build-support/emacs: refactor

- Remove superflous `let` with `defaultMeta`

These can just be assigned to meta directly instead.

- Hoist internal intermediate derivation

- Remove top-level `with lib`

- Inherit `lib`/`builtins` into scopes

pkgs/build-support/emacs/elpa.nix

···
 
 { lib, stdenv, emacs, texinfo, writeText, gcc }:
 
-with lib;
+let
+  handledArgs = [ "files" "fileSpecs" "meta" ];
+  genericBuild = import ./generic.nix { inherit lib stdenv emacs texinfo writeText gcc; };
+
+in
 
 { pname
 , version
···
 , ...
 }@args:
 
-let
-
-  defaultMeta = {
-    homepage = args.src.meta.homepage or "https://elpa.gnu.org/packages/${pname}.html";
-  };
-
-in
-
-import ./generic.nix { inherit lib stdenv emacs texinfo writeText gcc; } ({
+genericBuild ({
 
   dontUnpack = true;
 
···
     runHook postInstall
   '';
 
-  meta = defaultMeta // meta;
+  meta = {
+    homepage = args.src.meta.homepage or "https://elpa.gnu.org/packages/${pname}.html";
+  } // meta;
 }
 
-// removeAttrs args [ "files" "fileSpecs"
-                      "meta"
-                    ])
+// removeAttrs args handledArgs)

pkgs/build-support/emacs/generic.nix

···
 
 { lib, stdenv, emacs, texinfo, writeText, gcc, ... }:
 
+let
+  inherit (lib) optionalAttrs getLib;
+  handledArgs = [ "buildInputs" "packageRequires" "meta" ];
+
+  setupHook = writeText "setup-hook.sh" ''
+    source ${./emacs-funcs.sh}
+
+    if [[ ! -v emacsHookDone ]]; then
+      emacsHookDone=1
+
+      # If this is for a wrapper derivation, emacs and the dependencies are all
+      # run-time dependencies. If this is for precompiling packages into bytecode,
+      # emacs is a compile-time dependency of the package.
+      addEnvHooks "$hostOffset" addEmacsVars
+      addEnvHooks "$targetOffset" addEmacsVars
+    fi
+  '';
+
+in
+
 { pname
 , version
 , buildInputs ? []
···
 , ...
 }@args:
 
-let
-  defaultMeta = {
-    broken = false;
-    platforms = emacs.meta.platforms;
-  } // lib.optionalAttrs ((args.src.meta.homepage or "") != "") {
-    homepage = args.src.meta.homepage;
-  };
-in
-
 stdenv.mkDerivation (finalAttrs: ({
   name = "emacs-${pname}-${finalAttrs.version}";
 
···
   propagatedBuildInputs = packageRequires;
   propagatedUserEnvPkgs = packageRequires;
 
-  setupHook = writeText "setup-hook.sh" ''
-    source ${./emacs-funcs.sh}
-
-    if [[ ! -v emacsHookDone ]]; then
-      emacsHookDone=1
-
-      # If this is for a wrapper derivation, emacs and the dependencies are all
-      # run-time dependencies. If this is for precompiling packages into bytecode,
-      # emacs is a compile-time dependency of the package.
-      addEnvHooks "$hostOffset" addEmacsVars
-      addEnvHooks "$targetOffset" addEmacsVars
-    fi
-  '';
+  inherit setupHook;
 
   doCheck = false;
 
-  meta = defaultMeta // meta;
+  meta = {
+    broken = false;
+    platforms = emacs.meta.platforms;
+  } // optionalAttrs ((args.src.meta.homepage or "") != "") {
+    homepage = args.src.meta.homepage;
+  } // meta;
 }
 
-// lib.optionalAttrs (emacs.withNativeCompilation or false) {
+// optionalAttrs (emacs.withNativeCompilation or false) {
 
-  LIBRARY_PATH = "${lib.getLib stdenv.cc.libc}/lib";
+  LIBRARY_PATH = "${getLib stdenv.cc.libc}/lib";
 
   nativeBuildInputs = [ gcc ];
 
···
   '';
 }
 
-// removeAttrs args [ "buildInputs" "packageRequires" "meta" ]))
+// removeAttrs args handledArgs))

pkgs/build-support/emacs/melpa.nix

···
 
 { lib, stdenv, fetchFromGitHub, emacs, texinfo, writeText, gcc }:
 
-with lib;
+let
+  genericBuild = import ./generic.nix { inherit lib stdenv emacs texinfo writeText gcc; };
+
+  packageBuild = stdenv.mkDerivation {
+    name = "package-build";
+    src = fetchFromGitHub {
+      owner = "melpa";
+      repo = "package-build";
+      rev = "c48aa078c01b4f07b804270c4583a0a58ffea1c0";
+      sha256 = "sha256-MzPj375upIiYXdQR+wWXv3A1zMqbSrZlH0taLuxx/1M=";
+    };
+
+    patches = [ ./package-build-dont-use-mtime.patch ];
+
+    dontConfigure = true;
+    dontBuild = true;
+
+    installPhase = "
+      mkdir -p $out
+      cp -r * $out
+    ";
+  };
+
+in
 
 { /*
     pname: Nix package name without special symbols and without version or
···
 , ...
 }@args:
 
-let
-
-  defaultMeta = {
-    homepage = args.src.meta.homepage or "https://melpa.org/#/${pname}";
-  };
-
-in
-
-import ./generic.nix { inherit lib stdenv emacs texinfo writeText gcc; } ({
+genericBuild ({
 
   ename =
     if ename == null
     then pname
     else ename;
 
-  packageBuild = stdenv.mkDerivation {
-    name = "package-build";
-    src = fetchFromGitHub {
-      owner = "melpa";
-      repo = "package-build";
-      rev = "c48aa078c01b4f07b804270c4583a0a58ffea1c0";
-      sha256 = "sha256-MzPj375upIiYXdQR+wWXv3A1zMqbSrZlH0taLuxx/1M=";
-    };
-
-    patches = [ ./package-build-dont-use-mtime.patch ];
-
-    dontConfigure = true;
-    dontBuild = true;
-
-    installPhase = "
-      mkdir -p $out
-      cp -r * $out
-    ";
-  };
-
   elpa2nix = ./elpa2nix.el;
   melpa2nix = ./melpa2nix.el;
+
+  inherit packageBuild;
 
   preUnpack = ''
     mkdir -p "$NIX_BUILD_TOP/recipes"
···
     runHook postInstall
   '';
 
-  meta = defaultMeta // meta;
+  meta = {
+    homepage = args.src.meta.homepage or "https://melpa.org/#/${pname}";
+  } // meta;
 }
 
 // removeAttrs args [ "meta" ])

pkgs/build-support/emacs/trivial.nix

···
 
 { callPackage, lib, ... }@envargs:
 
-with lib;
-
 args:
 
 callPackage ./generic.nix envargs ({