[dev.typeparams] cmd/compile/internal/types2: replace optype() with under() in various cases (cleanup)
This makes the behavior for type parameter operands explicit
in those cases.
Change-Id: I38438af67de4432f1a691dc4947e4576445f031b
Reviewed-on: https://go-review.googlesource.com/c/go/+/332555
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
diff --git a/src/cmd/compile/internal/types2/builtins.go b/src/cmd/compile/internal/types2/builtins.go
index 7ba2650..83d1743 100644
--- a/src/cmd/compile/internal/types2/builtins.go
+++ b/src/cmd/compile/internal/types2/builtins.go
@@ -332,13 +332,15 @@
return
}
var src Type
- switch t := optype(y.typ).(type) {
+ switch t := under(y.typ).(type) {
case *Basic:
if isString(y.typ) {
src = universeByte
}
case *Slice:
src = t.elem
+ case *TypeParam:
+ check.error(x, "copy on generic operands not yet implemented")
}
if dst == nil || src == nil {
@@ -455,12 +457,12 @@
var valid func(t Type) bool
valid = func(t Type) bool {
var m int
- switch t := optype(t).(type) {
+ switch t := under(t).(type) {
case *Slice:
m = 2
case *Map, *Chan:
m = 1
- case *Union:
+ case *TypeParam:
return t.underIs(valid)
default:
return false
diff --git a/src/cmd/compile/internal/types2/expr.go b/src/cmd/compile/internal/types2/expr.go
index 1cb0ad4..bd35417 100644
--- a/src/cmd/compile/internal/types2/expr.go
+++ b/src/cmd/compile/internal/types2/expr.go
@@ -691,7 +691,7 @@
return nil, nil, _InvalidUntypedConversion
}
- switch t := optype(target).(type) {
+ switch t := under(target).(type) {
case *Basic:
if x.mode == constant_ {
v, code := check.representation(x, t)
@@ -723,7 +723,7 @@
default:
return nil, nil, _InvalidUntypedConversion
}
- case *Union:
+ case *TypeParam:
ok := t.underIs(func(t Type) bool {
target, _, _ := check.implicitTypeAndValue(x, t)
return target != nil
@@ -1197,7 +1197,7 @@
goto Error
}
- switch utyp := optype(base).(type) {
+ switch utyp := under(base).(type) {
case *Struct:
if len(e.ElemList) == 0 {
break
diff --git a/src/cmd/compile/internal/types2/index.go b/src/cmd/compile/internal/types2/index.go
index 5a4dcb4..d3e0c71 100644
--- a/src/cmd/compile/internal/types2/index.go
+++ b/src/cmd/compile/internal/types2/index.go
@@ -199,7 +199,7 @@
valid := false
length := int64(-1) // valid if >= 0
- switch typ := optype(x.typ).(type) {
+ switch typ := under(x.typ).(type) {
case *Basic:
if isString(typ) {
if e.Full {
@@ -239,7 +239,7 @@
valid = true
// x.typ doesn't change
- case *Union, *TypeParam:
+ case *TypeParam:
check.error(x, "generic slice expressions not yet implemented")
x.mode = invalid
return
diff --git a/src/cmd/compile/internal/types2/predicates.go b/src/cmd/compile/internal/types2/predicates.go
index 5ff7840..2f10898 100644
--- a/src/cmd/compile/internal/types2/predicates.go
+++ b/src/cmd/compile/internal/types2/predicates.go
@@ -25,10 +25,10 @@
}
func is(typ Type, what BasicInfo) bool {
- switch t := optype(typ).(type) {
+ switch t := under(typ).(type) {
case *Basic:
return t.info&what != 0
- case *Union:
+ case *TypeParam:
return t.underIs(func(t Type) bool { return is(t, what) })
}
return false
@@ -56,7 +56,7 @@
// are not fully set up.
func isTyped(typ Type) bool {
// isTyped is called with types that are not fully
- // set up. Must not call Basic()!
+ // set up. Must not call asBasic()!
// A *Named or *instance type is always typed, so
// we only need to check if we have a true *Basic
// type.
@@ -97,18 +97,19 @@
seen[T] = true
// If T is a type parameter not constrained by any type
- // list (i.e., it's operational type is the top type),
+ // (i.e., it's operational type is the top type),
// T is comparable if it has the == method. Otherwise,
// the operational type "wins". For instance
//
// interface{ comparable; type []byte }
//
// is not comparable because []byte is not comparable.
+ // TODO(gri) this code is not 100% correct (see comment for TypeSet.IsComparable)
if t := asTypeParam(T); t != nil && optype(t) == theTop {
return t.Bound().IsComparable()
}
- switch t := optype(T).(type) {
+ switch t := under(T).(type) {
case *Basic:
// assume invalid types to be comparable
// to avoid follow-up errors
@@ -124,24 +125,22 @@
return true
case *Array:
return comparable(t.elem, seen)
- case *Union:
+ case *TypeParam:
return t.underIs(func(t Type) bool {
return comparable(t, seen)
})
- case *TypeParam:
- return t.Bound().IsComparable()
}
return false
}
// hasNil reports whether a type includes the nil value.
func hasNil(typ Type) bool {
- switch t := optype(typ).(type) {
+ switch t := under(typ).(type) {
case *Basic:
return t.kind == UnsafePointer
case *Slice, *Pointer, *Signature, *Interface, *Map, *Chan:
return true
- case *Union:
+ case *TypeParam:
return t.underIs(hasNil)
}
return false
diff --git a/src/cmd/compile/internal/types2/testdata/check/typeparams.go2 b/src/cmd/compile/internal/types2/testdata/check/typeparams.go2
index 1235676..8a7f6eb 100644
--- a/src/cmd/compile/internal/types2/testdata/check/typeparams.go2
+++ b/src/cmd/compile/internal/types2/testdata/check/typeparams.go2
@@ -119,7 +119,7 @@
// slicing
// TODO(gri) implement this
-func _[T interface{ ~string }] (x T, i, j, k int) { _ = x /* ERROR invalid operation */ [i:j:k] }
+func _[T interface{ ~string }] (x T, i, j, k int) { _ = x /* ERROR generic slice expressions not yet implemented */ [i:j:k] }
// len/cap built-ins
diff --git a/src/cmd/compile/internal/types2/typeset.go b/src/cmd/compile/internal/types2/typeset.go
index 6ff8563..4aee8e4 100644
--- a/src/cmd/compile/internal/types2/typeset.go
+++ b/src/cmd/compile/internal/types2/typeset.go
@@ -28,6 +28,7 @@
func (s *TypeSet) IsMethodSet() bool { return s.types == nil && !s.IsComparable() }
// IsComparable reports whether each type in the set is comparable.
+// TODO(gri) this is not correct - there may be s.types values containing non-comparable types
func (s *TypeSet) IsComparable() bool {
_, m := s.LookupMethod(nil, "==")
return m != nil
