lisp/gud.el

   1 ;;; gud.el --- Grand Unified Debugger mode for gdb, sdb, dbx, or xdb
   2 ;;;            under Emacs
   3
   4 ;; Author: Eric S. Raymond <esr@snark.thyrsus.com>
   5 ;; Maintainer: FSF
   6 ;; Version: 1.3
   7 ;; Keywords: unix, tools
   8
   9 ;; Copyright (C) 1992, 1993 Free Software Foundation, Inc.
  10
  11 ;; This file is part of GNU Emacs.
  12
  13 ;; GNU Emacs is free software; you can redistribute it and/or modify
  14 ;; it under the terms of the GNU General Public License as published by
  15 ;; the Free Software Foundation; either version 2, or (at your option)
  16 ;; any later version.
  17
  18 ;; GNU Emacs is distributed in the hope that it will be useful,
  19 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  20 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21 ;; GNU General Public License for more details.
  22
  23 ;; You should have received a copy of the GNU General Public License
  24 ;; along with GNU Emacs; see the file COPYING.  If not, write to
  25 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  26
  27 ;;; Commentary:
  28
  29 ;; The ancestral gdb.el was by W. Schelter <wfs@rascal.ics.utexas.edu>
  30 ;; It was later rewritten by rms.  Some ideas were due to Masanobu.
  31 ;; Grand Unification (sdb/dbx support) by Eric S. Raymond <esr@thyrsus.com>
  32 ;; The overloading code was then rewritten by Barry Warsaw <bwarsaw@cen.com>,
  33 ;; who also hacked the mode to use comint.el.  Shane Hartman <shane@spr.com>
  34 ;; added support for xdb (HPUX debugger).  Rick Sladkey <jrs@world.std.com>
  35 ;; wrote the GDB command completion code.
  36
  37 ;;; Code:
  38
  39 (require 'comint)
  40 (require 'etags)
  41
  42 ;; ======================================================================
  43 ;; GUD commands must be visible in C buffers visited by GUD
  44
  45 (defvar gud-key-prefix "\C-x\C-a"
  46   "Prefix of all GUD commands valid in C buffers.")
  47
  48 (global-set-key (concat gud-key-prefix "\C-l") 'gud-refresh)
  49 (global-set-key "\C-x " 'gud-break)     ;; backward compatibility hack
  50
  51 ;; ======================================================================
  52 ;; the overloading mechanism
  53
  54 (defun gud-overload-functions (gud-overload-alist)
  55   "Overload functions defined in GUD-OVERLOAD-ALIST.
  56 This association list has elements of the form
  57      (ORIGINAL-FUNCTION-NAME  OVERLOAD-FUNCTION)"
  58   (mapcar
  59    (function (lambda (p) (fset (car p) (symbol-function (cdr p)))))
  60    gud-overload-alist))
  61
  62 (defun gud-massage-args (file args)
  63   (error "GUD not properly entered."))
  64
  65 (defun gud-marker-filter (str)
  66   (error "GUD not properly entered."))
  67
  68 (defun gud-find-file (f)
  69   (error "GUD not properly entered."))
  70 \f
  71 ;; ======================================================================
  72 ;; command definition
  73
  74 ;; This macro is used below to define some basic debugger interface commands.
  75 ;; Of course you may use `gud-def' with any other debugger command, including
  76 ;; user defined ones.
  77
  78 ;; A macro call like (gud-def FUNC NAME KEY DOC) expands to a form
  79 ;; which defines FUNC to send the command NAME to the debugger, gives
  80 ;; it the docstring DOC, and binds that function to KEY in the GUD
  81 ;; major mode.  The function is also bound in the global keymap with the
  82 ;; GUD prefix.
  83
  84 (defmacro gud-def (func cmd key &optional doc)
  85   "Define FUNC to be a command sending STR and bound to KEY, with
  86 optional doc string DOC.  Certain %-escapes in the string arguments
  87 are interpreted specially if present.  These are:
  88
  89   %f    name (without directory) of current source file.
  90   %d    directory of current source file.
  91   %l    number of current source line
  92   %e    text of the C lvalue or function-call expression surrounding point.
  93   %a    text of the hexadecimal address surrounding point
  94   %p    prefix argument to the command (if any) as a number
  95
  96   The `current' source file is the file of the current buffer (if
  97 we're in a C file) or the source file current at the last break or
  98 step (if we're in the GUD buffer).
  99   The `current' line is that of the current buffer (if we're in a
 100 source file) or the source line number at the last break or step (if
 101 we're in the GUD buffer)."
 102   (list 'progn
 103         (list 'defun func '(arg)
 104               (or doc "")
 105               '(interactive "p")
 106               (list 'gud-call cmd 'arg))
 107         (if key
 108             (list 'define-key
 109                   '(current-local-map)
 110                   (concat "\C-c" key)
 111                   (list 'quote func)))
 112         (if key
 113             (list 'global-set-key
 114                   (list 'concat 'gud-key-prefix key)
 115                   (list 'quote func)))))
 116
 117 ;; Where gud-display-frame should put the debugging arrow.  This is
 118 ;; set by the marker-filter, which scans the debugger's output for
 119 ;; indications of the current program counter.
 120 (defvar gud-last-frame nil)
 121
 122 ;; Used by gud-refresh, which should cause gud-display-frame to redisplay
 123 ;; the last frame, even if it's been called before and gud-last-frame has
 124 ;; been set to nil.
 125 (defvar gud-last-last-frame nil)
 126
 127 ;; All debugger-specific information is collected here.
 128 ;; Here's how it works, in case you ever need to add a debugger to the mode.
 129 ;;
 130 ;; Each entry must define the following at startup:
 131 ;;
 132 ;;<name>
 133 ;; comint-prompt-regexp
 134 ;; gud-<name>-massage-args
 135 ;; gud-<name>-marker-filter
 136 ;; gud-<name>-find-file
 137 ;;
 138 ;; The job of the massage-args method is to modify the given list of
 139 ;; debugger arguments before running the debugger.
 140 ;;
 141 ;; The job of the marker-filter method is to detect file/line markers in
 142 ;; strings and set the global gud-last-frame to indicate what display
 143 ;; action (if any) should be triggered by the marker.  Note that only
 144 ;; whatever the method *returns* is displayed in the buffer; thus, you
 145 ;; can filter the debugger's output, interpreting some and passing on
 146 ;; the rest.
 147 ;;
 148 ;; The job of the find-file method is to visit and return the buffer indicated
 149 ;; by the car of gud-tag-frame.  This may be a file name, a tag name, or
 150 ;; something else.
 151 \f
 152 ;; ======================================================================
 153 ;; gdb functions
 154
 155 ;;; History of argument lists passed to gdb.
 156 (defvar gud-gdb-history nil)
 157
 158 (defun gud-gdb-massage-args (file args)
 159   (cons "-fullname" (cons file args)))
 160
 161 ;; There's no guarantee that Emacs will hand the filter the entire
 162 ;; marker at once; it could be broken up across several strings.  We
 163 ;; might even receive a big chunk with several markers in it.  If we
 164 ;; receive a chunk of text which looks like it might contain the
 165 ;; beginning of a marker, we save it here between calls to the
 166 ;; filter.
 167 (defvar gud-gdb-marker-acc "")
 168
 169 (defun gud-gdb-marker-filter (string)
 170   (save-match-data
 171     (setq gud-gdb-marker-acc (concat gud-gdb-marker-acc string))
 172     (let ((output ""))
 173
 174       ;; Process all the complete markers in this chunk.
 175       (while (string-match "^\032\032\\([^:\n]*\\):\\([0-9]*\\):.*\n"
 176                            gud-gdb-marker-acc)
 177         (setq
 178
 179          ;; Extract the frame position from the marker.
 180          gud-last-frame
 181          (cons (substring gud-gdb-marker-acc (match-beginning 1) (match-end 1))
 182                (string-to-int (substring gud-gdb-marker-acc
 183                                          (match-beginning 2)
 184                                          (match-end 2))))
 185
 186          ;; Append any text before the marker to the output we're going
 187          ;; to return - we don't include the marker in this text.
 188          output (concat output
 189                         (substring gud-gdb-marker-acc 0 (match-beginning 0)))
 190
 191          ;; Set the accumulator to the remaining text.
 192          gud-gdb-marker-acc (substring gud-gdb-marker-acc (match-end 0))))
 193
 194       ;; Does the remaining text look like it might end with the
 195       ;; beginning of another marker?  If it does, then keep it in
 196       ;; gud-gdb-marker-acc until we receive the rest of it.  Since we
 197       ;; know the full marker regexp above failed, it's pretty simple to
 198       ;; test for marker starts.
 199       (if (string-match "^\032.*\\'" gud-gdb-marker-acc)
 200           (progn
 201             ;; Everything before the potential marker start can be output.
 202             (setq output (concat output (substring gud-gdb-marker-acc
 203                                                    0 (match-beginning 0))))
 204
 205             ;; Everything after, we save, to combine with later input.
 206             (setq gud-gdb-marker-acc
 207                   (substring gud-gdb-marker-acc (match-beginning 0))))
 208
 209         (setq output (concat output gud-gdb-marker-acc)
 210               gud-gdb-marker-acc ""))
 211
 212       output)))
 213
 214 (defun gud-gdb-find-file (f)
 215   (find-file-noselect f))
 216
 217 (defvar gdb-minibuffer-local-map nil
 218   "Keymap for minibuffer prompting of gdb startup command.")
 219 (if gdb-minibuffer-local-map
 220     ()
 221   (setq gdb-minibuffer-local-map (copy-keymap minibuffer-local-map))
 222   (define-key
 223     gdb-minibuffer-local-map "\C-i" 'comint-dynamic-complete-filename))
 224
 225 ;;;###autoload
 226 (defun gdb (command-line)
 227   "Run gdb on program FILE in buffer *gud-FILE*.
 228 The directory containing FILE becomes the initial working directory
 229 and source-file directory for your debugger."
 230   (interactive
 231    (list (read-from-minibuffer "Run gdb (like this): "
 232                                (if (consp gud-gdb-history)
 233                                    (car gud-gdb-history)
 234                                  "gdb ")
 235                                gdb-minibuffer-local-map nil
 236                                '(gud-gdb-history . 1))))
 237   (gud-overload-functions '((gud-massage-args . gud-gdb-massage-args)
 238                             (gud-marker-filter . gud-gdb-marker-filter)
 239                             (gud-find-file . gud-gdb-find-file)
 240                             ))
 241
 242   (gud-common-init command-line)
 243
 244   (gud-def gud-break  "break %f:%l"  "\C-b" "Set breakpoint at current line.")
 245   (gud-def gud-tbreak "tbreak %f:%l" "\C-t" "Set breakpoint at current line.")
 246   (gud-def gud-remove "clear %l"     "\C-d" "Remove breakpoint at current line")
 247   (gud-def gud-step   "step %p"      "\C-s" "Step one source line with display.")
 248   (gud-def gud-stepi  "stepi %p"     "\C-i" "Step one instruction with display.")
 249   (gud-def gud-next   "next %p"      "\C-n" "Step one line (skip functions).")
 250   (gud-def gud-cont   "cont"         "\C-r" "Continue with display.")
 251   (gud-def gud-finish "finish"       "\C-f" "Finish executing current function.")
 252   (gud-def gud-up     "up %p"        "<" "Up N stack frames (numeric arg).")
 253   (gud-def gud-down   "down %p"      ">" "Down N stack frames (numeric arg).")
 254   (gud-def gud-print  "print %e"     "\C-p" "Evaluate C expression at point.")
 255
 256   (local-set-key "\C-i" 'gud-gdb-complete-command)
 257   (setq comint-prompt-regexp "^(.*gdb[+]?) *")
 258   (run-hooks 'gdb-mode-hook)
 259   )
 260
 261 ;; One of the nice features of GDB is its impressive support for
 262 ;; context-sensitive command completion.  We preserve that feature
 263 ;; in the GUD buffer by using a GDB command designed just for Emacs.
 264
 265 ;; The completion process filter indicates when it is finished.
 266 (defvar gud-gdb-complete-in-progress)
 267
 268 ;; Since output may arrive in fragments we accumulate partials strings here.
 269 (defvar gud-gdb-complete-string)
 270
 271 ;; We need to know how much of the completion to chop off.
 272 (defvar gud-gdb-complete-break)
 273
 274 ;; The completion list is constructed by the process filter.
 275 (defvar gud-gdb-complete-list)
 276
 277 (defvar gud-comint-buffer nil)
 278
 279 (defun gud-gdb-complete-command ()
 280   "Perform completion on the GDB command preceding point.
 281 This is implemented using the GDB `complete' command which isn't
 282 available with older versions of GDB."
 283   (interactive)
 284   (let* ((end (point))
 285          (command (save-excursion
 286                     (beginning-of-line)
 287                     (and (looking-at comint-prompt-regexp)
 288                          (goto-char (match-end 0)))
 289                     (buffer-substring (point) end)))
 290          command-word)
 291     ;; Find the word break.  This match will always succeed.
 292     (string-match "\\(\\`\\| \\)\\([^ ]*\\)\\'" command)
 293     (setq gud-gdb-complete-break (match-beginning 2)
 294           command-word (substring command gud-gdb-complete-break))
 295     (unwind-protect
 296         (progn
 297           ;; Temporarily install our filter function.
 298           (gud-overload-functions
 299            '((gud-marker-filter . gud-gdb-complete-filter)))
 300           ;; Issue the command to GDB.
 301           (gud-basic-call (concat "complete " command))
 302           (setq gud-gdb-complete-in-progress t
 303                 gud-gdb-complete-string nil
 304                 gud-gdb-complete-list nil)
 305           ;; Slurp the output.
 306           (while gud-gdb-complete-in-progress
 307             (accept-process-output (get-buffer-process gud-comint-buffer))))
 308       ;; Restore the old filter function.
 309       (gud-overload-functions '((gud-marker-filter . gud-gdb-marker-filter))))
 310     ;; Protect against old versions of GDB.
 311     (and gud-gdb-complete-list
 312          (string-match "^Undefined command: \"complete\""
 313                        (car gud-gdb-complete-list))
 314          (error "This version of GDB doesn't support the `complete' command."))
 315     ;; Sort the list like readline.
 316     (setq gud-gdb-complete-list
 317           (sort gud-gdb-complete-list (function string-lessp)))
 318     ;; Remove duplicates.
 319     (let ((first gud-gdb-complete-list)
 320           (second (cdr gud-gdb-complete-list)))
 321       (while second
 322         (if (string-equal (car first) (car second))
 323             (setcdr first (setq second (cdr second)))
 324           (setq first second
 325                 second (cdr second)))))
 326     ;; Let comint handle the rest.
 327     (comint-dynamic-simple-complete command-word gud-gdb-complete-list)))
 328
 329 ;; The completion process filter is installed temporarily to slurp the
 330 ;; output of GDB up to the next prompt and build the completion list.
 331 (defun gud-gdb-complete-filter (string)
 332   (setq string (concat gud-gdb-complete-string string))
 333   (while (string-match "\n" string)
 334     (setq gud-gdb-complete-list
 335           (cons (substring string gud-gdb-complete-break (match-beginning 0))
 336                 gud-gdb-complete-list))
 337     (setq string (substring string (match-end 0))))
 338   (if (string-match comint-prompt-regexp string)
 339       (progn
 340         (setq gud-gdb-complete-in-progress nil)
 341         string)
 342     (progn
 343       (setq gud-gdb-complete-string string)
 344       "")))
 345
 346 \f
 347 ;; ======================================================================
 348 ;; sdb functions
 349
 350 ;;; History of argument lists passed to sdb.
 351 (defvar gud-sdb-history nil)
 352
 353 (defvar gud-sdb-needs-tags (not (file-exists-p "/var"))
 354   "If nil, we're on a System V Release 4 and don't need the tags hack.")
 355
 356 (defvar gud-sdb-lastfile nil)
 357
 358 (defun gud-sdb-massage-args (file args)
 359   (cons file args))
 360
 361 (defun gud-sdb-marker-filter (string)
 362   (cond
 363    ;; System V Release 3.2 uses this format
 364    ((string-match "\\(^0x\\w* in \\|^\\|\n\\)\\([^:\n]*\\):\\([0-9]*\\):.*\n"
 365                     string)
 366     (setq gud-last-frame
 367           (cons
 368            (substring string (match-beginning 2) (match-end 2))
 369            (string-to-int
 370             (substring string (match-beginning 3) (match-end 3))))))
 371    ;; System V Release 4.0
 372    ((string-match "^\\(BREAKPOINT\\|STEPPED\\) process [0-9]+ function [^ ]+ in \\(.+\\)\n"
 373                        string)
 374     (setq gud-sdb-lastfile
 375           (substring string (match-beginning 2) (match-end 2))))
 376    ((and gud-sdb-lastfile (string-match "^\\([0-9]+\\):" string))
 377          (setq gud-last-frame
 378                (cons
 379                 gud-sdb-lastfile
 380                 (string-to-int
 381                  (substring string (match-beginning 1) (match-end 1))))))
 382    (t
 383     (setq gud-sdb-lastfile nil)))
 384   string)
 385
 386 (defun gud-sdb-find-file (f)
 387   (if gud-sdb-needs-tags
 388       (find-tag-noselect f)
 389     (find-file-noselect f)))
 390
 391 ;;;###autoload
 392 (defun sdb (command-line)
 393   "Run sdb on program FILE in buffer *gud-FILE*.
 394 The directory containing FILE becomes the initial working directory
 395 and source-file directory for your debugger."
 396   (interactive
 397    (list (read-from-minibuffer "Run sdb (like this): "
 398                                (if (consp gud-sdb-history)
 399                                    (car gud-sdb-history)
 400                                  "sdb ")
 401                                nil nil
 402                                '(gud-sdb-history . 1))))
 403   (if (and gud-sdb-needs-tags
 404            (not (and (boundp 'tags-file-name) (file-exists-p tags-file-name))))
 405       (error "The sdb support requires a valid tags table to work."))
 406   (gud-overload-functions '((gud-massage-args . gud-sdb-massage-args)
 407                             (gud-marker-filter . gud-sdb-marker-filter)
 408                             (gud-find-file . gud-sdb-find-file)
 409                             ))
 410
 411   (gud-common-init command-line)
 412
 413   (gud-def gud-break  "%l b" "\C-b"   "Set breakpoint at current line.")
 414   (gud-def gud-tbreak "%l c" "\C-t"   "Set temporary breakpoint at current line.")
 415   (gud-def gud-remove "%l d" "\C-d"   "Remove breakpoint at current line")
 416   (gud-def gud-step   "s %p" "\C-s"   "Step one source line with display.")
 417   (gud-def gud-stepi  "i %p" "\C-i"   "Step one instruction with display.")
 418   (gud-def gud-next   "S %p" "\C-n"   "Step one line (skip functions).")
 419   (gud-def gud-cont   "c"    "\C-r"   "Continue with display.")
 420   (gud-def gud-print  "%e/"  "\C-p"   "Evaluate C expression at point.")
 421
 422   (setq comint-prompt-regexp  "\\(^\\|\n\\)\\*")
 423   (run-hooks 'sdb-mode-hook)
 424   )
 425 \f
 426 ;; ======================================================================
 427 ;; dbx functions
 428
 429 ;;; History of argument lists passed to dbx.
 430 (defvar gud-dbx-history nil)
 431
 432 (defun gud-dbx-massage-args (file args)
 433   (cons file args))
 434
 435 (defun gud-dbx-marker-filter (string)
 436   (if (or (string-match
 437          "stopped in .* at line \\([0-9]*\\) in file \"\\([^\"]*\\)\""
 438          string)
 439         (string-match
 440          "signal .* in .* at line \\([0-9]*\\) in file \"\\([^\"]*\\)\""
 441          string))
 442       (setq gud-last-frame
 443             (cons
 444              (substring string (match-beginning 2) (match-end 2))
 445              (string-to-int
 446               (substring string (match-beginning 1) (match-end 1))))))
 447   string)
 448
 449 ;; Functions for dbx on Mips/Ultrix.
 450 ;; This is very similar to the code for gdb. The trick is to start dbx
 451 ;; with the (undocumented) option `-emacs'.
 452
 453 ;; Are we running on a Mips system under Ultrix?
 454 (defvar gud-dbx-mips-p (file-exists-p "/usr/include/mips"))
 455
 456 (defun gud-mipsdbx-massage-args (file args)
 457   (cons "-emacs" (cons file args)))
 458
 459 ;; There's no guarantee that Emacs will hand the filter the entire
 460 ;; marker at once; it could be broken up across several strings.  We
 461 ;; might even receive a big chunk with several markers in it.  If we
 462 ;; receive a chunk of text which looks like it might contain the
 463 ;; beginning of a marker, we save it here between calls to the
 464 ;; filter.
 465 (defvar gud-mipsdbx-marker-acc "")
 466
 467 (defun gud-mipsdbx-marker-filter (string)
 468   (save-match-data
 469     (setq gud-mipsdbx-marker-acc (concat gud-mipsdbx-marker-acc string))
 470     (let ((output ""))
 471
 472       ;; Process all the complete markers in this chunk.
 473       (while (string-match
 474               "^[] [0-9]*\032\032\\([^:\n]*\\):\\([0-9]*\\):.*\n"
 475               gud-mipsdbx-marker-acc)
 476         (setq
 477
 478          ;; Extract the frame position from the marker.
 479          gud-last-frame (cons
 480                          (substring gud-mipsdbx-marker-acc
 481                                     (match-beginning 1) (match-end 1))
 482                          (string-to-int
 483                           (substring gud-mipsdbx-marker-acc
 484                                      (match-beginning 2) (match-end 2))))
 485
 486          ;; Append any text before the marker to the output we're going
 487          ;; to return - we don't include the marker in this text.
 488          output (concat output (substring gud-mipsdbx-marker-acc
 489                                           0 (match-beginning 0)))
 490
 491          ;; Set the accumulator to the remaining text.
 492          gud-mipsdbx-marker-acc (substring gud-mipsdbx-marker-acc
 493                                            (match-end 0))))
 494
 495       ;; Does the remaining text look like it might end with the
 496       ;; beginning of another marker?  If it does, then keep it in
 497       ;; gud-mipsdbx-marker-acc until we receive the rest of it.
 498       ;; Since we know the full marker regexp above failed, it's pretty
 499       ;; simple to test for marker starts.
 500       (if (string-match "^[] [0-9]*\032.*\\'" gud-mipsdbx-marker-acc)
 501           (setq
 502            ;; Everything before the potential marker start can be output.
 503            output (concat output (substring gud-mipsdbx-marker-acc
 504                                             0 (match-beginning 0)))
 505            ;; Everything after, we save, to combine with later input.
 506            gud-mipsdbx-marker-acc (substring gud-mipsdbx-marker-acc
 507                                              (match-beginning 0)))
 508         (setq output (concat output gud-mipsdbx-marker-acc)
 509               gud-mipsdbx-marker-acc ""))
 510
 511       output)))
 512
 513 (defun gud-dbx-find-file (f)
 514   (find-file-noselect f))
 515
 516 ;;;###autoload
 517 (defun dbx (command-line)
 518   "Run dbx on program FILE in buffer *gud-FILE*.
 519 The directory containing FILE becomes the initial working directory
 520 and source-file directory for your debugger."
 521   (interactive
 522    (list (read-from-minibuffer "Run dbx (like this): "
 523                                (if (consp gud-dbx-history)
 524                                    (car gud-dbx-history)
 525                                  "dbx ")
 526                                nil nil
 527                                '(gud-dbx-history . 1))))
 528
 529   (gud-overload-functions
 530    (cond
 531     (gud-dbx-mips-p
 532      '((gud-massage-args . gud-mipsdbx-massage-args)
 533        (gud-marker-filter . gud-mipsdbx-marker-filter)
 534        (gud-find-file . gud-dbx-find-file)))
 535     (t
 536      '((gud-massage-args . gud-dbx-massage-args)
 537        (gud-marker-filter . gud-dbx-marker-filter)
 538        (gud-find-file . gud-dbx-find-file)))))
 539
 540   (gud-common-init command-line)
 541
 542   (cond
 543    (gud-dbx-mips-p
 544     (gud-def gud-break "stop at \"%f\":%l"
 545                                   "\C-b" "Set breakpoint at current line.")
 546     (gud-def gud-finish "return"  "\C-f" "Finish executing current function."))
 547    (t
 548     (gud-def gud-break "file \"%d%f\"\nstop at %l"
 549                                   "\C-b" "Set breakpoint at current line.")))
 550
 551   (gud-def gud-remove "clear %l"  "\C-d" "Remove breakpoint at current line")
 552   (gud-def gud-step   "step %p"   "\C-s" "Step one line with display.")
 553   (gud-def gud-stepi  "stepi %p"  "\C-i" "Step one instruction with display.")
 554   (gud-def gud-next   "next %p"   "\C-n" "Step one line (skip functions).")
 555   (gud-def gud-cont   "cont"      "\C-r" "Continue with display.")
 556   (gud-def gud-up     "up %p"     "<" "Up (numeric arg) stack frames.")
 557   (gud-def gud-down   "down %p"   ">" "Down (numeric arg) stack frames.")
 558   (gud-def gud-print  "print %e"  "\C-p" "Evaluate C expression at point.")
 559
 560   (setq comint-prompt-regexp  "^[^)\n]*dbx) *")
 561   (run-hooks 'dbx-mode-hook)
 562   )
 563 \f
 564 ;; ======================================================================
 565 ;; xdb (HP PARISC debugger) functions
 566
 567 ;;; History of argument lists passed to xdb.
 568 (defvar gud-xdb-history nil)
 569
 570 (defvar gud-xdb-directories nil
 571   "*A list of directories that xdb should search for source code.
 572 If nil, only source files in the program directory
 573 will be known to xdb.
 574
 575 The file names should be absolute, or relative to the directory
 576 containing the executable being debugged.")
 577
 578 (defun gud-xdb-massage-args (file args)
 579   (nconc (let ((directories gud-xdb-directories)
 580                (result nil))
 581            (while directories
 582              (setq result (cons (car directories) (cons "-d" result)))
 583              (setq directories (cdr directories)))
 584            (nreverse (cons file result)))
 585          args))
 586
 587 (defun gud-xdb-file-name (f)
 588   "Transform a relative pathname to a full pathname in xdb mode"
 589   (let ((result nil))
 590     (if (file-exists-p f)
 591         (setq result (expand-file-name f))
 592       (let ((directories gud-xdb-directories))
 593         (while directories
 594           (let ((path (concat (car directories) "/" f)))
 595             (if (file-exists-p path)
 596                 (setq result (expand-file-name path)
 597                       directories nil)))
 598           (setq directories (cdr directories)))))
 599     result))
 600
 601 ;; xdb does not print the lines all at once, so we have to accumulate them
 602 (defvar gud-xdb-accumulation "")
 603
 604 (defun gud-xdb-marker-filter (string)
 605   (let (result)
 606     (if (or (string-match comint-prompt-regexp string)
 607             (string-match ".*\012" string))
 608         (setq result (concat gud-xdb-accumulation string)
 609               gud-xdb-accumulation "")
 610       (setq gud-xdb-accumulation (concat gud-xdb-accumulation string)))
 611     (if result
 612         (if (or (string-match "\\([^\n \t:]+\\): [^:]+: \\([0-9]+\\):" result)
 613                 (string-match "[^: \t]+:[ \t]+\\([^:]+\\): [^:]+: \\([0-9]+\\):"
 614                               result))
 615             (let ((line (string-to-int
 616                          (substring result (match-beginning 2) (match-end 2))))
 617                   (file (gud-xdb-file-name
 618                          (substring result (match-beginning 1) (match-end 1)))))
 619               (if file
 620                   (setq gud-last-frame (cons file line))))))
 621     (or result "")))
 622
 623 (defun gud-xdb-find-file (f)
 624   (let ((realf (gud-xdb-file-name f)))
 625     (if realf (find-file-noselect realf))))
 626
 627 ;;;###autoload
 628 (defun xdb (command-line)
 629   "Run xdb on program FILE in buffer *gud-FILE*.
 630 The directory containing FILE becomes the initial working directory
 631 and source-file directory for your debugger.
 632
 633 You can set the variable 'gud-xdb-directories' to a list of program source
 634 directories if your program contains sources from more than one directory."
 635   (interactive
 636    (list (read-from-minibuffer "Run xdb (like this): "
 637                                (if (consp gud-xdb-history)
 638                                    (car gud-xdb-history)
 639                                  "xdb ")
 640                                nil nil
 641                                '(gud-xdb-history . 1))))
 642   (gud-overload-functions '((gud-massage-args . gud-xdb-massage-args)
 643                             (gud-marker-filter . gud-xdb-marker-filter)
 644                             (gud-find-file . gud-xdb-find-file)))
 645
 646   (gud-common-init command-line)
 647
 648   (gud-def gud-break  "b %f:%l"    "\C-b" "Set breakpoint at current line.")
 649   (gud-def gud-tbreak "b %f:%l\\t" "\C-t"
 650            "Set temporary breakpoint at current line.")
 651   (gud-def gud-remove "db"         "\C-d" "Remove breakpoint at current line")
 652   (gud-def gud-step   "s %p"       "\C-s" "Step one line with display.")
 653   (gud-def gud-next   "S %p"       "\C-n" "Step one line (skip functions).")
 654   (gud-def gud-cont   "c"          "\C-r" "Continue with display.")
 655   (gud-def gud-up     "up %p"      "<"    "Up (numeric arg) stack frames.")
 656   (gud-def gud-down   "down %p"    ">"    "Down (numeric arg) stack frames.")
 657   (gud-def gud-finish "bu\\t"      "\C-f" "Finish executing current function.")
 658   (gud-def gud-print  "p %e"       "\C-p" "Evaluate C expression at point.")
 659
 660   (setq comint-prompt-regexp  "^>")
 661   (make-local-variable 'gud-xdb-accumulation)
 662   (setq gud-xdb-accumulation "")
 663   (run-hooks 'xdb-mode-hook))
 664 \f
 665 ;; ======================================================================
 666 ;; perldb functions
 667
 668 ;;; History of argument lists passed to perldb.
 669 (defvar gud-perldb-history nil)
 670
 671 (defun gud-perldb-massage-args (file args)
 672   (cons "-d" (cons file (cons "-emacs" args))))
 673
 674 ;; There's no guarantee that Emacs will hand the filter the entire
 675 ;; marker at once; it could be broken up across several strings.  We
 676 ;; might even receive a big chunk with several markers in it.  If we
 677 ;; receive a chunk of text which looks like it might contain the
 678 ;; beginning of a marker, we save it here between calls to the
 679 ;; filter.
 680 (defvar gud-perldb-marker-acc "")
 681
 682 (defun gud-perldb-marker-filter (string)
 683   (save-match-data
 684     (setq gud-perldb-marker-acc (concat gud-perldb-marker-acc string))
 685     (let ((output ""))
 686
 687       ;; Process all the complete markers in this chunk.
 688       (while (string-match "^\032\032\\([^:\n]*\\):\\([0-9]*\\):.*\n"
 689                            gud-perldb-marker-acc)
 690         (setq
 691
 692          ;; Extract the frame position from the marker.
 693          gud-last-frame
 694          (cons (substring gud-perldb-marker-acc (match-beginning 1) (match-end 1))
 695                (string-to-int (substring gud-perldb-marker-acc
 696                                          (match-beginning 2)
 697                                          (match-end 2))))
 698
 699          ;; Append any text before the marker to the output we're going
 700          ;; to return - we don't include the marker in this text.
 701          output (concat output
 702                         (substring gud-perldb-marker-acc 0 (match-beginning 0)))
 703
 704          ;; Set the accumulator to the remaining text.
 705          gud-perldb-marker-acc (substring gud-perldb-marker-acc (match-end 0))))
 706
 707       ;; Does the remaining text look like it might end with the
 708       ;; beginning of another marker?  If it does, then keep it in
 709       ;; gud-perldb-marker-acc until we receive the rest of it.  Since we
 710       ;; know the full marker regexp above failed, it's pretty simple to
 711       ;; test for marker starts.
 712       (if (string-match "^\032.*\\'" gud-perldb-marker-acc)
 713           (progn
 714             ;; Everything before the potential marker start can be output.
 715             (setq output (concat output (substring gud-perldb-marker-acc
 716                                                    0 (match-beginning 0))))
 717
 718             ;; Everything after, we save, to combine with later input.
 719             (setq gud-perldb-marker-acc
 720                   (substring gud-perldb-marker-acc (match-beginning 0))))
 721
 722         (setq output (concat output gud-perldb-marker-acc)
 723               gud-perldb-marker-acc ""))
 724
 725       output)))
 726
 727 (defun gud-perldb-find-file (f)
 728   (find-file-noselect f))
 729
 730 ;;;###autoload
 731 (defun perldb (command-line)
 732   "Run perldb on program FILE in buffer *gud-FILE*.
 733 The directory containing FILE becomes the initial working directory
 734 and source-file directory for your debugger."
 735   (interactive
 736    (list (read-from-minibuffer "Run perldb (like this): "
 737                                (if (consp gud-perldb-history)
 738                                    (car gud-perldb-history)
 739                                  "perl ")
 740                                nil nil
 741                                '(gud-perldb-history . 1))))
 742   (gud-overload-functions '((gud-massage-args . gud-perldb-massage-args)
 743                             (gud-marker-filter . gud-perldb-marker-filter)
 744                             (gud-find-file . gud-perldb-find-file)
 745                             ))
 746
 747   (gud-common-init command-line)
 748
 749   (gud-def gud-break  "b %l"         "\C-b" "Set breakpoint at current line.")
 750   (gud-def gud-remove "d %l"         "\C-d" "Remove breakpoint at current line")
 751   (gud-def gud-step   "s"            "\C-s" "Step one source line with display.")
 752   (gud-def gud-next   "n"            "\C-n" "Step one line (skip functions).")
 753   (gud-def gud-cont   "c"            "\C-r" "Continue with display.")
 754 ;  (gud-def gud-finish "finish"       "\C-f" "Finish executing current function.")
 755 ;  (gud-def gud-up     "up %p"        "<" "Up N stack frames (numeric arg).")
 756 ;  (gud-def gud-down   "down %p"      ">" "Down N stack frames (numeric arg).")
 757   (gud-def gud-print  "%e"           "\C-p" "Evaluate perl expression at point.")
 758
 759   (setq comint-prompt-regexp "^  DB<[0-9]+> ")
 760   (run-hooks 'perldb-mode-hook)
 761   )
 762
 763 ;;
 764 ;; End of debugger-specific information
 765 ;;
 766
 767 \f
 768 ;;; When we send a command to the debugger via gud-call, it's annoying
 769 ;;; to see the command and the new prompt inserted into the debugger's
 770 ;;; buffer; we have other ways of knowing the command has completed.
 771 ;;;
 772 ;;; If the buffer looks like this:
 773 ;;; --------------------
 774 ;;; (gdb) set args foo bar
 775 ;;; (gdb) -!-
 776 ;;; --------------------
 777 ;;; (the -!- marks the location of point), and we type `C-x SPC' in a
 778 ;;; source file to set a breakpoint, we want the buffer to end up like
 779 ;;; this:
 780 ;;; --------------------
 781 ;;; (gdb) set args foo bar
 782 ;;; Breakpoint 1 at 0x92: file make-docfile.c, line 49.
 783 ;;; (gdb) -!-
 784 ;;; --------------------
 785 ;;; Essentially, the old prompt is deleted, and the command's output
 786 ;;; and the new prompt take its place.
 787 ;;;
 788 ;;; Not echoing the command is easy enough; you send it directly using
 789 ;;; process-send-string, and it never enters the buffer.  However,
 790 ;;; getting rid of the old prompt is trickier; you don't want to do it
 791 ;;; when you send the command, since that will result in an annoying
 792 ;;; flicker as the prompt is deleted, redisplay occurs while Emacs
 793 ;;; waits for a response from the debugger, and the new prompt is
 794 ;;; inserted.  Instead, we'll wait until we actually get some output
 795 ;;; from the subprocess before we delete the prompt.  If the command
 796 ;;; produced no output other than a new prompt, that prompt will most
 797 ;;; likely be in the first chunk of output received, so we will delete
 798 ;;; the prompt and then replace it with an identical one.  If the
 799 ;;; command produces output, the prompt is moving anyway, so the
 800 ;;; flicker won't be annoying.
 801 ;;;
 802 ;;; So - when we want to delete the prompt upon receipt of the next
 803 ;;; chunk of debugger output, we position gud-delete-prompt-marker at
 804 ;;; the start of the prompt; the process filter will notice this, and
 805 ;;; delete all text between it and the process output marker.  If
 806 ;;; gud-delete-prompt-marker points nowhere, we leave the current
 807 ;;; prompt alone.
 808 (defvar gud-delete-prompt-marker nil)
 809
 810 \f
 811 (defun gud-mode ()
 812   "Major mode for interacting with an inferior debugger process.
 813
 814    You start it up with one of the commands M-x gdb, M-x sdb, M-x dbx,
 815 or M-x xdb.  Each entry point finishes by executing a hook; `gdb-mode-hook',
 816 `sdb-mode-hook', `dbx-mode-hook' or `xdb-mode-hook' respectively.
 817
 818 After startup, the following commands are available in both the GUD
 819 interaction buffer and any source buffer GUD visits due to a breakpoint stop
 820 or step operation:
 821
 822 \\[gud-break] sets a breakpoint at the current file and line.  In the
 823 GUD buffer, the current file and line are those of the last breakpoint or
 824 step.  In a source buffer, they are the buffer's file and current line.
 825
 826 \\[gud-remove] removes breakpoints on the current file and line.
 827
 828 \\[gud-refresh] displays in the source window the last line referred to
 829 in the gud buffer.
 830
 831 \\[gud-step], \\[gud-next], and \\[gud-stepi] do a step-one-line,
 832 step-one-line (not entering function calls), and step-one-instruction
 833 and then update the source window with the current file and position.
 834 \\[gud-cont] continues execution.
 835
 836 \\[gud-print] tries to find the largest C lvalue or function-call expression
 837 around point, and sends it to the debugger for value display.
 838
 839 The above commands are common to all supported debuggers except xdb which
 840 does not support stepping instructions.
 841
 842 Under gdb, sdb and xdb, \\[gud-tbreak] behaves exactly like \\[gud-break],
 843 except that the breakpoint is temporary; that is, it is removed when
 844 execution stops on it.
 845
 846 Under gdb, dbx, and xdb, \\[gud-up] pops up through an enclosing stack
 847 frame.  \\[gud-down] drops back down through one.
 848
 849 If you are using gdb or xdb, \\[gud-finish] runs execution to the return from
 850 the current function and stops.
 851
 852 All the keystrokes above are accessible in the GUD buffer
 853 with the prefix C-c, and in all buffers through the prefix C-x C-a.
 854
 855 All pre-defined functions for which the concept make sense repeat
 856 themselves the appropriate number of times if you give a prefix
 857 argument.
 858
 859 You may use the `gud-def' macro in the initialization hook to define other
 860 commands.
 861
 862 Other commands for interacting with the debugger process are inherited from
 863 comint mode, which see."
 864   (interactive)
 865   (comint-mode)
 866   (setq major-mode 'gud-mode)
 867   (setq mode-name "Debugger")
 868   (setq mode-line-process '(": %s"))
 869   (use-local-map (copy-keymap comint-mode-map))
 870   (define-key (current-local-map) "\C-c\C-l" 'gud-refresh)
 871   (make-local-variable 'gud-last-frame)
 872   (setq gud-last-frame nil)
 873   (make-local-variable 'comint-prompt-regexp)
 874   (make-local-variable 'gud-delete-prompt-marker)
 875   (setq gud-delete-prompt-marker (make-marker))
 876   (run-hooks 'gud-mode-hook)
 877 )
 878
 879 ;; Chop STRING into words separated by SPC or TAB and return a list of them.
 880 (defun gud-chop-words (string)
 881   (let ((i 0) (beg 0)
 882         (len (length string))
 883         (words nil))
 884     (while (< i len)
 885       (if (memq (aref string i) '(?\t ? ))
 886           (progn
 887             (setq words (cons (substring string beg i) words)
 888                   beg (1+ i))
 889             (while (and (< beg len) (memq (aref string beg) '(?\t ? )))
 890               (setq beg (1+ beg)))
 891             (setq i (1+ beg)))
 892         (setq i (1+ i))))
 893     (if (< beg len)
 894         (setq words (cons (substring string beg) words)))
 895     (nreverse words)))
 896
 897 ;; Perform initializations common to all debuggers.
 898 (defun gud-common-init (command-line)
 899   (let* ((words (gud-chop-words command-line))
 900          (program (car words))
 901          (file-word (let ((w (cdr words)))
 902                       (while (and w (= ?- (aref (car w) 0)))
 903                         (setq w (cdr w)))
 904                       (car w)))
 905          (args (delq file-word (cdr words)))
 906          (file (and file-word
 907                     (expand-file-name (substitute-in-file-name file-word))))
 908          (filepart (and file-word (file-name-nondirectory file))))
 909       (switch-to-buffer (concat "*gud-" filepart "*"))
 910       (and file-word (setq default-directory (file-name-directory file)))
 911       (or (bolp) (newline))
 912       (insert "Current directory is " default-directory "\n")
 913       (apply 'make-comint (concat "gud-" filepart) program nil
 914              (if file-word (gud-massage-args file args))))
 915   (gud-mode)
 916   (set-process-filter (get-buffer-process (current-buffer)) 'gud-filter)
 917   (set-process-sentinel (get-buffer-process (current-buffer)) 'gud-sentinel)
 918   (gud-set-buffer)
 919   )
 920
 921 (defun gud-set-buffer ()
 922   (cond ((eq major-mode 'gud-mode)
 923         (setq gud-comint-buffer (current-buffer)))))
 924
 925 ;; These functions are responsible for inserting output from your debugger
 926 ;; into the buffer.  The hard work is done by the method that is
 927 ;; the value of gud-marker-filter.
 928
 929 ;; Rather than duplicating all the work of comint-output-filter, perhaps
 930 ;; gud-filter should be implemented by adding appropriate hooks to
 931 ;; comint-output-filter.  Would somebody like to volunteer to do that?
 932 (defun gud-filter (proc string)
 933   ;; Here's where the actual buffer insertion is done
 934   (let ((inhibit-quit t))
 935     (save-excursion
 936       (set-buffer (process-buffer proc))
 937       (let (moving output-after-point)
 938         (save-excursion
 939           (goto-char (process-mark proc))
 940           ;; If we have been so requested, delete the debugger prompt.
 941           (if (marker-buffer gud-delete-prompt-marker)
 942               (progn
 943                 (delete-region (point) gud-delete-prompt-marker)
 944                 (set-marker gud-delete-prompt-marker nil)))
 945           (setq string (gud-marker-filter string))
 946           (insert-before-markers string)
 947           (and comint-last-input-end
 948                (marker-buffer comint-last-input-end)
 949                (= (point) comint-last-input-end)
 950                (set-marker comint-last-input-end
 951                            (- comint-last-input-end (length string))))
 952           (setq moving (= (point) (process-mark proc)))
 953           (setq output-after-point (< (point) (process-mark proc)))
 954           ;; Check for a filename-and-line number.
 955           ;; Don't display the specified file
 956           ;; unless (1) point is at or after the position where output appears
 957           ;; and (2) this buffer is on the screen.
 958           (if (and gud-last-frame
 959                    (not output-after-point)
 960                    (get-buffer-window (current-buffer)))
 961               (gud-display-frame)))
 962         (if moving (goto-char (process-mark proc)))))))
 963
 964 (defun gud-sentinel (proc msg)
 965   (cond ((null (buffer-name (process-buffer proc)))
 966          ;; buffer killed
 967          ;; Stop displaying an arrow in a source file.
 968          (setq overlay-arrow-position nil)
 969          (set-process-buffer proc nil))
 970         ((memq (process-status proc) '(signal exit))
 971          ;; Stop displaying an arrow in a source file.
 972          (setq overlay-arrow-position nil)
 973          ;; Fix the mode line.
 974          (setq mode-line-process
 975                (concat ": "
 976                        (symbol-name (process-status proc))))
 977          (let* ((obuf (current-buffer)))
 978            ;; save-excursion isn't the right thing if
 979            ;;  process-buffer is current-buffer
 980            (unwind-protect
 981                (progn
 982                  ;; Write something in *compilation* and hack its mode line,
 983                  (set-buffer (process-buffer proc))
 984                  ;; Force mode line redisplay soon
 985                  (set-buffer-modified-p (buffer-modified-p))
 986                  (if (eobp)
 987                      (insert ?\n mode-name " " msg)
 988                    (save-excursion
 989                      (goto-char (point-max))
 990                      (insert ?\n mode-name " " msg)))
 991                  ;; If buffer and mode line will show that the process
 992                  ;; is dead, we can delete it now.  Otherwise it
 993                  ;; will stay around until M-x list-processes.
 994                  (delete-process proc))
 995              ;; Restore old buffer, but don't restore old point
 996              ;; if obuf is the gud buffer.
 997              (set-buffer obuf))))))
 998
 999 (defun gud-display-frame ()
1000   "Find and obey the last filename-and-line marker from the debugger.
1001 Obeying it means displaying in another window the specified file and line."
1002   (interactive)
1003   (if gud-last-frame
1004    (progn
1005      (gud-set-buffer)
1006      (gud-display-line (car gud-last-frame) (cdr gud-last-frame))
1007      (setq gud-last-last-frame gud-last-frame
1008            gud-last-frame nil))))
1009
1010 ;; Make sure the file named TRUE-FILE is in a buffer that appears on the screen
1011 ;; and that its line LINE is visible.
1012 ;; Put the overlay-arrow on the line LINE in that buffer.
1013 ;; Most of the trickiness in here comes from wanting to preserve the current
1014 ;; region-restriction if that's possible.  We use an explicit display-buffer
1015 ;; to get around the fact that this is called inside a save-excursion.
1016
1017 (defun gud-display-line (true-file line)
1018   (let* ((buffer (gud-find-file true-file))
1019          (window (display-buffer buffer))
1020          (pos))
1021 ;;;    (if (equal buffer (current-buffer))
1022 ;;;     nil
1023 ;;;      (setq buffer-read-only nil))
1024     (save-excursion
1025 ;;;      (setq buffer-read-only t)
1026       (set-buffer buffer)
1027       (save-restriction
1028         (widen)
1029         (goto-line line)
1030         (setq pos (point))
1031         (setq overlay-arrow-string "=>")
1032         (or overlay-arrow-position
1033             (setq overlay-arrow-position (make-marker)))
1034         (set-marker overlay-arrow-position (point) (current-buffer)))
1035       (cond ((or (< pos (point-min)) (> pos (point-max)))
1036              (widen)
1037              (goto-char pos))))
1038     (set-window-point window overlay-arrow-position)))
1039
1040 ;;; The gud-call function must do the right thing whether its invoking
1041 ;;; keystroke is from the GUD buffer itself (via major-mode binding)
1042 ;;; or a C buffer.  In the former case, we want to supply data from
1043 ;;; gud-last-frame.  Here's how we do it:
1044
1045 (defun gud-format-command (str arg)
1046   (let ((insource (not (eq (current-buffer) gud-comint-buffer)))
1047         (frame (or gud-last-frame gud-last-last-frame))
1048         result)
1049     (while (and str (string-match "\\([^%]*\\)%\\([adeflp]\\)" str))
1050       (let ((key (string-to-char (substring str (match-beginning 2))))
1051             subst)
1052         (cond
1053          ((eq key ?f)
1054           (setq subst (file-name-nondirectory (if insource
1055                                                   (buffer-file-name)
1056                                                 (car frame)))))
1057          ((eq key ?d)
1058           (setq subst (file-name-directory (if insource
1059                                                (buffer-file-name)
1060                                              (car frame)))))
1061          ((eq key ?l)
1062           (setq subst (if insource
1063                           (save-excursion
1064                             (beginning-of-line)
1065                             (save-restriction (widen)
1066                                               (1+ (count-lines 1 (point)))))
1067                         (cdr frame))))
1068          ((eq key ?e)
1069           (setq subst (find-c-expr)))
1070          ((eq key ?a)
1071           (setq subst (gud-read-address)))
1072          ((eq key ?p)
1073           (setq subst (if arg (int-to-string arg) ""))))
1074         (setq result (concat result
1075                              (substring str (match-beginning 1) (match-end 1))
1076                              subst)))
1077       (setq str (substring str (match-end 2))))
1078     ;; There might be text left in STR when the loop ends.
1079     (concat result str)))
1080
1081 (defun gud-read-address ()
1082   "Return a string containing the core-address found in the buffer at point."
1083   (save-excursion
1084     (let ((pt (point)) found begin)
1085       (setq found (if (search-backward "0x" (- pt 7) t) (point)))
1086       (cond
1087        (found (forward-char 2)
1088               (buffer-substring found
1089                                 (progn (re-search-forward "[^0-9a-f]")
1090                                        (forward-char -1)
1091                                        (point))))
1092        (t (setq begin (progn (re-search-backward "[^0-9]")
1093                              (forward-char 1)
1094                              (point)))
1095           (forward-char 1)
1096           (re-search-forward "[^0-9]")
1097           (forward-char -1)
1098           (buffer-substring begin (point)))))))
1099
1100 (defun gud-call (fmt &optional arg)
1101   (let ((msg (gud-format-command fmt arg)))
1102     (message "Command: %s" msg)
1103     (sit-for 0)
1104     (gud-basic-call msg)))
1105
1106 (defun gud-basic-call (command)
1107   "Invoke the debugger COMMAND displaying source in other window."
1108   (interactive)
1109   (gud-set-buffer)
1110   (let ((command (concat command "\n"))
1111         (proc (get-buffer-process gud-comint-buffer)))
1112
1113     ;; Arrange for the current prompt to get deleted.
1114     (save-excursion
1115       (set-buffer gud-comint-buffer)
1116       (goto-char (process-mark proc))
1117       (beginning-of-line)
1118       (if (looking-at comint-prompt-regexp)
1119           (set-marker gud-delete-prompt-marker (point))))
1120     (process-send-string proc command)))
1121
1122 (defun gud-refresh (&optional arg)
1123   "Fix up a possibly garbled display, and redraw the arrow."
1124   (interactive "P")
1125   (recenter arg)
1126   (or gud-last-frame (setq gud-last-frame gud-last-last-frame))
1127   (gud-display-frame))
1128 \f
1129 ;;; Code for parsing expressions out of C code.  The single entry point is
1130 ;;; find-c-expr, which tries to return an lvalue expression from around point.
1131 ;;;
1132 ;;; The rest of this file is a hacked version of gdbsrc.el by
1133 ;;; Debby Ayers <ayers@asc.slb.com>,
1134 ;;; Rich Schaefer <schaefer@asc.slb.com> Schlumberger, Austin, Tx.
1135
1136 (defun find-c-expr ()
1137   "Returns the C expr that surrounds point."
1138   (interactive)
1139   (save-excursion
1140     (let ((p) (expr) (test-expr))
1141       (setq p (point))
1142       (setq expr (expr-cur))
1143       (setq test-expr (expr-prev))
1144       (while (expr-compound test-expr expr)
1145         (setq expr (cons (car test-expr) (cdr expr)))
1146         (goto-char (car expr))
1147         (setq test-expr (expr-prev)))
1148       (goto-char p)
1149       (setq test-expr (expr-next))
1150       (while (expr-compound expr test-expr)
1151         (setq expr (cons (car expr) (cdr test-expr)))
1152         (setq test-expr (expr-next))
1153         )
1154       (buffer-substring (car expr) (cdr expr)))))
1155
1156 (defun expr-cur ()
1157   "Returns the expr that point is in; point is set to beginning of expr.
1158 The expr is represented as a cons cell, where the car specifies the point in
1159 the current buffer that marks the beginning of the expr and the cdr specifies
1160 the character after the end of the expr."
1161   (let ((p (point)) (begin) (end))
1162     (expr-backward-sexp)
1163     (setq begin (point))
1164     (expr-forward-sexp)
1165     (setq end (point))
1166     (if (>= p end)
1167         (progn
1168          (setq begin p)
1169          (goto-char p)
1170          (expr-forward-sexp)
1171          (setq end (point))
1172          )
1173       )
1174     (goto-char begin)
1175     (cons begin end)))
1176
1177 (defun expr-backward-sexp ()
1178   "Version of `backward-sexp' that catches errors."
1179   (condition-case nil
1180       (backward-sexp)
1181     (error t)))
1182
1183 (defun expr-forward-sexp ()
1184   "Version of `forward-sexp' that catches errors."
1185   (condition-case nil
1186      (forward-sexp)
1187     (error t)))
1188
1189 (defun expr-prev ()
1190   "Returns the previous expr, point is set to beginning of that expr.
1191 The expr is represented as a cons cell, where the car specifies the point in
1192 the current buffer that marks the beginning of the expr and the cdr specifies
1193 the character after the end of the expr"
1194   (let ((begin) (end))
1195     (expr-backward-sexp)
1196     (setq begin (point))
1197     (expr-forward-sexp)
1198     (setq end (point))
1199     (goto-char begin)
1200     (cons begin end)))
1201
1202 (defun expr-next ()
1203   "Returns the following expr, point is set to beginning of that expr.
1204 The expr is represented as a cons cell, where the car specifies the point in
1205 the current buffer that marks the beginning of the expr and the cdr specifies
1206 the character after the end of the expr."
1207   (let ((begin) (end))
1208     (expr-forward-sexp)
1209     (expr-forward-sexp)
1210     (setq end (point))
1211     (expr-backward-sexp)
1212     (setq begin (point))
1213     (cons begin end)))
1214
1215 (defun expr-compound-sep (span-start span-end)
1216   "Returns '.' for '->' & '.', returns ' ' for white space,
1217 returns '?' for other punctuation."
1218   (let ((result ? )
1219         (syntax))
1220     (while (< span-start span-end)
1221       (setq syntax (char-syntax (char-after span-start)))
1222       (cond
1223        ((= syntax ? ) t)
1224        ((= syntax ?.) (setq syntax (char-after span-start))
1225         (cond
1226          ((= syntax ?.) (setq result ?.))
1227          ((and (= syntax ?-) (= (char-after (+ span-start 1)) ?>))
1228           (setq result ?.)
1229           (setq span-start (+ span-start 1)))
1230          (t (setq span-start span-end)
1231             (setq result ??)))))
1232       (setq span-start (+ span-start 1)))
1233     result))
1234
1235 (defun expr-compound (first second)
1236   "Non-nil if concatenating FIRST and SECOND makes a single C token.
1237 The two exprs are represented as a cons cells, where the car
1238 specifies the point in the current buffer that marks the beginning of the
1239 expr and the cdr specifies the character after the end of the expr.
1240 Link exprs of the form:
1241       Expr -> Expr
1242       Expr . Expr
1243       Expr (Expr)
1244       Expr [Expr]
1245       (Expr) Expr
1246       [Expr] Expr"
1247   (let ((span-start (cdr first))
1248         (span-end (car second))
1249         (syntax))
1250     (setq syntax (expr-compound-sep span-start span-end))
1251     (cond
1252      ((= (car first) (car second)) nil)
1253      ((= (cdr first) (cdr second)) nil)
1254      ((= syntax ?.) t)
1255      ((= syntax ? )
1256          (setq span-start (char-after (- span-start 1)))
1257          (setq span-end (char-after span-end))
1258          (cond
1259           ((= span-start ?) ) t )
1260           ((= span-start ?] ) t )
1261           ((= span-end ?( ) t )
1262           ((= span-end ?[ ) t )
1263           (t nil))
1264          )
1265      (t nil))))
1266
1267 (provide 'gud)
1268
1269 ;;; gud.el ends here