1 files changed, 121 insertions, 0 deletions
diff --git a/src/cmd/link/internal/ld/go_test.go b/src/cmd/link/internal/ld/go_test.go
new file mode 100644
index 0000000..0197196
--- /dev/null
+++ b/src/cmd/link/internal/ld/go_test.go
@@ -0,0 +1,121 @@
+// Copyright 2020 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 ld
+
+import (
+	"cmd/internal/objabi"
+	"internal/testenv"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"reflect"
+	"runtime"
+	"testing"
+)
+
+func TestDedupLibraries(t *testing.T) {
+	ctxt := &Link{}
+	ctxt.Target.HeadType = objabi.Hlinux
+
+	libs := []string{"libc.so", "libc.so.6"}
+
+	got := dedupLibraries(ctxt, libs)
+	if !reflect.DeepEqual(got, libs) {
+		t.Errorf("dedupLibraries(%v) = %v, want %v", libs, got, libs)
+	}
+}
+
+func TestDedupLibrariesOpenBSD(t *testing.T) {
+	ctxt := &Link{}
+	ctxt.Target.HeadType = objabi.Hopenbsd
+
+	tests := []struct {
+		libs []string
+		want []string
+	}{
+		{
+			libs: []string{"libc.so"},
+			want: []string{"libc.so"},
+		},
+		{
+			libs: []string{"libc.so", "libc.so.96.1"},
+			want: []string{"libc.so.96.1"},
+		},
+		{
+			libs: []string{"libc.so.96.1", "libc.so"},
+			want: []string{"libc.so.96.1"},
+		},
+		{
+			libs: []string{"libc.a", "libc.so.96.1"},
+			want: []string{"libc.a", "libc.so.96.1"},
+		},
+		{
+			libs: []string{"libpthread.so", "libc.so"},
+			want: []string{"libc.so", "libpthread.so"},
+		},
+		{
+			libs: []string{"libpthread.so.26.1", "libpthread.so", "libc.so.96.1", "libc.so"},
+			want: []string{"libc.so.96.1", "libpthread.so.26.1"},
+		},
+		{
+			libs: []string{"libpthread.so.26.1", "libpthread.so", "libc.so.96.1", "libc.so", "libfoo.so"},
+			want: []string{"libc.so.96.1", "libfoo.so", "libpthread.so.26.1"},
+		},
+	}
+
+	for _, test := range tests {
+		t.Run("dedup", func(t *testing.T) {
+			got := dedupLibraries(ctxt, test.libs)
+			if !reflect.DeepEqual(got, test.want) {
+				t.Errorf("dedupLibraries(%v) = %v, want %v", test.libs, got, test.want)
+			}
+		})
+	}
+}
+
+func TestDedupLibrariesOpenBSDLink(t *testing.T) {
+	// The behavior we're checking for is of interest only on OpenBSD.
+	if runtime.GOOS != "openbsd" {
+		t.Skip("test only useful on openbsd")
+	}
+
+	testenv.MustHaveGoBuild(t)
+	testenv.MustHaveCGO(t)
+	t.Parallel()
+
+	dir, err := ioutil.TempDir("", "dedup-build")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(dir)
+
+	// cgo_import_dynamic both the unversioned libraries and pull in the
+	// net package to get a cgo package with a versioned library.
+	srcFile := filepath.Join(dir, "x.go")
+	src := `package main
+
+import (
+	_ "net"
+)
+
+//go:cgo_import_dynamic _ _ "libc.so"
+
+func main() {}`
+	if err := ioutil.WriteFile(srcFile, []byte(src), 0644); err != nil {
+		t.Fatal(err)
+	}
+
+	exe := filepath.Join(dir, "deduped.exe")
+	out, err := exec.Command(testenv.GoToolPath(t), "build", "-o", exe, srcFile).CombinedOutput()
+	if err != nil {
+		t.Fatalf("build failure: %s\n%s\n", err, string(out))
+	}
+
+	// Result should be runnable.
+	if _, err = exec.Command(exe).CombinedOutput(); err != nil {
+		t.Fatal(err)
+	}
+}