; -*-Emacs-Lisp-*-
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;
; File:         xcscope.el
; RCS:          $RCSfile: xcscope.el,v $ $Revision: 1.14 $ $Date: 2002/04/10 16:59:00 $ $Author: darrylo $
; Description:  cscope interface for (X)Emacs
; Author:       Darryl Okahata
; Created:      Wed Apr 19 17:03:38 2000
; Modified:     Thu Apr  4 17:22:22 2002 (Darryl Okahata) darrylo@soco.agilent.com
; Language:     Emacs-Lisp
; Package:      N/A
; Status:       Experimental
;
; (C) Copyright 2000, 2001, 2002, Darryl Okahata <darrylo@sonic.net>,
;     all rights reserved.
; GNU Emacs enhancements (C) Copyright 2001,
;         Triet H. Lai <thlai@mail.usyd.edu.au>
; Fuzzy matching and navigation code (C) Copyright 2001,
;         Steven Elliott <selliott4@austin.rr.com>
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; ALPHA VERSION 0.96
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;
;; This program 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.
;;
;; This program 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, 675 Mass Ave, Cambridge, MA 02139, USA.
;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;
;; This is a cscope interface for (X)Emacs.
;; It currently runs under Unix only.
;;
;; Using cscope, you can easily search for where symbols are used and defined.
;; Cscope is designed to answer questions like:
;;
;;         Where is this variable used?
;;         What is the value of this preprocessor symbol?
;;         Where is this function in the source files?
;;         What functions call this function?
;;         What functions are called by this function?
;;         Where does the message "out of space" come from?
;;         Where is this source file in the directory structure?
;;         What files include this header file?
;;
;; Send comments to one of:     darrylo@soco.agilent.com
;;                              darryl_okahata@agilent.com
;;                              darrylo@sonic.net
;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;
;; ***** INSTALLATION *****
;;
;; * NOTE: this interface currently runs under Unix only.
;;
;; This module needs a shell script called "cscope-indexer", which
;; should have been supplied along with this emacs-lisp file.  The
;; purpose of "cscope-indexer" is to create and optionally maintain
;; the cscope databases.  If all of your source files are in one
;; directory, you don't need this script; it's very nice to have,
;; though, as it handles recursive subdirectory indexing, and can be
;; used in a nightly or weekly cron job to index very large source
;; repositories.  See the beginning of the file, "cscope-indexer", for
;; usage information.
;;
;; Installation steps:
;;
;; 0. (It is, of course, assumed that cscope is already properly
;;    installed on the current system.)
;;
;; 1. Install the "cscope-indexer" script into some convenient
;;    directory in $PATH.  The only real constraint is that (X)Emacs
;;    must be able to find and execute it.  You may also have to edit
;;    the value of PATH in the script, although this is unlikely; the
;;    majority of people should be able to use the script, "as-is".
;;
;; 2. Make sure that the "cscope-indexer" script is executable.  In
;;    particular, if you had to ftp this file, it is probably no
;;    longer executable.
;;
;; 3. Put this emacs-lisp file somewhere where (X)Emacs can find it.  It
;;    basically has to be in some directory listed in "load-path".
;;
;; 4. Edit your ~/.emacs file to add the line:
;;
;;      (require 'xcscope)
;;
;; 5. If you intend to use xcscope.el often you can optionally edit your
;;    ~/.emacs file to add keybindings that reduce the number of keystrokes
;;    required.  For example, the following will add "C-f#" keybindings, which
;;    are easier to type than the usual "C-c s" prefixed keybindings.  Note
;;    that specifying "global-map" instead of "cscope:map" makes the
;;    keybindings available in all buffers:
;;
;;	(define-key global-map [(control f3)]  'cscope-set-initial-directory)
;;	(define-key global-map [(control f4)]  'cscope-unset-initial-directory)
;;	(define-key global-map [(control f5)]  'cscope-find-this-symbol)
;;	(define-key global-map [(control f6)]  'cscope-find-global-definition)
;;	(define-key global-map [(control f7)]
;;	  'cscope-find-global-definition-no-prompting)
;;	(define-key global-map [(control f8)]  'cscope-pop-mark)
;;	(define-key global-map [(control f9)]  'cscope-next-symbol)
;;	(define-key global-map [(control f10)] 'cscope-next-file)
;;	(define-key global-map [(control f11)] 'cscope-prev-symbol)
;;	(define-key global-map [(control f12)] 'cscope-prev-file)
;;      (define-key global-map [(meta f9)]  'cscope-display-buffer)
;;      (defin-ekey global-map [(meta f10)] 'cscope-display-buffer-toggle)
;;
;; 6. Restart (X)Emacs.  That's it.
;;
;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;
;; ***** USING THIS MODULE *****
;;
;; * Basic usage:
;;
;; If all of your C/C++/lex/yacc source files are in the same
;; directory, you can just start using this module.  If your files are
;; spread out over multiple directories, see "Advanced usage", below.
;;
;; Just edit a source file, and use the pull-down or pop-up (button 3)
;; menus to select one of:
;;
;;         Find symbol
;;         Find global definition
;;         Find called functions
;;         Find functions calling a function
;;         Find text string
;;         Find egrep pattern
;;         Find a file
;;         Find files #including a file
;;
;; The cscope database will be automatically created in the same
;; directory as the source files (assuming that you've never used
;; cscope before), and a buffer will pop-up displaying the results.
;; You can then use button 2 (the middle button) on the mouse to edit
;; the selected file, or you can move the text cursor over a selection
;; and press [Enter].
;;
;; Hopefully, the interface should be fairly intuitive.
;;
;;
;; * Locating the cscope databases:
;;
;; This module will first use the variable, `cscope-database-regexps',
;; to search for a suitable database directory.  If a database location
;; cannot be found using this variable then a search is begun at the
;; variable, `cscope-initial-directory', if set, or the current
;; directory otherwise.  If the directory is not a cscope database
;; directory then the directory's parent, parent's parent, etc. is
;; searched until a cscope database directory is found, or the root
;; directory is reached.  If the root directory is reached, the current
;; directory will be used.
;;
;; A cscope database directory is one in which EITHER a cscope database
;; file (e.g., "cscope.out") OR a cscope file list (e.g.,
;; "cscope.files") exists.  If only "cscope.files" exists, the
;; corresponding "cscope.out" will be automatically created by cscope
;; when a search is done.  By default, the cscope database file is called
;; "cscope.out", but this can be changed (on a global basis) via the
;; variable, `cscope-database-file'.  There is limited support for cscope
;; databases that are named differently than that given by
;; `cscope-database-file', using the variable, `cscope-database-regexps'.
;;
;; Note that the variable, `cscope-database-regexps', is generally not
;; needed, as the normal hierarchical database search is sufficient
;; for placing and/or locating the cscope databases.  However, there
;; may be cases where it makes sense to place the cscope databases
;; away from where the source files are kept; in this case, this
;; variable is used to determine the mapping.  One use for this
;; variable is when you want to share the database file with other
;; users; in this case, the database may be located in a directory
;; separate from the source files.  
;;
;; Setting the variable, `cscope-initial-directory', is useful when a
;; search is to be expanded by specifying a cscope database directory
;; that is a parent of the directory that this module would otherwise
;; use.  For example, consider a project that contains the following
;; cscope database directories:
;;
;;     /users/jdoe/sources
;;     /users/jdoe/sources/proj1
;;     /users/jdoe/sources/proj2
;;
;; If a search is initiated from a .c file in /users/jdoe/sources/proj1
;; then (assuming the variable, `cscope-database-regexps', is not set)
;; /users/jdoe/sources/proj1 will be used as the cscope data base directory.
;; Only matches in files in /users/jdoe/sources/proj1 will be found.  This
;; can be remedied by typing "C-c s a" and then "M-del" to remove single
;; path element in order to use a cscope database directory of
;; /users/jdoe/sources.  Normal searching can be restored by typing "C-c s A".
;;
;;
;; * Keybindings:
;;
;; All keybindings use the "C-c s" prefix, but are usable only while
;; editing a source file, or in the cscope results buffer:
;;
;;      C-c s s         Find symbol.
;;      C-c s d         Find global definition.
;;      C-c s g         Find global definition (alternate binding).
;;      C-c s G         Find global definition without prompting.
;;      C-c s c         Find functions calling a function.
;;      C-c s C         Find called functions (list functions called
;;                      from a function).
;;      C-c s t         Find text string.
;;      C-c s e         Find egrep pattern.
;;      C-c s f         Find a file.
;;      C-c s i         Find files #including a file.
;;
;; These pertain to navigation through the search results:
;;
;;      C-c s b         Display *cscope* buffer.
;;      C-c s B         Auto display *cscope* buffer toggle.
;;      C-c s n         Next symbol.
;;      C-c s N         Next file.
;;      C-c s p         Previous symbol.
;;      C-c s P         Previous file.
;;      C-c s u         Pop mark.
;;
;; These pertain to setting and unsetting the variable,
;; `cscope-initial-directory', (location searched for the cscope database
;;  directory):
;;
;;      C-c s a         Set initial directory.
;;      C-c s A         Unset initial directory.
;;
;; These pertain to cscope database maintenance:
;;
;;      C-c s L         Create list of files to index.
;;      C-c s I         Create list and index.
;;      C-c s E         Edit list of files to index.
;;      C-c s W         Locate this buffer's cscope directory
;;                      ("W" --> "where").
;;      C-c s S         Locate this buffer's cscope directory.
;;                      (alternate binding: "S" --> "show").
;;      C-c s T         Locate this buffer's cscope directory.
;;                      (alternate binding: "T" --> "tell").
;;      C-c s D         Dired this buffer's directory.
;;
;;
;; * Advanced usage:
;;
;; If the source files are spread out over multiple directories,
;; you've got a few choices:
;;
;; [ NOTE: you will need to have the script, "cscope-indexer",
;;   properly installed in order for the following to work.  ]
;;
;; 1. If all of the directories exist below a common directory
;;    (without any extraneous, unrelated subdirectories), you can tell
;;    this module to place the cscope database into the top-level,
;;    common directory.  This assumes that you do not have any cscope
;;    databases in any of the subdirectories.  If you do, you should
;;    delete them; otherwise, they will take precedence over the
;;    top-level database.
;;
;;    If you do have cscope databases in any subdirectory, the
;;    following instructions may not work right.
;;
;;    It's pretty easy to tell this module to use a top-level, common
;;    directory:
;;
;;    a. Make sure that the menu pick, "Cscope/Index recursively", is
;;       checked (the default value).
;;
;;    b. Select the menu pick, "Cscope/Create list and index", and
;;       specify the top-level directory.  This will run the script,
;;       "cscope-indexer", in the background, so you can do other
;;       things if indexing takes a long time.  A list of files to
;;       index will be created in "cscope.files", and the cscope
;;       database will be created in "cscope.out".
;;
;;    Once this has been done, you can then use the menu picks
;;    (described in "Basic usage", above) to search for symbols.
;;
;;    Note, however, that, if you add or delete source files, you'll
;;    have to either rebuild the database using the above procedure,
;;    or edit the file, "cscope.files" to add/delete the names of the
;;    source files.  To edit this file, you can use the menu pick,
;;    "Cscope/Edit list of files to index".
;;
;;
;; 2. If most of the files exist below a common directory, but a few
;;    are outside, you can use the menu pick, "Cscope/Create list of
;;    files to index", and specify the top-level directory.  Make sure
;;    that "Cscope/Index recursively", is checked before you do so,
;;    though.  You can then edit the list of files to index using the
;;    menu pick, "Cscope/Edit list of files to index".  Just edit the
;;    list to include any additional source files not already listed.
;;
;;    Once you've created, edited, and saved the list, you can then
;;    use the menu picks described under "Basic usage", above, to
;;    search for symbols.  The first time you search, you will have to
;;    wait a while for cscope to fully index the source files, though.
;;    If you have a lot of source files, you may want to manually run
;;    cscope to build the database:
;;
;;            cd top-level-directory    # or wherever
;;            rm -f cscope.out          # not always necessary
;;            cscope -b
;;
;;
;; 3. If the source files are scattered in many different, unrelated
;;    places, you'll have to manually create cscope.files and put a
;;    list of all pathnames into it.  Then build the database using:
;;
;;            cd some-directory         # wherever cscope.files exists
;;            rm -f cscope.out          # not always necessary
;;            cscope -b
;;
;;    Next, read the documentation for the variable,
;;    "cscope-database-regexps", and set it appropriately, such that
;;    the above-created cscope database will be referenced when you
;;    edit a related source file.
;;
;;    Once this has been done, you can then use the menu picks
;;    described under "Basic usage", above, to search for symbols.
;;
;;
;; * Interesting configuration variables:
;;
;; "cscope-truncate-lines"
;;      This is the value of `truncate-lines' to use in cscope
;;      buffers; the default is the current setting of
;;      `truncate-lines'.  This variable exists because it can be
;;      easier to read cscope buffers with truncated lines, while
;;      other buffers do not have truncated lines.
;;
;; "cscope-use-relative-paths"
;;      If non-nil, use relative paths when creating the list of files
;;      to index.  The path is relative to the directory in which the
;;      cscope database will be created.  If nil, absolute paths will
;;      be used.  Absolute paths are good if you plan on moving the
;;      database to some other directory (if you do so, you'll
;;      probably also have to modify `cscope-database-regexps').
;;      Absolute paths may also be good if you share the database file
;;      with other users (you'll probably want to specify some
;;      automounted network path for this).
;;
;; "cscope-index-recursively"
;;      If non-nil, index files in the current directory and all
;;      subdirectories.  If nil, only files in the current directory
;;      are indexed.  This variable is only used when creating the
;;      list of files to index, or when creating the list of files and
;;      the corresponding cscope database.
;;
;; "cscope-name-line-width"
;;      The width of the combined "function name:line number" field in
;;      the cscope results buffer.  If negative, the field is
;;      left-justified.
;;
;; "cscope-do-not-update-database"
;;      If non-nil, never check and/or update the cscope database when
;;      searching.  Beware of setting this to non-nil, as this will
;;      disable automatic database creation, updating, and
;;      maintenance.
;;
;; "cscope-display-cscope-buffer" 
;;      If non-nil, display the *cscope* buffer after each search
;;      (default).  This variable can be set in order to reduce the
;;      number of keystrokes required to navigate through the matches.
;;
;; "cscope-database-regexps"
;; 	List to force directory-to-cscope-database mappings.
;; 	This is a list of `(REGEXP DBLIST [ DBLIST ... ])', where:
;;
;; 	REGEXP is a regular expression matched against the current buffer's
;; 	current directory.  The current buffer is typically some source file,
;; 	and you're probably searching for some symbol in or related to this
;; 	file.  Basically, this regexp is used to relate the current directory
;; 	to a cscope database.  You need to start REGEXP with "^" if you want
;; 	to match from the beginning of the current directory.
;;
;; 	DBLIST is a list that contains one or more of:
;;
;; 	    ( DBDIR )
;; 	    ( DBDIR ( OPTIONS ) )
;; 	    ( t )
;; 	    t
;;
;; 	Here, DBDIR is a directory (or a file) that contains a cscope
;; 	database.  If DBDIR is a directory, then it is expected that the
;; 	cscope database, if present, has the filename given by the variable,
;; 	`cscope-database-file'; if DBDIR is a file, then DBDIR is the path
;; 	name to a cscope database file (which does not have to be the same as
;; 	that given by `cscope-database-file').  If only DBDIR is specified,
;; 	then that cscope database will be searched without any additional
;; 	cscope command-line options.  If OPTIONS is given, then OPTIONS is a
;; 	list of strings, where each string is a separate cscope command-line
;; 	option.
;;
;; 	In the case of "( t )", this specifies that the search is to use the
;; 	normal hierarchical database search.  This option is used to
;; 	explicitly search using the hierarchical database search either before
;; 	or after other cscope database directories.
;;
;; 	If "t" is specified (not inside a list), this tells the searching
;; 	mechanism to stop searching if a match has been found (at the point
;; 	where "t" is encountered).  This is useful for those projects that
;; 	consist of many subprojects.  You can specify the most-used
;; 	subprojects first, followed by a "t", and then followed by a master
;; 	cscope database directory that covers all subprojects.  This will
;; 	cause the most-used subprojects to be searched first (hopefully
;; 	quickly), and the search will then stop if a match was found.  If not,
;; 	the search will continue using the master cscope database directory.
;;
;; 	Here, `cscope-database-regexps' is generally not used, as the normal
;; 	hierarchical database search is sufficient for placing and/or locating
;; 	the cscope databases.  However, there may be cases where it makes
;; 	sense to place the cscope databases away from where the source files
;; 	are kept; in this case, this variable is used to determine the
;; 	mapping.
;;
;; 	This module searches for the cscope databases by first using this
;; 	variable; if a database location cannot be found using this variable,
;; 	then the current directory is searched, then the parent, then the
;; 	parent's parent, until a cscope database directory is found, or the
;; 	root directory is reached.  If the root directory is reached, the
;; 	current directory will be used.
;;
;; 	A cscope database directory is one in which EITHER a cscope database
;; 	file (e.g., "cscope.out") OR a cscope file list (e.g.,
;; 	"cscope.files") exists.  If only "cscope.files" exists, the
;; 	corresponding "cscope.out" will be automatically created by cscope
;; 	when a search is done.  By default, the cscope database file is called
;; 	"cscope.out", but this can be changed (on a global basis) via the
;; 	variable, `cscope-database-file'.  There is limited support for cscope
;; 	databases that are named differently than that given by
;; 	`cscope-database-file', using the variable, `cscope-database-regexps'.
;;
;; 	Here is an example of `cscope-database-regexps':
;;
;;		(setq cscope-database-regexps
;;		      '(
;;			( "^/users/jdoe/sources/proj1"
;;			  ( t )
;;			  ( "/users/jdoe/sources/proj2")
;;			  ( "/users/jdoe/sources/proj3/mycscope.out")
;;			  ( "/users/jdoe/sources/proj4")
;;			  t
;;			  ( "/some/master/directory" ("-d" "-I/usr/local/include") )
;;			  )
;;			( "^/users/jdoe/sources/gnome/"
;;			  ( "/master/gnome/database" ("-d") )
;;			  )
;;			))
;;
;; 	If the current buffer's directory matches the regexp,
;; 	"^/users/jdoe/sources/proj1", then the following search will be
;; 	done:
;;
;; 	    1. First, the normal hierarchical database search will be used to
;;	       locate a cscope database.
;;
;; 	    2. Next, searches will be done using the cscope database
;;	       directories, "/users/jdoe/sources/proj2",
;;	       "/users/jdoe/sources/proj3/mycscope.out", and
;;	       "/users/jdoe/sources/proj4".  Note that, instead of the file,
;;	       "cscope.out", the file, "mycscope.out", will be used in the
;;	       directory "/users/jdoe/sources/proj3".
;;
;; 	    3. If a match was found, searching will stop.
;;
;; 	    4. If a match was not found, searching will be done using
;;	       "/some/master/directory", and the command-line options "-d"
;;	       and "-I/usr/local/include" will be passed to cscope.
;;
;; 	If the current buffer's directory matches the regexp,
;; 	"^/users/jdoe/sources/gnome", then the following search will be
;; 	done:
;;
;; 	    The search will be done only using the directory,
;; 	    "/master/gnome/database".  The "-d" option will be passed to
;; 	    cscope.
;;
;; 	If the current buffer's directory does not match any of the above
;; 	regexps, then only the normal hierarchical database search will be
;; 	done.
;;
;;
;; * Other notes:
;;
;; 1. The script, "cscope-indexer", uses a sed command to determine
;;    what is and is not a C/C++/lex/yacc source file.  It's idea of a
;;    source file may not correspond to yours.
;;
;; 2. This module is called, "xcscope", because someone else has
;;    already written a "cscope.el" (although it's quite old).
;;
;;
;; * KNOWN BUGS:
;;
;; 1. Cannot handle whitespace in directory or file names.
;;
;; 2. By default, colored faces are used to display results.  If you happen
;;    to use a black background, part of the results may be invisible
;;    (because the foreground color may be black, too).  There are at least
;;    two solutions for this:
;;
;;    2a. Turn off colored faces, by setting `cscope-use-face' to `nil',
;;        e.g.:
;;
;;            (setq cscope-use-face nil)
;;
;;    2b. Explicitly set colors for the faces used by cscope.  The faces
;;        are:
;;
;;            cscope-file-face
;;            cscope-function-face
;;            cscope-line-number-face
;;            cscope-line-face
;;            cscope-mouse-face
;;
;;        The face most likely to cause problems (e.g., black-on-black
;;        color) is `cscope-line-face'.
;;
;; 3. The support for cscope databases different from that specified by
;;    `cscope-database-file' is quirky.  If the file does not exist, it
;;    will not be auto-created (unlike files names by
;;    `cscope-database-file').  You can manually force the file to be
;;    created by using touch(1) to create a zero-length file; the
;;    database will be created the next time a search is done.
;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(require 'easymenu)


(defgroup cscope nil
  "Cscope interface for (X)Emacs.
Using cscope, you can easily search for where symbols are used and defined.
It is designed to answer questions like:

        Where is this variable used?
        What is the value of this preprocessor symbol?
        Where is this function in the source files?
        What functions call this function?
        What functions are called by this function?
        Where does the message \"out of space\" come from?
        Where is this source file in the directory structure?
        What files include this header file?
"
  :prefix "cscope-"
  :group 'tools)


(defcustom cscope-do-not-update-database nil
  "*If non-nil, never check and/or update the cscope database when searching.
Beware of setting this to non-nil, as this will disable automatic database
creation, updating, and maintenance."
  :type 'boolean
  :group 'cscope)


(defcustom cscope-database-regexps nil
  "*List to force directory-to-cscope-database mappings.
This is a list of `(REGEXP DBLIST [ DBLIST ... ])', where:

REGEXP is a regular expression matched against the current buffer's
current directory.  The current buffer is typically some source file,
and you're probably searching for some symbol in or related to this
file.  Basically, this regexp is used to relate the current directory
to a cscope database.  You need to start REGEXP with \"^\" if you want
to match from the beginning of the current directory.

DBLIST is a list that contains one or more of:

    ( DBDIR )
    ( DBDIR ( OPTIONS ) )
    ( t )
    t

Here, DBDIR is a directory (or a file) that contains a cscope database.
If DBDIR is a directory, then it is expected that the cscope database,
if present, has the filename given by the variable,
`cscope-database-file'; if DBDIR is a file, then DBDIR is the path name
to a cscope database file (which does not have to be the same as that
given by `cscope-database-file').  If only DBDIR is specified, then that
cscope database will be searched without any additional cscope
command-line options.  If OPTIONS is given, then OPTIONS is a list of
strings, where each string is a separate cscope command-line option.

In the case of \"( t )\", this specifies that the search is to use the
normal hierarchical database search.  This option is used to
explicitly search using the hierarchical database search either before
or after other cscope database directories.

If \"t\" is specified (not inside a list), this tells the searching
mechanism to stop searching if a match has been found (at the point
where \"t\" is encountered).  This is useful for those projects that
consist of many subprojects.  You can specify the most-used
subprojects first, followed by a \"t\", and then followed by a master
cscope database directory that covers all subprojects.  This will
cause the most-used subprojects to be searched first (hopefully
quickly), and the search will then stop if a match was found.  If not,
the search will continue using the master cscope database directory.

Here, `cscope-database-regexps' is generally not used, as the normal
hierarchical database search is sufficient for placing and/or locating
the cscope databases.  However, there may be cases where it makes
sense to place the cscope databases away from where the source files
are kept; in this case, this variable is used to determine the
mapping.

This module searches for the cscope databases by first using this
variable; if a database location cannot be found using this variable,
then the current directory is searched, then the parent, then the
parent's parent, until a cscope database directory is found, or the
root directory is reached.  If the root directory is reached, the
current directory will be used.

A cscope database directory is one in which EITHER a cscope database
file (e.g., \"cscope.out\") OR a cscope file list (e.g.,
\"cscope.files\") exists.  If only \"cscope.files\" exists, the
corresponding \"cscope.out\" will be automatically created by cscope
when a search is done.  By default, the cscope database file is called
\"cscope.out\", but this can be changed (on a global basis) via the
variable, `cscope-database-file'.  There is limited support for cscope
databases that are named differently than that given by
`cscope-database-file', using the variable, `cscope-database-regexps'.

Here is an example of `cscope-database-regexps':

        (setq cscope-database-regexps
              '(
                ( \"^/users/jdoe/sources/proj1\"
                  ( t )
                  ( \"/users/jdoe/sources/proj2\")
                  ( \"/users/jdoe/sources/proj3/mycscope.out\")
                  ( \"/users/jdoe/sources/proj4\")
                  t
                  ( \"/some/master/directory\" (\"-d\" \"-I/usr/local/include\") )
                  )
                ( \"^/users/jdoe/sources/gnome/\"
                  ( \"/master/gnome/database\" (\"-d\") )
                  )
                ))

If the current buffer's directory matches the regexp,
\"^/users/jdoe/sources/proj1\", then the following search will be
done:

    1. First, the normal hierarchical database search will be used to
       locate a cscope database.

    2. Next, searches will be done using the cscope database
       directories, \"/users/jdoe/sources/proj2\",
       \"/users/jdoe/sources/proj3/mycscope.out\", and
       \"/users/jdoe/sources/proj4\".  Note that, instead of the file,
       \"cscope.out\", the file, \"mycscope.out\", will be used in the
       directory \"/users/jdoe/sources/proj3\".

    3. If a match was found, searching will stop.

    4. If a match was not found, searching will be done using
       \"/some/master/directory\", and the command-line options \"-d\"
       and \"-I/usr/local/include\" will be passed to cscope.

If the current buffer's directory matches the regexp,
\"^/users/jdoe/sources/gnome\", then the following search will be
done:

    The search will be done only using the directory,
    \"/master/gnome/database\".  The \"-d\" option will be passed to
    cscope.

If the current buffer's directory does not match any of the above
regexps, then only the normal hierarchical database search will be
done.

"
  :type '(repeat (list :format "%v"
		       (choice :value ""
			       (regexp :tag "Buffer regexp")
			       string)
		       (choice :value ""
			       (directory :tag "Cscope database directory")
			       string)
		       (string :value ""
			       :tag "Optional cscope command-line arguments")
		       ))
  :group 'cscope)
(defcustom cscope-name-line-width -30
  "*The width of the combined \"function name:line number\" field in the
cscope results buffer.  If negative, the field is left-justified."
  :type 'integer
  :group 'cscope)


(defcustom cscope-truncate-lines truncate-lines
  "*The value of `truncate-lines' to use in cscope buffers.
This variable exists because it can be easier to read cscope buffers
with truncated lines, while other buffers do not have truncated lines."
  :type 'boolean
  :group 'cscope)


(defcustom cscope-display-times t
  "*If non-nil, display how long each search took.
The elasped times are in seconds.  Floating-point support is required
for this to work."
  :type 'boolean
  :group 'cscope)


(defcustom cscope-program "cscope"
  "*The pathname of the cscope executable to use."
  :type 'string
  :group 'cscope)


(defcustom cscope-index-file "cscope.files"
  "*The name of the cscope file list file."
  :type 'string
  :group 'cscope)


(defcustom cscope-database-file "cscope.out"
  "*The name of the cscope database file."
  :type 'string
  :group 'cscope)


(defcustom cscope-edit-single-match t
  "*If non-nil and only one match is output, edit the matched location."
  :type 'boolean
  :group 'cscope)


(defcustom cscope-display-cscope-buffer t
  "*If non-nil automatically display the *cscope* buffer after each search."
  :type 'boolean
  :group 'cscope)


(defcustom cscope-stop-at-first-match-dir nil
  "*If non-nil, stop searching through multiple databases if a match is found.
This option is useful only if multiple cscope database directories are being
used.  When multiple databases are searched, setting this variable to non-nil
will cause searches to stop when a search outputs anything; no databases after
this one will be searched."
  :type 'boolean
  :group 'cscope)


(defcustom cscope-use-relative-paths t
  "*If non-nil, use relative paths when creating the list of files to index.
The path is relative to the directory in which the cscope database
will be created.  If nil, absolute paths will be used.  Absolute paths
are good if you plan on moving the database to some other directory
(if you do so, you'll probably also have to modify
\`cscope-database-regexps\').  Absolute paths  may also be good if you
share the database file with other users (you\'ll probably want to
specify some automounted network path for this)."
  :type 'boolean
  :group 'cscope)


(defcustom cscope-index-recursively t
  "*If non-nil, index files in the current directory and all subdirectories.
If nil, only files in the current directory are indexed.  This
variable is only used when creating the list of files to index, or
when creating the list of files and the corresponding cscope database."
  :type 'boolean
  :group 'cscope)


(defcustom cscope-no-mouse-prompts nil
  "*If non-nil, use the symbol under the cursor instead of prompting.
Do not prompt for a value, except for when seaching for a egrep pattern
or a file."
  :type 'boolean
  :group 'cscope)


(defcustom cscope-suppress-empty-matches t
  "*If non-nil, delete empty matches.")


(defcustom cscope-indexing-script "cscope-indexer"
  "*The shell script used to create cscope indices."
  :type 'string
  :group 'cscope)


(defcustom cscope-symbol-chars "A-Za-z0-9_"
  "*A string containing legal characters in a symbol.
The current syntax table should really be used for this."
  :type 'string
  :group 'cscope)


(defcustom cscope-filename-chars "-.,/A-Za-z0-9_~!@#$%&+=\\\\"
  "*A string containing legal characters in a symbol.
The current syntax table should really be used for this."
  :type 'string
  :group 'cscope)


(defcustom cscope-allow-arrow-overlays t
  "*If non-nil, use an arrow overlay to show target lines.
Arrow overlays are only used when the following functions are used:

    cscope-show-entry-other-window
    cscope-show-next-entry-other-window
    cscope-show-prev-entry-other-window

The arrow overlay is removed when other cscope functions are used.
Note that the arrow overlay is not an actual part of the text, and can
be removed by quitting the cscope buffer."
  :type 'boolean
  :group 'cscope)


(defcustom cscope-overlay-arrow-string "=>"
  "*The overlay string to use when displaying arrow overlays."
  :type 'string
  :group 'cscope)


(defvar cscope-minor-mode-hooks nil
  "List of hooks to call when entering cscope-minor-mode.")


(defconst cscope-separator-line
  "-------------------------------------------------------------------------------\n"
  "Line of text to use as a visual separator.
Must end with a newline.")


;;;;
;;;; Faces for fontification
;;;;

(defcustom cscope-use-face t
  "*Whether to use text highlighting ( la font-lock) or not."
  :group 'cscope
  :type '(boolean))


(defface cscope-file-face
  '((((class color) (background dark))
     (:foreground "yellow"))
    (((class color) (background light))
     (:foreground "blue"))
    (t (:bold t)))
  "Face used to highlight file name in the *cscope* buffer."
  :group 'cscope)


(defface cscope-function-face
  '((((class color) (background dark))
     (:foreground "cyan"))
    (((class color) (background light))
     (:foreground "magenta"))
    (t (:bold t)))
  "Face used to highlight function name in the *cscope* buffer."
  :group 'cscope)


(defface cscope-line-number-face
  '((((class color) (background dark))
     (:foreground "red"))
    (((class color) (background light))
     (:foreground "red"))
    (t (:bold t)))
  "Face used to highlight line number in the *cscope* buffer."
  :group 'cscope)


(defface cscope-line-face
  '((((class color) (background dark))
     (:foreground "green"))
    (((class color) (background light))
     (:foreground "black"))
    (t (:bold nil)))
  "Face used to highlight the rest of line in the *cscope* buffer."
  :group 'cscope)


(defface cscope-mouse-face
  '((((class color) (background dark))
     (:foreground "white" :background "blue"))
    (((class color) (background light))
     (:foreground "white" :background "blue"))
    (t (:bold nil)))
  "Face used when mouse pointer is within the region of an entry."
  :group 'cscope)

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Probably, nothing user-customizable past this point.
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(defconst cscope-running-in-xemacs (string-match "XEmacs\\|Lucid" emacs-version))

(defvar cscope-list-entry-keymap nil
  "The keymap used in the *cscope* buffer which lists search results.")
(if cscope-list-entry-keymap
    nil
  (setq cscope-list-entry-keymap (make-keymap))
  (suppress-keymap cscope-list-entry-keymap)
  ;; The following section does not appear in the "Cscope" menu.
  (if cscope-running-in-xemacs
      (define-key cscope-list-entry-keymap [button2] 'cscope-mouse-select-entry-other-window)
    (define-key cscope-list-entry-keymap [mouse-2] 'cscope-mouse-select-entry-other-window))
  (define-key cscope-list-entry-keymap [return] 'cscope-select-entry-other-window)
  (define-key cscope-list-entry-keymap " " 'cscope-show-entry-other-window)
  (define-key cscope-list-entry-keymap "o" 'cscope-select-entry-one-window)
  (define-key cscope-list-entry-keymap "q" 'cscope-bury-buffer)
  (define-key cscope-list-entry-keymap "Q" 'cscope-quit)
  (define-key cscope-list-entry-keymap "h" 'cscope-help)
  (define-key cscope-list-entry-keymap "?" 'cscope-help)
  ;; The following line corresponds to be beginning of the "Cscope" menu.
  (define-key cscope-list-entry-keymap "s" 'cscope-find-this-symbol)
  (define-key cscope-list-entry-keymap "d" 'cscope-find-this-symbol)
  (define-key cscope-list-entry-keymap "g" 'cscope-find-global-definition)
  (define-key cscope-list-entry-keymap "G"
    'cscope-find-global-definition-no-prompting)
  (define-key cscope-list-entry-keymap "c" 'cscope-find-functions-calling-this-function)
  (define-key cscope-list-entry-keymap "C" 'cscope-find-called-functions)
  (define-key cscope-list-entry-keymap "t" 'cscope-find-this-text-string)
  (define-key cscope-list-entry-keymap "e" 'cscope-find-egrep-pattern)
  (define-key cscope-list-entry-keymap "f" 'cscope-find-this-file)
  (define-key cscope-list-entry-keymap "i" 'cscope-find-files-including-file)
  ;; --- (The '---' indicates that this line corresponds to a menu separator.)
  (define-key cscope-list-entry-keymap "n" 'cscope-next-symbol)
  (define-key cscope-list-entry-keymap "N" 'cscope-next-file)
  (define-key cscope-list-entry-keymap "p" 'cscope-prev-symbol)
  (define-key cscope-list-entry-keymap "P" 'cscope-prev-file)
  (define-key cscope-list-entry-keymap "u" 'cscope-pop-mark)
  ;; ---
  (define-key cscope-list-entry-keymap "a" 'cscope-set-initial-directory)
  (define-key cscope-list-entry-keymap "A" 'cscope-unset-initial-directory)
  ;; ---
  (define-key cscope-list-entry-keymap "L" 'cscope-create-list-of-files-to-index)
  (define-key cscope-list-entry-keymap "I" 'cscope-index-files)
  (define-key cscope-list-entry-keymap "E" 'cscope-edit-list-of-files-to-index)
  (define-key cscope-list-entry-keymap "W" 'cscope-tell-user-about-directory)
  (define-key cscope-list-entry-keymap "S" 'cscope-tell-user-about-directory)
  (define-key cscope-list-entry-keymap "T" 'cscope-tell-user-about-directory)
  (define-key cscope-list-entry-keymap "D" 'cscope-dired-directory)
  ;; The previous line corresponds to be end of the "Cscope" menu.
  )


(defvar cscope-list-entry-hook nil
  "*Hook run after cscope-list-entry-mode entered.")


(defun cscope-list-entry-mode ()
  "Major mode for jumping/showing entry from the list in the *cscope* buffer.

\\{cscope-list-entry-keymap}"
  (use-local-map cscope-list-entry-keymap)
  (setq buffer-read-only t
	mode-name "cscope"
	major-mode 'cscope-list-entry-mode
	overlay-arrow-string cscope-overlay-arrow-string)
  (or overlay-arrow-position
      (setq overlay-arrow-position (make-marker)))
  (run-hooks 'cscope-list-entry-hook))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defvar cscope-output-buffer-name "*cscope*"
  "The name of the cscope output buffer.")


(defvar cscope-info-buffer-name "*cscope-info*"
  "The name of the cscope information buffer.")


(defvar cscope-process nil
  "The current cscope process.")
(make-variable-buffer-local 'cscope-process)


(defvar cscope-process-output nil
  "A buffer for holding partial cscope process output.")
(make-variable-buffer-local 'cscope-process-output)


(defvar cscope-command-args nil
  "Internal variable for holding major command args to pass to cscope.")
(make-variable-buffer-local 'cscope-command-args)


(defvar cscope-start-directory nil
  "Internal variable used to save the initial start directory.
The results buffer gets reset to this directory when a search has
completely finished.")
(make-variable-buffer-local 'cscope-start-directory)


(defvar cscope-search-list nil
  "A list of (DIR . FLAGS) entries.
This is a list of database directories to search.  Each entry in the list
is a (DIR . FLAGS) cell.  DIR is the directory to search, and FLAGS are the
flags to pass to cscope when using this database directory.  FLAGS can be
nil (meaning, \"no flags\").")
(make-variable-buffer-local 'cscope-search-list)


(defvar cscope-searched-dirs nil
  "The list of database directories already searched.")
(make-variable-buffer-local 'cscope-searched-dirs)


(defvar cscope-filter-func nil
  "Internal variable for holding the filter function to use (if any) when
searching.")
(make-variable-buffer-local 'cscope-filter-func)


(defvar cscope-sentinel-func nil
  "Internal variable for holding the sentinel function to use (if any) when
searching.")
(make-variable-buffer-local 'cscope-filter-func)


(defvar cscope-last-file nil
  "The file referenced by the last line of cscope process output.")
(make-variable-buffer-local 'cscope-last-file)


(defvar cscope-start-time nil
  "The search start time, in seconds.")
(make-variable-buffer-local 'cscope-start-time)


(defvar cscope-first-match nil
  "The first match result output by cscope.")
(make-variable-buffer-local 'cscope-first-match)


(defvar cscope-first-match-point nil
  "Buffer location of the first match.")
(make-variable-buffer-local 'cscope-first-match-point)


(defvar cscope-item-start nil
  "The point location of the start of a search's output, before header info.")
(make-variable-buffer-local 'cscope-output-start)


(defvar cscope-output-start nil
  "The point location of the start of a search's output.")
(make-variable-buffer-local 'cscope-output-start)


(defvar cscope-matched-multiple nil
  "Non-nil if cscope output multiple matches.")
(make-variable-buffer-local 'cscope-matched-multiple)


(defvar cscope-stop-at-first-match-dir-meta nil
  "")
(make-variable-buffer-local 'cscope-stop-at-first-match-dir-meta)


(defvar cscope-symbol nil
  "The last symbol searched for.")


(defvar cscope-adjust t
  "True if the symbol searched for (cscope-symbol) should be on
the line specified by the cscope database.  In such cases the point will be
adjusted if need be (fuzzy matching).")


(defvar cscope-adjust-range 1000
  "How far the point should be adjusted if the symbol is not on the line
specified by the cscope database.")


(defvar cscope-marker nil
  "The location from which cscope was invoked.")


(defvar cscope-marker-window nil
  "The window which should contain cscope-marker.  This is the window from
which cscope-marker is set when searches are launched from the *cscope*
buffer.")


(defvar cscope-marker-ring-length 16
  "Length of the cscope marker ring.")


(defvar cscope-marker-ring (make-ring cscope-marker-ring-length)
  "Ring of markers which are locations from which cscope was invoked.")


(defvar cscope-initial-directory nil
  "When set the directory in which searches for the cscope database
directory should begin.")


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defvar cscope:map nil
  "The cscope keymap.")
(if cscope:map
    nil
  (setq cscope:map (make-sparse-keymap))
  ;; The following line corresponds to be beginning of the "Cscope" menu.
  (define-key cscope:map "\C-css" 'cscope-find-this-symbol)
  (define-key cscope:map "\C-csd" 'cscope-find-global-definition)
  (define-key cscope:map "\C-csg" 'cscope-find-global-definition)
  (define-key cscope:map "\C-csG" 'cscope-find-global-definition-no-prompting)
  (define-key cscope:map "\C-csc" 'cscope-find-functions-calling-this-function)
  (define-key cscope:map "\C-csC" 'cscope-find-called-functions)
  (define-key cscope:map "\C-cst" 'cscope-find-this-text-string)
  (define-key cscope:map "\C-cse" 'cscope-find-egrep-pattern)
  (define-key cscope:map "\C-csf" 'cscope-find-this-file)
  (define-key cscope:map "\C-csi" 'cscope-find-files-including-file)
  ;; --- (The '---' indicates that this line corresponds to a menu separator.)
  (define-key cscope:map "\C-csb" 'cscope-display-buffer)
  (define-key cscope:map "\C-csB" 'cscope-display-buffer-toggle)
  (define-key cscope:map "\C-csn" 'cscope-next-symbol)
  (define-key cscope:map "\C-csN" 'cscope-next-file)
  (define-key cscope:map "\C-csp" 'cscope-prev-symbol)
  (define-key cscope:map "\C-csP" 'cscope-prev-file)
  (define-key cscope:map "\C-csu" 'cscope-pop-mark)
  ;; ---
  (define-key cscope:map "\C-csa" 'cscope-set-initial-directory)
  (define-key cscope:map "\C-csA" 'cscope-unset-initial-directory)
  ;; ---
  (define-key cscope:map "\C-csL" 'cscope-create-list-of-files-to-index)
  (define-key cscope:map "\C-csI" 'cscope-index-files)
  (define-key cscope:map "\C-csE" 'cscope-edit-list-of-files-to-index)
  (define-key cscope:map "\C-csW" 'cscope-tell-user-about-directory)
  (define-key cscope:map "\C-csS" 'cscope-tell-user-about-directory)
  (define-key cscope:map "\C-csT" 'cscope-tell-user-about-directory)
  (define-key cscope:map "\C-csD" 'cscope-dired-directory))
  ;; The previous line corresponds to be end of the "Cscope" menu.

(easy-menu-define cscope:menu
		  (list cscope:map cscope-list-entry-keymap)
		  "cscope menu"
		  '("Cscope"
		    [ "Find symbol" cscope-find-this-symbol t ]
		    [ "Find global definition" cscope-find-global-definition t ]
		    [ "Find global definition no prompting"
		      cscope-find-global-definition-no-prompting t ]
		    [ "Find functions calling a function"
		      cscope-find-functions-calling-this-function t ]
		    [ "Find called functions" cscope-find-called-functions t ]
		    [ "Find text string" cscope-find-this-text-string t ]
		    [ "Find egrep pattern" cscope-find-egrep-pattern t ]
		    [ "Find a file" cscope-find-this-file t ]
		    [ "Find files #including a file"
		      cscope-find-files-including-file t ]
		    "-----------"
		    [ "Display *cscope* buffer" cscope-display-buffer t ]
		    [ "Auto display *cscope* buffer toggle"
		      cscope-display-buffer-toggle t ]
		    [ "Next symbol"     	cscope-next-symbol t ]
		    [ "Next file"       	cscope-next-file t ]
		    [ "Previous symbol" 	cscope-prev-symbol t ]
		    [ "Previous file"   	cscope-prev-file t ]
		    [ "Pop mark"        	cscope-pop-mark t ]
		    "-----------"
		    ( "Cscope Database"
		      [ "Set initial directory"
			cscope-set-initial-directory t ]
		      [ "Unset initial directory"
			cscope-unset-initial-directory t ]
		      "-----------"
		      [ "Create list of files to index"
			cscope-create-list-of-files-to-index t ]
		      [ "Create list and index"
			cscope-index-files t ]
		      [ "Edit list of files to index"
			cscope-edit-list-of-files-to-index t ]
		      [ "Locate this buffer's cscope directory"
			cscope-tell-user-about-directory t ]
		      [ "Dired this buffer's cscope directory"
			cscope-dired-directory t ]
		      )
		    "-----------"
		    ( "Options"
		      [ "Auto edit single match"
			(setq cscope-edit-single-match
			      (not cscope-edit-single-match))
			:style toggle :selected cscope-edit-single-match ]
		      [ "Auto display *cscope* buffer"
			(setq cscope-display-cscope-buffer
			      (not cscope-display-cscope-buffer))
			:style toggle :selected cscope-display-cscope-buffer ]
		      [ "Stop at first matching database"
			(setq cscope-stop-at-first-match-dir
			      (not cscope-stop-at-first-match-dir))
			:style toggle
			:selected cscope-stop-at-first-match-dir ]
		      [ "Never update cscope database"
			(setq cscope-do-not-update-database
			      (not cscope-do-not-update-database))
			:style toggle :selected cscope-do-not-update-database ]
		      [ "Index recursively"
			(setq cscope-index-recursively
			      (not cscope-index-recursively))
			:style toggle :selected cscope-index-recursively ]
		      [ "Suppress empty matches"
			(setq cscope-suppress-empty-matches
			      (not cscope-suppress-empty-matches))
			:style toggle :selected cscope-suppress-empty-matches ]
		      [ "Use relative paths"
			(setq cscope-use-relative-paths
			      (not cscope-use-relative-paths))
			:style toggle :selected cscope-use-relative-paths ]
		      [ "No mouse prompts" (setq cscope-no-mouse-prompts
						 (not cscope-no-mouse-prompts))
			:style toggle :selected cscope-no-mouse-prompts ] 
		      )
		    ))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Internal functions and variables
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defvar cscope-common-text-plist
  (let (plist)
    (setq plist (plist-put plist 'mouse-face 'cscope-mouse-face))
    plist)
  "List of common text properties to be added to the entry line.")


(defun cscope-insert-with-text-properties (text filename &optional line-number)
  "Insert an entry with given TEXT, add entry attributes as text properties.
The text properties to be added:
- common property: mouse-face,
- properties are used to open target file and its location: cscope-file,
  cscope-line-number"
  (let ((plist cscope-common-text-plist)
	beg end)
    (setq beg (point))
    (insert text)
    (setq end (point)
	  plist (plist-put plist 'cscope-file filename))
    (if line-number
	(progn
	  (if (stringp line-number)
	      (setq line-number (string-to-number line-number)))
	  (setq plist (plist-put plist 'cscope-line-number line-number))
	  ))
    (add-text-properties beg end plist)
    ))


(if cscope-running-in-xemacs
    (progn
      (defalias 'cscope-event-window 'event-window)
      (defalias 'cscope-event-point 'event-point)
      (defalias 'cscope-recenter 'recenter)
      )
  (defun cscope-event-window (event)
    "Return the window at which the mouse EVENT occurred."
    (posn-window (event-start event)))
  (defun cscope-event-point (event)
    "Return the point at which the mouse EVENT occurred."
    (posn-point (event-start event)))
  (defun cscope-recenter (&optional n window)
    "Center point in WINDOW and redisplay frame.  With N, put point on line N."
    (save-selected-window
      (if (windowp window)
	  (select-window window))
      (recenter n)))
  )


(defun cscope-show-entry-internal (file line-number 
					&optional save-mark-p window arrow-p)
  "Display the buffer corresponding to FILE and LINE-NUMBER
in some window.  If optional argument WINDOW is given,
display the buffer in that WINDOW instead.  The window is
not selected.  Save point on mark ring before goto
LINE-NUMBER if optional argument SAVE-MARK-P is non-nil.
Put `overlay-arrow-string' if arrow-p is non-nil.
Returns the window displaying BUFFER."
  (let (buffer old-pos old-point new-point forward-point backward-point
	       line-end line-length)
    (if (and (stringp file)
	     (integerp line-number))
	(progn
	  (unless (file-readable-p file)
	    (error "%s is not readable or exists" file))
	  (setq buffer (find-file-noselect file))
	  (if (windowp window)
	      (set-window-buffer window buffer)
	    (setq window (display-buffer buffer)))
	  (set-buffer buffer)
	  (if (> line-number 0)
	      (progn
		(setq old-pos (point))
		(goto-line line-number)
		(setq old-point (point))
		(if (and cscope-adjust cscope-adjust-range)
		    (progn
		      ;; Calculate the length of the line specified by cscope.
		      (end-of-line)
		      (setq line-end (point))
		      (goto-char old-point)
		      (setq line-length (- line-end old-point))

		      ;; Search forward and backward for the pattern.
		      (setq forward-point (search-forward
					   cscope-symbol
					   (+ old-point
					      cscope-adjust-range) t))
		      (goto-char old-point)
		      (setq backward-point (search-backward
					    cscope-symbol
					    (- old-point
					       cscope-adjust-range) t))
		      (if forward-point
			  (progn
			    (if backward-point
				(setq new-point
				      ;; Use whichever of forward-point or
				      ;; backward-point is closest to old-point.
				      ;; Give forward-point a line-length advantage
				      ;; so that if the symbol is on the current
				      ;; line the current line is chosen.
				      (if (<= (- (- forward-point line-length)
						 old-point)
					      (- old-point backward-point))
					  forward-point
					backward-point))
			      (setq new-point forward-point)))
			(if backward-point
			    (setq new-point backward-point)
			  (setq new-point old-point)))
		      (goto-char new-point)
		      (beginning-of-line)
		      (setq new-point (point)))
		  (setq new-point old-point))
		(set-window-point window new-point)
		(if (and cscope-allow-arrow-overlays arrow-p)
		    (set-marker overlay-arrow-position (point))
		  (set-marker overlay-arrow-position nil))
		(or (not save-mark-p)
		    (= old-pos (point))
		    (push-mark old-pos))
		))

	  (if cscope-marker
	      (progn ;; The search was successful.  Save the marker so it
                     ;; can be returned to by cscope-pop-mark.
		(ring-insert cscope-marker-ring cscope-marker)
		;; Unset cscope-marker so that moving between matches
		;; (cscope-next-symbol, etc.) does not fill
		;; cscope-marker-ring.
		(setq cscope-marker nil)))
          (setq cscope-marker-window window)
	  )
      (message "No entry found at point."))
    )
  window)

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; functions in *cscope* buffer which lists the search results
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defun cscope-select-entry-other-window ()
  "Display the entry at point in other window, select the window.
Push current point on mark ring and select the entry window."
  (interactive)
  (let ((file (get-text-property (point) 'cscope-file))
	(line-number (get-text-property (point) 'cscope-line-number))
	window)
    (setq window (cscope-show-entry-internal file line-number t))
    (if (windowp window)
	(select-window window))
    ))


(defun cscope-select-entry-one-window ()
  "Display the entry at point in one window, select the window."
  (interactive)
  (let ((file (get-text-property (point) 'cscope-file))
	(line-number (get-text-property (point) 'cscope-line-number))
	window)
    (setq window (cscope-show-entry-internal file line-number t))
    (if (windowp window)
	(progn
	  (select-window window)
	  (sit-for 0)	;; Redisplay hack to allow delete-other-windows
			;; to continue displaying the correct location.
	  (delete-other-windows window)
	  ))
    ))


(defun cscope-select-entry-specified-window (window)
  "Display the entry at point in a specified window, select the window."
  (interactive)
  (let ((file (get-text-property (point) 'cscope-file))
	(line-number (get-text-property (point) 'cscope-line-number)))
    (setq window (cscope-show-entry-internal file line-number t window))
    (if (windowp window)
	  (select-window window))
    ))


(defun cscope-mouse-select-entry-other-window (event)
  "Display the entry over which the mouse event occurred, select the window."
  (interactive "e")
  (let ((ep (cscope-event-point event))
	(win (cscope-event-window event))
	buffer file line-number window)
    (if ep
        (progn
          (setq buffer (window-buffer win)
                file (get-text-property ep 'cscope-file buffer)
                line-number (get-text-property ep 'cscope-line-number buffer))
          (select-window win)
          (setq window (cscope-show-entry-internal file line-number t))
          (if (windowp window)
              (select-window window))
          )
      (message "No entry found at point.")
      )
    ))


(defun cscope-show-entry-other-window ()
  "Display the entry at point in other window.
Point is not saved on mark ring."
  (interactive)
  (let ((file (get-text-property (point) 'cscope-file))
	(line-number (get-text-property (point) 'cscope-line-number)))
    (cscope-show-entry-internal file line-number nil nil t)
    ))


(defun cscope-buffer-search (do-symbol do-next)
  "The body of the following four functions."
  (let* (line-number old-point point
		     (search-file (not do-symbol))
		     (search-prev (not do-next))
		     (direction (if do-next 1 -1))
		     (old-buffer (current-buffer))
		     (old-buffer-window (get-buffer-window old-buffer))
		     (buffer (get-buffer cscope-output-buffer-name))
		     (buffer-window (get-buffer-window (or buffer (error "The *cscope* buffer does not exist yet"))))
		     )
    (set-buffer buffer)
    (setq old-point (point))
    (forward-line direction)
    (setq point (point))
    (setq line-number (get-text-property point 'cscope-line-number))
    (while (or (not line-number)
	       (or (and do-symbol (= line-number -1))
		   (and search-file  (/= line-number -1))))
      (forward-line direction)
      (setq point (point))
      (if (or (and do-next (>= point (point-max)))
	      (and search-prev (<= point (point-min))))
	  (progn
	    (goto-char old-point)
	    (error "The %s of the *cscope* buffer has been reached"
		   (if do-next "end" "beginning"))))
      (setq line-number (get-text-property point 'cscope-line-number)))
    (if (eq old-buffer buffer) ;; In the *cscope* buffer.
	(cscope-show-entry-other-window)
      (cscope-select-entry-specified-window old-buffer-window) ;; else
      (if (windowp buffer-window)
	  (set-window-point buffer-window point)))
    (set-buffer old-buffer)
    ))


(defun cscope-display-buffer ()
  "Display the *cscope* buffer."
  (interactive)
  (let ((buffer (get-buffer cscope-output-buffer-name)))
    (if buffer
        (pop-to-buffer buffer)
      (error "The *cscope* buffer does not exist yet"))))


(defun cscope-display-buffer-toggle ()
  "Toggle cscope-display-cscope-buffer, which corresponds to
\"Auto display *cscope* buffer\"."
  (interactive)
  (setq cscope-display-cscope-buffer (not cscope-display-cscope-buffer))
  (message "The cscope-display-cscope-buffer variable is now %s."
           (if cscope-display-cscope-buffer "set" "unset")))


(defun cscope-next-symbol ()
  "Move to the next symbol in the *cscope* buffer."
  (interactive)
  (cscope-buffer-search t t))


(defun cscope-next-file ()
  "Move to the next file in the *cscope* buffer."
  (interactive)
  (cscope-buffer-search nil t))


(defun cscope-prev-symbol ()
  "Move to the previous symbol in the *cscope* buffer."
  (interactive)
  (cscope-buffer-search t nil))


(defun cscope-prev-file ()
  "Move to the previous file in the *cscope* buffer."
  (interactive)
  (cscope-buffer-search nil nil))


(defun cscope-pop-mark ()
  "Pop back to where cscope was last invoked."
  (interactive)

  ;; This function is based on pop-tag-mark, which can be found in
  ;; lisp/progmodes/etags.el.

  (if (ring-empty-p cscope-marker-ring)
      (error "There are no marked buffers in the cscope-marker-ring yet"))
  (let* ( (marker (ring-remove cscope-marker-ring 0))
	  (old-buffer (current-buffer))
	  (marker-buffer (marker-buffer marker))
	  marker-window
	  (marker-point (marker-position marker))
	  (cscope-buffer (get-buffer cscope-output-buffer-name)) )

    ;; After the following both cscope-marker-ring and cscope-marker will be
    ;; in the state they were immediately after the last search.  This way if
    ;; the user now makes a selection in the previously generated *cscope*
    ;; buffer things will behave the same way as if that selection had been
    ;; made immediately after the last search.
    (setq cscope-marker marker)

    (if marker-buffer
	(if (eq old-buffer cscope-buffer)
	    (progn ;; In the *cscope* buffer.
	      (set-buffer marker-buffer)
	      (setq marker-window (display-buffer marker-buffer))
	      (set-window-point marker-window marker-point)
	      (select-window marker-window))
	  (switch-to-buffer marker-buffer))
      (error "The marked buffer has been deleted"))
    (goto-char marker-point)
    (set-buffer old-buffer)))


(defun cscope-set-initial-directory (cs-id)
  "Set the cscope-initial-directory variable.  The
cscope-initial-directory variable, when set, specifies the directory
where searches for the cscope database directory should begin.  This
overrides the current directory, which would otherwise be used."
  (interactive "DCscope Initial Directory: ")
  (setq cscope-initial-directory cs-id))


(defun cscope-unset-initial-directory ()
  "Unset the cscope-initial-directory variable."
  (interactive)
  (setq cscope-initial-directory nil)
  (message "The cscope-initial-directory variable is now unset."))


(defun cscope-help ()
  (interactive)
  (message
   (format "RET=%s, SPC=%s, o=%s, n=%s, p=%s, q=%s, h=%s"
	   "Select"
	   "Show"
	   "SelectOneWin"
	   "ShowNext"
	   "ShowPrev"
	   "Quit"
	   "Help")))


(defun cscope-bury-buffer ()
  "Clean up cscope, if necessary, and bury the buffer."
  (interactive)
  (let ()
    (if overlay-arrow-position
	(set-marker overlay-arrow-position nil))
    (setq overlay-arrow-position nil
	  overlay-arrow-string nil)
    (bury-buffer (get-buffer cscope-output-buffer-name))
    ))


(defun cscope-quit ()
  (interactive)
  (cscope-bury-buffer)
  (kill-buffer cscope-output-buffer-name)
  )

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defun cscope-canonicalize-directory (dir)
  (or dir
      (setq dir default-directory))
  (setq dir (file-name-as-directory
	     (expand-file-name (substitute-in-file-name dir))))
  dir
  )


(defun cscope-search-directory-hierarchy (directory)
  "Look for a cscope database in the directory hierarchy.
Starting from DIRECTORY, look upwards for a cscope database."
  (let (this-directory database-dir)
    (catch 'done
      (if (file-regular-p directory)
	  (throw 'done directory))
      (setq directory (cscope-canonicalize-directory directory)
	    this-directory directory)
      (while this-directory
	(if (or (file-exists-p (concat this-directory cscope-database-file))
		(file-exists-p (concat this-directory cscope-index-file)))
	    (progn
	      (setq database-dir this-directory)
	      (throw 'done database-dir)
	      ))
	(if (string-match "^\\(/\\|[A-Za-z]:[\\/]\\)$" this-directory)
	    (throw 'done directory))
	(setq this-directory (file-name-as-directory
			      (file-name-directory
			       (directory-file-name this-directory))))
	))
    ))


(defun cscope-find-info (top-directory)
  "Locate a suitable cscope database directory.
First, `cscope-database-regexps' is used to search for a suitable
database directory.  If a database location cannot be found using this
variable, then the current directory is searched, then the parent,
then the parent's parent, until a cscope database directory is found,
or the root directory is reached.  If the root directory is reached,
the current directory will be used."
  (let (info regexps dir-regexp this-directory)
    (setq top-directory (cscope-canonicalize-directory
			 (or top-directory cscope-initial-directory)))
    (catch 'done
      ;; Try searching using `cscope-database-regexps' ...
      (setq regexps cscope-database-regexps)
      (while regexps
	(setq dir-regexp (car (car regexps)))
	(cond
	 ( (stringp dir-regexp)
	   (if (string-match dir-regexp top-directory)
	       (progn
		 (setq info (cdr (car regexps)))
		 (throw 'done t)
		 )) )
	 ( (and (symbolp dir-regexp) dir-regexp)
	   (progn
	     (setq info (cdr (car regexps)))
	     (throw 'done t)
	     ) ))
	(setq regexps (cdr regexps))
	)

      ;; Try looking in the directory hierarchy ...
      (if (setq this-directory
		(cscope-search-directory-hierarchy top-directory))
	  (progn
	    (setq info (list (list this-directory)))
	    (throw 'done t)
	    ))

      ;; Should we add any more places to look?

      )		;; end catch
    (if (not info)
	(setq info (list (list top-directory))))
    info
    ))


(defun cscope-make-entry-line (func-name line-number line)
  ;; The format of entry line:
  ;; func-name[line-number]______line
  ;; <- cscope-name-line-width ->
  ;; `format' of Emacs doesn't have "*s" spec.
  (let* ((fmt (format "%%%ds %%s" cscope-name-line-width))
	 (str (format fmt (format "%s[%s]" func-name line-number) line))
	 beg end)
    (if cscope-use-face
	(progn
	  (setq end (length func-name))
	  (put-text-property 0 end 'face 'cscope-function-face str)
	  (setq beg (1+ end)
		end (+ beg (length line-number)))
	  (put-text-property beg end 'face 'cscope-line-number-face str)
	  (setq end (length str)
		beg (- end (length line)))
	  (put-text-property beg end 'face 'cscope-line-face str)
	  ))
    str))


(defun cscope-process-filter (process output)
  "Accept cscope process output and reformat it for human readability.
Magic text properties are added to allow the user to select lines
using the mouse."
  (let ( (old-buffer (current-buffer)) )
    (unwind-protect
	(progn
	  (set-buffer (process-buffer process))
	  ;; Make buffer-read-only nil
	  (let (buffer-read-only line file function-name line-number moving)
	    (setq moving (= (point) (process-mark process)))
	    (save-excursion
	      (goto-char (process-mark process))
	      ;; Get the output thus far ...
	      (if cscope-process-output
		  (setq cscope-process-output (concat cscope-process-output
						      output))
		(setq cscope-process-output output))
	      ;; Slice and dice it into lines.
	      ;; While there are whole lines left ...
	      (while (and cscope-process-output
			  (string-match "\\([^\n]+\n\\)\\(\\(.\\|\n\\)*\\)"
					cscope-process-output))
		(setq file				nil
		      glimpse-stripped-directory	nil
		      )
		;; Get a line
		(setq line (substring cscope-process-output
				      (match-beginning 1) (match-end 1)))
		(setq cscope-process-output (substring cscope-process-output
						       (match-beginning 2)
						       (match-end 2)))
		(if (= (length cscope-process-output) 0)
		    (setq cscope-process-output nil))

		;; This should always match.
		(if (string-match
		     "^\\([^ \t]+\\)[ \t]+\\([^ \t]+\\)[ \t]+\\([0-9]+\\)[ \t]+\\(.*\\)\n"
		     line)
		    (progn
		      (let (str)
			(setq file (substring line (match-beginning 1)
					      (match-end 1))
			      function-name (substring line (match-beginning 2)
						       (match-end 2))
			      line-number (substring line (match-beginning 3)
						     (match-end 3))
			      line (substring line (match-beginning 4)
					      (match-end 4))
			      )
			;; If the current file is not the same as the previous
			;; one ...
			(if (not (and cscope-last-file
				      (string= file cscope-last-file)))
			    (progn
			      ;; The current file is different.

			      ;; Insert a separating blank line if
			      ;; necessary.
			      (if cscope-last-file (insert "\n"))
			      ;; Insert the file name
			      (setq str (concat "*** " file ":"))
			      (if cscope-use-face
				  (put-text-property 0 (length str)
						     'face 'cscope-file-face
						     str))
			      (cscope-insert-with-text-properties
			       str
			       (expand-file-name file)
			       ;; Yes, -1 is intentional
			       -1)
			      (insert "\n")
			      ))
			(if (not cscope-first-match)
			    (setq cscope-first-match-point (point)))
			;; ... and insert the line, with the
			;; appropriate indentation.
			(cscope-insert-with-text-properties
			 (cscope-make-entry-line function-name
						 line-number
						 line)
			 (expand-file-name file)
			 line-number)
			(insert "\n")
			(setq cscope-last-file file)
			(if cscope-first-match
			    (setq cscope-matched-multiple t)
			  (setq cscope-first-match
				(cons (expand-file-name file)
				      (string-to-number line-number))))
			))
		  (insert line "\n")
		  ))
	      (set-marker (process-mark process) (point))
	      )
	    (if moving
		(goto-char (process-mark process)))
	    (set-buffer-modified-p nil)
	    ))
      (set-buffer old-buffer))
    ))


(defun cscope-process-sentinel (process event)
  "Sentinel for when the cscope process dies."
  (let* ( (buffer (process-buffer process)) window update-window
         (done t) (old-buffer (current-buffer))
	 (old-buffer-window (get-buffer-window old-buffer)) )
    (set-buffer buffer)
    (save-window-excursion
      (save-excursion
	(if (or (and (setq window (get-buffer-window buffer))
		     (= (window-point window) (point-max)))
		(= (point) (point-max)))
	    (progn
	      (setq update-window t)
	      ))
	(delete-process process)
	(let (buffer-read-only continue)
	  (goto-char (point-max))
	  (if (and cscope-suppress-empty-matches
		   (= cscope-output-start (point)))
	      (delete-region cscope-item-start (point-max))
	    (progn
	      (if (not cscope-start-directory)
		  (setq cscope-start-directory default-directory))
	      (insert cscope-separator-line)
	      ))
	  (setq continue
		(and cscope-search-list
		     (not (and cscope-first-match
			       cscope-stop-at-first-match-dir
			       (not cscope-stop-at-first-match-dir-meta)))))
	  (if continue
	      (setq continue (cscope-search-one-database)))
	  (if continue
	      (progn
		(setq done nil)
		)
	    (progn
	      (insert "\nSearch complete.")
	      (if cscope-display-times
		  (let ( (times (current-time)) cscope-stop elapsed-time )
		    (setq cscope-stop (+ (* (car times) 65536.0)
					 (car (cdr times))
					 (* (car (cdr (cdr times))) 1.0E-6)))
		    (setq elapsed-time (- cscope-stop cscope-start-time))
		    (insert (format "  Search time = %.2f seconds."
				    elapsed-time))
		    ))
	      (setq cscope-process nil)
	      (if cscope-running-in-xemacs
		  (setq modeline-process ": Search complete"))
	      (if cscope-start-directory
		  (setq default-directory cscope-start-directory))
	      (if (not cscope-first-match)
		  (message "No matches were found."))
	      )
	    ))
	(set-buffer-modified-p nil)
	))
    (if (and done cscope-first-match-point update-window)
	(if window
	    (set-window-point window cscope-first-match-point)
	  (goto-char cscope-first-match-point))
      )
    (cond
     ( (not done)		;; we're not done -- do nothing for now
       (if update-window
	   (if window
	       (set-window-point window (point-max))
	     (goto-char (point-max))))
       )
     ( cscope-first-match
       (if cscope-display-cscope-buffer
           (if (and cscope-edit-single-match (not cscope-matched-multiple))
               (cscope-show-entry-internal(car cscope-first-match)
                                           (cdr cscope-first-match) t))
         (cscope-select-entry-specified-window old-buffer-window))
       )
     )
    (if (and done (eq old-buffer buffer) cscope-first-match)
	(cscope-help))
    (set-buffer old-buffer)
    ))


(defun cscope-search-one-database ()
  "Pop a database entry from cscope-search-list and do a search there."
  (let ( next-item options cscope-directory database-file outbuf done
		   base-database-file-name)
    (setq outbuf (get-buffer-create cscope-output-buffer-name))
    (save-excursion
      (catch 'finished
	(set-buffer outbuf)
	(setq options '("-L"))
	(while (and (not done) cscope-search-list)
	  (setq next-item (car cscope-search-list)
		cscope-search-list (cdr cscope-search-list)
		base-database-file-name cscope-database-file
		)
	  (if (listp next-item)
	      (progn
		(setq cscope-directory (car next-item))
		(if (not (stringp cscope-directory))
		    (setq cscope-directory
			  (cscope-search-directory-hierarchy
			   default-directory)))
		(if (file-regular-p cscope-directory)
		    (progn
		      ;; Handle the case where `cscope-directory' is really
		      ;; a full path name to a cscope database.
		      (setq base-database-file-name
			    (file-name-nondirectory cscope-directory)
			    cscope-directory
			    (file-name-directory cscope-directory))
		      ))
		(setq cscope-directory 
		      (file-name-as-directory cscope-directory))
		(if (not (member cscope-directory cscope-searched-dirs))
		    (progn
		      (setq cscope-searched-dirs (cons cscope-directory
						       cscope-searched-dirs)
			    done t)
		      ))
		)
	    (progn
	      (if (and cscope-first-match
		       cscope-stop-at-first-match-dir
		       cscope-stop-at-first-match-dir-meta)
		  (throw 'finished nil))
	      ))
	  )
	(if (not done)
	    (throw 'finished nil))
	(if (car (cdr next-item))
	    (let (newopts)
	      (setq newopts (car (cdr next-item)))
	      (if (not (listp newopts))
		  (error (format "Cscope options must be a list: %s" newopts)))
	      (setq options (append options newopts))
	      ))
	(if cscope-command-args
	    (setq options (append options cscope-command-args)))
	(setq database-file (concat cscope-directory base-database-file-name)
	      cscope-searched-dirs (cons cscope-directory
					 cscope-searched-dirs)
	      )

	;; The database file and the directory containing the database file
	;; must both be writable.
	(if (or (not (file-writable-p database-file))
		(not (file-writable-p (file-name-directory database-file)))
		cscope-do-not-update-database)
	    (setq options (cons "-d" options)))

	(goto-char (point-max))
	(setq cscope-item-start (point))
	(if (string= base-database-file-name cscope-database-file)
	    (insert "\nDatabase directory: " cscope-directory "\n"
		    cscope-separator-line)
	  (insert "\nDatabase directory/file: "
		  cscope-directory base-database-file-name "\n"
		  cscope-separator-line))
	;; Add the correct database file to search
	(setq options (cons base-database-file-name options))
	(setq options (cons "-f" options))
	(setq cscope-output-start (point))
	(setq default-directory cscope-directory)
	(if cscope-filter-func
	    (progn
	      (setq cscope-process-output nil
		    cscope-last-file nil
		    )
	      (setq cscope-process
		    (apply 'start-process "cscope" outbuf
			   cscope-program options))
	      (set-process-filter cscope-process cscope-filter-func)
	      (set-process-sentinel cscope-process cscope-sentinel-func)
	      (set-marker (process-mark cscope-process) (point))
	      (process-kill-without-query cscope-process)
	      (if cscope-running-in-xemacs
		  (setq modeline-process ": Searching ..."))
	      (setq buffer-read-only t)
	      )
	  (apply 'call-process cscope-program nil outbuf t options)
	  )
	t
	))
    ))


(defun cscope-call (msg args &optional directory filter-func sentinel-func)
  "Generic function to call to process cscope requests.
ARGS is a list of command-line arguments to pass to the cscope
process.  DIRECTORY is the current working directory to use (generally,
the directory in which the cscope database is located, but not
necessarily), if different that the current one.  FILTER-FUNC and
SENTINEL-FUNC are optional process filter and sentinel, respectively."
  (let ( (outbuf (get-buffer-create cscope-output-buffer-name))
         (old-buffer (current-buffer)) )
    (if cscope-process
	(error "A cscope search is still in progress -- only one at a time is allowed"))
    (setq directory (cscope-canonicalize-directory
                     (or cscope-initial-directory directory)))
    (if (eq outbuf old-buffer) ;; In the *cscope* buffer.
	(if cscope-marker-window
	    (progn
	      ;; Assume that cscope-marker-window is the window, from the
	      ;; users perspective, from which the search was launched and the
	      ;; window that should be returned to upon cscope-pop-mark.
	      (set-buffer (window-buffer cscope-marker-window))
	      (setq cscope-marker (point-marker))
	      (set-buffer old-buffer)))
	(progn ;; Not in the *cscope buffer.
	  ;; Set the cscope-marker-window to whichever window this search
	  ;; was launched from.
	  (setq cscope-marker-window (get-buffer-window old-buffer))
	(setq cscope-marker (point-marker))))
    (save-excursion
      (set-buffer outbuf)
      (if cscope-display-times
	  (let ( (times (current-time)) )
	    (setq cscope-start-time (+ (* (car times) 65536.0) (car (cdr times))
				       (* (car (cdr (cdr times))) 1.0E-6)))))
      (setq default-directory directory
	    cscope-start-directory nil
	    cscope-search-list (cscope-find-info directory)
	    cscope-searched-dirs nil
	    cscope-command-args args
	    cscope-filter-func filter-func
	    cscope-sentinel-func sentinel-func
	    cscope-first-match nil
	    cscope-first-match-point nil
	    cscope-stop-at-first-match-dir-meta (memq t cscope-search-list)
	    cscope-matched-multiple nil
	    buffer-read-only nil)
      (buffer-disable-undo)
      (erase-buffer)
      (setq truncate-lines cscope-truncate-lines)
      (if msg
	  (insert msg "\n"))
      (cscope-search-one-database)
      )
    (if cscope-display-cscope-buffer
	(progn
	  (pop-to-buffer outbuf)
	  (cscope-help))
      (set-buffer outbuf))
    (goto-char (point-max))
    (cscope-list-entry-mode)
    ))


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defvar cscope-unix-index-process-buffer-name "*cscope-indexing-buffer*"
  "The name of the buffer to use for displaying indexing status/progress.")


(defvar cscope-unix-index-process-buffer nil
  "The buffer to use for displaying indexing status/progress.")


(defvar cscope-unix-index-process nil
  "The current indexing process.")


(defun cscope-unix-index-files-sentinel (process event)
  "Simple sentinel to print a message saying that indexing is finished."
  (let (buffer)
    (save-window-excursion
      (save-excursion
	(setq buffer (process-buffer process))
	(set-buffer buffer)
	(goto-char (point-max))
	(insert cscope-separator-line "\nIndexing finished\n")
	(delete-process process)
	(setq cscope-unix-index-process nil)
	(set-buffer-modified-p nil)
	))
    ))


(defun cscope-unix-index-files-internal (top-directory header-text args)
  "Core function to call the indexing script."
  (let ()
    (save-excursion
      (setq top-directory (cscope-canonicalize-directory top-directory))
      (setq cscope-unix-index-process-buffer
	    (get-buffer-create cscope-unix-index-process-buffer-name))
      (display-buffer cscope-unix-index-process-buffer)
      (set-buffer cscope-unix-index-process-buffer)
      (setq buffer-read-only nil)
      (setq default-directory top-directory)
      (buffer-disable-undo)
      (erase-buffer)
      (if header-text
	  (insert header-text))
      (setq args (append args
			 (list "-v"
			       "-i" cscope-index-file
			       "-f" cscope-database-file
			       (if cscope-use-relative-paths
				   "." top-directory))))
      (if cscope-index-recursively
	  (setq args (cons "-r" args)))
      (setq cscope-unix-index-process
	    (apply 'start-process "cscope-indexer"
		   cscope-unix-index-process-buffer
		   cscope-indexing-script args))
      (set-process-sentinel cscope-unix-index-process
			    'cscope-unix-index-files-sentinel)
      (process-kill-without-query cscope-unix-index-process)
      )
    ))


(defun cscope-index-files (top-directory)
  "Index files in a directory.
This function creates a list of files to index, and then indexes
the listed files.
The variable, \"cscope-index-recursively\", controls whether or not
subdirectories are indexed."
  (interactive "DIndex files in directory: ")
  (let ()
    (cscope-unix-index-files-internal
     top-directory
     (format "Creating cscope index `%s' in:\n\t%s\n\n%s"
	     cscope-database-file top-directory cscope-separator-line)
     nil)
    ))


(defun cscope-create-list-of-files-to-index (top-directory)
  "Create a list of files to index.
The variable, \"cscope-index-recursively\", controls whether or not
subdirectories are indexed."
  (interactive "DCreate file list in directory: ")
  (let ()
    (cscope-unix-index-files-internal
     top-directory
     (format "Creating cscope file list `%s' in:\n\t%s\n\n"
	     cscope-index-file top-directory)
     '("-l"))
    ))


(defun cscope-edit-list-of-files-to-index ()
  "Search for and edit the list of files to index.
If this functions causes a new file to be edited, that means that a
cscope.out file was found without a corresponding cscope.files file."
  (interactive)
  (let (info directory file)
    (setq info (cscope-find-info nil))
    (if (/= (length info) 1)
	(error "There is no unique cscope database directory!"))
    (setq directory (car (car info)))
    (if (not (stringp directory))
	(setq directory
	      (cscope-search-directory-hierarchy default-directory)))
    (setq file (concat (file-name-as-directory directory) cscope-index-file))
    (find-file file)
    (message (concat "File: " file))
    ))


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defun cscope-tell-user-about-directory ()
  "Display the name of the directory containing the cscope database."
  (interactive)
  (let (info directory)
    (setq info (cscope-find-info nil))
    (if (= (length info) 1)
	(progn
	  (setq directory (car (car info)))
	  (message (concat "Cscope directory: " directory))
	  )
      (let ( (outbuf (get-buffer-create cscope-info-buffer-name)) )
	(display-buffer outbuf)
	(save-excursion
	  (set-buffer outbuf)
	  (buffer-disable-undo)
	  (erase-buffer)
	  (insert "Cscope search directories:\n")
	  (while info
	    (if (listp (car info))
		(progn
		  (setq directory (car (car info)))
		  (if (not (stringp directory))
		      (setq directory
			    (cscope-search-directory-hierarchy
			     default-directory)))
		  (insert "\t" directory "\n")
		  ))
	    (setq info (cdr info))
	    )
	  )
	))
    ))


(defun cscope-dired-directory ()
  "Run dired upon the cscope database directory.
If possible, the cursor is moved to the name of the cscope database
file."
  (interactive)
  (let (info directory buffer p1 p2 pos)
    (setq info (cscope-find-info nil))
    (if (/= (length info) 1)
	(error "There is no unique cscope database directory!"))
    (setq directory (car (car info)))
    (if (not (stringp directory))
	(setq directory
	      (cscope-search-directory-hierarchy default-directory)))
    (setq buffer (dired-noselect directory nil))
    (switch-to-buffer buffer)
    (set-buffer buffer)
    (save-excursion
      (goto-char (point-min))
      (setq p1 (search-forward cscope-index-file nil t))
      (if p1
	  (setq p1 (- p1 (length cscope-index-file))))
      )
    (save-excursion
      (goto-char (point-min))
      (setq p2 (search-forward cscope-database-file nil t))
      (if p2
	  (setq p2 (- p2 (length cscope-database-file))))
      )
    (cond
     ( (and p1 p2)
       (if (< p1 p2)
	   (setq pos p1)
	 (setq pos p2))
       )
     ( p1
       (setq pos p1)
       )
     ( p2
       (setq pos p2)
       )
     )
    (if pos
	(set-window-point (get-buffer-window buffer) pos))
    ))


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defun cscope-extract-symbol-at-cursor (extract-filename)
  (let* ( (symbol-chars (if extract-filename
			    cscope-filename-chars
			  cscope-symbol-chars))
	  (symbol-char-regexp (concat "[" symbol-chars "]"))
	  )
    (save-excursion
      (buffer-substring-no-properties
       (progn
	 (if (not (looking-at symbol-char-regexp))
	     (re-search-backward "\\w" nil t))
	 (skip-chars-backward symbol-chars)
	 (point))
       (progn
	 (skip-chars-forward symbol-chars)
	 (point)
	 )))
    ))


(defun cscope-prompt-for-symbol (prompt extract-filename)
  "Prompt the user for a cscope symbol."
  (let (sym)
    (setq sym (cscope-extract-symbol-at-cursor extract-filename))
    (if (or (not sym)
	    (string= sym "")
	    (not (and cscope-running-in-xemacs
		      cscope-no-mouse-prompts current-mouse-event
		      (or (mouse-event-p current-mouse-event)
			  (misc-user-event-p current-mouse-event))))
	    ;; Always prompt for symbol in dired mode.
	    (eq major-mode 'dired-mode)
	    )
	(setq sym (read-from-minibuffer prompt sym))
      sym)
    ))


(defun cscope-find-this-symbol (symbol)
  "Locate a symbol in source code."
  (interactive (list
		(cscope-prompt-for-symbol "Find this symbol: " nil)
		))
  (let ( (cscope-adjust t) )	 ;; Use fuzzy matching.
    (setq cscope-symbol symbol)
    (cscope-call (format "Finding symbol: %s" symbol)
		 (list "-0" symbol) nil 'cscope-process-filter
		 'cscope-process-sentinel)
    ))


(defun cscope-find-global-definition (symbol)
  "Find a symbol's global definition."
  (interactive (list
		(cscope-prompt-for-symbol "Find this global definition: " nil)
		))
  (let ( (cscope-adjust t) )	 ;; Use fuzzy matching.
    (setq cscope-symbol symbol)
    (cscope-call (format "Finding global definition: %s" symbol)
		 (list "-1" symbol) nil 'cscope-process-filter
		 'cscope-process-sentinel)
    ))


(defun cscope-find-global-definition-no-prompting ()
  "Find a symbol's global definition without prompting."
  (interactive)
  (let ( (symbol (cscope-extract-symbol-at-cursor nil))
	 (cscope-adjust t) )	 ;; Use fuzzy matching.
    (setq cscope-symbol symbol)
    (cscope-call (format "Finding global definition: %s" symbol)
		 (list "-1" symbol) nil 'cscope-process-filter
		 'cscope-process-sentinel)
    ))


(defun cscope-find-called-functions (symbol)
  "Display functions called by a function."
  (interactive (list
		(cscope-prompt-for-symbol
		 "Find functions called by this function: " nil)
		))
  (let ( (cscope-adjust nil) )	 ;; Disable fuzzy matching.
    (setq cscope-symbol symbol)
    (cscope-call (format "Finding functions called by: %s" symbol)
		 (list "-2" symbol) nil 'cscope-process-filter
		 'cscope-process-sentinel)
    ))


(defun cscope-find-functions-calling-this-function (symbol)
  "Display functions calling a function."
  (interactive (list
		(cscope-prompt-for-symbol
		 "Find functions calling this function: " nil)
		))
  (let ( (cscope-adjust t) )	 ;; Use fuzzy matching.
    (setq cscope-symbol symbol)
    (cscope-call (format "Finding functions calling: %s" symbol)
		 (list "-3" symbol) nil 'cscope-process-filter
		 'cscope-process-sentinel)
    ))


(defun cscope-find-this-text-string (symbol)
  "Locate where a text string occurs."
  (interactive (list
		(cscope-prompt-for-symbol "Find this text string: " nil)
		))
  (let ( (cscope-adjust t) )	 ;; Use fuzzy matching.
    (setq cscope-symbol symbol)
    (cscope-call (format "Finding text string: %s" symbol)
		 (list "-4" symbol) nil 'cscope-process-filter
		 'cscope-process-sentinel)
    ))


(defun cscope-find-egrep-pattern (symbol)
  "Run egrep over the cscope database."
  (interactive (list
		(let (cscope-no-mouse-prompts)
		  (cscope-prompt-for-symbol "Find this egrep pattern: " nil))
		))
  (let ( (cscope-adjust t) )	 ;; Use fuzzy matching.
    (setq cscope-symbol symbol)
    (cscope-call (format "Finding egrep pattern: %s" symbol)
		 (list "-6" symbol) nil 'cscope-process-filter
		 'cscope-process-sentinel)
    ))


(defun cscope-find-this-file (symbol)
  "Locate a file."
  (interactive (list
		(let (cscope-no-mouse-prompts)
		  (cscope-prompt-for-symbol "Find this file: " t))
		))
  (let ( (cscope-adjust nil) )	 ;; Disable fuzzy matching.
    (setq cscope-symbol symbol)
    (cscope-call (format "Finding file: %s" symbol)
		 (list "-7" symbol) nil 'cscope-process-filter
		 'cscope-process-sentinel)
    ))


(defun cscope-find-files-including-file (symbol)
  "Locate all files #including a file."
  (interactive (list
		(let (cscope-no-mouse-prompts)
		  (cscope-prompt-for-symbol
		   "Find files #including this file: " t))
		))
  (let ( (cscope-adjust t) )	;; Use fuzzy matching.
    (setq cscope-symbol symbol)
    (cscope-call (format "Finding files #including file: %s" symbol)
		 (list "-8" symbol) nil 'cscope-process-filter
		 'cscope-process-sentinel)
    ))


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defvar cscope-minor-mode nil
  "")
(make-variable-buffer-local 'cscope-minor-mode)
(put 'cscope-minor-mode 'permanent-local t)


(defun cscope-minor-mode (&optional arg)
  ""
  (progn
    (setq cscope-minor-mode (if (null arg) t (car arg)))
    (if cscope-minor-mode
	(progn
	  (easy-menu-add cscope:menu cscope:map)
	  (run-hooks 'cscope-minor-mode-hooks)
	  ))
    cscope-minor-mode
    ))


(defun cscope:hook ()
  ""
  (progn
    (cscope-minor-mode)
    ))


(or (assq 'cscope-minor-mode minor-mode-map-alist)
    (setq minor-mode-map-alist (cons (cons 'cscope-minor-mode cscope:map)
				     minor-mode-map-alist)))

(add-hook 'c-mode-hook (function cscope:hook))
(add-hook 'c++-mode-hook (function cscope:hook))
(add-hook 'dired-mode-hook (function cscope:hook))

(provide 'xcscope)