[Driver] -print-target-triple and -print-effective-triple options

These can be used to print Clang target and effective triple.

Differential Revision: https://reviews.llvm.org/D50755

llvm-svn: 339834
diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
index 952a716..350ee0e3 100644
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -1672,6 +1672,18 @@
     }
     return false;
   }
+
+  if (C.getArgs().hasArg(options::OPT_print_target_triple)) {
+    llvm::outs() << TC.getTripleString() << "\n";
+    return false;
+  }
+
+  if (C.getArgs().hasArg(options::OPT_print_effective_triple)) {
+    const llvm::Triple Triple(TC.ComputeEffectiveClangTriple(C.getArgs()));
+    llvm::outs() << Triple.getTriple() << "\n";
+    return false;
+  }
+
   return true;
 }