Add Rust support to Soong.

Adds support to Soong for building rust modules. This currently only
supports x86_64 device and x86 linux host targets. The functionality
is sufficient to build crosvm.

Bug: 136189233
Test: Test module builds.
Test: crosvm builds.
Change-Id: I6ea04615834a6d673578ab10ea1a2eb04259fe09

rust/rust_test.go

@@ -0,0 +1,167 @@
+// Copyright 2019 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 (
+	"io/ioutil"
+	"os"
+	"testing"
+
+	"android/soong/android"
+)
+
+var (
+	buildDir string
+)
+
+func setUp() {
+	var err error
+	buildDir, err = ioutil.TempDir("", "soong_rust_test")
+	if err != nil {
+		panic(err)
+	}
+}
+
+func tearDown() {
+	os.RemoveAll(buildDir)
+}
+
+func TestMain(m *testing.M) {
+	run := func() int {
+		setUp()
+		defer tearDown()
+
+		return m.Run()
+	}
+
+	os.Exit(run())
+}
+
+func testRust(t *testing.T, bp string) *android.TestContext {
+	t.Helper()
+	config := android.TestArchConfig(buildDir, nil)
+
+	t.Helper()
+	ctx := CreateTestContext(bp)
+	ctx.Register()
+
+	_, errs := ctx.ParseFileList(".", []string{"Android.bp"})
+	android.FailIfErrored(t, errs)
+	_, errs = ctx.PrepareBuildActions(config)
+	android.FailIfErrored(t, errs)
+
+	return ctx
+}
+
+func testRustError(t *testing.T, pattern string, bp string) {
+	t.Helper()
+	config := android.TestArchConfig(buildDir, nil)
+
+	ctx := CreateTestContext(bp)
+	ctx.Register()
+
+	_, errs := ctx.ParseFileList(".", []string{"Android.bp"})
+	if len(errs) > 0 {
+		android.FailIfNoMatchingErrors(t, pattern, errs)
+		return
+	}
+
+	_, errs = ctx.PrepareBuildActions(config)
+	if len(errs) > 0 {
+		android.FailIfNoMatchingErrors(t, pattern, errs)
+		return
+	}
+
+	t.Fatalf("missing expected error %q (0 errors are returned)", pattern)
+}
+
+// Test that we can extract the lib name from a lib path.
+func TestLibNameFromFilePath(t *testing.T) {
+	barPath := android.PathForTesting("out/soong/.intermediates/external/libbar/libbar/linux_glibc_x86_64_shared/libbar.so")
+	libName := libNameFromFilePath(barPath)
+	expectedResult := "bar"
+
+	if libName != expectedResult {
+		t.Errorf("libNameFromFilePath returned the wrong name; expected '%#v', got '%#v'", expectedResult, libName)
+	}
+}
+
+// Test that we can extract the link path from a lib path.
+func TestLinkPathFromFilePath(t *testing.T) {
+	barPath := android.PathForTesting("out/soong/.intermediates/external/libbar/libbar/linux_glibc_x86_64_shared/libbar.so")
+	libName := linkPathFromFilePath(barPath)
+	expectedResult := "out/soong/.intermediates/external/libbar/libbar/linux_glibc_x86_64_shared/"
+
+	if libName != expectedResult {
+		t.Errorf("libNameFromFilePath returned the wrong name; expected '%#v', got '%#v'", expectedResult, libName)
+	}
+}
+
+// Test default crate names from module names are generated correctly.
+func TestDefaultCrateName(t *testing.T) {
+	ctx := testRust(t, `
+		rust_library_host_dylib {
+			name: "fizz-buzz",
+			srcs: ["foo.rs"],
+		}`)
+	module := ctx.ModuleForTests("fizz-buzz", "linux_glibc_x86_64_dylib").Module().(*Module)
+	crateName := module.CrateName()
+	expectedResult := "fizz_buzz"
+
+	if crateName != expectedResult {
+		t.Errorf("CrateName() returned the wrong default crate name; expected '%#v', got '%#v'", expectedResult, crateName)
+	}
+}
+
+// Test to make sure dependencies are being picked up correctly.
+func TestDepsTracking(t *testing.T) {
+	ctx := testRust(t, `
+		rust_library_host_dylib {
+			name: "libfoo",
+			srcs: ["foo.rs"],
+		}
+		rust_library_host_rlib {
+			name: "libbar",
+			srcs: ["foo.rs"],
+		}
+		rust_proc_macro {
+			name: "libpm",
+			srcs: ["foo.rs"],
+			host_supported: true,
+		}
+		rust_binary_host {
+			name: "fizz-buzz",
+			dylibs: ["libfoo"],
+			rlibs: ["libbar"],
+			proc_macros: ["libpm"],
+			srcs: ["foo.rs"],
+		}
+	`)
+	module := ctx.ModuleForTests("fizz-buzz", "linux_glibc_x86_64").Module().(*Module)
+
+	// Since dependencies are added to AndroidMk* properties, we can check these to see if they've been picked up.
+	if !android.InList("libfoo", module.Properties.AndroidMkDylibs) {
+		t.Errorf("Dylib dependency not detected (dependency missing from AndroidMkDylibs)")
+	}
+
+	if !android.InList("libbar", module.Properties.AndroidMkRlibs) {
+		t.Errorf("Rlib dependency not detected (dependency missing from AndroidMkRlibs)")
+	}
+
+	if !android.InList("libpm", module.Properties.AndroidMkProcMacroLibs) {
+		t.Errorf("Proc_macro dependency not detected (dependency missing from AndroidMkProcMacroLibs)")
+	}
+
+}