1 files changed, 38 insertions, 0 deletions
diff --git a/tools/emacs-pkgs/buildEmacsPackage.nix b/tools/emacs-pkgs/buildEmacsPackage.nix
new file mode 100644
index 0000000000..990b53b763
--- /dev/null
+++ b/tools/emacs-pkgs/buildEmacsPackage.nix
@@ -0,0 +1,38 @@
+# Builder for depot-internal Emacs packages. Packages built using this
+# builder are added into the Emacs packages fixpoint under
+# `emacsPackages.tvlPackages`, which in turn makes it possible to use
+# them with special Emacs features like native compilation.
+#
+# Arguments passed to the builder are the same as
+# emacsPackages.trivialBuild, except:
+#
+# * packageRequires is not used
+#
+# * externalRequires takes a selection function for packages from
+#   emacsPackages
+#
+# * internalRequires takes other depot packages
+{ pkgs, ... }:
+
+buildArgs:
+
+pkgs.callPackage
+  ({ emacsPackages }:
+
+  let
+    # Select external dependencies from the emacsPackages set
+    externalDeps = (buildArgs.externalRequires or (_: [ ])) emacsPackages;
+
+    # Override emacsPackages for depot-internal packages
+    internalDeps = map (p: p.override { inherit emacsPackages; })
+      (buildArgs.internalRequires or [ ]);
+
+    trivialBuildArgs = builtins.removeAttrs buildArgs [
+      "externalRequires"
+      "internalRequires"
+    ] // {
+      packageRequires = externalDeps ++ internalDeps;
+    };
+  in
+  emacsPackages.trivialBuild trivialBuildArgs)
+{ }