contrib: add compilation-mode linking for our test output

These regular expressions will cause compilation-mode buffers in emacs
to link to source when there are check-code errors in the output of a
.t test.

In the true tradition of this file, I also have no idea what I'm doing.

Differential Revision: https://phab.mercurial-scm.org/D6000

contrib/hg-test-mode.el

@@ -1,56 +1,63 b''
 ;; hg-test-mode.el - Major mode for editing Mercurial tests
 ;;
 ;; Copyright 2014 Matt Mackall <[e-mail]>
 ;; "I have no idea what I'm doing"
 ;;
 ;; This software may be used and distributed according to the terms of the
 ;; GNU General Public License version 2 or any later version.
 ;;
 ;; To enable, add something like the following to your .emacs:
 ;;
 ;; (if (file-exists-p "~/hg/contrib/hg-test-mode.el")
 ;;    (load "~/hg/contrib/hg-test-mode.el"))
 
 (defvar hg-test-mode-hook nil)
 
 (defvar hg-test-mode-map
   (let ((map (make-keymap)))
     (define-key map "\C-j" 'newline-and-indent)
     map)
   "Keymap for hg test major mode")
 
 (add-to-list 'auto-mode-alist '("\\.t\\'" . hg-test-mode))
 
 (defconst hg-test-font-lock-keywords-1
   (list
    '("^  \\(\\$\\|>>>\\) " 1 font-lock-builtin-face)
    '("^  \\(>\\|\\.\\.\\.\\) " 1 font-lock-constant-face)
    '("^  \\([[][0-9]+[]]\\)$" 1 font-lock-warning-face)
    '("^  \\(.*?\\)\\(\\( [(][-a-z]+[)]\\)*\\)$" 1 font-lock-string-face)
    '("\\$?\\(HG\\|TEST\\)\\w+=?" . font-lock-variable-name-face)
    '("^  \\(.*?\\)\\(\\( [(][-a-z]+[)]\\)+\\)$" 2 font-lock-type-face)
    '("^#.*" . font-lock-preprocessor-face)
    '("^\\([^ ].*\\)$" 1 font-lock-comment-face)
    )
   "Minimal highlighting expressions for hg-test mode")
 
 (defvar hg-test-font-lock-keywords hg-test-font-lock-keywords-1
   "Default highlighting expressions for hg-test mode")
 
 (defvar hg-test-mode-syntax-table
   (let ((st (make-syntax-table)))
     (modify-syntax-entry ?\" "w" st) ;; disable standard quoting
     st)
 "Syntax table for hg-test mode")
 
 (defun hg-test-mode ()
   (interactive)
   (kill-all-local-variables)
   (use-local-map hg-test-mode-map)
   (set-syntax-table hg-test-mode-syntax-table)
   (set (make-local-variable 'font-lock-defaults) '(hg-test-font-lock-keywords))
   (setq major-mode 'hg-test-mode)
   (setq mode-name "hg-test")
   (run-hooks 'hg-test-mode-hook))
 
+(with-eval-after-load "compile"
+  ;; Link to source files in test-check-code.t violations.
+  (add-to-list 'compilation-error-regexp-alist-alist
+               '(hg-test-check-code-output
+                 "\\+  \\([^:\n]+\\):\\([0-9]+\\):$" 1 2))
+  (add-to-list 'compilation-error-regexp-alist 'hg-test-check-code-output))
+
 (provide 'hg-test-mode)