Clang standard library selection.

* Add new ENV function for selecting stdlib for Clang.
  - The selection is no-op for non-system-clang compilers.
  - Both superenv and stdenv are handled.
* Add new HOMEBREW_CCCFG flag and ccwrapper handling.

1 files changed, 2 insertions, 0 deletions

diff --git a/Library/ENV/4.3/cc b/Library/ENV/4.3/cc
index 102f6c64e..e8e586da4 100755
--- a/Library/ENV/4.3/cc
+++ b/Library/ENV/4.3/cc
@@ -161,6 +161,7 @@ class Cmd
     if mode == :cxx
       args << '-std=c++11' if cccfg? 'x'
       args << '-stdlib=libc++' if cccfg? 'g'
+      args << '-stdlib=libstdc++' if cccfg? 'h'
     end
 
     return args unless cccfg? 'O'
@@ -216,6 +217,7 @@ class Cmd
     when :cxxld
       args << '-Wl,-headerpad_max_install_names'
       args << '-stdlib=libc++' if cccfg? 'g'
+      args << '-stdlib=libstdc++' if cccfg? 'h'
     end
     args
   end