Imported Upstream version 1.1~hg20130323upstream/1.1_hg20130323

1 files changed, 301 insertions, 120 deletions

diff --git a/misc/emacs/go-mode.el b/misc/emacs/go-mode.el
index 8a16d8a4f..9b6ea74f3 100644
--- a/misc/emacs/go-mode.el
+++ b/misc/emacs/go-mode.el
@@ -5,18 +5,71 @@
 ;; license that can be found in the LICENSE file.
 
 (require 'cl)
-(require 'diff-mode)
 (require 'ffap)
-(require 'find-lisp)
 (require 'url)
 
+;; XEmacs compatibility guidelines
+;; - Minimum required version of XEmacs: 21.5.32
+;;   - Feature that cannot be backported: POSIX character classes in
+;;     regular expressions
+;;   - Functions that could be backported but won't because 21.5.32
+;;     covers them: plenty.
+;;   - Features that are still partly broken:
+;;     - godef will not work correctly if multibyte characters are
+;;       being used
+;;     - Fontification will not handle unicode correctly
+;;
+;; - Do not use \_< and \_> regexp delimiters directly; use
+;;   go--regexp-enclose-in-symbol
+;;
+;; - The character `_` must not be a symbol constituent but a
+;;   character constituent
+;;
+;; - Do not use process-lines
+;;
+;; - Use go--old-completion-list-style when using a plain list as the
+;;   collection for completing-read
+;;
+;; - Use go--kill-whole-line instead of kill-whole-line (called
+;;   kill-entire-line in XEmacs)
+;;
+;; - Use go--position-bytes instead of position-bytes
+(defmacro go--xemacs-p ()
+  `(featurep 'xemacs))
+
+(defalias 'go--kill-whole-line
+  (if (fboundp 'kill-whole-line)
+      'kill-whole-line
+    'kill-entire-line))
+
+;; XEmacs unfortunately does not offer position-bytes. We can fall
+;; back to just using (point), but it will be incorrect as soon as
+;; multibyte characters are being used.
+(if (fboundp 'position-bytes)
+    (defalias 'go--position-bytes 'position-bytes)
+  (defun go--position-bytes (point) point))
+
+(defun go--old-completion-list-style (list)
+  (mapcar (lambda (x) (cons x nil)) list))
+
+
+(defun go--regexp-enclose-in-symbol (s)
+  ;; XEmacs does not support \_<, GNU Emacs does. In GNU Emacs we make
+  ;; extensive use of \_< to support unicode in identifiers. Until we
+  ;; come up with a better solution for XEmacs, this solution will
+  ;; break fontification in XEmacs for identifiers such as "typeµ".
+  ;; XEmacs will consider "type" a keyword, GNU Emacs won't.
+
+  (if (go--xemacs-p)
+      (concat "\\<" s "\\>")
+    (concat "\\_<" s "\\_>")))
+
 (defconst go-dangling-operators-regexp "[^-]-\\|[^+]\\+\\|[/*&><.=|^]")
-(defconst gofmt-stdin-tag "<standard input>")
-(defconst go-identifier-regexp "[[:word:][:multibyte:]_]+")
+(defconst go-identifier-regexp "[[:word:][:multibyte:]]+")
 (defconst go-label-regexp go-identifier-regexp)
-(defconst go-type-regexp "[[:word:][:multibyte:]_*]+")
-(defconst go-func-regexp (concat "\\<func\\>\\s *\\(" go-identifier-regexp "\\)"))
-(defconst go-func-meth-regexp (concat "\\<func\\>\\s *\\(?:(\\s *" go-identifier-regexp "\\s +" go-type-regexp "\\s *)\\s *\\)?\\(" go-identifier-regexp "\\)("))
+(defconst go-type-regexp "[[:word:][:multibyte:]*]+")
+(defconst go-func-regexp (concat (go--regexp-enclose-in-symbol "func") "\\s *\\(" go-identifier-regexp "\\)"))
+(defconst go-func-meth-regexp (concat (go--regexp-enclose-in-symbol "func") "\\s *\\(?:(\\s *" go-identifier-regexp "\\s +" go-type-regexp "\\s *)\\s *\\)?\\(" go-identifier-regexp "\\)("))
 (defconst go-builtins
   '("append" "cap"   "close"   "complex" "copy"
     "delete" "imag"  "len"     "make"    "new"
@@ -35,6 +88,7 @@
 (defconst go-type-name-regexp (concat "\\(?:[*(]\\)*\\(?:" go-identifier-regexp "\\.\\)?\\(" go-identifier-regexp "\\)"))
 
 (defvar go-dangling-cache)
+(defvar go-godoc-history nil)
 
 (defgroup go nil
   "Major mode for editing Go code"
@@ -57,23 +111,27 @@
     (modify-syntax-entry ?=  "." st)
     (modify-syntax-entry ?<  "." st)
     (modify-syntax-entry ?>  "." st)
-    (modify-syntax-entry ?/  ". 124b" st)
+    (modify-syntax-entry ?/ (if (go--xemacs-p) ". 1456" ". 124b") st)
     (modify-syntax-entry ?*  ". 23" st)
     (modify-syntax-entry ?\n "> b" st)
     (modify-syntax-entry ?\" "\"" st)
     (modify-syntax-entry ?\' "\"" st)
     (modify-syntax-entry ?`  "\"" st)
     (modify-syntax-entry ?\\ "\\" st)
-    (modify-syntax-entry ?_  "_" st)
+    ;; It would be nicer to have _ as a symbol constituent, but that
+    ;; would trip up XEmacs, which does not support the \_< anchor
+    (modify-syntax-entry ?_  "w" st)
 
     st)
   "Syntax table for Go mode.")
 
 (defun go--build-font-lock-keywords ()
+  ;; we cannot use 'symbols in regexp-opt because emacs <24 doesn't
+  ;; understand that
   (append
-   `((,(regexp-opt go-mode-keywords 'symbols) . font-lock-keyword-face)
-     (,(regexp-opt go-builtins 'symbols) . font-lock-builtin-face)
-     (,(regexp-opt go-constants 'symbols) . font-lock-constant-face)
+   `((,(go--regexp-enclose-in-symbol (regexp-opt go-mode-keywords t)) . font-lock-keyword-face)
+     (,(go--regexp-enclose-in-symbol (regexp-opt go-builtins t)) . font-lock-builtin-face)
+     (,(go--regexp-enclose-in-symbol (regexp-opt go-constants t)) . font-lock-constant-face)
      (,go-func-regexp 1 font-lock-function-name-face)) ;; function (not method) name
 
    (if go-fontify-function-calls
@@ -82,22 +140,22 @@
      `((,go-func-meth-regexp 1 font-lock-function-name-face))) ;; method name
 
    `(
-     ("\\<type\\>[[:space:]]*\\([^[:space:]]+\\)" 1 font-lock-type-face) ;; types
-     (,(concat "\\<type\\>[[:space:]]*" go-identifier-regexp "[[:space:]]*" go-type-name-regexp) 1 font-lock-type-face) ;; types
-     (,(concat "\\(?:[[:space:]]+\\|\\]\\)\\[\\([[:digit:]]+\\|\\.\\.\\.\\)?\\]" go-type-name-regexp) 2 font-lock-type-face) ;; Arrays/slices
-     (,(concat "map\\[[^]]+\\]" go-type-name-regexp) 1 font-lock-type-face) ;; map value type
+     (,(concat (go--regexp-enclose-in-symbol "type") "[[:space:]]*\\([^[:space:]]+\\)") 1 font-lock-type-face) ;; types
+     (,(concat (go--regexp-enclose-in-symbol "type") "[[:space:]]*" go-identifier-regexp "[[:space:]]*" go-type-name-regexp) 1 font-lock-type-face) ;; types
+     (,(concat "[^[:word:][:multibyte:]]\\[\\([[:digit:]]+\\|\\.\\.\\.\\)?\\]" go-type-name-regexp) 2 font-lock-type-face) ;; Arrays/slices
      (,(concat "\\(" go-identifier-regexp "\\)" "{") 1 font-lock-type-face)
-     (,(concat "\\<map\\[" go-type-name-regexp) 1 font-lock-type-face) ;; map key type
-     (,(concat "\\<chan\\>[[:space:]]*\\(?:<-\\)?" go-type-name-regexp) 1 font-lock-type-face) ;; channel type
-     (,(concat "\\<\\(?:new\\|make\\)\\>\\(?:[[:space:]]\\|)\\)*(" go-type-name-regexp) 1 font-lock-type-face) ;; new/make type
+     (,(concat (go--regexp-enclose-in-symbol "map") "\\[[^]]+\\]" go-type-name-regexp) 1 font-lock-type-face) ;; map value type
+     (,(concat (go--regexp-enclose-in-symbol "map") "\\[" go-type-name-regexp) 1 font-lock-type-face) ;; map key type
+     (,(concat (go--regexp-enclose-in-symbol "chan") "[[:space:]]*\\(?:<-\\)?" go-type-name-regexp) 1 font-lock-type-face) ;; channel type
+     (,(concat (go--regexp-enclose-in-symbol "\\(?:new\\|make\\)") "\\(?:[[:space:]]\\|)\\)*(" go-type-name-regexp) 1 font-lock-type-face) ;; new/make type
      ;; TODO do we actually need this one or isn't it just a function call?
      (,(concat "\\.\\s *(" go-type-name-regexp) 1 font-lock-type-face) ;; Type conversion
-     (,(concat "\\<func\\>[[:space:]]+(" go-identifier-regexp "[[:space:]]+" go-type-name-regexp ")") 1 font-lock-type-face) ;; Method receiver
+     (,(concat (go--regexp-enclose-in-symbol "func") "[[:space:]]+(" go-identifier-regexp "[[:space:]]+" go-type-name-regexp ")") 1 font-lock-type-face) ;; Method receiver
      ;; Like the original go-mode this also marks compound literal
      ;; fields. There, it was marked as to fix, but I grew quite
      ;; accustomed to it, so it'll stay for now.
      (,(concat "^[[:space:]]*\\(" go-label-regexp "\\)[[:space:]]*:\\(\\S.\\|$\\)") 1 font-lock-constant-face) ;; Labels and compound literal fields
-     (,(concat "\\<\\(goto\\|break\\|continue\\)\\>[[:space:]]*\\(" go-label-regexp "\\)") 2 font-lock-constant-face)))) ;; labels in goto/break/continue
+     (,(concat (go--regexp-enclose-in-symbol "\\(goto\\|break\\|continue\\)") "[[:space:]]*\\(" go-label-regexp "\\)") 2 font-lock-constant-face)))) ;; labels in goto/break/continue
 
 (defvar go-mode-map
   (let ((m (make-sparse-keymap)))
@@ -107,6 +165,8 @@
     (define-key m ":" 'go-mode-insert-and-indent)
     (define-key m "=" 'go-mode-insert-and-indent)
     (define-key m (kbd "C-c C-a") 'go-import-add)
+    (define-key m (kbd "C-c C-j") 'godef-jump)
+    (define-key m (kbd "C-c C-d") 'godef-describe)
     m)
   "Keymap used by Go mode to implement electric keys.")
 
@@ -140,7 +200,7 @@ It skips over whitespace, comments, cases and labels and, if
 STOP-AT-STRING is not true, over strings."
 
   (let (pos (start-pos (point)))
-    (skip-chars-backward "\n[:blank:]")
+    (skip-chars-backward "\n\s\t")
     (if (and (save-excursion (beginning-of-line) (go-in-string-p)) (looking-back "`") (not stop-at-string))
         (backward-char))
     (if (and (go-in-string-p) (not stop-at-string))
@@ -177,6 +237,28 @@ STOP-AT-STRING is not true, over strings."
               (puthash cur-line val go-dangling-cache))))
     val))
 
+(defun go--at-function-definition ()
+  "Return non-nil if point is on the opening curly brace of a
+function definition.
+
+We do this by first calling (beginning-of-defun), which will take
+us to the start of *some* function. We then look for the opening
+curly brace of that function and compare its position against the
+curly brace we are checking. If they match, we return non-nil."
+  (if (= (char-after) ?\{)
+      (save-excursion
+        (let ((old-point (point))
+              start-nesting)
+          (beginning-of-defun)
+          (when (looking-at "func ")
+            (setq start-nesting (go-paren-level))
+            (skip-chars-forward "^{")
+            (while (> (go-paren-level) start-nesting)
+              (forward-char)
+              (skip-chars-forward "^{") 0)
+            (if (and (= (go-paren-level) start-nesting) (= old-point (point)))
+                t))))))
+
 (defun go-goto-opening-parenthesis (&optional char)
   (let ((start-nesting (go-paren-level)))
     (while (and (not (bobp))
@@ -189,6 +271,20 @@ STOP-AT-STRING is not true, over strings."
               (go-goto-beginning-of-string-or-comment)
             (backward-char))))))
 
+(defun go--indentation-for-opening-parenthesis ()
+  "Return the semantic indentation for the current opening parenthesis.
+
+If point is on an opening curly brace and said curly brace
+belongs to a function declaration, the indentation of the func
+keyword will be returned. Otherwise the indentation of the
+current line will be returned."
+  (save-excursion
+    (if (go--at-function-definition)
+        (progn
+          (beginning-of-defun)
+          (current-indentation))
+      (current-indentation))))
+
 (defun go-indentation-at-point ()
   (save-excursion
     (let (start-nesting (outindent 0))
@@ -202,7 +298,7 @@ STOP-AT-STRING is not true, over strings."
         (go-goto-opening-parenthesis (char-after))
         (if (go-previous-line-has-dangling-op-p)
             (- (current-indentation) tab-width)
-          (current-indentation)))
+          (go--indentation-for-opening-parenthesis)))
        ((progn (go--backward-irrelevant t) (looking-back go-dangling-operators-regexp))
         ;; only one nesting for all dangling operators in one operation
         (if (go-previous-line-has-dangling-op-p)
@@ -213,7 +309,7 @@ STOP-AT-STRING is not true, over strings."
        ((progn (go-goto-opening-parenthesis) (< (go-paren-level) start-nesting))
         (if (go-previous-line-has-dangling-op-p)
             (current-indentation)
-          (+ (current-indentation) tab-width)))
+          (+ (go--indentation-for-opening-parenthesis) tab-width)))
        (t
         (current-indentation))))))
 
@@ -299,12 +395,26 @@ The following extra functions are defined:
 - `go-goto-imports'
 - `go-play-buffer' and `go-play-region'
 - `go-download-play'
+- `godef-describe' and `godef-jump'
 
 If you want to automatically run `gofmt' before saving a file,
 add the following hook to your emacs configuration:
 
 \(add-hook 'before-save-hook 'gofmt-before-save)
 
+If you want to use `godef-jump' instead of etags (or similar),
+consider binding godef-jump to `M-.', which is the default key
+for `find-tag':
+
+\(add-hook 'go-mode-hook (lambda ()
+                          (local-set-key (kbd \"M-.\") 'godef-jump)))
+
+Please note that godef is an external dependency. You can install
+it with
+
+go get code.google.com/p/rog-go/exp/cmd/godef
+
+
 If you're looking for even more integration with Go, namely
 on-the-fly syntax checking, auto-completion and snippets, it is
 recommended that you look at goflymake
@@ -360,99 +470,93 @@ recommended that you look at goflymake
 ;;;###autoload
 (add-to-list 'auto-mode-alist (cons "\\.go\\'" 'go-mode))
 
+(defun go--apply-rcs-patch (patch-buffer)
+  "Apply an RCS-formatted diff from PATCH-BUFFER to the current
+buffer."
+  (let ((target-buffer (current-buffer))
+        ;; Relative offset between buffer line numbers and line numbers
+        ;; in patch.
+        ;;
+        ;; Line numbers in the patch are based on the source file, so
+        ;; we have to keep an offset when making changes to the
+        ;; buffer.
+        ;;
+        ;; Appending lines decrements the offset (possibly making it
+        ;; negative), deleting lines increments it. This order
+        ;; simplifies the forward-line invocations.
+        (line-offset 0))
+    (save-excursion
+      (with-current-buffer patch-buffer
+        (goto-char (point-min))
+        (while (not (eobp))
+          (unless (looking-at "^\\([ad]\\)\\([0-9]+\\) \\([0-9]+\\)")
+            (error "invalid rcs patch or internal error in go--apply-rcs-patch"))
+          (forward-line)
+          (let ((action (match-string 1))
+                (from (string-to-number (match-string 2)))
+                (len  (string-to-number (match-string 3))))
+            (cond
+             ((equal action "a")
+              (let ((start (point)))
+                (forward-line len)
+                (let ((text (buffer-substring start (point))))
+                  (with-current-buffer target-buffer
+                    (decf line-offset len)
+                    (goto-char (point-min))
+                    (forward-line (- from len line-offset))
+                    (insert text)))))
+             ((equal action "d")
+              (with-current-buffer target-buffer
+                (goto-char (point-min))
+                (forward-line (- from line-offset 1))
+                (incf line-offset len)
+                (go--kill-whole-line len)))
+             (t
+              (error "invalid rcs patch or internal error in go--apply-rcs-patch")))))))))
+
 (defun gofmt ()
-  "Pipe the current buffer through the external tool `gofmt`.
-Replace the current buffer on success; display errors on failure."
+  "Formats the current buffer according to the gofmt tool."
 
   (interactive)
-  (let ((currconf (current-window-configuration)))
-    (let ((srcbuf (current-buffer))
-          (filename buffer-file-name)
-          (patchbuf (get-buffer-create "*Gofmt patch*")))
-      (with-current-buffer patchbuf
-        (let ((errbuf (get-buffer-create "*Gofmt Errors*"))
-              ;; use utf-8 with subprocesses
-              (coding-system-for-read 'utf-8)
-              (coding-system-for-write 'utf-8))
-          (with-current-buffer errbuf
-            (setq buffer-read-only nil)
-            (erase-buffer))
-          (with-current-buffer srcbuf
-            (save-restriction
-              (let (deactivate-mark)
-                (widen)
-                ;; If this is a new file, diff-mode can't apply a
-                ;; patch to a non-exisiting file, so replace the buffer
-                ;; completely with the output of 'gofmt'.
-                ;; If the file exists, patch it to keep the 'undo' list happy.
-                (let* ((newfile (not (file-exists-p filename)))
-                       (flag (if newfile "" " -d")))
-
-                  ;; diff-mode doesn't work too well with missing
-                  ;; end-of-file newline, so add one
-                  (if (/= (char-after (1- (point-max))) ?\n)
-                      (save-excursion
-                        (goto-char (point-max))
-                        (insert ?\n)))
-
-                  (if (zerop (shell-command-on-region (point-min) (point-max)
-                                                      (concat "gofmt" flag)
-                                                      patchbuf nil errbuf))
-                      ;; gofmt succeeded: replace buffer or apply patch hunks.
-                      (let ((old-point (point))
-                            (old-mark (mark t)))
-                        (kill-buffer errbuf)
-                        (if newfile
-                            ;; New file, replace it (diff-mode won't work)
-                            (gofmt--replace-buffer srcbuf patchbuf)
-                          ;; Existing file, patch it
-                          (gofmt--apply-patch filename srcbuf patchbuf))
-                        (goto-char (min old-point (point-max)))
-                        ;; Restore the mark and point
-                        (if old-mark (push-mark (min old-mark (point-max)) t))
-                        (set-window-configuration currconf))
-
-                    ;; gofmt failed: display the errors
-                    (message "Could not apply gofmt. Check errors for details")
-                    (gofmt--process-errors filename errbuf))))))
-
-          ;; Collapse any window opened on outbuf if shell-command-on-region
-          ;; displayed it.
-          (delete-windows-on patchbuf)))
-      (kill-buffer patchbuf))))
-
-(defun gofmt--replace-buffer (srcbuf patchbuf)
-  (with-current-buffer srcbuf
-    (erase-buffer)
-    (insert-buffer-substring patchbuf))
-  (message "Applied gofmt"))
-
-(defun gofmt--apply-patch (filename srcbuf patchbuf)
-  ;; apply all the patch hunks
-  (let (changed)
+  (let ((tmpfile (make-temp-file "gofmt" nil ".go"))
+        (patchbuf (get-buffer-create "*Gofmt patch*"))
+        (errbuf (get-buffer-create "*Gofmt Errors*"))
+        (coding-system-for-read 'utf-8)
+        (coding-system-for-write 'utf-8))
+
+    (with-current-buffer errbuf
+      (setq buffer-read-only nil)
+      (erase-buffer))
     (with-current-buffer patchbuf
-      (goto-char (point-min))
-      ;; The .* is for TMPDIR, but to avoid dealing with TMPDIR
-      ;; having a trailing / or not, it's easier to just search for .*
-      ;; especially as we're only replacing the first instance.
-      (if (re-search-forward "^--- \\(.*/gofmt[0-9]*\\)" nil t)
-          (replace-match filename nil nil nil 1))
-      (condition-case nil
-          (while t
-            (diff-hunk-next)
-            (diff-apply-hunk)
-            (setq changed t))
-        ;; When there's no more hunks, diff-hunk-next signals an error, ignore it
-        (error nil)))
-    (if changed (message "Applied gofmt") (message "Buffer was already gofmted"))))
-
-(defun gofmt--process-errors (filename errbuf)
+      (erase-buffer))
+
+    (write-region nil nil tmpfile)
+
+    ;; We're using errbuf for the mixed stdout and stderr output. This
+    ;; is not an issue because gofmt -w does not produce any stdout
+    ;; output in case of success.
+    (if (zerop (call-process "gofmt" nil errbuf nil "-w" tmpfile))
+        (if (zerop (call-process-region (point-min) (point-max) "diff" nil patchbuf nil "-n" "-" tmpfile))
+            (progn
+              (kill-buffer errbuf)
+              (message "Buffer is already gofmted"))
+          (go--apply-rcs-patch patchbuf)
+          (kill-buffer errbuf)
+          (message "Applied gofmt"))
+      (message "Could not apply gofmt. Check errors for details")
+      (gofmt--process-errors (buffer-file-name) tmpfile errbuf))
+
+    (kill-buffer patchbuf)
+    (delete-file tmpfile)))
+
+
+(defun gofmt--process-errors (filename tmpfile errbuf)
   ;; Convert the gofmt stderr to something understood by the compilation mode.
   (with-current-buffer errbuf
     (goto-char (point-min))
     (insert "gofmt errors:\n")
-    (if (search-forward gofmt-stdin-tag nil t)
-        (replace-match (file-name-nondirectory filename) nil t))
+    (while (search-forward-regexp (concat "^\\(" (regexp-quote tmpfile) "\\):") nil t)
+      (replace-match (file-name-nondirectory filename) t t nil 1))
     (display-buffer errbuf)
     (compilation-mode)))
 
@@ -476,10 +580,10 @@ you save any file, kind of defeating the point of autoloading."
          (symbol (if bounds
                      (buffer-substring-no-properties (car bounds)
                                                      (cdr bounds)))))
-    (read-string (if symbol
-                     (format "godoc (default %s): " symbol)
-                   "godoc: ")
-                 nil nil symbol)))
+    (completing-read (if symbol
+                         (format "godoc (default %s): " symbol)
+                       "godoc: ")
+                     (go--old-completion-list-style (go-packages)) nil nil nil 'go-godoc-history symbol)))
 
 (defun godoc--get-buffer (query)
   "Get an empty buffer for a godoc query."
@@ -628,7 +732,7 @@ uncommented, otherwise a new import will be added."
   (interactive
    (list
     current-prefix-arg
-    (replace-regexp-in-string "^[\"']\\|[\"']$" "" (completing-read "Package: " (go-packages)))))
+    (replace-regexp-in-string "^[\"']\\|[\"']$" "" (completing-read "Package: " (go--old-completion-list-style (go-packages))))))
   (save-excursion
     (let (as line import-start)
       (if arg
@@ -653,11 +757,34 @@ uncommented, otherwise a new import will be added."
           ('none (insert "\nimport (\n\t" line "\n)\n")))))))
 
 (defun go-root-and-paths ()
-  (let* ((output (process-lines "go" "env" "GOROOT" "GOPATH"))
+  (let* ((output (split-string (shell-command-to-string "go env GOROOT GOPATH") "\n"))
          (root (car output))
-         (paths (split-string (car (cdr output)) ":")))
+         (paths (split-string (cadr output) ":")))
     (append (list root) paths)))
 
+(defun go--string-prefix-p (s1 s2 &optional ignore-case)
+  "Return non-nil if S1 is a prefix of S2.
+If IGNORE-CASE is non-nil, the comparison is case-insensitive."
+  (eq t (compare-strings s1 nil nil
+                         s2 0 (length s1) ignore-case)))
+
+(defun go--directory-dirs (dir)
+  "Recursively return all subdirectories in DIR."
+  (if (file-directory-p dir)
+      (let ((dir (directory-file-name dir))
+            (dirs '())
+            (files (directory-files dir nil nil t)))
+        (dolist (file files)
+          (unless (member file '("." ".."))
+            (let ((file (concat dir "/" file)))
+              (if (file-directory-p file)
+                  (setq dirs (append (cons file
+                                           (go--directory-dirs file))
+                                     dirs))))))
+        dirs)
+    '()))
+
+
 (defun go-packages ()
   (sort
    (delete-dups
@@ -667,12 +794,12 @@ uncommented, otherwise a new import will be added."
          (mapcan (lambda (dir)
                    (mapcar (lambda (file)
                              (let ((sub (substring file (length pkgdir) -2)))
-                               (unless (or (string-prefix-p "obj/" sub) (string-prefix-p "tool/" sub))
+                               (unless (or (go--string-prefix-p "obj/" sub) (go--string-prefix-p "tool/" sub))
                                  (mapconcat 'identity (cdr (split-string sub "/")) "/"))))
                            (if (file-directory-p dir)
                                (directory-files dir t "\\.a$"))))
                  (if (file-directory-p pkgdir)
-                     (find-lisp-find-files-internal pkgdir 'find-lisp-file-predicate-is-directory 'find-lisp-default-directory-predicate)))))
+                     (go--directory-dirs pkgdir)))))
      (go-root-and-paths)))
    'string<))
 
@@ -712,9 +839,63 @@ will be commented, otherwise they will be removed completely."
           (beginning-of-line)
           (if arg
               (comment-region (line-beginning-position) (line-end-position))
-            (let ((kill-whole-line t))
-              (kill-line))))
+            (go--kill-whole-line)))
         (message "Removed %d imports" (length lines)))
       (if flymake-state (flymake-mode-on)))))
 
+(defun godef--find-file-line-column (specifier)
+  "Given a file name in the format of `filename:line:column',
+visit FILENAME and go to line LINE and column COLUMN."
+  (let* ((components (split-string specifier ":"))
+         (line (string-to-number (nth 1 components)))
+         (column (string-to-number (nth 2 components))))
+    (with-current-buffer (find-file (car components))
+      (goto-char (point-min))
+      (forward-line (1- line))
+      (beginning-of-line)
+      (forward-char (1- column))
+      (if (buffer-modified-p)
+          (message "Buffer is modified, file position might not have been correct")))))
+
+(defun godef--call (point)
+  "Call godef, acquiring definition position and expression
+description at POINT."
+  (if (go--xemacs-p)
+      (message "godef does not reliably work in XEmacs, expect bad results"))
+  (if (not buffer-file-name)
+      (message "Cannot use godef on a buffer without a file name")
+    (let ((outbuf (get-buffer-create "*godef*")))
+      (with-current-buffer outbuf
+        (erase-buffer))
+      (call-process-region (point-min) (point-max) "godef" nil outbuf nil "-i" "-t" "-f" (file-truename buffer-file-name) "-o" (number-to-string (go--position-bytes (point))))
+      (with-current-buffer outbuf
+        (split-string (buffer-substring-no-properties (point-min) (point-max)) "\n")))))
+
+(defun godef-describe (point)
+  "Describe the expression at POINT."
+  (interactive "d")
+  (condition-case nil
+      (let ((description (nth 1 (godef--call point))))
+        (if (string= "" description)
+            (message "No description found for expression at point")
+          (message "%s" description)))
+    (file-error (message "Could not run godef binary"))))
+
+(defun godef-jump (point)
+  "Jump to the definition of the expression at POINT."
+  (interactive "d")
+  (condition-case nil
+      (let ((file (car (godef--call point))))
+        (cond
+         ((string= "-" file)
+          (message "godef: expression is not defined anywhere"))
+         ((string= "godef: no identifier found" file)
+          (message "%s" file))
+         ((go--string-prefix-p "godef: no declaration found for " file)
+          (message "%s" file))
+         (t
+          (push-mark)
+          (godef--find-file-line-column file))))
+    (file-error (message "Could not run godef binary"))))
+
 (provide 'go-mode)