Merge "LinuxBionic supports arm64"

rust/config/Android.bp

@@ -16,5 +16,6 @@ bootstrap_go_package {
         "x86_linux_host.go",
         "x86_device.go",
         "x86_64_device.go",
+        "arm64_linux_host.go",
     ],
 }

rust/config/arm64_device.go

@@ -71,9 +71,16 @@ func (t *toolchainArm64) Supported() bool {
 }
 
 func Arm64ToolchainFactory(arch android.Arch) Toolchain {
+	archVariant := arch.ArchVariant
+	if archVariant == "" {
+		// arch variants defaults to armv8-a. This is mostly for
+		// the host target which borrows toolchain configs from here.
+		archVariant = "armv8-a"
+	}
+
 	toolchainRustFlags := []string{
 		"${config.Arm64ToolchainRustFlags}",
-		"${config.Arm64" + arch.ArchVariant + "VariantRustFlags}",
+		"${config.Arm64" + archVariant + "VariantRustFlags}",
 	}
 
 	toolchainRustFlags = append(toolchainRustFlags, deviceGlobalRustFlags...)

rust/config/arm64_linux_host.go

@@ -0,0 +1,24 @@
+// 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 config
+
+import (
+	"android/soong/android"
+)
+
+func init() {
+	// Linux_cross-arm64 uses the same rust toolchain as the Android-arm64
+	registerToolchainFactory(android.LinuxBionic, android.Arm64, Arm64ToolchainFactory)
+}