Add unit test to verify default linkage for rust binaries

Test: go test
Change-Id: I16eed90dffc8f98a880aa801e96601227dcc37be

rust/binary_test.go

@@ -21,6 +21,27 @@ import (
 	"android/soong/android"
 )
 
+// Test that rustlibs default linkage is always rlib for host binaries.
+func TestBinaryHostLinkage(t *testing.T) {
+	ctx := testRust(t, `
+		rust_binary_host {
+			name: "fizz-buzz",
+			srcs: ["foo.rs"],
+			rustlibs: ["libfoo"],
+		}
+		rust_library {
+			name: "libfoo",
+			srcs: ["foo.rs"],
+			crate_name: "foo",
+			host_supported: true,
+		}
+	`)
+	fizzBuzz := ctx.ModuleForTests("fizz-buzz", "linux_glibc_x86_64").Module().(*Module)
+	if !android.InList("libfoo.rlib-std", fizzBuzz.Properties.AndroidMkRlibs) {
+		t.Errorf("rustlibs dependency libfoo should be an rlib dep for host binaries")
+	}
+}
+
 // Test that rustlibs default linkage is correct for binaries.
 func TestBinaryLinkage(t *testing.T) {
 	ctx := testRust(t, `
@@ -54,6 +75,12 @@ func TestBinaryLinkage(t *testing.T) {
 	if !android.InList("libfoo", fizzBuzzDevice.Properties.AndroidMkDylibs) {
 		t.Errorf("rustlibs dependency libfoo should be an dylib dep for device modules")
 	}
+
+	rlibLinkDevice := ctx.ModuleForTests("rlib_linked", "android_arm64_armv8-a").Module().(*Module)
+
+	if !android.InList("libfoo.rlib-std", rlibLinkDevice.Properties.AndroidMkRlibs) {
+		t.Errorf("rustlibs dependency libfoo should be an rlib dep for device modules when prefer_rlib is set")
+	}
 }
 
 // Test that prefer_rlib links in libstd statically as well as rustlibs.