pkgs/development/libraries/pcre: fixed build on Darwin

The gcc version used on Darwin fails to compile the C++ interface to the PCRE
library when optimizations are enabled. Building C++ code with -O0 remedies the
problem. This is unsatisfactory, though, because the resulting library is
likely to perform more poorly than it would if built with -O2 or -O3.

svn path=/nixpkgs/trunk/; revision=24072

pkgs/development/libraries/pcre/default.nix

@@ -8,7 +8,12 @@ stdenv.mkDerivation {
     sha256 = "1zsqk352mx2zklf9bgpg9d88ckfdssbbbiyslhrycfckw8m3qpvr";
   };
 
+  # The compiler on Darwin crashes with an internal error while building the
+  # C++ interface. Disabling optimizations on that platform remedies the
+  # problem. In case we ever update the Darwin GCC version, the exception for
+  # that platform ought to be removed.
   configureFlags = ''
+    CPPFLAGS=-NDEBUG CFLAGS=-O3 CXXFLAGS=${if stdenv.isDarwin then "-O0" else "-O3"}
     ${if unicodeSupport then "--enable-unicode-properties" else ""}
     ${if !cplusplusSupport then "--disable-cpp" else ""}
   '';