treewide: Use pkgs/build-support/roles.bash to remove copy pasta

Also fix some setup hooks that unnecessarily used environment hooks,
which revolted in the same variable being modified too many times.

pkgs/os-specific/bsd/netbsd/compat-setup-hook.sh

@@ -1,18 +1,6 @@
-setupCompatFlags() {
-    # The `depHostOffset` describes how the host platform of the dependencies
-    # are slid relative to the depending package. It is brought into scope of
-    # the environment hook defined as the role of the dependency being applied.
-    case $depHostOffset in
-        -1) local role='BUILD_' ;;
-        0)  local role='' ;;
-        1)  local role='TARGET_' ;;
-        *)  echo "cc-wrapper: Error: Cannot be used with $depHostOffset-offset deps" >2;
-            return 1 ;;
-    esac
+# See pkgs/build-support/setup-hooks/role.bash
+getHostRole
 
-    export NIX_${role}LDFLAGS+=" -lnbcompat"
-    export NIX_${role}CFLAGS_COMPILE+=" -DHAVE_NBTOOL_CONFIG_H"
-    export NIX_${role}CFLAGS_COMPILE+=" -include nbtool_config.h"
-}
-
-addEnvHooks "$hostOffset" setupCompatFlags
+export NIX_${role_pre}LDFLAGS+=" -lnbcompat"
+export NIX_${role_pre}CFLAGS_COMPILE+=" -DHAVE_NBTOOL_CONFIG_H"
+export NIX_${role_pre}CFLAGS_COMPILE+=" -include nbtool_config.h"

pkgs/os-specific/bsd/netbsd/default.nix

@@ -167,7 +167,10 @@ let
     sha256 = "17phkfafybxwhzng44k5bhmag6i55br53ky1nwcmw583kg2fa86z";
     version = "7.1.2";
 
-    setupHook = ./compat-setup-hook.sh;
+    setupHooks = [
+      ../../../build-support/setup-hooks/role.bash
+      ./compat-setup-hook.sh
+    ];
 
     # override defaults to prevent infinite recursion
     nativeBuildInputs = [ makeMinimal ];
@@ -270,7 +273,10 @@ let
 
       runHook postInstall
     '';
-    setupHook = ./fts-setup-hook.sh;
+    setupHooks = [
+      ../../../build-support/setup-hooks/role.bash
+      ./fts-setup-hook.sh
+    ];
   };
 
   stat = netBSDDerivation {

pkgs/os-specific/bsd/netbsd/fts-setup-hook.sh

@@ -1,16 +1,4 @@
-ftsLdflags() {
-    # The `depHostOffset` describes how the host platform of the dependencies
-    # are slid relative to the depending package. It is brought into scope of
-    # the environment hook defined as the role of the dependency being applied.
-    case $depHostOffset in
-        -1) local role='BUILD_' ;;
-        0)  local role='' ;;
-        1)  local role='TARGET_' ;;
-        *)  echo "cc-wrapper: Error: Cannot be used with $depHostOffset-offset deps" >2;
-            return 1 ;;
-    esac
+# See pkgs/build-support/setup-hooks/role.bash
+getHostRole
 
-    export NIX_${role}LDFLAGS+=" -lfts"
-}
-
-addEnvHooks "$hostOffset" ftsLdflags
+export NIX_${role_pre}LDFLAGS+=" -lfts"