LinuxBionic supports arm64
LinuxBionic now supports arm64 architecture in addition to the existing
x86_64 arch. This is to make it possible to build host tools like adb,
fastboot, crosvm, etc. for Linux/ARM on regular Linux/x86 machines.
The arm64 target can be selected in various ways in Android.bp files:
- target.host (because this is still considered as a host target)
- target.linux (provided that the module is also enabled for host)
- target.linux_bionic (use the OS name directly)
- target.linux_bionic_arm64 (OS name + arch combo)
- target.linux_arm64 (provided that the module is also for host)
- target.not_windows
- arch.arm64
The toolchain for the new target is almost the same as the toolchain
config for Android/ARM64. One notable difference is that the clang
triple is aarch64-linux instead of aarch64-linux-android, so that
__ANDROID__ is not defined for the new OS type.
Bug: 134795810
Test: HOST_CROSS_OS=linux_bionic HOST_CROSS_ARCH=arm64 m nothing
Change-Id: If4300583edfb6d75bd4d984b38f73b6a406b4447
diff --git a/cc/config/arm64_linux_host.go b/cc/config/arm64_linux_host.go
new file mode 100644
index 0000000..74642c2
--- /dev/null
+++ b/cc/config/arm64_linux_host.go
@@ -0,0 +1,94 @@
+// Copyright 2020 Google Inc. All rights reserved.
+//
+// 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"
+ "strings"
+)
+
+var (
+ // This is a host toolchain but flags for device toolchain are required
+ // as the flags are actually for Bionic-based builds.
+ linuxCrossCflags = ClangFilterUnknownCflags(append(deviceGlobalCflags,
+ // clang by default enables PIC when the clang triple is set to *-android.
+ // See toolchain/llvm-project/clang/lib/Driver/ToolChains/CommonArgs.cpp#920.
+ // However, for this host target, we don't set "-android" to avoid __ANDROID__ macro
+ // which stands for "Android device target". Keeping PIC on is required because
+ // many modules we have (e.g. Bionic) assume PIC.
+ "-fpic",
+ ))
+
+ linuxCrossLdflags = ClangFilterUnknownCflags([]string{
+ "-Wl,-z,noexecstack",
+ "-Wl,-z,relro",
+ "-Wl,-z,now",
+ "-Wl,--build-id=md5",
+ "-Wl,--warn-shared-textrel",
+ "-Wl,--fatal-warnings",
+ "-Wl,--hash-style=gnu",
+ "-Wl,--no-undefined-version",
+ })
+)
+
+func init() {
+ pctx.StaticVariable("LinuxBionicArm64Cflags", strings.Join(linuxCrossCflags, " "))
+ pctx.StaticVariable("LinuxBionicArm64Ldflags", strings.Join(linuxCrossLdflags, " "))
+}
+
+// toolchain config for ARM64 Linux CrossHost. Almost everything is the same as the ARM64 Android
+// target. The overridden methods below show the differences.
+type toolchainLinuxArm64 struct {
+ toolchainArm64
+}
+
+func (toolchainLinuxArm64) ClangTriple() string {
+ // Note the absence of "-android" suffix. The compiler won't define __ANDROID__
+ return "aarch64-linux"
+}
+
+func (toolchainLinuxArm64) ClangCflags() string {
+ // The inherited flags + extra flags
+ return "${config.Arm64ClangCflags} ${config.LinuxBionicArm64Cflags}"
+}
+
+func linuxArm64ToolchainFactory(arch android.Arch) Toolchain {
+ archVariant := "armv8-a" // for host, default to armv8-a
+ toolchainClangCflags := []string{arm64ClangArchVariantCflagsVar[archVariant]}
+
+ // We don't specify CPU architecture for host. Conservatively assume
+ // the host CPU needs the fix
+ extraLdflags := "-Wl,--fix-cortex-a53-843419"
+
+ ret := toolchainLinuxArm64{}
+
+ // add the extra ld and lld flags
+ ret.toolchainArm64.ldflags = strings.Join([]string{
+ "${config.Arm64Ldflags}",
+ "${config.LinuxBionicArm64Ldflags}",
+ extraLdflags,
+ }, " ")
+ ret.toolchainArm64.lldflags = strings.Join([]string{
+ "${config.Arm64Lldflags}",
+ "${config.LinuxBionicArm64Ldflags}",
+ extraLdflags,
+ }, " ")
+ ret.toolchainArm64.toolchainClangCflags = strings.Join(toolchainClangCflags, " ")
+ return &ret
+}
+
+func init() {
+ registerToolchainFactory(android.LinuxBionic, android.Arm64, linuxArm64ToolchainFactory)
+}