cc-wrapper: set FC when langFortran is on

We need to set FC so that CMake and other tools can find the fortran
compiler. Also we need to limit the hardening flags since fortify and
format don’t work with fortran.

Fixes #88449

pkgs/build-support/cc-wrapper/default.nix

@@ -214,6 +214,7 @@ stdenv.mkDerivation {
       wrap ${targetPrefix}gfortran $wrapper $ccPath/${targetPrefix}gfortran
       ln -sv ${targetPrefix}gfortran $out/bin/${targetPrefix}g77
       ln -sv ${targetPrefix}gfortran $out/bin/${targetPrefix}f77
+      export named_fc=${targetPrefix}gfortran
     ''
 
     + optionalString cc.langJava or false ''
@@ -232,8 +233,8 @@ stdenv.mkDerivation {
 
   setupHooks = [
     ../setup-hooks/role.bash
-    ./setup-hook.sh
+  ] ++ stdenv.lib.optional (cc.langC or true) ./setup-hook.sh
-  ];
+    ++ stdenv.lib.optional (cc.langFortran or false) ./fortran-hook.sh;
 
   postFixup =
     ''

pkgs/build-support/cc-wrapper/fortran-hook.sh

@@ -0,0 +1,11 @@
+getTargetRole
+getTargetRoleWrapper
+
+export FC${role_post}=@named_fc@
+
+# If unset, assume the default hardening flags.
+# These are different for fortran.
+: ${NIX_HARDENING_ENABLE="stackprotector pic strictoverflow relro bindnow"}
+export NIX_HARDENING_ENABLE
+
+unset -v role_post