[COFF, ARM64] Add support for Windows ARM64 COFF format

[mgrang]

Summary

This is the clang part of the initial implementation to support Windows ARM64 COFF format.

[mgrang]

Here is the llvm part of this patch: https://reviews.llvm.org/D34705

[ruiu]

lib/Basic/Targets.cpp

6553

I cannot imagine there will be MicrosoftARM64beTargetInfo, so I wonder if we should name this MicrosoftARM64TargetInfo.

[mgrang]

Comments addressed.

[ruiu]

LGTM. I don't think I have enough knowledge to sign off, but as Saleem has already LGTM'ed, I guess it should be okay.

lib/Basic/Targets.cpp

public:
   }
   void getTargetDefines(const LangOptions &Opts,
                         MacroBuilder &Builder) const override {
     Builder.defineMacro("__AARCH64EL__");
     AArch64TargetInfo::getTargetDefines(Opts, Builder);
   }
 };
 
+class MicrosoftARM64TargetInfo
+    : public WindowsTargetInfo<AArch64leTargetInfo> {
+  const llvm::Triple Triple;
+
+public:
+  MicrosoftARM64TargetInfo(const llvm::Triple &Triple,
+                             const TargetOptions &Opts)
+      : WindowsTargetInfo<AArch64leTargetInfo>(Triple, Opts), Triple(Triple) {
+    WCharType = UnsignedShort;
+    SizeType = UnsignedLongLong;
+    TheCXXABI.set(TargetCXXABI::Microsoft);
+  }
+
+  void setDataLayout() override {
+    resetDataLayout("e-m:w-i64:64-i128:128-n32:64-S128");
+  }
+
+  void getVisualStudioDefines(const LangOptions &Opts,
+                              MacroBuilder &Builder) const {
+    WindowsTargetInfo<AArch64leTargetInfo>::getVisualStudioDefines(Opts,
+                                                                   Builder);
+    Builder.defineMacro("_WIN32", "1");
+    Builder.defineMacro("_WIN64", "1");
+    Builder.defineMacro("_M_ARM64", "1");
+  }
+
+  void getTargetDefines(const LangOptions &Opts,
+                        MacroBuilder &Builder) const override {
+    WindowsTargetInfo::getTargetDefines(Opts, Builder);
+    getVisualStudioDefines(Opts, Builder);
+  }
+
+  BuiltinVaListKind getBuiltinVaListKind() const override {
+    return TargetInfo::CharPtrBuiltinVaList;
+  }
+};
+
 class AArch64beTargetInfo : public AArch64TargetInfo {
   void setDataLayout() override {
     assert(!getTriple().isOSBinFormatMachO());
     resetDataLayout("E-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128");
   }
 
 public:
   AArch64beTargetInfo(const llvm::Triple &Triple, const TargetOptions &Opts)
case llvm::Triple::aarch64:
     case llvm::Triple::Fuchsia:
       return new FuchsiaTargetInfo<AArch64leTargetInfo>(Triple, Opts);
     case llvm::Triple::Linux:
       return new LinuxTargetInfo<AArch64leTargetInfo>(Triple, Opts);
     case llvm::Triple::NetBSD:
       return new NetBSDTargetInfo<AArch64leTargetInfo>(Triple, Opts);
     case llvm::Triple::OpenBSD:
       return new OpenBSDTargetInfo<AArch64leTargetInfo>(Triple, Opts);
+    case llvm::Triple::Win32:
+      return new MicrosoftARM64TargetInfo(Triple, Opts);
     default:
       return new AArch64leTargetInfo(Triple, Opts);
     }
 
   case llvm::Triple::aarch64_be:
     switch (os) {
     case llvm::Triple::FreeBSD:
       return new FreeBSDTargetInfo<AArch64beTargetInfo>(Triple, Opts);

test/Preprocessor/predefined-macros.c

 // CHECK-CL20: #define CL_VERSION_1_0 100
 // CHECK-CL20: #define CL_VERSION_1_1 110
 // CHECK-CL20: #define CL_VERSION_1_2 120
 // CHECK-CL20: #define CL_VERSION_2_0 200
 // CHECK-CL20: #define __OPENCL_C_VERSION__ 200
 // CHECK-CL20-NOT: #define __FAST_RELAXED_MATH__ 1
 // CHECK-FRM: #define __FAST_RELAXED_MATH__ 1
 
+// RUN: %clang_cc1 -triple aarch64-windows %s -E -dM -o - -x cl \
+// RUN:   | FileCheck -match-full-lines %s --check-prefix=CHECK-ARM64-WIN
+
+// CHECK-ARM64-WIN: #define _M_ARM64 1
+// CHECK-ARM64-WIN: #define _WIN32 1
+// CHECK-ARM64-WIN: #define _WIN64 1