go/types, types2: remove superfluous assertion (fix build)

Remove an assertion that was overly restrictive and hard to get
correct under all circumstances (i.e., in the presence of incorrect)
code. This matches the code for *Named types in that specific switch.

Fixes #71284.

Change-Id: Ifccf8b73dc70cac9cb1c8b24946d16851d511454
Reviewed-on: https://go-review.googlesource.com/c/go/+/643255
Reviewed-by: Robert Findley <rfindley@google.com>
Auto-Submit: Robert Griesemer <gri@google.com>
Reviewed-by: Robert Griesemer <gri@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

diff --git a/src/cmd/compile/internal/types2/typexpr.go b/src/cmd/compile/internal/types2/typexpr.go
index fa6a6f622af7cfd8ce892b7ffc3a01dd3a919fc9..e9b5ca9aa6c329068d2917da2dbf5dd96fca3ff9 100644 (file)
--- a/src/cmd/compile/internal/types2/typexpr.go
+++ b/src/cmd/compile/internal/types2/typexpr.go
@@ -423,11 +423,6 @@ func setDefType(def *TypeName, typ Type) {
        if def != nil {
                switch t := def.typ.(type) {
                case *Alias:
-                       // t.fromRHS should always be set, either to an invalid type
-                       // in the beginning, or to typ in certain cyclic declarations.
-                       if t.fromRHS != Typ[Invalid] && t.fromRHS != typ {
-                               panic(sprintf(nil, true, "t.fromRHS = %s, typ = %s\n", t.fromRHS, typ))
-                       }
                        t.fromRHS = typ
                case *Basic:
                        assert(t == Typ[Invalid])

diff --git a/src/go/types/typexpr.go b/src/go/types/typexpr.go
index e560f2c131bd37db9e57ee8015a3fe7a7f9daa0f..7928ed8ef368de6363b5376faf9c633fc1808b9b 100644 (file)
--- a/src/go/types/typexpr.go
+++ b/src/go/types/typexpr.go
@@ -419,11 +419,6 @@ func setDefType(def *TypeName, typ Type) {
        if def != nil {
                switch t := def.typ.(type) {
                case *Alias:
-                       // t.fromRHS should always be set, either to an invalid type
-                       // in the beginning, or to typ in certain cyclic declarations.
-                       if t.fromRHS != Typ[Invalid] && t.fromRHS != typ {
-                               panic(sprintf(nil, nil, true, "t.fromRHS = %s, typ = %s\n", t.fromRHS, typ))
-                       }
                        t.fromRHS = typ
                case *Basic:
                        assert(t == Typ[Invalid])

diff --git a/src/internal/types/testdata/fixedbugs/issue71284.go b/src/internal/types/testdata/fixedbugs/issue71284.go
new file mode 100644 (file)
index 0000000..4b73087
--- /dev/null
+++ b/src/internal/types/testdata/fixedbugs/issue71284.go
@@ -0,0 +1,10 @@
+// Copyright 2025 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package A
+
+type (
+       _ = A
+       A /* ERROR "invalid recursive type: A refers to itself" */ = A
+)