cmd/compile: don't use dictionary convert to shaped empty interface
Fixes: #53254
Change-Id: I3153d6ebb9f25957b09363f45c5cd4651ee84c2d
Reviewed-on: https://go-review.googlesource.com/c/go/+/410655
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Wayne Zuo <wdvxdr@golangcn.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
diff --git a/src/cmd/compile/internal/noder/stencil.go b/src/cmd/compile/internal/noder/stencil.go
index d463c85..89869c7 100644
--- a/src/cmd/compile/internal/noder/stencil.go
+++ b/src/cmd/compile/internal/noder/stencil.go
@@ -1349,7 +1349,7 @@
mce := m.(*ir.ConvExpr)
// Note: x's argument is still typed as a type parameter.
// m's argument now has an instantiated type.
- if mce.X.Type().HasShape() || m.Type().HasShape() {
+ if mce.X.Type().HasShape() || (m.Type().HasShape() && !m.Type().IsEmptyInterface()) {
m = convertUsingDictionary(info, info.dictParam, m.Pos(), mce.X, m, m.Type())
}
case ir.ODOTTYPE, ir.ODOTTYPE2:
@@ -1446,7 +1446,7 @@
// instantiated node of the CONVIFACE node or XDOT node (for a bound method call) that is causing the
// conversion.
func convertUsingDictionary(info *instInfo, dictParam *ir.Name, pos src.XPos, v ir.Node, in ir.Node, dst *types.Type) ir.Node {
- assert(v.Type().HasShape() || in.Type().HasShape())
+ assert(v.Type().HasShape() || (in.Type().HasShape() && !in.Type().IsEmptyInterface()))
assert(dst.IsInterface())
if v.Type().IsInterface() {
diff --git a/test/typeparam/issue53254.go b/test/typeparam/issue53254.go
new file mode 100644
index 0000000..afc0f18
--- /dev/null
+++ b/test/typeparam/issue53254.go
@@ -0,0 +1,19 @@
+// compile
+
+// Copyright 2022 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 main
+
+type Interface[T any] interface {
+}
+
+func F[T any]() Interface[T] {
+ var i int
+ return i
+}
+
+func main() {
+ F[int]()
+}
