Add rust_benchmark module to soong.

This commit adds rust_benchmark and rust_benchmark_host commands to
soong. Respectively running rust benchmarks on device and host. Currently
only criterion based benchmarks are supported and criterion library is
automatically linked.

Test: atest <module with rust_benchmark defined>
Bug: 155309706
Change-Id: I6edfc2b4bf30b1163fe59b8c2ecdcd4e7125e7b9
diff --git a/rust/benchmark_test.go b/rust/benchmark_test.go
new file mode 100644
index 0000000..734dda7
--- /dev/null
+++ b/rust/benchmark_test.go
@@ -0,0 +1,54 @@
+// Copyright 2021 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package rust
+
+import (
+	"strings"
+	"testing"
+
+	"android/soong/android"
+)
+
+func TestRustBenchmark(t *testing.T) {
+	ctx := testRust(t, `
+		rust_benchmark_host {
+			name: "my_bench",
+			srcs: ["foo.rs"],
+		}`)
+
+	testingModule := ctx.ModuleForTests("my_bench", "linux_glibc_x86_64")
+	expectedOut := "my_bench/linux_glibc_x86_64/my_bench"
+	outPath := testingModule.Output("my_bench").Output.String()
+	if !strings.Contains(outPath, expectedOut) {
+		t.Errorf("wrong output path: %v;  expected: %v", outPath, expectedOut)
+	}
+}
+
+func TestRustBenchmarkLinkage(t *testing.T) {
+	ctx := testRust(t, `
+		rust_benchmark {
+			name: "my_bench",
+			srcs: ["foo.rs"],
+		}`)
+
+	testingModule := ctx.ModuleForTests("my_bench", "android_arm64_armv8-a").Module().(*Module)
+
+	if !android.InList("libcriterion.rlib-std", testingModule.Properties.AndroidMkRlibs) {
+		t.Errorf("rlib-std variant for libcriterion not detected as a rustlib-defined rlib dependency for device rust_benchmark module")
+	}
+	if !android.InList("libstd", testingModule.Properties.AndroidMkRlibs) {
+		t.Errorf("Device rust_benchmark module 'my_bench' does not link libstd as an rlib")
+	}
+}