func equalType(x, y types.Type) error {
if reflect.TypeOf(x) != reflect.TypeOf(y) {
return fmt.Errorf("unequal kinds: %T vs %T", x, y)
}
switch x := x.(type) {
case *types.Interface:
y := y.(*types.Interface)
// TODO(gri): enable separate emission of Embedded interfaces
// and ExplicitMethods then use this logic.
// if x.NumEmbeddeds() != y.NumEmbeddeds() {
// return fmt.Errorf("unequal number of embedded interfaces: %d vs %d",
// x.NumEmbeddeds(), y.NumEmbeddeds())
// }
// for i := 0; i < x.NumEmbeddeds(); i++ {
// xi := x.Embedded(i)
// yi := y.Embedded(i)
// if xi.String() != yi.String() {
// return fmt.Errorf("mismatched %th embedded interface: %s vs %s",
// i, xi, yi)
// }
// }
// if x.NumExplicitMethods() != y.NumExplicitMethods() {
// return fmt.Errorf("unequal methods: %d vs %d",
// x.NumExplicitMethods(), y.NumExplicitMethods())
// }
// for i := 0; i < x.NumExplicitMethods(); i++ {
// xm := x.ExplicitMethod(i)
// ym := y.ExplicitMethod(i)
// if xm.Name() != ym.Name() {
// return fmt.Errorf("mismatched %th method: %s vs %s", i, xm, ym)
// }
// if err := equalType(xm.Type(), ym.Type()); err != nil {
// return fmt.Errorf("mismatched %s method: %s", xm.Name(), err)
// }
// }
if x.NumMethods() != y.NumMethods() {
return fmt.Errorf("unequal methods: %d vs %d",
x.NumMethods(), y.NumMethods())
}
for i := 0; i < x.NumMethods(); i++ {
xm := x.Method(i)
ym := y.Method(i)
if xm.Name() != ym.Name() {
return fmt.Errorf("mismatched %dth method: %s vs %s", i, xm, ym)
}
if err := equalType(xm.Type(), ym.Type()); err != nil {
return fmt.Errorf("mismatched %s method: %s", xm.Name(), err)
}
}
case *types.Array:
y := y.(*types.Array)
if x.Len() != y.Len() {
return fmt.Errorf("unequal array lengths: %d vs %d", x.Len(), y.Len())
}
if err := equalType(x.Elem(), y.Elem()); err != nil {
return fmt.Errorf("array elements: %s", err)
}
case *types.Basic:
y := y.(*types.Basic)
if x.Kind() != y.Kind() {
return fmt.Errorf("unequal basic types: %s vs %s", x, y)
}
case *types.Chan:
y := y.(*types.Chan)
if x.Dir() != y.Dir() {
return fmt.Errorf("unequal channel directions: %d vs %d", x.Dir(), y.Dir())
}
if err := equalType(x.Elem(), y.Elem()); err != nil {
return fmt.Errorf("channel elements: %s", err)
}
case *types.Map:
y := y.(*types.Map)
if err := equalType(x.Key(), y.Key()); err != nil {
return fmt.Errorf("map keys: %s", err)
}
if err := equalType(x.Elem(), y.Elem()); err != nil {
return fmt.Errorf("map values: %s", err)
}
case *types.Named:
y := y.(*types.Named)
if x.String() != y.String() {
return fmt.Errorf("unequal named types: %s vs %s", x, y)
}
case *types.Pointer:
y := y.(*types.Pointer)
if err := equalType(x.Elem(), y.Elem()); err != nil {
return fmt.Errorf("pointer elements: %s", err)
}
case *types.Signature:
y := y.(*types.Signature)
if err := equalType(x.Params(), y.Params()); err != nil {
return fmt.Errorf("parameters: %s", err)
}
if err := equalType(x.Results(), y.Results()); err != nil {
return fmt.Errorf("results: %s", err)
}
if x.Variadic() != y.Variadic() {
return fmt.Errorf("unequal varidicity: %t vs %t",
x.Variadic(), y.Variadic())
}
if (x.Recv() != nil) != (y.Recv() != nil) {
return fmt.Errorf("unequal receivers: %s vs %s", x.Recv(), y.Recv())
}
if x.Recv() != nil {
// TODO(adonovan): fix: this assertion fires for interface methods.
// The type of the receiver of an interface method is a named type
// if the Package was loaded from export data, or an unnamed (interface)
// type if the Package was produced by type-checking ASTs.
// if err := equalType(x.Recv().Type(), y.Recv().Type()); err != nil {
// return fmt.Errorf("receiver: %s", err)
// }
}
case *types.Slice:
y := y.(*types.Slice)
if err := equalType(x.Elem(), y.Elem()); err != nil {
return fmt.Errorf("slice elements: %s", err)
}
case *types.Struct:
y := y.(*types.Struct)
if x.NumFields() != y.NumFields() {
return fmt.Errorf("unequal struct fields: %d vs %d",
x.NumFields(), y.NumFields())
}
for i := 0; i < x.NumFields(); i++ {
xf := x.Field(i)
yf := y.Field(i)
if xf.Name() != yf.Name() {
return fmt.Errorf("mismatched fields: %s vs %s", xf, yf)
}
if err := equalType(xf.Type(), yf.Type()); err != nil {
return fmt.Errorf("struct field %s: %s", xf.Name(), err)
}
if x.Tag(i) != y.Tag(i) {
return fmt.Errorf("struct field %s has unequal tags: %q vs %q",
xf.Name(), x.Tag(i), y.Tag(i))
}
}
case *types.Tuple:
y := y.(*types.Tuple)
if x.Len() != y.Len() {
return fmt.Errorf("unequal tuple lengths: %d vs %d", x.Len(), y.Len())
}
for i := 0; i < x.Len(); i++ {
if err := equalType(x.At(i).Type(), y.At(i).Type()); err != nil {
return fmt.Errorf("tuple element %d: %s", i, err)
}
}
}
return nil
}
// 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].Type
if typ == nil {
return true // probably a type check problem
}
}
// If the type implements fmt.Formatter, we have nothing to check.
// formatterTyp may be nil - be conservative and check for Format method in that case.
if formatterType != nil && types.Implements(typ, formatterType) || f.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.AssertableTo(errorType, typ) || stringerType != nil && types.AssertableTo(stringerType, typ) {
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.Identical(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.Identical(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
}
func (w *Walker) writeType(buf *bytes.Buffer, typ types.Type) {
switch typ := typ.(type) {
case *types.Basic:
s := typ.Name()
switch typ.Kind() {
case types.UnsafePointer:
s = "unsafe.Pointer"
case types.UntypedBool:
s = "ideal-bool"
case types.UntypedInt:
s = "ideal-int"
case types.UntypedRune:
// "ideal-char" for compatibility with old tool
// TODO(gri) change to "ideal-rune"
s = "ideal-char"
case types.UntypedFloat:
s = "ideal-float"
case types.UntypedComplex:
s = "ideal-complex"
case types.UntypedString:
s = "ideal-string"
case types.UntypedNil:
panic("should never see untyped nil type")
default:
switch s {
case "byte":
s = "uint8"
case "rune":
s = "int32"
}
}
buf.WriteString(s)
case *types.Array:
fmt.Fprintf(buf, "[%d]", typ.Len())
w.writeType(buf, typ.Elem())
case *types.Slice:
buf.WriteString("[]")
w.writeType(buf, typ.Elem())
case *types.Struct:
buf.WriteString("struct")
case *types.Pointer:
buf.WriteByte('*')
w.writeType(buf, typ.Elem())
case *types.Tuple:
panic("should never see a tuple type")
case *types.Signature:
buf.WriteString("func")
w.writeSignature(buf, typ)
case *types.Interface:
buf.WriteString("interface{")
if typ.NumMethods() > 0 {
buf.WriteByte(' ')
buf.WriteString(strings.Join(sortedMethodNames(typ), ", "))
buf.WriteByte(' ')
}
buf.WriteString("}")
case *types.Map:
buf.WriteString("map[")
w.writeType(buf, typ.Key())
buf.WriteByte(']')
w.writeType(buf, typ.Elem())
case *types.Chan:
var s string
switch typ.Dir() {
case types.SendOnly:
s = "chan<- "
case types.RecvOnly:
s = "<-chan "
case types.SendRecv:
s = "chan "
default:
panic("unreachable")
}
buf.WriteString(s)
w.writeType(buf, typ.Elem())
case *types.Named:
obj := typ.Obj()
pkg := obj.Pkg()
if pkg != nil && pkg != w.current {
buf.WriteString(pkg.Name())
buf.WriteByte('.')
}
buf.WriteString(typ.Obj().Name())
default:
panic(fmt.Sprintf("unknown type %T", typ))
}
}
// hashFor computes the hash of t.
func (h Hasher) hashFor(t types.Type) uint32 {
// See Identical for rationale.
switch t := t.(type) {
case *types.Basic:
return uint32(t.Kind())
case *types.Array:
return 9043 + 2*uint32(t.Len()) + 3*h.Hash(t.Elem())
case *types.Slice:
return 9049 + 2*h.Hash(t.Elem())
case *types.Struct:
var hash uint32 = 9059
for i, n := 0, t.NumFields(); i < n; i++ {
f := t.Field(i)
if f.Anonymous() {
hash += 8861
}
hash += hashString(t.Tag(i))
hash += hashString(f.Name()) // (ignore f.Pkg)
hash += h.Hash(f.Type())
}
return hash
case *types.Pointer:
return 9067 + 2*h.Hash(t.Elem())
case *types.Signature:
var hash uint32 = 9091
if t.Variadic() {
hash *= 8863
}
return hash + 3*h.hashTuple(t.Params()) + 5*h.hashTuple(t.Results())
case *types.Interface:
var hash uint32 = 9103
for i, n := 0, t.NumMethods(); i < n; i++ {
// See go/types.identicalMethods for rationale.
// Method order is not significant.
// Ignore m.Pkg().
m := t.Method(i)
hash += 3*hashString(m.Name()) + 5*h.Hash(m.Type())
}
return hash
case *types.Map:
return 9109 + 2*h.Hash(t.Key()) + 3*h.Hash(t.Elem())
case *types.Chan:
return 9127 + 2*uint32(t.Dir()) + 3*h.Hash(t.Elem())
case *types.Named:
// Not safe with a copying GC; objects may move.
return uint32(reflect.ValueOf(t.Obj()).Pointer())
case *types.Tuple:
return h.hashTuple(t)
}
panic(t)
}