vms/make-mms-derivative.el

   1 ;;; make-mms-derivative.el --- framework to do horrible things for VMS support
   2
   3 ;; Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008
   4 ;;   Free Software Foundation, Inc.
   5
   6 ;; Author: Thien-Thi Nguyen <ttn@gnu.org>
   7 ;; Keywords: maint build vms mms makefile levitte autoconf war-is-a-lose
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software: you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation, either version 3 of the License, or
  14 ;; (at your option) any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  23
  24 ;;; Commentary:
  25
  26 ;; Under VMS the standard make-like program is called MMS, which looks
  27 ;; for an input file in the default directory named DESCRIP.MMS and runs
  28 ;; the DCL command rules therein.  As of 2005, the build process
  29 ;; requires a hand translation of the Makefile.in and Emacs-specific
  30 ;; methodology to DCL and TPU commands, so to alleviate this pain, we
  31 ;; provide `make-mms-derivative', which given a source FILENAME, inserts
  32 ;; the file contents in a new buffer and loads FILENAME-2mms.  The lisp
  33 ;; code in the -2mms file can (do whatever -- it's emacs -- and), as
  34 ;; long as it arranges to write out the modified buffer after loading by
  35 ;; specifying, on a line of its own, the directive:
  36 ;;
  37 ;;  :output RELATIVE-OUTPUT
  38 ;;
  39 ;; where RELATIVE-OUTPUT is a filename (a string) relative to FILENAME's
  40 ;; directory, typically something simple like "descrip.mms_in_in".  Only
  41 ;; the first :output directive is recognized.
  42 ;;
  43 ;; The only other special directive at this time has the form:
  44 ;;
  45 ;;  :gigo NAME
  46 ;;  ;;blah blah blah
  47 ;;  ;;(more text here)
  48 ;;
  49 ;; NAME is anything distinguishable w/ `eq' (number, symbol or keyword).
  50 ;; This associates NAME with the block of text starting immediately below
  51 ;; the :gigo directive and ending at the first line that does not begin
  52 ;; with two semicolons (which are stripped from each line in the block).
  53 ;; To insert this block of text, pass NAME to `make-mms-derivative-gigo'.
  54 ;;
  55 ;; Directives are scanned before normal evaluation, so their placement
  56 ;; in the file is not important.  During loading, plain strings are
  57 ;; displayed in the echo area, prefixed with the current line number.
  58 ;;
  59 ;; Over the long run, the convenience functions provided (see source)
  60 ;; will be augmented by factoring maximally the -2mms files, squeezing
  61 ;; as much algorithm out of those nasty heuristics as possible.  What
  62 ;; makes them nasty is not that they rely on the conventions of the
  63 ;; Emacs makefiles; that's no big deal.  What makes them nasty is that
  64 ;; they rely on the conventions of separately maintained tools (namely
  65 ;; Autoconf for VMS and GNU Autoconf), and the separation of conventions
  66 ;; is how people drift apart, dragging their software behind
  67 ;; mercilessly.
  68 ;;
  69 ;; In general, codified thought w/o self-synchronization is doomed.
  70 ;; That a generation would eat its young (most discriminatingly, even)
  71 ;; is no reason GNU cannot build around such woe.
  72
  73 ;;; Code:
  74
  75 (defvar make-mms-derivative-data nil
  76   "Plist of data specific to `make-mms-derivative'.")
  77
  78 (defun make-mms-derivative-data (key &optional newval)
  79   (if newval (setq make-mms-derivative-data
  80                    (plist-put make-mms-derivative-data key newval))
  81     (plist-get make-mms-derivative-data key)))
  82
  83 (defun make-mms-derivative-gigo (name)
  84   "Insert the text associated with :gigo NAME."
  85   (insert (cdr (assq name (make-mms-derivative-data :gigo)))))
  86
  87 (defun make-mms-derivative (filename)
  88   "Take FILENAME contents, load FILENAME-2mms, and write out the result.
  89 The output file is specified by the :output directive in FILENAME-2mms.
  90 See commentary of make-mms-derivative.el for full documentation."
  91   (interactive "fSource File: ")
  92   (let* ((todo (let ((fn (concat filename "-2mms")))
  93                  (unless (file-exists-p fn)
  94                    (error "Could not find %s" fn))
  95                  (set-buffer (get-buffer-create " *make-mms-derivative todo*"))
  96                  (insert-file-contents fn)
  97                  (current-buffer)))
  98          (deriv (get-buffer-create (format "*mms-derivative: %s"
  99                                            (file-relative-name filename))))
 100          output gigo form)
 101     (set-buffer todo)
 102     (re-search-forward "^:output")
 103     (setq output (expand-file-name (read (current-buffer))
 104                                    (file-name-directory filename)))
 105     (goto-char (point-min))
 106     (while (re-search-forward "^:gigo" (point-max) t)
 107       (let ((name (read (current-buffer)))
 108             (p (progn (forward-line 1) (point))))
 109         (while (looking-at ";;")
 110           (delete-char 2)
 111           (forward-line 1))
 112         (setq gigo (cons (cons name (buffer-substring p (point))) gigo))
 113         (delete-region p (point))))
 114     (message "Munging...")
 115     (switch-to-buffer deriv)
 116     (erase-buffer)
 117     (insert-file-contents filename)
 118     (set (make-local-variable 'make-mms-derivative-data)
 119          (list :gigo gigo))
 120     (set-buffer todo)
 121     (goto-char (point-min))
 122     (while (condition-case nil
 123                (setq form (read (current-buffer)))
 124              (end-of-file nil))
 125       (if (stringp form)
 126           (message "%d: %s" (count-lines (point-min) (point)) form)
 127         (save-excursion
 128           (set-buffer deriv)
 129           (eval form))))
 130     (set-buffer deriv)
 131     (message "Munging...done")
 132     (write-file output)
 133     (kill-buffer todo)
 134     (kill-buffer deriv)))
 135
 136 (provide 'make-mms-derivative)
 137
 138 ;; arch-tag: a5b08625-3952-4053-be16-296220e27bb0
 139 ;;; make-mms-derivative.el ends here