From: Tim King <taking@google.com>
Date: Fri, 9 Aug 2024 17:50:00 +0000 (-0700)
Subject: [release-branch.go1.23] cmd/compile/internal/importer: enable aliases
X-Git-Tag: go1.23.5~7
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=69c8cfe29bb677614c01f8dae3901d6954411af8;p=gostls13.git

[release-branch.go1.23] cmd/compile/internal/importer: enable aliases

Flips the pkgReader.enableAlias flag to true when reading unified IR.
This was disabled while resolving #66873. This resolves the TODO to
flip it back to true.

Fixes #70394
Fixes #70517
Updates #66873

Change-Id: Ifd52b0f9510d6bcf151de1c9a18d71ab548c14e4
Reviewed-on: https://go-review.googlesource.com/c/go/+/604099
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: David Chase <drchase@google.com>
(cherry picked from commit 209ed1a9c75d17046285c416b74a14bb89799757)
Reviewed-on: https://go-review.googlesource.com/c/go/+/631855
Commit-Queue: Tim King <taking@google.com>
Reviewed-by: Robert Griesemer <gri@google.com>
---

diff --git a/src/cmd/compile/internal/importer/gcimporter_test.go b/src/cmd/compile/internal/importer/gcimporter_test.go
index 7fe4445dad..ffeddea0c9 100644
--- a/src/cmd/compile/internal/importer/gcimporter_test.go
+++ b/src/cmd/compile/internal/importer/gcimporter_test.go
@@ -582,6 +582,23 @@ func TestIssue25596(t *testing.T) {
 	compileAndImportPkg(t, "issue25596")
 }
 
+func TestIssue70394(t *testing.T) {
+	testenv.MustHaveGoBuild(t)
+
+	// This package only handles gc export data.
+	if runtime.Compiler != "gc" {
+		t.Skipf("gc-built packages not available (compiler = %s)", runtime.Compiler)
+	}
+
+	pkg := compileAndImportPkg(t, "alias")
+	obj := lookupObj(t, pkg.Scope(), "A")
+
+	typ := obj.Type()
+	if _, ok := typ.(*types2.Alias); !ok {
+		t.Fatalf("type of %s is %s, wanted an alias", obj, typ)
+	}
+}
+
 func importPkg(t *testing.T, path, srcDir string) *types2.Package {
 	pkg, err := Import(make(map[string]*types2.Package), path, srcDir, nil)
 	if err != nil {
diff --git a/src/cmd/compile/internal/importer/testdata/alias.go b/src/cmd/compile/internal/importer/testdata/alias.go
new file mode 100644
index 0000000000..51492fc943
--- /dev/null
+++ b/src/cmd/compile/internal/importer/testdata/alias.go
@@ -0,0 +1,7 @@
+// Copyright 2024 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 testdata
+
+type A = int32
diff --git a/src/cmd/compile/internal/importer/ureader.go b/src/cmd/compile/internal/importer/ureader.go
index 7eda375bd5..9d267e6db4 100644
--- a/src/cmd/compile/internal/importer/ureader.go
+++ b/src/cmd/compile/internal/importer/ureader.go
@@ -29,11 +29,9 @@ func ReadPackage(ctxt *types2.Context, imports map[string]*types2.Package, input
 	pr := pkgReader{
 		PkgDecoder: input,
 
-		ctxt:    ctxt,
-		imports: imports,
-		// Currently, the compiler panics when using Alias types.
-		// TODO(gri) set to true once this is fixed (issue #66873)
-		enableAlias: false,
+		ctxt:        ctxt,
+		imports:     imports,
+		enableAlias: true,
 
 		posBases: make([]*syntax.PosBase, input.NumElems(pkgbits.RelocPosBase)),
 		pkgs:     make([]*types2.Package, input.NumElems(pkgbits.RelocPkg)),