Merge pull request #23560 from lheckemann/precision-strike

Precision strike

pkgs/applications/networking/syncthing/default.nix

@@ -1,11 +1,6 @@
-{ stdenv, lib, fetchFromGitHub, go, pkgs }:
+{ stdenv, lib, fetchFromGitHub, go, pkgs, removeReferencesTo }:
 
-let
-  removeExpr = ref: ''
-    sed -i "s,${ref},$(echo "${ref}" | sed "s,$NIX_STORE/[^-]*,$NIX_STORE/eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee,"),g" \
-  '';
-
-in stdenv.mkDerivation rec {
+stdenv.mkDerivation rec {
   version = "0.14.24";
   name = "syncthing-${version}";
 
@@ -16,7 +11,7 @@ in stdenv.mkDerivation rec {
     sha256 = "15jjk49ibry7crc3sw5zg09zsm5ir0ph5c0f3acas66wd02rnvl1";
   };
 
-  buildInputs = [ go ];
+  buildInputs = [ go removeReferencesTo ];
 
   buildPhase = ''
     mkdir -p src/github.com/syncthing
@@ -48,7 +43,7 @@ in stdenv.mkDerivation rec {
   '';
 
   preFixup = ''
-    find $out/bin -type f -exec ${removeExpr go} '{}' '+'
+    find $out/bin -type f -exec remove-references-to -t ${go} '{}' '+'
   '';
 
   meta = with stdenv.lib; {

pkgs/build-support/remove-references-to/default.nix

@@ -0,0 +1,34 @@
+# The program `remove-references-to' created by this derivation replaces all
+# references to the given Nix store paths in the specified files by a
+# non-existent path (/nix/store/eeee...).  This is useful for getting rid of
+# dependencies that you know are not actually needed at runtime.
+
+{ stdenv, writeScriptBin }:
+
+writeScriptBin "remove-references-to" ''
+#! ${stdenv.shell} -e
+
+# References to remove
+targets=()
+while getopts t: o; do
+    case "$o" in
+        t) storeId=$(echo "$OPTARG" | sed -n "s|^$NIX_STORE/\\([a-z0-9]\{32\}\\)-.*|\1|p")
+           if [ -z "$storeId" ]; then
+               echo "-t argument must be a Nix store path"
+               exit 1
+           fi
+           targets+=("$storeId")
+    esac
+done
+shift $(($OPTIND-1))
+
+# Files to remove the references from
+regions=()
+for i in "$@"; do
+    test ! -L "$i" -a -f "$i" && regions+=("$i")
+done
+
+for target in "''${targets[@]}" ; do
+    sed -i -e "s|$NIX_STORE/$target-|$NIX_STORE/eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee-|g" "''${regions[@]}"
+done
+''

pkgs/top-level/all-packages.nix

@@ -291,6 +291,8 @@ with pkgs;
 
   nukeReferences = callPackage ../build-support/nuke-references/default.nix { };
 
+  removeReferencesTo = callPackage ../build-support/remove-references-to/default.nix { };
+
   vmTools = callPackage ../build-support/vm/default.nix { };
 
   releaseTools = callPackage ../build-support/release/default.nix { };