* lisp/progmodes/xref.el (xref--insert-xrefs): Tweak the faces.
Always insert a newline at the end (to avoid mouse-face background
tail at the last line).
* lisp/progmodes/elisp-mode.el (elisp--xref-find-references): New function.
(elisp-xref-find): Use it.
* lisp/progmodes/etags.el (etags-xref-find): Use `xref-collect-references'.
* lisp/progmodes/xref.el (xref-collect-references):
(xref--collect-reference): New functions.
* lisp/progmodes/xref.el (xref-location-marker, xref-location-group):
Use `cl-defgeneric' and `cl-defmethod' instead of the EIEIO
counterparts.
* lisp/progmodes/etags.el (xref-location-marker): Same.
* lisp/progmodes/xref.el (xref--current): Rename from `xref--selected'.
(xref--inhibit-mark-current): Rename from
`xref--inhibit-mark-selected'. Update the usages.
(xref-quit): Reword the docstring. Kill buffers after quitting
windows instead of before.
(xref--insert-xrefs): Tweak help-echo.
(xref--read-identifier-history, xref--read-pattern-history):
New variables.
(xref--read-identifier, xref-find-apropos): Use them.
Fixes: debbugs:19466
* lisp/progmodes/xref.el (xref--xref-buffer-mode-map): Define before
the major mode. Remap `quit-window' to `xref-quit'.
(xref--xref-buffer-mode): Inherit from special-mode.
Fixes: debbugs:19466
xref: Keep track of temporary buffers.
* lisp/progmodes/xref.el (xref--temporary-buffers, xref--selected)
(xref--inhibit-mark-selected): New variables.
(xref--mark-selected): New function.
(xref--show-location): Maybe add the buffer to
`xref--temporary-buffers', add `xref--mark-selected' to
`buffer-list-update-hook' there.
(xref--window): Add docstring.
(xref-quit): Rename from `xref--quit'. Update both references.
Add KILL argument. When it's non-nil, kill the temporary buffers
that haven't been selected by the user.
(xref--show-xref-buffer): Change the second argument to alist,
extract the values for `xref--window' and
`xref--temporary-buffers' from it. Add `xref--mark-selected' to
`buffer-list-update-hook' to each buffer in the list.
(xref--show-xrefs): Move the logic of calling `xref-find-function'
here. Save the difference between buffer lists before and after
it's called as "temporary buffers", and `pass it to
`xref-show-xrefs-function'.
(xref--find-definitions, xref-find-references)
(xref-find-apropos): Update accordingly.
* progmodes/etags.el (xref-etags-location): New class.
(xref-make-etags-location): New function.
(etags--xref-find-definitions): Use it.
(xref-location-marker): New method implementation.
* lisp/progmodes/xref.el: Mention that xref-location is an EIEIO class.
* lisp/progmodes/xref.el (xref--display-history): New variable.
(xref--window-configuration): Remove.
(xref--save-to-history): New function.
(xref--display-position): Use it. Add new argument.
(xref--restore-window-configuration): Remove.
(xref--show-location, xref-show-location-at-point): Update
accordingly.
(xref--xref-buffer-mode): Don't use `pre-command-hook'.
(xref--quit): New command.
(xref-goto-xref): Use it.
(xref--xref-buffer-mode-map): Bind `q' to it.
* lisp/progmodes/xref.el (xref--button-map): New variable.
(xref--mouse-2): New command.
(xref--insert-xrefs): Add `mouse-face' and `keymap' properties to
the inserted references.
* lisp/progmodes/xref.el (xref--window-configuration): New variable.
(xref-show-location-at-point): New command.
(xref--restore-window-configuration): New function.
(xref-next-line, xref-prev-line): Delegate to
`xref-show-location-at-point'.
(xref--location-at-point): Don't signal the error.
(xref-goto-xref): Do that here instead.
(xref--xref-buffer-mode): Add `xref--restore-window-configuration'
to `pre-command-hook'.
(xref--xref-buffer-mode-map): Don't remap `next-line' and
`previous-line'. Additionally bind `xref-next-line' and
`xref-prev-line' to `n' and `p' respectively. Bind
`xref-show-location-at-point' to `C-o'.
* lisp/emacs-lisp/find-func.el (find-function-library): New function,
extracted from `find-function-noselect'.
* lisp/progmodes/elisp-mode.el (elisp--identifier-location): Fold back
into `elisp--company-location'.
(elisp--identifier-completion-table): Rename to
`elisp--identifier-completion-table', and do not include just any
symbols with a property list.
(elisp-completion-at-point): Revert the 2014-12-25 change.
(elisp--xref-identifier-file): New function.
(elisp--xref-find-definitions): Use it.
* lisp/progmodes/xref.el (xref-elisp-location): New class.
(xref-make-elisp-location): New function.
(xref-location-marker): New implementation.
* lisp/progmodes/elisp-mode.el (elisp--xref-find-definitions):
Filter out nil results.
(elisp--xref-find-apropos): New function.
(elisp-xref-find): Use it.
* lisp/progmodes/xref.el (xref--show-xrefs): Use `user-error'.
Move autoloaded bindings for `M-.', `M-,', `C-x 4 .' and
`C-x 5 .' from etags.el to xref.el.
* progmodes/xref.el: New file.
* progmodes/elisp-mode.el (elisp--identifier-types): New variable.
(elisp--identifier-location): New function, extracted from
`elisp--company-location'.
(elisp--company-location): Use it.
(elisp--identifier-completion-table): New variable.
(elisp-completion-at-point): Use it.
(emacs-lisp-mode): Set the local values of `xref-find-function'
and `xref-identifier-completion-table-function'.
(elisp-xref-find, elisp--xref-find-definitions)
(elisp--xref-identifier-completion-table): New functions.
* progmodes/etags.el (find-tag-marker-ring): Mark obsolete in
favor of `xref--marker-ring'.
(tags-lazy-completion-table): Autoload.
(tags-reset-tags-tables): Use `xref-clear-marker-stack'.
(find-tag-noselect): Use `xref-push-marker-stack'.
(pop-tag-mark): Make an alias for `xref-pop-marker-stack'.
(etags--xref-limit): New constant.
(etags-xref-find, etags--xref-find-definitions): New functions.
