethod,
				types.NewMethodSet(t).Lookup(method.Pkg(), method.Name()))
		}
		for _, t := range from {
			fromMethod = append(fromMethod,
				types.NewMethodSet(t).Lookup(method.Pkg(), method.Name()))
		}
		for _, t := range fromPtr {
			fromPtrMethod = append(fromPtrMethod,
				types.NewMethodSet(t).Lookup(method.Pkg(), method.Name()))
		}
	}

	return &implementsResult{qpos, T, pos, to, from, fromPtr, method, toMethod, fromMethod, fromPtrMethod}, nil
}