diff -ru -x '*~' a/tools/clang/lib/Frontend/InitHeaderSearch.cpp b/tools/clang/lib/Frontend/InitHeaderSearch.cpp
--- a/tools/clang/lib/Frontend/InitHeaderSearch.cpp	2010-09-03 18:45:53.000000000 +0200
+++ b/tools/clang/lib/Frontend/InitHeaderSearch.cpp	2011-02-05 14:59:08.669573190 +0100
@@ -443,6 +443,7 @@
       AddPath(*i, System, false, false, false);
     return;
   }
+#if 0
   llvm::Triple::OSType os = triple.getOS();
   switch (os) {
   case llvm::Triple::Win32:
@@ -532,6 +533,8 @@
   }
 
   AddPath("/usr/include", System, false, false, false);
+#endif
+  AddPath(C_INCLUDE_PATH, System, false, false, false);
 }
 
 void InitHeaderSearch::
@@ -550,6 +553,7 @@
                                   triple);
     return;
   }
+#if 0  
   // FIXME: temporary hack: hard-coded paths.
   switch (os) {
   case llvm::Triple::Cygwin:
@@ -769,6 +773,10 @@
   default:
     break;
   }
+#endif
+  AddGnuCPlusPlusIncludePaths(
+      CPP_INCLUDE_PATH,
+      CPP_HOST, "", "", triple);
 }
 
 void InitHeaderSearch::AddDefaultSystemIncludePaths(const LangOptions &Lang,