Index: llvm-toolchain-5.0-5.0.2~+rc1/clang/lib/Driver/ToolChains/Linux.cpp
===================================================================
--- llvm-toolchain-5.0-5.0.2~+rc1.orig/clang/lib/Driver/ToolChains/Linux.cpp
+++ llvm-toolchain-5.0-5.0.2~+rc1/clang/lib/Driver/ToolChains/Linux.cpp
@@ -571,6 +571,11 @@ void Linux::AddClangSystemIncludeArgs(co
     return;
   }
 
+  // Force the inclusion of the gcc headers (objc/objc.h)
+  addExternCSystemIncludeIfExists(
+     DriverArgs, CC1Args, GCCInstallation.getInstallPath() + "/include");
+//  std::cout << GCCInstallation.getInstallPath().str() << "/include" << std::endl;
+
   // Lacking those, try to detect the correct set of system includes for the
   // target triple.