1 files changed, 34 insertions, 0 deletions
diff --git a/tools/emacs-pkgs/buildEmacsPackage.nix b/tools/emacs-pkgs/buildEmacsPackage.nix
new file mode 100644
index 0000000000..160c062613
--- /dev/null
+++ b/tools/emacs-pkgs/buildEmacsPackage.nix
@@ -0,0 +1,34 @@
+# 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) {}