Add AArch64 support to ASan instrumentation

[christophe.lyon]

Summary

Hi,

The attached patch adds AArch64 support to ASan instrumentation.
For the time being, it is still hardcoded to support only the 39 VA bits variant, I plan to work on supporting 42 and 48 VA bits variants, but I don't have access to such hardware at the moment.

I have another patch (for compiler-rt) to activate the tests (submitted separately).

[kcc]

LGTM, thanks!

[rengolin]

Committed in r227965

[christophe.lyon]

Thank you Renato for committing on my behalf.

Kostya, Renato, is my other request OK? (http://reviews.llvm.org/D7244)
It enables testing ASAN on AArch64.

Thanks.

[rengolin]

Yes, I just committed. Keep an eye on the bot:

http://lab.llvm.org:8011/builders/clang-native-aarch64-full

Right now it's failing on Clang, but it shouldn't fail on RT as well.

cheers,
--renato

lib/Transforms/Instrumentation/AddressSanitizer.cpp

 static const uint64_t kPPC64_ShadowOffset64 = 1ULL << 41;
 static const uint64_t kMIPS32_ShadowOffset32 = 0x0aaa0000;
 static const uint64_t kMIPS64_ShadowOffset64 = 1ULL << 36;
+static const uint64_t kAArch64_ShadowOffset64 = 1ULL << 36;
 static const uint64_t kFreeBSD_ShadowOffset32 = 1ULL << 30;
 static const uint64_t kFreeBSD_ShadowOffset64 = 1ULL << 46;
 static const uint64_t kWindowsShadowOffset32 = 3ULL << 28;

                   TargetTriple.getArch() == llvm::Triple::mipsel;
   bool IsMIPS64 = TargetTriple.getArch() == llvm::Triple::mips64 ||
                   TargetTriple.getArch() == llvm::Triple::mips64el;
+  bool IsAArch64 = TargetTriple.getArch() == llvm::Triple::aarch64;
   bool IsWindows = TargetTriple.isOSWindows();
 
   ShadowMapping Mapping;

       Mapping.Offset = kSmallX86_64ShadowOffset;
     else if (IsMIPS64)
       Mapping.Offset = kMIPS64_ShadowOffset64;
+    else if (IsAArch64)
+      Mapping.Offset = kAArch64_ShadowOffset64;
     else
       Mapping.Offset = kDefaultShadowOffset64;
   }