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go/types: clean up asT converters (step 1 of 2)

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This is a port of CL 358597 to go/types. A comment was missing in the
base of applyTypeFunc, which had been there since the initial check-in
of types2; somehow it was not in go/types.

Change-Id: If08efd92d782dd3099b26254ae6e311c6cea8c3b
Reviewed-on: https://go-review.googlesource.com/c/go/+/360477
Trust: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
This commit is contained in:
Robert Findley 2021-11-01 15:27:13 -04:00
parent 7c9510ef3e
commit b29182b54a
16 changed files with 83 additions and 117 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
src/go/types/assignments.go
View File

@ -71,7 +71,7 @@ func (check *Checker) assignment(x *operand, T Type, context string) {
}
// A generic (non-instantiated) function value cannot be assigned to a variable.
if sig := asSignature(x.typ); sig != nil && sig.TypeParams().Len() > 0 {
if sig := toSignature(x.typ); sig != nil && sig.TypeParams().Len() > 0 {
check.errorf(x, _Todo, "cannot use generic function %s without instantiation in %s", x, context)
}

24
src/go/types/builtins.go
View File

@ -83,7 +83,7 @@ func (check *Checker) builtin(x *operand, call *ast.CallExpr, id builtinId) (_ b
// of S and the respective parameter passing rules apply."
S := x.typ
var T Type
if s := asSlice(S); s != nil {
if s, _ := singleUnder(S).(*Slice); s != nil {
T = s.elem
} else {
check.invalidArg(x, _InvalidAppend, "%s is not a slice", x)
@ -296,8 +296,10 @@ func (check *Checker) builtin(x *operand, call *ast.CallExpr, id builtinId) (_ b
}
// the argument types must be of floating-point type
f := func(x Type) Type {
if t := asBasic(x); t != nil {
// (applyTypeFunc never calls f with a type parameter)
f := func(typ Type) Type {
assert(asTypeParam(typ) == nil)
if t := toBasic(typ); t != nil {
switch t.kind {
case Float32:
return Typ[Complex64]
@ -418,8 +420,10 @@ func (check *Checker) builtin(x *operand, call *ast.CallExpr, id builtinId) (_ b
}
// the argument must be of complex type
f := func(x Type) Type {
if t := asBasic(x); t != nil {
// (applyTypeFunc never calls f with a type parameter)
f := func(typ Type) Type {
assert(asTypeParam(typ) == nil)
if t := toBasic(typ); t != nil {
switch t.kind {
case Complex64:
return Typ[Float32]
@ -709,7 +713,7 @@ func (check *Checker) builtin(x *operand, call *ast.CallExpr, id builtinId) (_ b
return
}
typ := asPointer(x.typ)
typ := toPointer(x.typ)
if typ == nil {
check.invalidArg(x, _InvalidUnsafeSlice, "%s is not a pointer", x)
return
@ -825,7 +829,7 @@ func hasVarSize(t Type) bool {
}
case *TypeParam:
return true
case *Named, *Union, *top:
case *Named, *Union:
unreachable()
}
return false
@ -856,8 +860,8 @@ func (check *Checker) applyTypeFunc(f func(Type) Type, x Type) Type {
return nil
}
// Construct a suitable new type parameter for the sum type. The
// type param is placed in the current package so export/import
// Construct a suitable new type parameter for the result type.
// The type parameter is placed in the current package so export/import
// works as expected.
tpar := NewTypeName(token.NoPos, check.pkg, "<type parameter>", nil)
ptyp := check.newTypeParam(tpar, NewInterfaceType(nil, []Type{NewUnion(terms)})) // assigns type to tpar as a side-effect
@ -889,7 +893,7 @@ func makeSig(res Type, args ...Type) *Signature {
// otherwise it returns typ.
func arrayPtrDeref(typ Type) Type {
if p, ok := typ.(*Pointer); ok {
if a := asArray(p.base); a != nil {
if a := toArray(p.base); a != nil {
return a
}
}

8
src/go/types/call.go
View File

@ -141,10 +141,9 @@ func (check *Checker) callExpr(x *operand, call *ast.CallExpr) exprKind {
check.errorf(call.Args[0], _BadDotDotDotSyntax, "invalid use of ... in conversion to %s", T)
break
}
if t := asInterface(T); t != nil {
if t := toInterface(T); t != nil {
if !t.IsMethodSet() {
// TODO(rfindley): remove the phrase "type list" from this error.
check.errorf(call, _Todo, "cannot use interface %s in conversion (contains type list or is comparable)", T)
check.errorf(call, _Todo, "cannot use interface %s in conversion (contains specific type constraints or is comparable)", T)
break
}
}
@ -175,7 +174,8 @@ func (check *Checker) callExpr(x *operand, call *ast.CallExpr) exprKind {
// signature may be generic
cgocall := x.mode == cgofunc
sig := asSignature(x.typ)
// a type parameter may be "called" if all types have the same signature
sig, _ := singleUnder(x.typ).(*Signature)
if sig == nil {
check.invalidOp(x, _InvalidCall, "cannot call non-function %s", x)
x.mode = invalid

24
src/go/types/conversions.go
View File

@ -21,7 +21,7 @@ func (check *Checker) conversion(x *operand, T Type) {
switch {
case constArg && isConstType(T):
// constant conversion (T cannot be a type parameter)
switch t := asBasic(T); {
switch t := toBasic(T); {
case representableConst(x.val, check, t, &x.val):
ok = true
case isInteger(x.typ) && isString(t):
@ -198,9 +198,9 @@ func convertibleToImpl(check *Checker, V, T Type, cause *string) bool {
// "V is a slice, T is a pointer-to-array type,
// and the slice and array types have identical element types."
if s := asSlice(V); s != nil {
if p := asPointer(T); p != nil {
if a := asArray(p.Elem()); a != nil {
if s := toSlice(V); s != nil {
if p := toPointer(T); p != nil {
if a := toArray(p.Elem()); a != nil {
if Identical(s.Elem(), a.Elem()) {
if check == nil || check.allowVersion(check.pkg, 1, 17) {
return true
@ -216,27 +216,31 @@ func convertibleToImpl(check *Checker, V, T Type, cause *string) bool {
return false
}
// Helper predicates for convertibleToImpl. The types provided to convertibleToImpl
// may be type parameters but they won't have specific type terms. Thus it is ok to
// use the toT convenience converters in the predicates below.
func isUintptr(typ Type) bool {
t := asBasic(typ)
t := toBasic(typ)
return t != nil && t.kind == Uintptr
}
func isUnsafePointer(typ Type) bool {
// TODO(gri): Is this asBasic(typ) instead of typ.(*Basic) correct?
// TODO(gri): Is this toBasic(typ) instead of typ.(*Basic) correct?
// (The former calls under(), while the latter doesn't.)
// The spec does not say so, but gc claims it is. See also
// issue 6326.
t := asBasic(typ)
t := toBasic(typ)
return t != nil && t.kind == UnsafePointer
}
func isPointer(typ Type) bool {
return asPointer(typ) != nil
return toPointer(typ) != nil
}
func isBytesOrRunes(typ Type) bool {
if s := asSlice(typ); s != nil {
t := asBasic(s.elem)
if s := toSlice(typ); s != nil {
t := toBasic(s.elem)
return t != nil && (t.kind == Byte || t.kind == Rune)
}
return false

8
src/go/types/expr.go
View File

@ -100,8 +100,10 @@ func (check *Checker) overflow(x *operand, op token.Token, opPos token.Pos) {
// Typed constants must be representable in
// their type after each constant operation.
// x.typ cannot be a type parameter (type
// parameters cannot be constant types).
if isTyped(x.typ) {
check.representable(x, asBasic(x.typ))
check.representable(x, toBasic(x.typ))
return
}
@ -554,7 +556,7 @@ func (check *Checker) updateExprType(x ast.Expr, typ Type, final bool) {
// If the new type is not final and still untyped, just
// update the recorded type.
if !final && isUntyped(typ) {
old.typ = asBasic(typ)
old.typ = toBasic(typ)
check.untyped[x] = old
return
}
@ -1353,7 +1355,7 @@ func (check *Checker) exprInternal(x *operand, e ast.Expr, hint Type) exprKind {
duplicate := false
// if the key is of interface type, the type is also significant when checking for duplicates
xkey := keyVal(x.val)
if asInterface(utyp.key) != nil {
if toInterface(utyp.key) != nil {
for _, vtyp := range visited[xkey] {
if Identical(vtyp, x.typ) {
duplicate = true

6
src/go/types/index.go
View File

@ -35,7 +35,7 @@ func (check *Checker) indexExpr(x *operand, e *typeparams.IndexExpr) (isFuncInst
return false
case value:
if sig := asSignature(x.typ); sig != nil && sig.TypeParams().Len() > 0 {
if sig := toSignature(x.typ); sig != nil && sig.TypeParams().Len() > 0 {
// function instantiation
return true
}
@ -72,7 +72,7 @@ func (check *Checker) indexExpr(x *operand, e *typeparams.IndexExpr) (isFuncInst
x.typ = typ.elem
case *Pointer:
if typ := asArray(typ.base); typ != nil {
if typ := toArray(typ.base); typ != nil {
valid = true
length = typ.len
x.mode = variable
@ -242,7 +242,7 @@ func (check *Checker) sliceExpr(x *operand, e *ast.SliceExpr) {
x.typ = &Slice{elem: u.elem}
case *Pointer:
if u := asArray(u.base); u != nil {
if u := toArray(u.base); u != nil {
valid = true
length = u.len
x.typ = &Slice{elem: u.elem}

4
src/go/types/infer.go
View File

@ -270,7 +270,7 @@ func (w *tpWalker) isParameterized(typ Type) (res bool) {
}()
switch t := typ.(type) {
case nil, *top, *Basic: // TODO(gri) should nil be handled here?
case nil, *Basic: // TODO(gri) should nil be handled here?
break
case *Array:
@ -499,7 +499,7 @@ func (w *cycleFinder) typ(typ Type) {
defer delete(w.seen, typ)
switch t := typ.(type) {
case *Basic, *top:
case *Basic:
// nothing to do
case *Array:

8
src/go/types/lookup.go
View File

@ -302,7 +302,7 @@ func (check *Checker) missingMethod(V Type, T *Interface, static bool) (method,
return
}
if ityp := asInterface(V); ityp != nil {
if ityp := toInterface(V); ityp != nil {
// TODO(gri) the methods are sorted - could do this more efficiently
for _, m := range T.typeSet().methods {
_, f := ityp.typeSet().LookupMethod(m.pkg, m.name)
@ -400,7 +400,7 @@ func (check *Checker) assertableTo(V *Interface, T Type) (method, wrongType *Fun
// no static check is required if T is an interface
// spec: "If T is an interface type, x.(T) asserts that the
// dynamic type of x implements the interface T."
if asInterface(T) != nil && !forceStrict {
if toInterface(T) != nil && !forceStrict {
return
}
return check.missingMethod(T, V, false)
@ -418,8 +418,8 @@ func deref(typ Type) (Type, bool) {
// derefStructPtr dereferences typ if it is a (named or unnamed) pointer to a
// (named or unnamed) struct and returns its base. Otherwise it returns typ.
func derefStructPtr(typ Type) Type {
if p := asPointer(typ); p != nil {
if asStruct(p.base) != nil {
if p := toPointer(typ); p != nil {
if toStruct(p.base) != nil {
return p.base
}
}

10
src/go/types/predicates.go
View File

@ -58,7 +58,7 @@ func isNumericOrString(typ Type) bool { return is(typ, IsNumeric|IsString) }
// are not fully set up.
func isTyped(typ Type) bool {
// isTyped is called with types that are not fully
// set up. Must not call asBasic()!
// set up. Must not call toBasic()!
t, _ := typ.(*Basic)
return t == nil || t.info&IsUntyped == 0
}
@ -72,13 +72,13 @@ func isOrdered(typ Type) bool { return is(typ, IsOrdered) }
func isConstType(typ Type) bool {
// Type parameters are never const types.
t, _ := under(typ).(*Basic)
t := toBasic(typ)
return t != nil && t.info&IsConstType != 0
}
// IsInterface reports whether typ is an interface type.
func IsInterface(typ Type) bool {
return asInterface(typ) != nil
return toInterface(typ) != nil
}
// Comparable reports whether values of type T are comparable.
@ -341,10 +341,6 @@ func identical(x, y Type, cmpTags bool, p *ifacePair) bool {
case *TypeParam:
// nothing to do (x and y being equal is caught in the very beginning of this function)
case *top:
// Either both types are theTop in which case the initial x == y check
// will have caught them. Otherwise they are not identical.
case nil:
// avoid a crash in case of nil type

1
src/go/types/sizeof_test.go
View File

@ -33,7 +33,6 @@ func TestSizeof(t *testing.T) {
{Named{}, 68, 128},
{TypeParam{}, 28, 48},
{term{}, 12, 24},
{top{}, 0, 0},
// Objects
{PkgName{}, 48, 88},

2
src/go/types/sizes.go
View File

@ -243,7 +243,7 @@ func (conf *Config) offsetsof(T *Struct) []int64 {
func (conf *Config) offsetof(typ Type, index []int) int64 {
var o int64
for _, i := range index {
s := asStruct(typ)
s := toStruct(typ)
o += conf.offsetsof(s)[i]
typ = s.fields[i].typ
}

2
src/go/types/subst.go
View File

@ -74,7 +74,7 @@ func (subst *subster) typ(typ Type) Type {
// Call typOrNil if it's possible that typ is nil.
panic("nil typ")
case *Basic, *top:
case *Basic:
// nothing to do
case *Array:

7
src/go/types/testdata/check/issues.go2 vendored
View File

@ -224,6 +224,13 @@ func _[T interface{ ~func() }](f T) {
go f()
}
type F1 func()
type F2 func()
func _[T interface{ func()|F1|F2 }](f T) {
f()
go f()
}
// We must compare against the underlying type of term list entries
// when checking if a constraint is satisfied by a type. The under-
// lying type of each term list entry must be computed after the

85
src/go/types/type.go
View File

@ -9,26 +9,13 @@ package types
type Type interface {
// Underlying returns the underlying type of a type
// w/o following forwarding chains. Only used by
// client packages (here for backward-compatibility).
// client packages.
Underlying() Type
// String returns a string representation of a type.
String() string
}
// top represents the top of the type lattice.
// It is the underlying type of a type parameter that
// can be satisfied by any type (ignoring methods),
// because its type constraint contains no restrictions
// besides methods.
type top struct{}
// theTop is the singleton top type.
var theTop = &top{}
func (t *top) Underlying() Type { return t }
func (t *top) String() string { return TypeString(t, nil) }
// under returns the true expanded underlying type.
// If it doesn't exist, the result is Typ[Invalid].
// under must only be called when a type is known
@ -40,77 +27,47 @@ func under(t Type) Type {
return t
}
// optype returns a type's operational type. Except for
// type parameters, the operational type is the same
// as the underlying type (as returned by under). For
// Type parameters, the operational type is the structural
// type, if any; otherwise it's the top type.
// The result is never the incoming type parameter.
func optype(typ Type) Type {
if t := asTypeParam(typ); t != nil {
// TODO(gri) review accuracy of this comment
// If the optype is typ, return the top type as we have
// no information. It also prevents infinite recursion
// via the asTypeParam converter function. This can happen
// for a type parameter list of the form:
// (type T interface { type T }).
// See also issue #39680.
if u := t.structuralType(); u != nil {
assert(u != typ) // "naked" type parameters cannot be embedded
return under(u) // optype should always return an underlying type
}
return theTop
}
return under(typ)
}
// Convenience converters
// Converters
//
// A converter must only be called when a type is
// known to be fully set up. A converter returns
// a type's operational type (see comment for optype)
// or nil if the type argument is not of the
// respective type.
func asBasic(t Type) *Basic {
op, _ := optype(t).(*Basic)
func toBasic(t Type) *Basic {
op, _ := under(t).(*Basic)
return op
}
func asArray(t Type) *Array {
op, _ := optype(t).(*Array)
func toArray(t Type) *Array {
op, _ := under(t).(*Array)
return op
}
func asSlice(t Type) *Slice {
op, _ := optype(t).(*Slice)
func toSlice(t Type) *Slice {
op, _ := under(t).(*Slice)
return op
}
func asStruct(t Type) *Struct {
op, _ := optype(t).(*Struct)
func toStruct(t Type) *Struct {
op, _ := under(t).(*Struct)
return op
}
func asPointer(t Type) *Pointer {
op, _ := optype(t).(*Pointer)
func toPointer(t Type) *Pointer {
op, _ := under(t).(*Pointer)
return op
}
func asSignature(t Type) *Signature {
op, _ := optype(t).(*Signature)
func toSignature(t Type) *Signature {
op, _ := under(t).(*Signature)
return op
}
// If the argument to asInterface, asNamed, or asTypeParam is of the respective type
// (possibly after expanding an instance type), these methods return that type.
func toInterface(t Type) *Interface {
op, _ := under(t).(*Interface)
return op
}
// If the argument to asNamed, or asTypeParam is of the respective type
// (possibly after expanding resolving a *Named type), these methods return that type.
// Otherwise the result is nil.
func asInterface(t Type) *Interface {
op, _ := optype(t).(*Interface)
return op
}
func asNamed(t Type) *Named {
e, _ := t.(*Named)
if e != nil {

5
src/go/types/typestring.go
View File

@ -283,9 +283,6 @@ func (w *typeWriter) typ(typ Type) {
w.string(subscript(t.id))
}
case *top:
w.error("⊤")
default:
// For externally defined implementations of Type.
// Note: In this case cycles won't be caught.
@ -369,7 +366,7 @@ func (w *typeWriter) tuple(tup *Tuple, variadic bool) {
} else {
// special case:
// append(s, "foo"...) leads to signature func([]byte, string...)
if t := asBasic(typ); t == nil || t.kind != String {
if t := toBasic(typ); t == nil || t.kind != String {
w.error("expected string type")
continue
}

4
src/go/types/typexpr.go
View File

@ -141,11 +141,11 @@ func (check *Checker) typ(e ast.Expr) Type {
// constraint interface.
func (check *Checker) varType(e ast.Expr) Type {
typ := check.definedType(e, nil)
// We don't want to call under() (via asInterface) or complete interfaces while we
// We don't want to call under() (via toInterface) or complete interfaces while we
// are in the middle of type-checking parameter declarations that might belong to
// interface methods. Delay this check to the end of type-checking.
check.later(func() {
if t := asInterface(typ); t != nil {
if t := toInterface(typ); t != nil {
tset := computeInterfaceTypeSet(check, e.Pos(), t) // TODO(gri) is this the correct position?
if !tset.IsMethodSet() {
if tset.comparable {