[release-branch.go1.18] cmd/compile: fix missing dict pass for type assertions

For type assertions, if either src or dst type has shape, we must
convert them to dynamic type assertions.

Fixes #53357

Change-Id: Ia3362fa67c011febcbdb5b26f856d081b5c366de
Reviewed-on: https://go-review.googlesource.com/c/go/+/411617
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-on: https://go-review.googlesource.com/c/go/+/411934
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 58b7b9e8ddfaccce5d5dd05c45a934c26cf2d277..7cfd70ec546cb272939db2e67dedc26d99c1572f 100644 (file)
--- a/src/cmd/compile/internal/noder/stencil.go
+++ b/src/cmd/compile/internal/noder/stencil.go
@@ -1297,10 +1297,10 @@ func (g *genInst) dictPass(info *instInfo) {
                                m = convertUsingDictionary(info, info.dictParam, m.Pos(), mce.X, m, m.Type(), false)
                        }
                case ir.ODOTTYPE, ir.ODOTTYPE2:
-                       if !m.Type().HasShape() {
+                       dt := m.(*ir.TypeAssertExpr)
+                       if !dt.Type().HasShape() && !dt.X.Type().HasShape() {
                                break
                        }
-                       dt := m.(*ir.TypeAssertExpr)
                        var rt ir.Node
                        if dt.Type().IsInterface() || dt.X.Type().IsEmptyInterface() {
                                ix := findDictType(info, m.Type())

diff --git a/test/typeparam/issue53309.go b/test/typeparam/issue53309.go
new file mode 100644 (file)
index 0000000..d505f6b
--- /dev/null
+++ b/test/typeparam/issue53309.go
@@ -0,0 +1,42 @@
+// run -gcflags=-G=3
+
+// 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 TaskInput interface {
+       deps() []*taskDefinition
+}
+
+type Value[T any] interface {
+       metaValue
+}
+
+type metaValue interface {
+       TaskInput
+}
+
+type taskDefinition struct {
+}
+
+type taskResult struct {
+       task *taskDefinition
+}
+
+func (tr *taskResult) deps() []*taskDefinition {
+       return nil
+}
+
+func use[T any](v Value[T]) {
+       _, ok := v.(*taskResult)
+       if !ok {
+               panic("output must be *taskResult")
+       }
+}
+
+func main() {
+       tr := &taskResult{&taskDefinition{}}
+       use(Value[string](tr))
+}