bug#18721: 25.0.50; choose major mode from .dir-locals.el

[Tom Tromey]

It would be nice if there were a way to associate
file extensions with major modes in .dir-locals.el.
This would let projects use project-specific extensions
without requiring per-file mode cookies or having
everybody modify their .emacs




In GNU Emacs 25.0.50.3 (x86_64-unknown-linux-gnu, GTK+ Version 3.10.9)
 of 2014-10-09 on pokyo
Repository revision: 118080 eggert@cs.ucla.edu-20141009065410-dhgjku4gclzl71kj
Windowing system distributor `Fedora Project', version 11.0.11404000
System Description:     Fedora release 20 (Heisenbug)

Configured using:
 `configure --prefix=/home/tromey/Emacs/install'

Configured features:
XPM JPEG TIFF GIF PNG SOUND GPM DBUS GSETTINGS NOTIFY ACL LIBSELINUX
GNUTLS LIBXML2 FREETYPE LIBOTF XFT ZLIB

Important settings:
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix

Major mode: C++/l

Minor modes in effect:
  shell-dirtrack-mode: t
  erc-spelling-mode: t
  erc-truncate-mode: t
  diff-auto-refine-mode: t
  bug-reference-prog-mode: t
  flyspell-mode: t
  which-function-mode: t
  projectile-global-mode: t
  projectile-mode: t
  global-auto-revert-mode: t
  desktop-save-mode: t
  erc-status-mode: t
  erc-services-mode: t
  erc-list-mode: t
  erc-menu-mode: t
  erc-autojoin-mode: t
  erc-ring-mode: t
  erc-networks-mode: t
  erc-pcomplete-mode: t
  erc-track-mode: t
  erc-track-minor-mode: t
  erc-match-mode: t
  erc-button-mode: t
  erc-fill-mode: t
  erc-stamp-mode: t
  erc-netsplit-mode: t
  erc-irccontrols-mode: t
  erc-noncommands-mode: t
  erc-move-to-prompt-mode: t
  erc-readonly-mode: t
  savehist-mode: t
  tooltip-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  column-number-mode: t
  line-number-mode: t
  auto-fill-function: tromey-c++-do-auto-fill
  abbrev-mode: t

Recent input:
n e n o SPC 1 3 RET SPC 3 0 : SPC SPC SPC 1 3 SPC SPC 
SPC SPC 9 5 SPC [ SPC SPC SPC 0 ] SPC c o l s p a n 
SPC 1 RET SPC 3 2 : SPC SPC SPC 1 3 SPC SPC SPC 1 0 
8 SPC [ SPC SPC 1 3 ] SPC x d e l t a SPC SPC RET SPC 
3 3 : SPC SPC SPC 1 3 SPC SPC SPC 1 0 8 SPC [ SPC SPC 
SPC 0 ] SPC c o l s p a n SPC 8 RET RET E x c e p t 
i o n SPC t a b l e : RET k i n d SPC SPC SPC SPC SPC 
SPC s t a c k SPC SPC SPC SPC s t a r t SPC SPC SPC 
SPC SPC SPC e n d RET SPC c a t c h SPC SPC SPC SPC 
SPC SPC SPC SPC 0 SPC SPC SPC SPC SPC SPC SPC 1 4 SPC 
SPC SPC SPC SPC SPC SPC 4 3 RET SPC f i n a l l y SPC 
SPC SPC SPC SPC SPC 0 SPC SPC SPC SPC SPC SPC SPC 1 
4 SPC SPC SPC SPC SPC SPC SPC 7 9 ESC [ 2 0 1 ~ RET 
C-a C-k C-x C-x C-g C-u C-@ C-x C-s <switch-frame> 
C-z n C-z n <f10> <f10> C-z n C-z n <f10> <f10> <switch-frame> 
<switch-frame> C-z n C-z n <f10> <f10> <f10> <switch-frame> 
<switch-frame> C-x C-c <switch-frame> C-z n M-x r e 
o p r <M-backspace> r e p r <backspace> <backspace> 
p o e r <backspace> r <backspace> t <backspace> <backspace> 
r t - e m <tab> <return>

Recent messages:
C-z C-z is undefined
Quit
(New file)
When done with a buffer, type C-x #
Mark set
Auto-saving...
Quit
Saving file /tmp/L...
Wrote /tmp/L
(No files need saving)

Load-path shadows:
/home/tromey/.emacs.d/elpa/css-mode-1.0/css-mode hides 
/home/tromey/Emacs/install/share/emacs/25.0.50/lisp/textmodes/css-mode
/home/tromey/.emacs.d/elpa/bubbles-0.5/bubbles hides 
/home/tromey/Emacs/install/share/emacs/25.0.50/lisp/play/bubbles
/home/tromey/Emacs/install/share/emacs/25.0.50/lisp/loaddefs hides 
/home/tromey/Emacs/install/share/emacs/25.0.50/lisp/obsolete/loaddefs

Features:
(shadow emacsbug nxml-uchnm rng-xsd xsd-regexp rng-cmpct rng-nxml
rng-valid rng-loc rng-uri rng-parse nxml-parse rng-match rng-dt rng-util
rng-pttrn nxml-ns nxml-mode nxml-outln nxml-rap nxml-util nxml-glyph
nxml-enc xmltok vc-annotate ido log-edit eww log-view pcvs-util novice
etags find-dired ffap two-column autoconf autoconf-mode sh-script smie
executable shell find-file eieio-opt speedbar sb-image ezimage dframe
help-mode gdb-shell webjump dabbrev copyright idutils derived gnus-fun
flow-fill gnus-html xml mm-url mailalias bbdb-sc supercite regi
mail-hist nnir shr-color color xterm url-http url-gw url-auth url-queue
url-cache url url-proxy url-privacy url-expand url-methods url-history
url-cookie url-domsuf url-util url-parse url-vars shr browse-url
misearch multi-isearch erc-spelling erc-truncate bbdb-gui bbdb-hooks
mule-util sort smiley gnus-cite mm-archive gnus-async gnus-bcklg qp
gnus-ml disp-table gnus-topic nndraft nnmh nnfolder utf-7 bbdb-gnus
bbdb-snarf mail-extr bbdb-com warnings cl gv gnutls network-stream
starttls gnus-agent gnus-srvr gnus-score score-mode nnvirtual gnus-msg
nntp gnus-cache gnus-registry registry eieio-base gnus-art mm-uu mml2015
mm-view mml-smime smime dig mailcap gnus-sum gnus-group gnus-undo
smtpmail sendmail gnus-start gnus-cloud nnimap nnmail mail-source tls
utf7 netrc nnoo parse-time gnus-spec gnus-int gnus-range gnus-win gnus
gnus-ems nnheader message rfc822 mml mml-sec mm-decode mm-bodies
mm-encode mail-parse rfc2231 rfc2047 rfc2045 ietf-drums mailabbrev
mail-utils gmm-utils mailheader goto-addr add-log dired-aux gud
org-element org-rmail org-mhe org-irc org-info org-gnus org-docview
doc-view jka-compr image-mode dired org-bibtex bibtex org-bbdb org-w3m
org org-macro org-footnote org-pcomplete org-list org-faces org-entities
noutline outline org-version ob-emacs-lisp ob ob-tangle ob-ref ob-lob
ob-table ob-exp org-src ob-keys ob-comint ob-core ob-eval org-compat
org-macs org-loaddefs conf-mode python sgml-mode vc-arch vc-mtn vc-hg
vc-bzr vc-sccs vc-svn vc-cvs vc-rcs js json smerge-mode diff-mode
easy-mmode bug-reference vc-git cc-mode cc-fonts cc-guess cc-menus
cc-cmds flyspell ispell eldoc diminish appt diary-lib diary-loaddefs
cal-menu calendar cal-loaddefs which-func imenu projectile edmacro
kmacro pkg-info find-func lisp-mnt epl grep compile dash s minimap
autorevert filenotify desktop frameset cus-start cus-load status
erc-services erc-list erc-menu erc-join erc-ring erc-networks
erc-pcomplete pcomplete erc-track erc-match erc-button wid-edit
cl-loaddefs cl-lib erc-fill erc-stamp erc-netsplit erc-goodies erc
erc-backend erc-compat format-spec auth-source eieio byte-opt bytecomp
byte-compile cconv eieio-core gnus-util mm-util mail-prsvr
password-cache thingatpt pp advice help-fns vc-dir ewoc vc vc-dispatcher
cc-styles cc-align cc-engine cc-vars cc-defs bbdb timezone ange-ftp
comint ansi-color ring server savehist dwarf-mode-autoloads
jabber-autoloads lisppaste-autoloads pydoc-info-autoloads info-look info
easymenu weblogger-autoloads package epg-config bbdb-autoloads time-date
tooltip electric uniquify ediff-hook vc-hooks lisp-float-type mwheel
x-win x-dnd tool-bar dnd fontset image regexp-opt fringe tabulated-list
newcomment elisp-mode lisp-mode prog-mode register page menu-bar
rfn-eshadow timer select scroll-bar mouse jit-lock font-lock syntax
facemenu font-core frame cham georgian utf-8-lang misc-lang vietnamese
tibetan thai tai-viet lao korean japanese hebrew greek romanian slovak
czech european ethiopic indian cyrillic chinese case-table epa-hook
jka-cmpr-hook help simple abbrev minibuffer nadvice loaddefs button
faces cus-face macroexp files text-properties overlay sha1 md5 base64
format env code-pages mule custom widget hashtable-print-readable
backquote make-network-process dbusbind gfilenotify dynamic-setting
system-font-setting font-render-setting move-toolbar gtk x-toolkit x
multi-tty emacs)

Memory information:
((conses 16 2621370 283762)
 (symbols 48 136643 5)
 (miscs 40 63207 11870)
 (strings 32 404536 58294)
 (string-bytes 1 18990197)
 (vectors 16 116801)
 (vector-slots 8 2921863 191230)
 (floats 8 758 1153)
 (intervals 56 289543 1523)
 (buffers 976 821)
 (heap 1024 349107 75634))

Tom