Function: find-function-search-for-symbol

find-function-search-for-symbol is an autoloaded and byte-compiled function defined in find-func.el.gz.

Signature

(find-function-search-for-symbol SYMBOL TYPE LIBRARY)

Documentation

Search for SYMBOL's definition of type TYPE in LIBRARY.

Visit the library in a buffer, and return a cons cell (BUFFER . POSITION), or just (BUFFER . nil) if the definition can't be found in the file.

If TYPE is nil, look for a function definition. Otherwise, TYPE specifies the kind of definition, and it is interpreted via find-function-regexp-alist. The search is done in the source for library LIBRARY.

Source Code

;; Defined in /usr/src/emacs/lisp/emacs-lisp/find-func.el.gz
;;;###autoload
(defun find-function-search-for-symbol (symbol type library)
  "Search for SYMBOL's definition of type TYPE in LIBRARY.
Visit the library in a buffer, and return a cons cell (BUFFER . POSITION),
or just (BUFFER . nil) if the definition can't be found in the file.

If TYPE is nil, look for a function definition.
Otherwise, TYPE specifies the kind of definition,
and it is interpreted via `find-function-regexp-alist'.
The search is done in the source for library LIBRARY."
  (if (null library)
      (error "Don't know where `%s' is defined" symbol))
  ;; Some functions are defined as part of the construct
  ;; that defines something else.
  (while (and (symbolp symbol) (get symbol 'definition-name))
    (setq symbol (get symbol 'definition-name)))
  (if (string-match "\\`src/\\(.*\\.\\(c\\|m\\)\\)\\'" library)
      (find-function-C-source symbol (match-string 1 library) type)
    (when (string-match "\\.el\\(c\\)\\'" library)
      (setq library (substring library 0 (match-beginning 1))))
    ;; Strip extension from .emacs.el to make sure symbol is searched in
    ;; .emacs too.
    (when (string-match "\\.emacs\\(.el\\)" library)
      (setq library (substring library 0 (match-beginning 1))))
    (let* ((filename (find-library-name library))
	   (regexp-symbol (cdr (assq type find-function-regexp-alist))))
      (with-current-buffer (find-file-noselect filename)
	(let ((regexp (if (functionp regexp-symbol) regexp-symbol
                        (format (symbol-value regexp-symbol)
                                ;; Entry for ` (backquote) macro in loaddefs.el,
                                ;; (defalias (quote \`)..., has a \ but
                                ;; (symbol-name symbol) doesn't.  Add an
                                ;; optional \ to catch this.
                                (concat "\\\\?"
                                        (regexp-quote (symbol-name symbol))))))
	      (case-fold-search))
          (save-restriction
            (widen)
            (with-syntax-table emacs-lisp-mode-syntax-table
              (goto-char (point-min))
              (if (if (functionp regexp)
                      (funcall regexp symbol)
                    (or (re-search-forward regexp nil t)
                        ;; `regexp' matches definitions using known forms like
                        ;; `defun', or `defvar'.  But some functions/variables
                        ;; are defined using special macros (or functions), so
                        ;; if `regexp' can't find the definition, we look for
                        ;; something of the form "(SOMETHING <symbol> ...)".
                        ;; This fails to distinguish function definitions from
                        ;; variable declarations (or even uses thereof), but is
                        ;; a good pragmatic fallback.
                        (re-search-forward
                         (concat "^([^ ]+" find-function-space-re "['(]?"
                                 (regexp-quote (symbol-name symbol))
                                 "\\_>")
                         nil t)))
                  (progn
                    (beginning-of-line)
                    (cons (current-buffer) (point)))
                ;; If the regexp search didn't find the location of
                ;; the symbol (for example, because it is generated by
                ;; a macro), try a slightly more expensive search that
                ;; expands macros until it finds the symbol.
                (cons (current-buffer)
                      (find-function--search-by-expanding-macros
                       (current-buffer) symbol type))))))))))