cmd/cgo/internal/testtls: build and run everywhere

This makes testtls build and run on all platforms in the default build
configuration (though it will Skip on some).

Change-Id: I6aba96a82d618c9798a0d4418b40b2644cfceec9
Reviewed-on: https://go-review.googlesource.com/c/go/+/496177
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Bryan Mills <bcmills@google.com>

4 files changed, 18 insertions, 3 deletions

diff --git a/src/cmd/cgo/internal/testtls/tls_unix.c b/src/cmd/cgo/internal/testtls/tls.c
index 957afce90d..0e2bbee542 100644
--- a/src/cmd/cgo/internal/testtls/tls_unix.c
+++ b/src/cmd/cgo/internal/testtls/tls.c
@@ -2,6 +2,10 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Darwin does not have __thread.
+
+//go:build cgo && unix && !darwin
+
 #include <pthread.h>
 
 static __thread int tls;
diff --git a/src/cmd/cgo/internal/testtls/tls.go b/src/cmd/cgo/internal/testtls/tls.go
index 4684f82ebd..eb59ad41eb 100644
--- a/src/cmd/cgo/internal/testtls/tls.go
+++ b/src/cmd/cgo/internal/testtls/tls.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build unix
+//go:build cgo && unix && !darwin
 
 package cgotlstest
 
diff --git a/src/cmd/cgo/internal/testtls/tls_none.go b/src/cmd/cgo/internal/testtls/tls_none.go
new file mode 100644
index 0000000000..81c9c5e23d
--- /dev/null
+++ b/src/cmd/cgo/internal/testtls/tls_none.go
@@ -0,0 +1,13 @@
+// Copyright 2023 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.
+
+//go:build !(cgo && unix && !darwin)
+
+package cgotlstest
+
+import "testing"
+
+func testTLS(t *testing.T) {
+	t.Skip("__thread is not supported")
+}
diff --git a/src/cmd/cgo/internal/testtls/tls_test.go b/src/cmd/cgo/internal/testtls/tls_test.go
index 10b71f074e..8e14add988 100644
--- a/src/cmd/cgo/internal/testtls/tls_test.go
+++ b/src/cmd/cgo/internal/testtls/tls_test.go
@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build cgo && unix
-
 package cgotlstest
 
 import "testing"