From 261cbdbe194f9d80b8e6d710c21000ded15389cf Mon Sep 17 00:00:00 2001
From: Daiderd Jordan <daiderd@gmail.com>
Date: Wed, 16 Aug 2017 22:35:06 +0200
Subject: [PATCH] gcc6: port darwin changes from 5.x

---
 pkgs/development/compilers/gcc/6/default.nix | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/pkgs/development/compilers/gcc/6/default.nix b/pkgs/development/compilers/gcc/6/default.nix
index b091fd1ae370..71e2238a27fb 100644
--- a/pkgs/development/compilers/gcc/6/default.nix
+++ b/pkgs/development/compilers/gcc/6/default.nix
@@ -226,6 +226,19 @@ stdenv.mkDerivation ({
 
   hardeningDisable = [ "format" ];
 
+  # This should kill all the stdinc frameworks that gcc and friends like to
+  # insert into default search paths.
+  prePatch = stdenv.lib.optionalString hostPlatform.isDarwin ''
+    substituteInPlace gcc/config/darwin-c.c \
+      --replace 'if (stdinc)' 'if (0)'
+
+    substituteInPlace libgcc/config/t-slibgcc-darwin \
+      --replace "-install_name @shlib_slibdir@/\$(SHLIB_INSTALL_NAME)" "-install_name $lib/lib/\$(SHLIB_INSTALL_NAME)"
+
+    substituteInPlace libgfortran/configure \
+      --replace "-install_name \\\$rpath/\\\$soname" "-install_name $lib/lib/\\\$soname"
+  '';
+
   postPatch =
     if (hostPlatform.isHurd
         || (libcCross != null                  # e.g., building `gcc.crossDrv'