1 files changed, 63 insertions, 0 deletions
diff --git a/src/text/template/link_test.go b/src/text/template/link_test.go
new file mode 100644
index 0000000..9dc70df
--- /dev/null
+++ b/src/text/template/link_test.go
@@ -0,0 +1,63 @@
+// Copyright 2019 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 template_test
+
+import (
+	"bytes"
+	"internal/testenv"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"testing"
+)
+
+// Issue 36021: verify that text/template doesn't prevent the linker from removing
+// unused methods.
+func TestLinkerGC(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping in short mode")
+	}
+	testenv.MustHaveGoBuild(t)
+	const prog = `package main
+
+import (
+	_ "text/template"
+)
+
+type T struct{}
+
+func (t *T) Unused() { println("THIS SHOULD BE ELIMINATED") }
+func (t *T) Used() {}
+
+var sink *T
+
+func main() {
+	var t T
+	sink = &t
+	t.Used()
+}
+`
+	td, err := os.MkdirTemp("", "text_template_TestDeadCodeElimination")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(td)
+
+	if err := os.WriteFile(filepath.Join(td, "x.go"), []byte(prog), 0644); err != nil {
+		t.Fatal(err)
+	}
+	cmd := exec.Command(testenv.GoToolPath(t), "build", "-o", "x.exe", "x.go")
+	cmd.Dir = td
+	if out, err := cmd.CombinedOutput(); err != nil {
+		t.Fatalf("go build: %v, %s", err, out)
+	}
+	slurp, err := os.ReadFile(filepath.Join(td, "x.exe"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if bytes.Contains(slurp, []byte("THIS SHOULD BE ELIMINATED")) {
+		t.Error("binary contains code that should be deadcode eliminated")
+	}
+}