[PATCH] RHEL: Look in more places to find g++ headers and runtime

[Michael Lampe via cfe-commits]

Some distros with ten years of support ship an old gcc but later offer 
more recent versions for installation in parallel. These versions are 
typically not only needed for the compilation of llvm/clang, but also to 
properly use the clang binary that comes out.

Clang already searches /usr at runtime for the most recent installation 
of gcc. This patch appends paths for add-on installations of gcc in RHEL.

-------------- next part --------------
--- a/tools/clang/lib/Driver/ToolChains.cpp	2014-08-27
22:07:31.000000000 +0200
+++ b/tools/clang/lib/Driver/ToolChains.cpp	2014-09-08
02:51:38.197987523 +0200
@@ -1249,8 +1249,14 @@
     Prefixes.push_back(D.InstalledDir + "/..");
 
     // And finally in /usr.
-    if (D.SysRoot.empty())
+    if (D.SysRoot.empty()) {
+      Prefixes.push_back("/opt/rh/devtoolset-4/root/usr");
+      Prefixes.push_back("/opt/rh/devtoolset-3/root/usr");
+      Prefixes.push_back("/opt/rh/devtoolset-2/root/usr");
+      Prefixes.push_back("/opt/rh/devtoolset-1.1/root/usr");
+      Prefixes.push_back("/opt/rh/devtoolset-1.0/root/usr");
       Prefixes.push_back("/usr");
+    }
   }
 
   // Loop over the various components which exist and select the best GCC