gcc5: Reduce diff to gcc6

pkgs/development/compilers/gcc/5/default.nix

@@ -201,8 +201,6 @@ stdenv.mkDerivation ({
     inherit sha256;
   };
 
-  hardeningDisable = [ "format" ];
-
   inherit patches;
 
   outputs = [ "out" "lib" "man" "info" ];
@@ -211,6 +209,8 @@ stdenv.mkDerivation ({
 
   libc_dev = stdenv.cc.libc_dev;
 
+  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 ''
@@ -356,9 +356,6 @@ stdenv.mkDerivation ({
       }"
     ] ++
 
-    # Optional features
-    optional (isl != null) "--with-isl=${isl}" ++
-
     (if enableMultilib
       then ["--enable-multilib" "--disable-libquadmath"]
       else ["--disable-multilib"]) ++
@@ -367,6 +364,9 @@ stdenv.mkDerivation ({
       then ["--enable-plugin"]
       else ["--disable-plugin"]) ++
 
+    # Optional features
+    optional (isl != null) "--with-isl=${isl}" ++
+
     # Java options
     optionals langJava [
       "--with-ecj-jar=${javaEcj}"
@@ -431,7 +431,7 @@ stdenv.mkDerivation ({
     CC_FOR_TARGET = "${targetPlatform.config}-gcc";
     NM_FOR_TARGET = "${targetPlatform.config}-nm";
     CXX_FOR_TARGET = "${targetPlatform.config}-g++";
-    # If we are making a cross compiler, cross != null
+    # If we are making a cross compiler, targetPlatform != hostPlatform
     NIX_CC_CROSS = optionalString (targetPlatform == hostPlatform) builtins.toString stdenv.cc;
     dontStrip = true;
     configureFlags =
@@ -490,7 +490,7 @@ stdenv.mkDerivation ({
 
   CPATH = makeSearchPathOutput "dev" "include" ([]
     ++ optional (zlib != null) zlib
-    ++ optionals langJava [ boehmgc ]
+    ++ optional langJava boehmgc
     ++ optionals javaAwtGtk xlibs
     ++ optionals javaAwtGtk [ gmp mpfr ]
     ++ optional (libpthread != null) libpthread

pkgs/development/compilers/gcc/6/default.nix

@@ -383,7 +383,7 @@ stdenv.mkDerivation ({
     # Ada
     optional langAda "--enable-libada" ++
 
-    # Cross compilation
+    # Cross-compilation
     optional (targetPlatform == hostPlatform) (
       let incDir = if hostPlatform.isDarwin
                      then "${darwin.usr-include}"
@@ -396,7 +396,7 @@ stdenv.mkDerivation ({
 
     # Platform-specific flags
     optional (targetPlatform == hostPlatform && targetPlatform.isi686) "--with-arch=i686" ++
-    optionals (hostPlatform.isSunOS) [
+    optionals hostPlatform.isSunOS [
       "--enable-long-long" "--enable-libssp" "--enable-threads=posix" "--disable-nls" "--enable-__cxa_atexit"
       # On Illumos/Solaris GNU as is preferred
       "--with-gnu-as" "--without-gnu-ld"