cc-wrapper: Pull variable mangler into utils.sh

In preparation for splitting out binutils-wrapper

pkgs/build-support/cc-wrapper/add-flags.sh

@@ -36,16 +36,7 @@ fi
 # We need to mangle names for hygiene, but also take parameters/overrides
 # from the environment.
 for var in "${var_templates[@]}"; do
-    outputVar="${var/+/_@infixSalt@_}"
+    mangleVarList "$var" "${role_infixes[@]}"
-    export ${outputVar}+=''
-    # For each role we serve, we accumulate the input parameters into our own
-    # cc-wrapper-derivation-specific environment variables.
-    for infix in "${role_infixes[@]}"; do
-        inputVar="${var/+/${infix}}"
-        if [ -v "$inputVar" ]; then
-            export ${outputVar}+="${!outputVar:+ }${!inputVar}"
-        fi
-    done
 done
 
 # `-B@out@/bin' forces cc to use ld-wrapper.sh when calling ld.

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

@@ -11,12 +11,12 @@ if [[ -n "@coreutils_bin@" && -n "@gnugrep_bin@" ]]; then
     PATH="@coreutils_bin@/bin:@gnugrep_bin@/bin"
 fi
 
+source @out@/nix-support/utils.sh
+
 if [ -z "${NIX_CC_WRAPPER_@infixSalt@_FLAGS_SET:-}" ]; then
     source @out@/nix-support/add-flags.sh
 fi
 
-source @out@/nix-support/utils.sh
-
 
 # Parse command line options and set several variables.
 # For instance, figure out if linker flags should be passed.

pkgs/build-support/cc-wrapper/gnat-wrapper.sh

@@ -13,12 +13,12 @@ if [ -n "@coreutils_bin@" ]; then
     PATH="@coreutils_bin@/bin"
 fi
 
+source @out@/nix-support/utils.sh
+
 if [ -z "${NIX_@infixSalt@_GNAT_WRAPPER_FLAGS_SET:-}" ]; then
     source @out@/nix-support/add-flags.sh
 fi
 
-source @out@/nix-support/utils.sh
-
 
 # Figure out if linker flags should be passed.  GCC prints annoying
 # warnings when they are not needed.

pkgs/build-support/cc-wrapper/ld-wrapper.sh

@@ -10,12 +10,12 @@ if [ -n "@coreutils_bin@" ]; then
     PATH="@coreutils_bin@/bin"
 fi
 
+source @out@/nix-support/utils.sh
+
 if [ -z "${NIX_CC_WRAPPER_@infixSalt@_FLAGS_SET:-}" ]; then
     source @out@/nix-support/add-flags.sh
 fi
 
-source @out@/nix-support/utils.sh
-
 
 # Optionally filter out paths not refering to the store.
 expandResponseParams "$@"

pkgs/build-support/cc-wrapper/utils.sh

@@ -1,3 +1,20 @@
+mangleVarList() {
+    declare var="$1"
+    shift
+    declare -a role_infixes=("$@")
+
+    outputVar="${var/+/_@infixSalt@_}"
+    export ${outputVar}+=''
+    # For each role we serve, we accumulate the input parameters into our own
+    # cc-wrapper-derivation-specific environment variables.
+    for infix in "${role_infixes[@]}"; do
+        inputVar="${var/+/${infix}}"
+        if [ -v "$inputVar" ]; then
+            export ${outputVar}+="${!outputVar:+ }${!inputVar}"
+        fi
+    done
+}
+
 skip () {
     if [ -n "${NIX_DEBUG:-}" ]; then
         echo "skipping impure path $1" >&2