[arm64] Build NDK with PAuth and BTI
This change adds a new arch named "armv8-a-branchprot". The new target
is no different from the usual "armv8-a" variant except it has the
compiler flag "-mbranch-protection=standard" set.
With this flag compiler emits Armv8.3-A Pointer Authentication and
Armv8.5-A Branch Target Identification instructions. All of these
instructions are in the hint space; therefore devices which do not
support any of these extensions would execute them as NOPs.
In terms of directory structure there is no change in the output of
build/soong/scripts/build-ndk-prebuilts.sh script.
Test: build NDK prebuilts
Change-Id: Ie52ccba5653fbf567f0b7ca312d8a8e71602ad06
diff --git a/cc/config/arm64_device.go b/cc/config/arm64_device.go
index e6024aa..d083d2a 100644
--- a/cc/config/arm64_device.go
+++ b/cc/config/arm64_device.go
@@ -31,6 +31,10 @@
"armv8-a": []string{
"-march=armv8-a",
},
+ "armv8-a-branchprot": []string{
+ "-march=armv8-a",
+ "-mbranch-protection=standard",
+ },
"armv8-2a": []string{
"-march=armv8.2-a",
},
@@ -102,6 +106,7 @@
pctx.StaticVariable("Arm64ClangCppflags", strings.Join(ClangFilterUnknownCflags(arm64Cppflags), " "))
pctx.StaticVariable("Arm64ClangArmv8ACflags", strings.Join(arm64ArchVariantCflags["armv8-a"], " "))
+ pctx.StaticVariable("Arm64ClangArmv8ABranchProtCflags", strings.Join(arm64ArchVariantCflags["armv8-a-branchprot"], " "))
pctx.StaticVariable("Arm64ClangArmv82ACflags", strings.Join(arm64ArchVariantCflags["armv8-2a"], " "))
pctx.StaticVariable("Arm64ClangArmv82ADotprodCflags", strings.Join(arm64ArchVariantCflags["armv8-2a-dotprod"], " "))
@@ -124,6 +129,7 @@
var (
arm64ClangArchVariantCflagsVar = map[string]string{
"armv8-a": "${config.Arm64ClangArmv8ACflags}",
+ "armv8-a-branchprot": "${config.Arm64ClangArmv8ABranchProtCflags}",
"armv8-2a": "${config.Arm64ClangArmv82ACflags}",
"armv8-2a-dotprod": "${config.Arm64ClangArmv82ADotprodCflags}",
}
@@ -202,6 +208,7 @@
func arm64ToolchainFactory(arch android.Arch) Toolchain {
switch arch.ArchVariant {
case "armv8-a":
+ case "armv8-a-branchprot":
case "armv8-2a":
case "armv8-2a-dotprod":
// Nothing extra for armv8-a/armv8-2a