Android support for SafeStack.

Add two new ways of accessing the unsafe stack pointer:

* At a fixed offset from the thread TLS base. This is very similar to
  StackProtector cookies, but we plan to extend it to other backends
  (ARM in particular) soon. Bionic-side implementation here:
  https://android-review.googlesource.com/170988.
* Via a function call, as a fallback for platforms that provide
  neither a fixed TLS slot, nor a reasonable TLS implementation (i.e.
  not emutls).

llvm-svn: 248357

1 files changed, 3 insertions, 0 deletions

diff --git a/llvm/lib/Target/X86/X86Subtarget.h b/llvm/lib/Target/X86/X86Subtarget.h
index c5d74e66b7b..52e68c08180 100644
--- a/llvm/lib/Target/X86/X86Subtarget.h
+++ b/llvm/lib/Target/X86/X86Subtarget.h
@@ -394,6 +394,9 @@ public:
   bool isTargetMachO() const { return TargetTriple.isOSBinFormatMachO(); }
 
   bool isTargetLinux() const { return TargetTriple.isOSLinux(); }
+  bool isTargetAndroid() const {
+    return TargetTriple.getEnvironment() == Triple::Android;
+  }
   bool isTargetNaCl() const { return TargetTriple.isOSNaCl(); }
   bool isTargetNaCl32() const { return isTargetNaCl() && !is64Bit(); }
   bool isTargetNaCl64() const { return isTargetNaCl() && is64Bit(); }