--- /dev/null
+;;; libc.el -- lookup C symbols in the GNU C Library Reference Manual.
+
+;; Copyright (C) 1993--1997 Free Software Foundation, Inc.
+
+;;; Author: Ralph Schleicher <rs@purple.UL.BaWue.DE>
+;;; Keywords: local c info
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 2, or (at your option)
+;; any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs; see the file COPYING. If not, write to the
+;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+;; Boston, MA 02111-1307, USA.
+
+;;; Commentary:
+
+;; This code has a long history. It started as a minor
+;; mode for C mode. This era ended with the release of version 2
+;; of the GNU C Library in 1997. The code was therefore rewritten
+;; more or less from scratch so that all lookups are performed via
+;; indices. Not finding an existing symbol in an index means that
+;; there is an error in the manual. Long missed features like a
+;; separate input history, symbol name completion in the mini-buffer,
+;; highlighting of looked up symbol names in the Info buffer, and
+;; implicitly prepending `struct', `union' or `enum' to data types
+;; were added in this phase too.
+
+;;; Code:
+
+(require 'info)
+
+\f
+(defvar libc-info-file-name "libc"
+ "Basename of the Info file of the GNU C Library Reference Manual.")
+
+(defvar libc-highlight-face 'highlight
+ "*Face for highlighting looked up symbol names in the Info buffer;
+`nil' disables highlighting.")
+
+(defconst libc-symbol-completions nil
+ "Alist of documented C symbols.")
+
+(defconst libc-file-completions nil
+ "Alist of documented programs or files.")
+
+(defvar libc-history nil
+ "History of previous input lines.")
+
+;;;###autoload
+(defun libc-describe-symbol (symbol-name)
+ "Display the documentation of a C symbol in another window.
+SYMBOL-NAME must be documented in the GNU C Library Reference Manual.
+
+If called interactively, SYMBOL-NAME will be read from the mini-buffer.
+Optional prefix argument means insert the default symbol (if any) into
+the mini-buffer so that it can be edited. The default symbol is the
+one found at point.
+
+If SYMBOL-NAME is a public function, variable, or data type of the GNU
+C Library but `libc-describe-symbol' fails to display it's documentation,
+then you have found a bug in the manual. Please report that to the mail
+address `bug-glibc-manual@prep.ai.mit.edu' so that it can be fixed."
+ (interactive
+ (let* ((completion-ignore-case nil)
+ (enable-recursive-minibuffers t)
+ (symbol (libc-symbol-at-point))
+ (value (completing-read
+ (if symbol
+ (format "Describe symbol (default %s): " symbol)
+ (format "Describe symbol: "))
+ libc-symbol-completions nil nil
+ (and current-prefix-arg symbol) 'libc-history)))
+ (list (if (equal value "") symbol value))))
+ (or (assoc symbol-name libc-symbol-completions)
+ (error "Not documented as a C symbol: %s" (or symbol-name "")))
+ (or (libc-lookup-function symbol-name)
+ (libc-lookup-variable symbol-name)
+ (libc-lookup-type symbol-name)))
+
+;;;###autoload
+(defun libc-describe-file (file-name)
+ "Display the documentation of a program or file in another window.
+FILE-NAME must be documented in the GNU C Library Reference Manual."
+ (interactive
+ (let* ((completion-ignore-case nil)
+ (enable-recursive-minibuffers t))
+ (list (completing-read
+ "Describe program or file: "
+ libc-file-completions nil nil nil 'libc-history))))
+ (or (assoc file-name libc-file-completions)
+ (error "Not documented as a program or file: %s" (or file-name "")))
+ (libc-lookup-file file-name))
+
+;;;###autoload
+(defun libc-search (regexp &optional arg)
+ "Search in the GNU C Library Reference Manual for REGEXP.
+Prefix argument means search should ignore case."
+ (interactive "sSearch `libc.info' for regexp: \nP")
+ (or (get-buffer "*info*")
+ (save-window-excursion
+ (info)))
+ (switch-to-buffer-other-window "*info*")
+ (Info-goto-node (concat "(" libc-info-file-name ")"))
+ (let ((case-fold-search arg))
+ (Info-search regexp)))
+
+\f
+(defun libc-make-completion-alist (info-nodes &optional regexp)
+ "Create a unique alist from all menu items in the Info nodes INFO-NODES
+of the GNU C Reference Manual.
+
+Optional second argument REGEXP means include only menu items matching the
+regular expression REGEXP."
+ (condition-case nil
+ (let (completions item)
+ (save-window-excursion
+ (info libc-info-file-name)
+ (while info-nodes
+ (Info-goto-node (car info-nodes))
+ (goto-char (point-min))
+ (and (search-forward "\n* Menu:" nil t)
+ (while (re-search-forward "\n\\* \\([^:\t\n]*\\):" nil t)
+ (setq item (buffer-substring
+ (match-beginning 1) (match-end 1)))
+ (and (not (assoc item completions))
+ (if regexp (string-match regexp item) t)
+ (setq completions (cons (cons item nil)
+ completions)))))
+ (setq info-nodes (cdr info-nodes)))
+ (Info-directory))
+ completions)
+ (error nil)))
+
+(defun libc-after-manual-update ()
+ "This function must only be called after a new version of the
+GNU C Library Reference Manual was installed on your system."
+ (setq libc-symbol-completions (libc-make-completion-alist
+ '("Function Index"
+ "Variable Index"
+ "Type Index"))
+ libc-file-completions (libc-make-completion-alist
+ '("File Index") "^[^ \t]+$")))
+
+(or (and libc-symbol-completions
+ libc-file-completions)
+ (libc-after-manual-update))
+
+(defun libc-symbol-at-point ()
+ "Get the C symbol at point."
+ (condition-case nil
+ (save-excursion
+ (backward-sexp)
+ (let ((start (point))
+ prefix name)
+ ;; Test for a leading `struct', `union', or `enum' keyword
+ ;; but ignore names like `foo_struct'.
+ (setq prefix (and (< (skip-chars-backward " \t\n") 0)
+ (< (skip-chars-backward "_a-zA-Z0-9") 0)
+ (looking-at "\\(struct\\|union\\|enum\\)\\s ")
+ (concat (buffer-substring
+ (match-beginning 1) (match-end 1))
+ " ")))
+ (goto-char start)
+ (and (looking-at "[_a-zA-Z][_a-zA-Z0-9]*")
+ (setq name (buffer-substring
+ (match-beginning 0) (match-end 0))))
+ ;; Caveat! Look forward if point is at `struct' etc.
+ (and (not prefix)
+ (or (string-equal name "struct")
+ (string-equal name "union")
+ (string-equal name "enum"))
+ (looking-at "[a-z]+\\s +\\([_a-zA-Z][_a-zA-Z0-9]*\\)")
+ (setq prefix (concat name " ")
+ name (buffer-substring
+ (match-beginning 1) (match-end 1))))
+ (and (or prefix name)
+ (concat prefix name))))
+ (error nil)))
+
+(defun libc-lookup-function (function)
+ (libc-search-index "Function Index" function
+ "^[ \t]+- \\(Function\\|Macro\\): .*\\<" "\\>"))
+
+(defun libc-lookup-variable (variable)
+ (libc-search-index "Variable Index" variable
+ "^[ \t]+- \\(Variable\\|Macro\\): .*\\<" "\\>"))
+
+(defun libc-lookup-type (data-type)
+ (libc-search-index "Type Index" data-type
+ "^[ \t]+- Data Type: \\<" "\\>"))
+
+(defun libc-lookup-file (file-name)
+ (libc-search-index "File Index" file-name))
+
+(defun libc-search-index (index item &optional prefix suffix)
+ "Search ITEM in the Info index INDEX and go to that Info node.
+
+Value is ITEM or `nil' if an error occurs.
+
+If PREFIX and/or SUFFIX are non-`nil', then search the Info node for
+the first occurrence of the regular expression `PREFIX ITEM SUFFIX' and
+leave point at the beginning of the first line of the match. ITEM will
+be highlighted with `libc-highlight-face' iff `libc-highlight-face' is
+not `nil'."
+ (condition-case nil
+ (save-selected-window
+ (or (get-buffer "*info*")
+ (save-window-excursion
+ (info)))
+ (switch-to-buffer-other-window "*info*")
+ (Info-goto-node (concat "(" libc-info-file-name ")" index))
+ (Info-menu item)
+ (if (or prefix suffix)
+ (let ((case-fold-search nil)
+ (buffer-read-only nil))
+ (goto-char (point-min))
+ (re-search-forward
+ (concat prefix (regexp-quote item) suffix))
+ (goto-char (match-beginning 0))
+ (and window-system libc-highlight-face
+ ;; Search again for ITEM so that the first
+ ;; occurence of ITEM will be highlighted.
+ (save-excursion
+ (re-search-forward (regexp-quote item))
+ (put-text-property
+ (match-beginning 0) (match-end 0)
+ 'face libc-highlight-face)))
+ (beginning-of-line)))
+ item)
+ (error nil)))
+
+\f
+(provide 'libc)
+
+;;; libc.el ends here