[bug#44775] WIP: Add gccemacs

From 03ab270db130b9991fcbfa87b9d1fcc009fba059 Mon Sep 17 00:00:00 2001
From: John Soo <jsoo1@asu.edu>
Date: Fri, 20 Nov 2020 22:06:52 -0800
Subject: [PATCH] gnu: Add gccemacs.

---
 gnu/packages/emacs.scm                        | 109 ++++++++++++++++++
 gnu/packages/patches/gccemacs-exec-path.patch |  18 +++
 2 files changed, 127 insertions(+)
 create mode 100644 gnu/packages/patches/gccemacs-exec-path.patch

diff --git a/gnu/packages/emacs.scm b/gnu/packages/emacs.scm
index 7a5dd9010c..98a9aae69b 100644
--- a/gnu/packages/emacs.scm
+++ b/gnu/packages/emacs.scm
@@ -53,6 +53,7 @@ 
   #:use-module (gnu packages compression)
   #:use-module (gnu packages fontutils)
   #:use-module (gnu packages fribidi)
+  #:use-module (gnu packages gcc)
   #:use-module (gnu packages gd)
   #:use-module (gnu packages gettext)
   #:use-module (gnu packages glib)
@@ -426,6 +427,114 @@  editor (console only)")
            (delete 'strip-double-wrap)))))
     (inputs (package-inputs emacs-no-x))))
 
+;; feature/native-comp
+(define-public gccemacs-commit
+  "6781cd670d1487bbf0364d80de68ca9733342769")
+
+(define-public gccemacs-version
+  (git-version "28.0.50" "0" gccemacs-commit))
+
+(define-public gccemacs-source
+  (origin
+   (method git-fetch)
+   (uri (git-reference
+         (url "git://git.sv.gnu.org/emacs.git")
+         (commit gccemacs-commit)))
+   (sha256
+    (base32
+     "13pmrak5jvk5qp4i5iccn0fqa6by8ig8l0n3qqirm67dxrqiz2ya"))
+   (patches (search-patches "gccemacs-exec-path.patch"
+                            "emacs-fix-scheme-indent-function.patch"
+                            "emacs-ignore-empty-xim-styles.patch"
+                            "emacs-source-date-epoch.patch"))
+   (modules '((guix build utils)))
+   (snippet
+    '(with-directory-excursion "lisp"
+      ;; Delete the bundled byte-compiled elisp files and generated
+      ;; autoloads.
+      (for-each delete-file
+                (append (find-files "." "\\.elc$")
+                        (find-files "." "loaddefs\\.el$")
+                        (find-files "eshell" "^esh-groups\\.el$")))
+
+      ;; Make sure Tramp looks for binaries in the right places on
+      ;; remote Guix System machines, where 'getconf PATH' returns
+      ;; something bogus.
+      (substitute* "net/tramp-sh.el"
+       ;; Patch the line after "(defcustom tramp-remote-path".
+       (("\\(tramp-default-remote-path")
+        (format #f "(tramp-default-remote-path ~s ~s ~s ~s "
+                "~/.guix-profile/bin" "~/.guix-profile/sbin"
+                "/run/current-system/profile/bin"
+                "/run/current-system/profile/sbin")))
+
+      ;; Make sure Man looks for C header files in the right
+      ;; places.
+      (substitute* "man.el"
+       (("\"/usr/local/include\"" line)
+        (string-join
+         (list line
+               "\"~/.guix-profile/include\""
+               "\"/var/guix/profiles/system/profile/include\"")
+         " ")))
+      #t))))
+
+(define add-libgccjit-gcc-lib-to-library-path
+  '(lambda* (#:key inputs #:allow-other-keys)
+     (define (prepend-to-env val var)
+       (let ((current (getenv var)))
+         (setenv
+          var (if (and current (not (string-null? current)))
+                  (string-append val ":" current)
+                  val))))
+     (let* ((libgccjit (assoc-ref inputs "libgccjit"))
+            (gcc-dirs (find-files
+                       libgccjit "^gcc$" #:directories? #t))
+            (gcc-dirs-paths (string-join gcc-dirs ":")))
+       (prepend-to-env gcc-dirs-paths "LIBRARY_PATH")
+       (prepend-to-env gcc-dirs-paths "LD_LIBRARY_PATH")
+       (prepend-to-env gcc-dirs-paths "PATH")
+       #t)))
+
+(define-public gccemacs
+  (package
+   (inherit emacs-next)
+   (name "gccemacs")
+   (version gccemacs-version)
+   (source gccemacs-source)
+   (synopsis "The extensible, customizeable, self-documenting text
+editor (from the native compilation branch)")
+   (inputs
+    `(("libgccjit" ,(canonical-package libgccjit))
+      ,@(package-inputs emacs-next)))
+   (arguments
+    (substitute-keyword-arguments (package-arguments emacs-next)
+     ((#:phases p)
+      `(modify-phases ,p
+         (add-after 'bootstrap 'add-libgccjit-gcc-lib-to-library-path
+           ,add-libgccjit-gcc-lib-to-library-path)))
+     ((#:configure-flags flags ''())
+      `(cons "--with-nativecomp" ,flags))))))
+
+(define-public gccemacs-no-x
+  (package/inherit emacs-next-no-x
+   (name "gccemacs-no-x")
+   (version gccemacs-version)
+   (source gccemacs-source)
+   (synopsis "The extensible, customizable, self-documenting text
+editor (console only, from the native compilation branch)")
+   (build-system gnu-build-system)
+   (inputs
+    `(("libgccjit" ,(canonical-package libgccjit))
+      ,@(package-inputs emacs-next-no-x)))
+   (arguments
+    (substitute-keyword-arguments (package-arguments emacs-next-no-x)
+      ((#:phases p)
+       `(modify-phases ,p
+          (add-after 'bootstrap 'add-libgccjit-gcc-lib-to-library-path
+            ,add-libgccjit-gcc-lib-to-library-path)))
+      ((#:configure-flags flags ''())
+       `(cons "--with-nativecomp" ,flags))))))
 
 (define-public emacs-no-x-toolkit
   (package/inherit emacs
diff --git a/gnu/packages/patches/gccemacs-exec-path.patch b/gnu/packages/patches/gccemacs-exec-path.patch
new file mode 100644
index 0000000000..3c75f9465e
--- /dev/null
+++ b/gnu/packages/patches/gccemacs-exec-path.patch
@@ -0,0 +1,18 @@ 
+Do not capture the build-time value of $PATH in the 'emacs' executable
+since this can noticeably increase the size of the closure of Emacs
+with things like GCC being referenced.
+
+diff --git a/lisp/loadup.el.old b/lisp/loadup.el
+index 158a4bf..f853a48 100644
+--- a/lisp/loadup.el
++++ b/lisp/loadup.el
+@@ -509,7 +509,8 @@ lost after dumping")))
+                         ((equal dump-mode "dump") "emacs")
+                         ((equal dump-mode "bootstrap") "emacs")
+                         ((equal dump-mode "pbootstrap") "bootstrap-emacs.pdmp")
+-                        (t (error "unrecognized dump mode %s" dump-mode)))))
++                        (t (error "unrecognized dump mode %s" dump-mode))))
++          (exec-path nil))
+       (when (and (featurep 'nativecomp)
+                  (equal dump-mode "pdump"))
+         ;; Don't enable this before bootstrap is completed the as the
-- 
2.29.2