Add Support for the cygwin64 target

[martell]

Summary

Add a basic to use for when building for cygwin on x86_64

[martell]

Hi Yaron,

I'm not quite sure how you dealt with the blank namespace the last time.
I assume this is okay as it is between one?

[yaron.keren]

All these classes are already inside a bug anonymous namespace and so is the new one you add, this is OK.

[yaron.keren]

What target cygwin x64 uses on current SVN? or we have 32 bits only?

[martell]

In D11349#208086, @yaron.keren wrote:

What target cygwin x64 uses on current SVN? or we have 32 bits only?

Currently it seems you only have 32bits

I assume it used a generic x86_64 target but now that you set MSVC at the default it probably uses that which isn't good for cygwin64

[chapuni]

FYI, I tried, in past, to build cyg64. https://github.com/chapuni/llvm-project/commits/cygwin64/trunk

[martell]

In D11349#208721, @chapuni wrote:

FYI, I tried, in past, to build cyg64. https://github.com/chapuni/llvm-project/commits/cygwin64/trunk

Yes I see this commit https://github.com/chapuni/llvm-project/commit/9a1fcf7d0a897ce82b7b1a81431e04304f116d51
Is quite similar to what I have submitted. :)
I'm just 2 years behind

Yaron
There are other considerations such as the include dirs having i686 hard coded.
I plan to add a driver to Cygwin very similar to the MINGW Driver to deal with these kinds of issues.
Actually having the target is a good start though :)

[yaron.keren]

LGTM after fixing the comment.

tools/clang/lib/Basic/Targets.cpp

4005

This should be X86_64TargetInfo::getTargetDefines(Opts, Builder);

[martell]

And this is why we have reviews :)
fixed

[yaron.keren]

r242914

tools/clang/lib/Basic/Targets.cpp

   }
 };
 
+// x86-64 Cygwin target
+class CygwinX86_64TargetInfo : public X86_64TargetInfo {
+public:
+  CygwinX86_64TargetInfo(const llvm::Triple &Triple)
+      : X86_64TargetInfo(Triple) {
+    TLSSupported = false;
+    WCharType = UnsignedShort;
+  }
+  void getTargetDefines(const LangOptions &Opts,
+                        MacroBuilder &Builder) const override {
+    X86_64TargetInfo::getTargetDefines(Opts, Builder);
+    Builder.defineMacro("__x86_64__");
+    Builder.defineMacro("__CYGWIN__");
+    Builder.defineMacro("__CYGWIN64__");
+    addCygMingDefines(Opts, Builder);
+    DefineStd(Builder, "unix", Opts);
+    if (Opts.CPlusPlus)
+      Builder.defineMacro("_GNU_SOURCE");
+
+    // GCC defines this macro when it is using __gxx_personality_seh0.
+    if (!Opts.SjLjExceptions)
+      Builder.defineMacro("__SEH__");
+  }
+};
+
 class DarwinX86_64TargetInfo : public DarwinTargetInfo<X86_64TargetInfo> {
 public:
   DarwinX86_64TargetInfo(const llvm::Triple &Triple)

       return new SolarisTargetInfo<X86_64TargetInfo>(Triple);
     case llvm::Triple::Win32: {
       switch (Triple.getEnvironment()) {
+      case llvm::Triple::Cygnus:
+        return new CygwinX86_64TargetInfo(Triple);
       case llvm::Triple::GNU:
         return new MinGWX86_64TargetInfo(Triple);
       case llvm::Triple::MSVC: