mcxx: remove build dependency with icc

bsc/mcxx/default.nix

@@ -10,7 +10,6 @@
 , flex
 , bison
 , gcc
-, icc
 }:
 
 stdenv.mkDerivation rec {
@@ -38,12 +37,18 @@ stdenv.mkDerivation rec {
     bison
     flex
     gcc
-    icc
   ];
 
+  patches = [ ./intel.patch ];
+
+  preConfigure = ''
+    export ICC=icc
+    export ICPC=icpc
+    export IFORT=ifort
+  '';
+
   configureFlags = [
     "--enable-ompss-2"
     "--with-nanos6=${nanos6}"
   ];
-    
 }

bsc/mcxx/intel.patch

@@ -0,0 +1,19 @@
+--- a/configure.ac	2020-07-10 16:15:11.431606455 +0200
++++ b/configure.ac	2020-07-10 16:15:24.291586572 +0200
+@@ -367,16 +367,6 @@
+   [ enable_intel_compilers="yes"])
+ AC_MSG_RESULT([$enable_intel_compilers])
+ 
+-
+-IFORT=
+-ICC=
+-ICPC=
+-if test x"$enable_intel_compilers" = x"yes";
+-then
+-   AC_CHECK_PROG([IFORT], [ifort], [ifort])
+-   AC_CHECK_PROG([ICC], [icc], [icc])
+-   AC_CHECK_PROG([ICPC], [icpc], [icpc])
+-fi
+ dnl --------------- END Intel Compilers ---------------------
+ 
+ mic_compilation="no"

default.nix

@@ -72,7 +72,6 @@ let
     };
 
     mcxx = callPackage ./bsc/mcxx/default.nix {
-      icc = icc;
       stdenv = pkgs.gcc9Stdenv;
       nanos6 = nanos6-git;
     };