Index: llvm/trunk/lib/ObjectYAML/YAML.cpp
===================================================================
--- llvm/trunk/lib/ObjectYAML/YAML.cpp
+++ llvm/trunk/lib/ObjectYAML/YAML.cpp
@@ -31,7 +31,7 @@
   // TODO: Can we improve YAMLIO to permit a more accurate diagnostic here?
   // (e.g. a caret pointing to the offending character).
   for (unsigned I = 0, N = Scalar.size(); I != N; ++I)
-    if (!isxdigit(Scalar[I]))
+    if (!llvm::isHexDigit(Scalar[I]))
       return "BinaryRef hex string must contain only hex digits.";
   Val = yaml::BinaryRef(Scalar);
   return {};
@@ -43,8 +43,9 @@
     return;
   }
   for (unsigned I = 0, N = Data.size(); I != N; I += 2) {
-    uint8_t Byte;
-    StringRef((const char *)&Data[I],  2).getAsInteger(16, Byte);
+    uint8_t Byte = llvm::hexDigitValue(Data[I]);
+    Byte <<= 4;
+    Byte |= llvm::hexDigitValue(Data[I + 1]);
     OS.write(Byte);
   }
 }