Exemple #1
0
func FindImplentations(i *types.Interface, pkg *types.Package) []string {
	var names []string

	scope := pkg.Scope()
	allNames := scope.Names()

	for _, name := range allNames {
		obj := scope.Lookup(name)
		if typeName, ok := obj.(*types.TypeName); ok {
			if types.Implements(typeName.Type(), i) {
				names = append(names, typeName.Name())
			} else {
				println(typeName.Name(), "cannot be an ensurer")
				println(types.NewMethodSet(typeName.Type()).String())
			}
		}
	}

	return names
}
// matchArgTypeInternal is the internal version of matchArgType. It carries a map
// remembering what types are in progress so we don't recur when faced with recursive
// types or mutually recursive types.
func (f *File) matchArgTypeInternal(t printfArgType, typ types.Type, arg ast.Expr, inProgress map[types.Type]bool) bool {
	// %v, %T accept any argument type.
	if t == anyType {
		return true
	}
	if typ == nil {
		// external call
		typ = f.pkg.types[arg]
		if typ == nil {
			return true // probably a type check problem
		}
	}
	// If the type implements fmt.Formatter, we have nothing to check.
	// But (see issue 6259) that's not easy to verify, so instead we see
	// if its method set contains a Format function. We could do better,
	// even now, but we don't need to be 100% accurate. Wait for 6259 to
	// be fixed instead. TODO.
	if hasMethod(typ, "Format") {
		return true
	}
	// If we can use a string, might arg (dynamically) implement the Stringer or Error interface?
	if t&argString != 0 {
		if types.Implements(typ, errorType, false) || types.Implements(typ, stringerType, false) {
			return true
		}
	}

	typ = typ.Underlying()
	if inProgress[typ] {
		// We're already looking at this type. The call that started it will take care of it.
		return true
	}
	inProgress[typ] = true

	switch typ := typ.(type) {
	case *types.Signature:
		return t&argPointer != 0

	case *types.Map:
		// Recur: map[int]int matches %d.
		return t&argPointer != 0 ||
			(f.matchArgTypeInternal(t, typ.Key(), arg, inProgress) && f.matchArgTypeInternal(t, typ.Elem(), arg, inProgress))

	case *types.Chan:
		return t&argPointer != 0

	case *types.Array:
		// Same as slice.
		if types.IsIdentical(typ.Elem().Underlying(), types.Typ[types.Byte]) && t&argString != 0 {
			return true // %s matches []byte
		}
		// Recur: []int matches %d.
		return t&argPointer != 0 || f.matchArgTypeInternal(t, typ.Elem().Underlying(), arg, inProgress)

	case *types.Slice:
		// Same as array.
		if types.IsIdentical(typ.Elem().Underlying(), types.Typ[types.Byte]) && t&argString != 0 {
			return true // %s matches []byte
		}
		// Recur: []int matches %d. But watch out for
		//	type T []T
		// If the element is a pointer type (type T[]*T), it's handled fine by the Pointer case below.
		return t&argPointer != 0 || f.matchArgTypeInternal(t, typ.Elem(), arg, inProgress)

	case *types.Pointer:
		// Ugly, but dealing with an edge case: a known pointer to an invalid type,
		// probably something from a failed import.
		if typ.Elem().String() == "invalid type" {
			if *verbose {
				f.Warnf(arg.Pos(), "printf argument %v is pointer to invalid or unknown type", f.gofmt(arg))
			}
			return true // special case
		}
		// If it's actually a pointer with %p, it prints as one.
		if t == argPointer {
			return true
		}
		// If it's pointer to struct, that's equivalent in our analysis to whether we can print the struct.
		if str, ok := typ.Elem().Underlying().(*types.Struct); ok {
			return f.matchStructArgType(t, str, arg, inProgress)
		}
		// The rest can print with %p as pointers, or as integers with %x etc.
		return t&(argInt|argPointer) != 0

	case *types.Struct:
		return f.matchStructArgType(t, typ, arg, inProgress)

	case *types.Interface:
		// If the static type of the argument is empty interface, there's little we can do.
		// Example:
		//	func f(x interface{}) { fmt.Printf("%s", x) }
		// Whether x is valid for %s depends on the type of the argument to f. One day
		// we will be able to do better. For now, we assume that empty interface is OK
		// but non-empty interfaces, with Stringer and Error handled above, are errors.
		return typ.NumMethods() == 0

	case *types.Basic:
		switch typ.Kind() {
		case types.UntypedBool,
			types.Bool:
			return t&argBool != 0

		case types.UntypedInt,
			types.Int,
			types.Int8,
			types.Int16,
			types.Int32,
			types.Int64,
			types.Uint,
			types.Uint8,
			types.Uint16,
			types.Uint32,
			types.Uint64,
			types.Uintptr:
			return t&argInt != 0

		case types.UntypedFloat,
			types.Float32,
			types.Float64:
			return t&argFloat != 0

		case types.UntypedComplex,
			types.Complex64,
			types.Complex128:
			return t&argComplex != 0

		case types.UntypedString,
			types.String:
			return t&argString != 0

		case types.UnsafePointer:
			return t&(argPointer|argInt) != 0

		case types.UntypedRune:
			return t&(argInt|argRune) != 0

		case types.UntypedNil:
			return t&argPointer != 0 // TODO?

		case types.Invalid:
			if *verbose {
				f.Warnf(arg.Pos(), "printf argument %v has invalid or unknown type", f.gofmt(arg))
			}
			return true // Probably a type check problem.
		}
		panic("unreachable")
	}

	return false
}