[comp.emacs] c comment mode

hartzell@boulder.Colorado.EDU (George Hartzell) (03/17/88)

The code below works under gnu 18.47, but fails under 18.50.  I spent
some time looking around, but haven't been able to solve the problem and
am out of spare time for it.  Under 18.47 it makes pretty comments like
the ones in the authors notes, but under 18.50 it inserts the comment
opening, inserts the comment close on a carriage return or auto-fill,
and then complains about "args out of range" on subsequent <cr>'s.  When
you exit the recursive-edit it inserts another comment close.  The
problem/difference in behavior seems to be in the function
indent-new-comment-line, which is called by both set-fill-and-fill and 
set-fill-and-return.  

Alternatively, does anyone have a similar package that they would share
with me?

George Hartzell			                 (303) 492-4535
MCD Biology, University of Colorado-Boulder, Boulder, CO 80309
hartzell@Boulder.Colorado.EDU  ..!{hao,nbires}!boulder!hartzell
(bitnet hosts try: hartzell%boulder.colorado.edu@jvnca.csc.org)
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; C comment mode - An auto-filled comment mode for gnu c-mode.
;;;
;;; Author:  	Robert Mecklenburg
;;;		Computer Science Dept.
;;;          	University of Utah
;;; From: mecklen@utah-gr.UUCP (Robert Mecklenburg)
;;;
;;; (c) 1986, University of Utah
;;;
;;; Everyone is granted permission to copy, modify and redistribute
;;; this file, provided the people they give it to can.
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;
;;; I have written a "global comment" minor-mode which performs auto-fill,
;;; fill-paragraph, and auto-indentation functions.  This function only
;;; works for comments which occupy an entire line (not comments to the
;;; right of code).  The mode has several options set through variables.
;;; If the variable c-comment-starting-blank is non-nil multi-line
;;; comments come out like this:
;;; 
;;; 	/*
;;; 	 * Your favorite 
;;; 	 * multi-line comment.
;;; 	 */
;;; 
;;; otherwise they look like this:
;;; 
;;; 	/* Your Favorite
;;; 	 * multi-line comment.
;;; 	 */
;;; 
;;; If the variable c-comment-hanging-indent is non-nil K&R style comments
;;; are indented automatically like this:
;;; 
;;; 	/* my_func - For multi-line comments with hanging indent
;;; 	 *	     the text is lined up after the dash.
;;; 	 */
;;; 
;;; otherwise the text "the text" (!) is lined up under my_func.  If a
;;; comment fits (as typed) on a single line it remains a single line
;;; comment even if c-comment-starting-blank is set.  If
;;; c-comment-indenting is non-nil hitting carriage return resets the
;;; indentation for the next line to the current line's indentation
;;; (within the comment) like this:
;;; 
;;; 	/* Typing along merrily....
;;; 	 *     Now I indent with spaces, when I hit return
;;; 	 *     the indentation is automatically set to 
;;; 	 *     ^ here.
;;; 	 */
;;; 
;;; Due to my lack of understanding of keymaps this permanently resets M-q
;;; to my own fill function.  I would like to have the comment mode
;;; bindings only in comment mode but I can't seem to get that to work.
;;; If some gnu guru can clue me in, I'd appreciate it.

;;;
(defvar c-comment-starting-blank nil
  "*Controls whether global comments have an initial blank line.")
(defvar c-comment-indenting t
  "*If set global comments are indented to the level of the previous line.")
(defvar c-comment-hanging-indent nil
  "*If true, comments will be automatically indented to the dash.")
(defvar c-hang-already-done t
  "If true we have performed the haning indent already for this comment.")


;;;
;;; c-comment-map - This is a sparse keymap for comment mode which
;;; 		    gets inserted when c-comment is called.
;;; 
(defvar c-comment-mode-map ()
  "Keymap used in C comment mode.")
(if c-comment-mode-map
    ()
;  (setq c-comment-mode-map (copy-sequence c-mode-map))
  (setq c-comment-mode-map (make-sparse-keymap))
  (define-key c-comment-mode-map "{" 'electric-c-brace)
  (define-key c-comment-mode-map "}" 'electric-c-brace)
  (define-key c-comment-mode-map ";" 'electric-c-semi)
  (define-key c-comment-mode-map ":" 'electric-c-terminator)
  (define-key c-comment-mode-map "\e\r" 'newline)
  (define-key c-comment-mode-map "\e\C-h" 'mark-c-function)
  (define-key c-comment-mode-map "\e\C-q" 'indent-c-exp)
  (define-key c-comment-mode-map "\eq" 'set-fill-and-fill)
  (define-key c-comment-mode-map "\177" 'backward-delete-char-untabify)
  (define-key c-comment-mode-map "\t" 'c-indent-command)
  (define-key c-comment-mode-map "\r" 'set-fill-and-return)
  )
 
;;;
;;; c-comment - This is a filled comment mode which can format
;;; 		indented text, do hanging indents, and symetric
;;; 		placement of comment delimiters.
;;; 
(defun c-comment ()
  "Edit a C comment with filling and indentation.
This performs hanging indentation, symetric placement of delimiters,
 and Indented-Text mode style indentation.  Type 'M-x apropos
c-comment' for information on options."

  (interactive)
  (let
      ;; Save old state.
      ((auto-fill-hook (if c-comment-indenting
			   'do-indented-auto-fill 'do-auto-fill))
;       (comment-start nil)
       (comment-multi-line t)
       (comment-start-skip "/*\\*+[ 	]*")
       (paragraph-start-ref paragraph-start)
       fill-prefix paragraph-start paragraph-separate opoint)

    ;; Determine if we are inside a comment.
    (setq in-comment
	  (save-excursion
	    (and (re-search-backward "/\\*\\|\\*/" 0 t)
		 (string= "/*" (buffer-substring (point) (+ (point) 2))))))

    ;; Indent the comment and set the fill prefix to comment continuation
    ;; string.  If we are already in a comment get the indentation on
    ;; the current line.
    (setq c-hang-already-done nil)

    ;; Set the beginning of the comment and insert the blank line if needed.
    (use-local-map c-comment-mode-map)
    (if (not in-comment)
	(progn (c-indent-line)
	       (insert "/* ")
	       (setq fill-prefix (get-current-fill (point)))
	       (recursive-edit)

	       ;; If the comment fits on one line, place the close
	       ;; comment at the end of the line.  Otherwise, newline.
	       (setq opoint (point))
	       (if (and (save-excursion (beginning-of-line)
					(search-forward "/*" opoint t))
			(<= (+ (current-column) 3) 79))
		   (insert " */")
		 (insert "\n*/"))

	       (c-indent-line))
      (progn (setq fill-prefix (get-current-fill (point)))
	     (recursive-edit)
	     (search-forward "*/" (buffer-size) t)
	     (forward-line 1)))

    ;; If starting blank enabled, insert a newline, etc., but only if
    ;; this comment requires multiple lines.
    (if c-comment-starting-blank
	(save-excursion
	  (setq opoint (point))
	  (forward-line -1)
	  (if (or (null (search-forward "/*" opoint t))
		  (null (search-forward "*/" opoint t)))
	      (progn
		(search-backward "/*")
		(re-search-forward comment-start-skip opoint t)
		(setq fill-prefix (get-current-fill (point)))
		(if (not (looking-at "\n"))
		    (indent-new-comment-line))))))

    ;; Move cursor to indentation.
    (c-indent-line)
    (use-local-map c-mode-map)
    )
  )


;;;
;;; set-fill-and-fill - Get the current fill for this line and fill
;;; 			the paragraph.
;;; 
(defun set-fill-and-fill (arg)
  "Get the fill-prefix and fill the current paragraph."

  (interactive "P")
  (setq fill-prefix (get-current-fill (point)))
  (fill-paragraph arg)
  )


;;;
;;; set-fill-and-return - Set the current fill prefix and
;;; 			  indent-new-comment-line.
;;; 
(defun set-fill-and-return ()
  "Set the current fill prefix and move to the next line."

  (interactive)
  (if c-comment-indenting
      (setq fill-prefix (get-current-fill (point))))
  (indent-new-comment-line)
  )


;;;
;;; do-indented-auto-fill - Perform the auto-fill function, but get
;;; 			    the fill-prefix first.
;;; 
(defun do-indented-auto-fill ()
  "Perform auto-fill, but get fill-prefix first."

  (let ((opoint (point)))
    (save-excursion
      (move-to-column (1+ fill-column))
      (skip-chars-backward "^ \t\n")
      (if (bolp)
	  (re-search-forward "[ \t]" opoint t))
      ;; If there is a space on the line before fill-point,
      ;; and nonspaces precede it, break the line there.
      (if (save-excursion
	    (skip-chars-backward " \t")
	    (not (bolp)))

	  ;; If we are wrapping to a new line, figure out the indentation on
	  ;; the current line first.
	  (progn
	    (setq fill-prefix (get-current-fill opoint))
	    (indent-new-comment-line)))))
  )


;;;
;;; get-current-fill - Get the fill-prefix for the current line.  This
;;; 		       assumes that the valid fill prefix is between
;;; 		       (beginning-of-line) and (point).
;;; 
(defun get-current-fill (pnt)
  "Get the current fill prefix.
A valid fill prefix must be between the beginning of the line and point."

  (let ((opoint pnt) fill last-char)
    (save-excursion
      (beginning-of-line)
      (setq fill
	    (buffer-substring (point)
			      (progn
				(re-search-forward comment-start-skip opoint t)
				(point))))

      ;; Be sure there is trailing white space.
      (setq last-char (substring fill (1- (length fill)) (length fill)))
      (if (and (not (string= " " last-char))
	       (not (string= "	" last-char)))
	  (setq fill (concat fill " ")))

      (setq fill (replace-letter fill "/" " "))

      ;; Get the hanging indentation if we haven't already.
      (if (and c-comment-hanging-indent (not c-hang-already-done))
	  (let ((curr (point))
		(opnt (progn (end-of-line) (point))))
	    (beginning-of-line)
	    (if (search-forward " - " opnt t)
		(progn
		  (setq fill (concat fill (make-string (- (point) curr) 32)))
		  (setq c-hang-already-done t)))))

      ;; Set the paragraph delimiters.
      (setq paragraph-start (concat paragraph-start-ref
				    "\\|^"
				    (regexp-quote
				     (substring fill
						0 (1- (length fill))))
				    "$"))
      (setq paragraph-separate paragraph-start))
    fill)
  )
  

;;;
;;; replace-letter - Given a string, an old letter and a new letter,
;;; 		     perform the substitution.
;;; 
(defun replace-letter (str old-letter new-letter)
  (let (new-str c
	(sp 0)
	(size (length str)))
    (while (< sp size)
      (setq c (substring str sp (1+ sp)))
      (setq new-str (concat new-str (if (string= c old-letter) new-letter c)))
      (setq sp (1+ sp)))
    new-str)
    )

;(define-key c-mode-map "\C-j" 'c-reindent-then-newline-and-indent)
;(define-key c-mode-map "\015" 'c-newline)
;(define-key c-mode-map "\e:" 'c-comment)
George Hartzell			                 (303) 492-4535
MCD Biology, University of Colorado-Boulder, Boulder, CO 80309
hartzell@Boulder.Colorado.EDU  ..!{hao,nbires}!boulder!hartzell
(bitnet hosts try: hartzell%boulder.colorado.edu@jvnca.csc.org)

ward@cfa.harvard.EDU (Steve Ward) (03/17/88)

on a new topic...

I compiled microemacs under VMS4.6 using VAX C2.3 and it compiled and
linked without any errors.

Naturally, I edited the estruct.h file  first.  I GUESSED that I  had to
set the "generic Unix type C compiler"  flag since the comment demanded
that one of the compiler flags ber set and there was not a flag for VMS
C.  It worked, so I guess this is correct.

The editor works but I have a "bug" using split windows.  I can generate
split windows but when I type the text appears in all of the windows at
more or less the same time rather than just the active window.  It is
very strange!  I have only a dirt-simple emacs.rc file.  This problem
occurs even when I do not use any emacs.rc, also.

This window problem appears on Vt100, vt220, or VWS terminals.

I assume I must have  a terminal characteristic screwed up or failed to
edit something beond estruct.h.  There were no VMS instructions so I
need some pointers.  Also,   there are some comments about using a mouse
with the editor when on a VWS workstation.   How does one turn this on?
Perhaps someone can send me a good VWS and VT100/VT220 emacs.rc file or
files, too.

I actually have the 3.9i version which is labelled as 3.9e with
bugfixes.  The "i" stands for interim.  The comments say that version
3.10 will come out this summer.  This is the only problem I have with
the editor so far.  This and not figuring how to activate the VWS
mousing.

Responses will probably be of general interest, so go ahead and post
here.

Thanks for any help.

claude@INTECH.ARPA (Claude Laferriere) (03/18/88)

In his posting, Steve Ward <cfa!ward@HUSC6.HARVARD.EDU> mentions the
following problem with microEMACS 3.9i.

> The editor works but I have a "bug" using split windows.  I can generate
> split windows but when I type the text appears in all of the windows at
> more or less the same time rather than just the active window.  It is
> very strange!  I have only a dirt-simple emacs.rc file.  This problem
> occurs even when I do not use any emacs.rc, also.

Steve, you did not specify how it happened.  When you split the screen
and have the same buffer, whatever goes on the current buffer will
also go on the other.  If both windows display the same portion of the
buffer, then you get the behaviour you described.

Hope this helps.

Claude Laferriere		Internet:	claude@intech.arpa
Intellitech			Phone:		(613)236-7803

    / /|    / ----- ----- /	/     /	----- ----- ----- /    /
   / / |   /   /   /     /     /     / 	 /   /	   /	 /    /
  / /  |  /   /   /____ /     /	    /  	/   /____ / 	/____/
 / /   | /   / 	 /     /     /	   /   /   /	 /     /    /
/ /    |/   /   /____ /____ /____ /   /	  /____	/____ /	   / 

jthomp@convex.UUCP (Jim "Cookie" Thompson) (03/20/88)

(It would seem, that for once, the notes feed got an article
here before the news feed did... strange.)

Skip Montnaro sez:
I'm trying to build GNU Emacs 18.50 on a Convex C2. At the recommendation of
a person at Convex, I'm using the m-convex.h and s-bsd4-2.h files. It
creates temacs okay, but when it tries to dump xemacs it fails with an
"invalid magic number" error. Can somebody give me a clue as to what I might
be doing wrong? Is there a C2-specific machine-dependent file for Emacs?

Thanks,

Skip Montanaro (montanaro@sprite.steinmetz.ge.com, montanaro@ge-crd.arpa)

(And I sez:)
I don't know who you talked to here, but it wasn't me.
(I'll bet it was someone in the TAC, huh!?)
I don't even know who sent in the m-convex.h file, it wasn't me.
Convex Unix 6.1 (and later) OS does not use the Berkley 'a.out' executable
file format (read header(s)).  Rather, we've gone to a 'SOFF' 
format.  (SOFF is like COFF, but different, the structure members have 
different names, essentially.)

You have but two choices:

1)  Back out to 6.0 OS.  re-make GNUmacs,go back to 6.1 
	or 6.1.1, since that's what you have.)
	I don't recommend this, its hard, and unnecessary.

2)  Use m-convex.h and s-bsd4-3.h.  Convex 6.1 does all the Bezerkly
    	kernel stuff.  Substitute the included unexec.c for the 
	one you have, add the two lines:

#define COFF
#define TEXT_START 0x80001000

	to the bottom of m-convex.h.
	
	mutter:  "rm *.o; make -f xmakefile", wait ~10 minutes,
	type "xemacs".  

					--enjoy
						--jim

Jim Thompson		 		Convex Computer Corporation
(214) 952-0536		 		701 N. Plano Road
"panic: getfs: bad magic"		Richardson, Texas 75081
{uiucdcs,ihnp4,sun,allegra,harvard,killer,usenix}!convex!jthomp

just for funzies, I'll announce that gdb 2.5 is finished too.
RMS will be getting all the diffs by this Wed.  I swear, or your
money back.

munged unexec.c
	(note:  This is a hack, but I'll be putting this in 
	  shape for the next distribution, time permitting.)


-------------------- cut here ----------------------
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/* modifyed for C-1 arch by jthomp@convex 871103 */

/*
 * unexec.c - Convert a running program into an a.out file.
 *
 * Author:	Spencer W. Thomas
 * 		Computer Science Dept.
 * 		University of Utah
 * Date:	Tue Mar  2 1982
 * Modified heavily since then.
 *
 * Synopsis:
 *	unexec (new_name, a_name, data_start, bss_start, entry_address)
 *	char *new_name, *a_name;
 *	unsigned data_start, bss_start, entry_address;
 *
 * Takes a snapshot of the program and makes an a.out format file in the
 * file named by the string argument new_name.
 * If a_name is non-NULL, the symbol table will be taken from the given file.
 * On some machines, an existing a_name file is required.
 *
 * The boundaries within the a.out file may be adjusted with the data_start
 * and bss_start arguments.  Either or both may be given as 0 for defaults.
 *
 * Data_start gives the boundary between the text segment and the data
 * segment of the program.  The text segment can contain shared, read-only
 * program code and literal data, while the data segment is always unshared
 * and unprotected.  Data_start gives the lowest unprotected address.
 * The value you specify may be rounded down to a suitable boundary
 * as required by the machine you are using.
 *
 * Specifying zero for data_start means the boundary between text and data
 * should not be the same as when the program was loaded.
 * If NO_REMAP is defined, the argument data_start is ignored and the
 * segment boundaries are never changed.
 *
 * Bss_start indicates how much of the data segment is to be saved in the
 * a.out file and restored when the program is executed.  It gives the lowest
 * unsaved address, and is rounded up to a page boundary.  The default when 0
 * is given assumes that the entire data segment is to be stored, including
 * the previous data and bss as well as any additional storage allocated with
 * break (2).
 *
 * The new file is set up to start at entry_address.
 *
 * If you make improvements I'd like to get them too.
 * harpo!utah-cs!thomas, thomas@Utah-20
 *
 */

/* There are several compilation parameters affecting unexec:

* COFF

Define this if your system uses COFF for executables.
Otherwise we assume you use Berkeley format.

* NO_REMAP

Define this if you do not want to try to save Emacs's pure data areas
as part of the text segment.

Saving them as text is good because it allows users to share more.

However, on machines that locate the text area far from the data area,
the boundary cannot feasibly be moved.  Such machines require
NO_REMAP.

Also, remapping can cause trouble with the built-in startup routine
/lib/crt0.o, which defines `environ' as an initialized variable.
Dumping `environ' as pure does not work!  So, to use remapping,
you must write a startup routine for your machine in Emacs's crt0.c.
If NO_REMAP is defined, Emacs uses the system's crt0.o.

* SECTION_ALIGNMENT

Some machines that use COFF executables require that each section
start on a certain boundary *in the COFF file*.  Such machines should
define SECTION_ALIGNMENT to a mask of the low-order bits that must be
zero on such a boundary.  This mask is used to control padding between
segments in the COFF file.

If SECTION_ALIGNMENT is not defined, the segments are written
consecutively with no attempt at alignment.  This is right for
unmodified system V.

* SEGMENT_MASK

Some machines require that the beginnings and ends of segments
*in core* be on certain boundaries.  For most machines, a page
boundary is sufficient.  That is the default.  When a larger
boundary is needed, define SEGMENT_MASK to a mask of
the bits that must be zero on such a boundary.

* A_TEXT_OFFSET(HDR)

Some machines count the a.out header as part of the size of the text
segment (a_text); they may actually load the header into core as the
first data in the text segment.  Some have additional padding between
the header and the real text of the program that is counted in a_text.

For these machines, define A_TEXT_OFFSET(HDR) to examine the header
structure HDR and return the number of bytes to add to `a_text'
before writing it (above and beyond the number of bytes of actual
program text).  HDR's standard fields are already correct, except that
this adjustment to the `a_text' field has not yet been made;
thus, the amount of offset can depend on the data in the file.
  
* A_TEXT_SEEK(HDR)

If defined, this macro specifies the number of bytes to seek into the
a.out file before starting to write the text segment.a

* EXEC_MAGIC

For machines using COFF, this macro, if defined, is a value stored
into the magic number field of the output file.

* ADJUST_EXEC_HEADER

This macro can be used to generate statements to adjust or
initialize nonstandard fields in the file header

* ADDR_CORRECT(ADDR)

Macro to correct an int which is the bit pattern of a pointer to a byte
into an int which is the number of a byte.

This macro has a default definition which is usually right.
This default definition is a no-op on most machines (where a
pointer looks like an int) but not on all machines.

*/

#ifndef emacs
#define PERROR(arg) perror (arg); return -1
#else
#include "config.h"
#define PERROR(file) report_error (file, new)
#endif

#ifndef CANNOT_DUMP  /* all rest of file!  */

#ifndef CANNOT_UNEXEC /* most of rest of file */

#ifndef mips  /* mips machine requires completely separate code.  */

#include <a.out.h>
/* Define getpagesize () if the system does not.
   Note that this may depend on symbols defined in a.out.h
 */
#include "getpagesize.h"

#ifndef makedev			/* Try to detect types.h already loaded */
#include <sys/types.h>
#endif
#include <stdio.h>
#include <sys/stat.h>
#include <errno.h>

extern char *start_of_text ();		/* Start of text */
extern char *start_of_data ();		/* Start of initialized data */

#ifdef COFF
#ifndef USG
#ifndef STRIDE
#ifndef UMAX
/* I have a suspicion that these are turned off on all systems
   and can be deleted.  Try it in version 19.  */
#include <machine/filehdr.h>
#include <machine/opthdr.h>
#include <machine/scnhdr.h>
#include <machine/pte.h>
#include <machine/symtab.h>
#endif /* not UMAX */
#endif /* Not STRIDE */
#endif /* not USG */
static long block_copy_start;		/* Old executable start point */
static struct filehdr f_hdr;		/* File header */
static struct opthdr f_ohdr;		/* Optional file header (a.out) */
long bias;			/* Bias to add for growth */
long lnnoptr;			/* Pointer to line-number info within file */
#define SYMS_START block_copy_start

static long text_scnptr;
static long data_scnptr;

#else /* not COFF */

extern char *sbrk ();

#define SYMS_START ((long) N_SYMOFF (ohdr))

#ifdef HPUX
#ifdef HP9000S200_ID
#define MY_ID HP9000S200_ID
#else
#include <model.h>
#define MY_ID MYSYS
#endif /* no HP9000S200_ID */
static MAGIC OLDMAGIC = {MY_ID, SHARE_MAGIC};
static MAGIC NEWMAGIC = {MY_ID, DEMAND_MAGIC};
#define N_TXTOFF(x) TEXT_OFFSET(x)
#define N_SYMOFF(x) LESYM_OFFSET(x)
static struct exec hdr, ohdr;

#else /* not HPUX */

#if defined (USG) && !defined (IRIS)
static struct bhdr hdr, ohdr;
#define a_magic fmagic
#define a_text tsize
#define a_data dsize
#define a_bss bsize
#define a_syms ssize
#define a_trsize rtsize
#define a_drsize rdsize
#define a_entry entry
#define	N_BADMAG(x) \
    (((x).fmagic)!=OMAGIC && ((x).fmagic)!=NMAGIC &&\
     ((x).fmagic)!=FMAGIC && ((x).fmagic)!=IMAGIC)
#define NEWMAGIC FMAGIC
#else /* IRIS or not USG */
static struct exec hdr, ohdr;
#define NEWMAGIC ZMAGIC
#endif /* IRIS or not USG */
#endif /* not HPUX */

static int unexec_text_start;
static int unexec_data_start;

#endif /* not COFF */

static int pagemask;

/* Correct an int which is the bit pattern of a pointer to a byte
   into an int which is the number of a byte.
   This is a no-op on ordinary machines, but not on all.  */

#ifndef ADDR_CORRECT   /* Let m-*.h files override this definition */
#define ADDR_CORRECT(x) ((char *)(x) - (char*)0)
#endif

#ifdef emacs

static
report_error (file, fd)
     char *file;
     int fd;
{
  if (fd)
    close (fd);
  error ("Failure operating on %s", file);
}
#endif /* emacs */

#define ERROR0(msg) report_error_1 (new, msg, 0, 0); return -1
#define ERROR1(msg,x) report_error_1 (new, msg, x, 0); return -1
#define ERROR2(msg,x,y) report_error_1 (new, msg, x, y); return -1

static
report_error_1 (fd, msg, a1, a2)
     int fd;
     char *msg;
     int a1, a2;
{
  close (fd);
#ifdef emacs
  error (msg, a1, a2);
#else
  fprintf (stderr, msg, a1, a2);
  fprintf (stderr, "\n");
#endif
}

/* ****************************************************************
 * unexec
 *
 * driving logic.
 */
unexec (new_name, a_name, data_start, bss_start, entry_address)
     char *new_name, *a_name;
     unsigned data_start, bss_start, entry_address;
{
  int new, a_out = -1;

  if (a_name && (a_out = open (a_name, 0)) < 0)
    {
      PERROR (a_name);
    }
  if ((new = creat (new_name, 0666)) < 0)
    {
      PERROR (new_name);
    }

  if (make_hdr (new, a_out, data_start, bss_start, entry_address, a_name, new_name) < 0
      || copy_text_and_data (new) < 0
      || copy_sym (new, a_out, a_name, new_name) < 0
#ifdef COFF
      || adjust_lnnoptrs (new, a_out, new_name) < 0
#endif
      )
    {
      close (new);
      /* unlink (new_name);	    	/* Failed, unlink new a.out */
      return -1;	
    }

  close (new);
  if (a_out >= 0)
    close (a_out);
  mark_x (new_name);
  return 0;
}

/* ****************************************************************
 * make_hdr
 *
 * Make the header in the new a.out from the header in core.
 * Modify the text and data sizes.
 */
#ifdef COFF
 struct scnhdr f_thdr;		/* Text section header */
 struct scnhdr f_dhdr;		/* Data section header */
 struct scnhdr f_bhdr;		/* Bss section header */
 struct scnhdr scntemp;		/* Temporary section header */
#endif /* COFF */
static int
make_hdr (new, a_out, data_start, bss_start, entry_address, a_name, new_name)
     int new, a_out;
     unsigned data_start, bss_start, entry_address;
     char *a_name;
     char *new_name;
{
  int tem;
  register int scns;
  unsigned int bss_end;

  pagemask = getpagesize () - 1;

  /* Adjust text/data boundary. */
#ifdef NO_REMAP
  data_start = (int) start_of_data ();
#else /* not NO_REMAP */
  if (!data_start)
    data_start = (int) start_of_data ();
#endif /* not NO_REMAP */
  data_start = ADDR_CORRECT (data_start);

#ifdef SEGMENT_MASK
  data_start = data_start & ~SEGMENT_MASK; /* (Down) to segment boundary. */
#else
  data_start = data_start & ~pagemask; /* (Down) to page boundary. */
#endif

  bss_end = (ADDR_CORRECT (sbrk (0)) + pagemask) & ~pagemask;

  /* Adjust data/bss boundary. */
  if (bss_start != 0)
    {
      bss_start = (ADDR_CORRECT (bss_start) + pagemask) & ~pagemask;	      /* (Up) to page bdry. */
      if (bss_start > bss_end)
	{
	  ERROR1 ("unexec: Specified bss_start (%u) is past end of program",
		  bss_start);
	}
    }
  else
    bss_start = bss_end;

  if (data_start > bss_start)	/* Can't have negative data size. */
    {
      ERROR2 ("unexec: data_start (%u) can't be greater than bss_start (%u)",
	      data_start, bss_start);
    }

#ifdef COFF
  /* Salvage as much info from the existing file as possible */
  if (a_out >= 0)
    {
      if (read (a_out, &f_hdr, sizeof (f_hdr)) != sizeof (f_hdr))
	{
	  PERROR (a_name);
	}
      block_copy_start += sizeof (f_hdr);
      if (f_hdr.h_opthdr > 0)
	{
	  if (read (a_out, &f_ohdr, sizeof (f_ohdr)) != sizeof (f_ohdr))
	    {
	      PERROR (a_name);
	    }
	  block_copy_start += sizeof (f_ohdr);
	}
      /* Loop through section headers, copying them in */
      for (scns = f_hdr.h_nscns; scns > 0; scns--) {
	if (read (a_out, &scntemp, sizeof (scntemp)) != sizeof (scntemp))
	  {
	    PERROR (a_name);
	  }
	if (scntemp.s_scnptr > 0L)
	  {
            if (block_copy_start < scntemp.s_scnptr + scntemp.s_size)
	      block_copy_start = scntemp.s_scnptr + scntemp.s_size;
	  }
	if (scntemp.s_flags & S_TEXT)
	  {
	    f_thdr = scntemp;
	  }
	else if (scntemp.s_flags & S_DATA)
	  {
	    f_dhdr = scntemp;
	  }
	else if (scntemp.s_flags & S_BSS)
	  {
	    f_bhdr = scntemp;
	  }
      }
    }
  else
    {
      ERROR0 ("can't build a COFF file from scratch yet");
    }

  /* Now we alter the contents of all the f_*hdr variables
     to correspond to what we want to dump.  */

  f_hdr.h_flags |= (0);      /* this isn't really correct..*/
#ifdef EXEC_MAGIC
  f_ohdr.magic = EXEC_MAGIC;
#endif
  f_thdr.s_vaddr = (long) start_of_text ();
  f_thdr.s_size = data_start - f_thdr.s_vaddr;
  f_thdr.s_scnptr = 4096;
  f_thdr.s_relptr = 0;
  f_thdr.s_nrel = 0;
  f_thdr.s_prot = 0xA;

  f_dhdr.s_vaddr = data_start;
  f_dhdr.s_size = bss_start - data_start;
  f_dhdr.s_scnptr = 4096 + (data_start - f_thdr.s_vaddr);
  f_dhdr.s_relptr = 0;
  f_dhdr.s_nrel = 0;
  f_dhdr.s_prot = 0xC;
  
  f_bhdr.s_vaddr = bss_start;
  f_bhdr.s_size = bss_end - bss_start + 4096 /* fudge */;
  f_bhdr.s_scnptr = 0;
  f_bhdr.s_relptr = 0;
  f_bhdr.s_nrel = 0;
  f_bhdr.s_prot = 0xC;
#ifdef SECTION_ALIGNMENT
  /* Some systems require special alignment
     of the sections in the file itself.  */
  f_thdr.s_scnptr
    = (f_thdr.s_scnptr + SECTION_ALIGNMENT) & ~SECTION_ALIGNMENT;
#endif /* SECTION_ALIGNMENT */
  text_scnptr = f_thdr.s_scnptr;
  data_scnptr = f_dhdr.s_scnptr;
  bias = f_dhdr.s_scnptr + f_dhdr.s_size - block_copy_start;

  if (f_ohdr.o_symptr > 0L)
    {
      f_ohdr.o_symptr += bias;
    }

  if (f_hdr.h_strptr > 0)
  {
      f_hdr.h_strptr += bias;
  }

#ifdef ADJUST_EXEC_HEADER
  ADJUST_EXEC_HEADER
#endif /* ADJUST_EXEC_HEADER */

  if (write (new, &f_hdr, sizeof (f_hdr)) != sizeof (f_hdr))
    {
      PERROR (new_name);
    }

  if (write (new, &f_ohdr, sizeof (f_ohdr)) != sizeof (f_ohdr))
    {
      PERROR (new_name);
    }

  if (write (new, &f_thdr, sizeof (f_thdr)) != sizeof (f_thdr))
    {
      PERROR (new_name);
    }

  if (write (new, &f_dhdr, sizeof (f_dhdr)) != sizeof (f_dhdr))
    {
      PERROR (new_name);
    }

  if (write (new, &f_bhdr, sizeof (f_bhdr)) != sizeof (f_bhdr))
    {
      PERROR (new_name);
    }
  return (0);

#else /* if not COFF */

  /* Get symbol table info from header of a.out file if given one. */
  if (a_out >= 0)
    {
      if (read (a_out, &ohdr, sizeof hdr) != sizeof hdr)
	{
	  PERROR (a_name);
	}

      if N_BADMAG (ohdr)
	{
	  ERROR1 ("invalid magic number in %s", a_name);
	}
      hdr = ohdr;
    }
  else
    {
      bzero (hdr, sizeof hdr);
    }

  unexec_text_start = (long) start_of_text ();
  unexec_data_start = data_start;

  /* Machine-dependent fixup for header, or maybe for unexec_text_start */
#ifdef ADJUST_EXEC_HEADER
  ADJUST_EXEC_HEADER;
#endif /* ADJUST_EXEC_HEADER */

  hdr.a_trsize = 0;
  hdr.a_drsize = 0;
  if (entry_address != 0)
    hdr.a_entry = entry_address;

  hdr.a_bss = bss_end - bss_start;
  hdr.a_data = bss_start - data_start;
#ifdef NO_REMAP
  hdr.a_text = ohdr.a_text;
#else /* not NO_REMAP */
  hdr.a_text = data_start - unexec_text_start;
#endif /* not NO_REMAP */

#ifdef A_TEXT_OFFSET
  hdr.a_text += A_TEXT_OFFSET (ohdr);
#endif

  if (write (new, &hdr, sizeof hdr) != sizeof hdr)
    {
      PERROR (new_name);
    }

#ifdef A_TEXT_OFFSET
  hdr.a_text -= A_TEXT_OFFSET (ohdr);
#endif

  return 0;

#endif /* not COFF */
}

/* ****************************************************************
 * copy_text_and_data
 *
 * Copy the text and data segments from memory to the new a.out
 */
static int
copy_text_and_data (new)
     int new;
{
  register char *end;
  register char *ptr;

#ifdef COFF
  lseek (new, (long) text_scnptr, 0);
  ptr = (char *) f_thdr.s_vaddr;
  end = ptr + f_thdr.s_size;
  write_segment (new, ptr, end);

  lseek (new, (long) data_scnptr, 0);
  ptr = (char *) f_dhdr.s_vaddr;
  end = ptr + f_dhdr.s_size;
  write_segment (new, ptr, end);

#else /* if not COFF */

/* Some machines count the header as part of the text segment.
   That is to say, the header appears in core
   just before the address that start_of_text () returns.
   For them, N_TXTOFF is the place where the header goes.
   We must adjust the seek to the place after the header.
   Note that at this point hdr.a_text does *not* count
   the extra A_TEXT_OFFSET bytes, only the actual bytes of code.  */

#ifdef A_TEXT_SEEK
  lseek (new, (long) A_TEXT_SEEK (hdr), 0);
#else
#ifdef A_TEXT_OFFSET
  /* Note that on the Sequent machine A_TEXT_OFFSET != sizeof (hdr)
     and sizeof (hdr) is the correct amount to add here.  */
  /* In version 19, eliminate this case and use A_TEXT_SEEK whenever
     N_TXTOFF is not right.  */
  lseek (new, (long) N_TXTOFF (hdr) + sizeof (hdr), 0);
#else
  lseek (new, (long) N_TXTOFF (hdr), 0);
#endif /* no A_TEXT_OFFSET */
#endif /* no A_TEXT_SEEK */

  ptr = (char *) unexec_text_start;
  end = ptr + hdr.a_text;
  write_segment (new, ptr, end);

  ptr = (char *) unexec_data_start;
  end = ptr + hdr.a_data;
/*  This lseek is certainly incorrect when A_TEXT_OFFSET
    and I believe it is a no-op otherwise.
    Let's see if its absence ever fails.  */
/*  lseek (new, (long) N_TXTOFF (hdr) + hdr.a_text, 0); */
  write_segment (new, ptr, end);

#endif /* not COFF */

  return 0;
}

write_segment (new, ptr, end)
     int new;
     register char *ptr, *end;
{
  register int i, nwrite, ret;
  char buf[80];
  extern int errno;
  char zeros[128];

  bzero (zeros, sizeof zeros);

  for (i = 0; ptr < end;)
    {
      /* distance to next multiple of 128.  */
      nwrite = (((int) ptr + 128) & -128) - (int) ptr;
      /* But not beyond specified end.  */
      if (nwrite > end - ptr) nwrite = end - ptr;
      ret = write (new, ptr, nwrite);
      /* If write gets a page fault, it means we reached
	 a gap between the old text segment and the old data segment.
	 This gap has probably been remapped into part of the text segment.
	 So write zeros for it.  */
      if (ret == -1 && errno == EFAULT)
	write (new, zeros, nwrite);
      else if (nwrite != ret)
	{
	  sprintf (buf,
		   "unexec write failure: addr 0x%x, fileno %d, size 0x%x, wrote 0x%x, errno %d",
		   ptr, new, nwrite, ret, errno);
	  PERROR (buf);
	}
      i += nwrite;
      ptr += nwrite;
    }
}

/* ****************************************************************
 * copy_sym
 *
 * Copy the relocation information and symbol table from the a.out to the new
 */
static int
copy_sym (new, a_out, a_name, new_name)
     int new, a_out;
     char *a_name, *new_name;
{
  char page[1024];
  int n;

  if (a_out < 0)
    return 0;

#ifdef COFF
  if (SYMS_START == 0L)
    return 0;
#endif  /* COFF */

#ifdef COFF
  if (lnnoptr)			/* if there is line number info */
    lseek (a_out, lnnoptr, 0);	/* start copying from there */
  else
#endif /* COFF */
    lseek (a_out, SYMS_START, 0);	/* Position a.out to symtab. */

  while ((n = read (a_out, page, sizeof page)) > 0)
    {
      if (write (new, page, n) != n)
	{
	  PERROR (new_name);
	}
    }
  if (n < 0)
    {
      PERROR (a_name);
    }
  return 0;
}

/* ****************************************************************
 * mark_x
 *
 * After succesfully building the new a.out, mark it executable
 */
static
mark_x (name)
     char *name;
{
  struct stat sbuf;
  int um;
  int new = 0;  /* for PERROR */

  um = umask (777);
  umask (um);
  if (stat (name, &sbuf) == -1)
    {
      PERROR (name);
    }
  sbuf.st_mode |= 0111 & ~um;
  if (chmod (name, sbuf.st_mode) == -1)
    PERROR (name);
}

/*
 *	If the COFF file contains a symbol table and a line number section,
 *	then any auxiliary entries that have values for x_lnnoptr must
 *	be adjusted by the amount that the line number section has moved
 *	in the file (bias computed in make_hdr).  The #@$%&* designers of
 *	the auxiliary entry structures used the absolute file offsets for
 *	the line number entry rather than an offset from the start of the
 *	line number section!
 *
 *	When I figure out how to scan through the symbol table and pick out
 *	the auxiliary entries that need adjustment, this routine will
 *	be fixed.  As it is now, all such entries are wrong and sdb
 *	will complain.   Fred Fish, UniSoft Systems Inc.
 */

#ifdef COFF

/* This function is probably very slow.  Instead of reopening the new
   file for input and output it should copy from the old to the new
   using the two descriptors already open (WRITEDESC and READDESC).
   Instead of reading one small structure at a time it should use
   a reasonable size buffer.  But I don't have time to work on such
   things, so I am installing it as submitted to me.  -- RMS.  */

adjust_lnnoptrs (writedesc, readdesc, new_name)
     int writedesc;
     int readdesc;
     char *new_name;
{
#if 0
  register int nsyms;
  register int new;
#ifdef amdahl_uts
  SYMENT symentry;
  AUXENT auxentry;
#else
  struct syment symentry;
  struct auxent auxentry;
#endif

  if (!lnnoptr || !f_hdr.f_symptr)
    return 0;

  if ((new = open (new_name, 2)) < 0)
    {
      PERROR (new_name);
      return -1;
    }

  lseek (new, f_hdr.f_symptr, 0);
  for (nsyms = 0; nsyms < f_hdr.f_nsyms; nsyms++)
    {
      read (new, &symentry, SYMESZ);
      if (symentry.n_numaux)
	{
	  read (new, &auxentry, AUXESZ);
	  nsyms++;
	  if (ISFCN (symentry.n_type)) {
	    auxentry.x_sym.x_fcnary.x_fcn.x_lnnoptr += bias;
	    lseek (new, -AUXESZ, 1);
	    write (new, &auxentry, AUXESZ);
	  }
	}
    }
  close (new);
#endif 0
}

#endif /* COFF */


#else /* mips */

/* Unexec for mips machines.
   Note that I regard it as the responsibility of people at Mips
   to tell me about any changes that need to be made in this code.
   I won't take responsibility to think about it even if a change
   I make elsewhere causes it to break.  -- RMS.  */

#include <sys/types.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <stdio.h>
#include <varargs.h>
#include <filehdr.h>
#include <aouthdr.h>
#include <scnhdr.h>
#include <sym.h>

#define private static

extern int errno;
extern int sys_nerr;
extern char *sys_errlist[];
#define EEOF -1

private void
fatal(s, va_alist)
    va_dcl
{
    va_list ap;
    if (errno == EEOF) {
	fputs("unexec: unexpected end of file, ", stderr);
    }
    else if (errno < sys_nerr) {
	fprintf(stderr, "unexec: %s, ", sys_errlist[errno]);
    }
    else {
	fprintf(stderr, "unexec: error code %d, ", errno);
    }
    va_start(ap);
    _doprnt(s, ap, stderr);
    fputs(".\n", stderr);
    exit(1);
}

#define READ(_fd, _buffer, _size, _error_message, _error_arg) \
	errno = EEOF; \
	if (read(_fd, _buffer, _size) != _size) \
	  fatal(_error_message, _error_arg);

#define WRITE(_fd, _buffer, _size, _error_message, _error_arg) \
	if (write(_fd, _buffer, _size) != _size) \
	  fatal(_error_message, _error_arg);

#define SEEK(_fd, _position, _error_message, _error_arg) \
	errno = EEOF; \
	if (lseek(_fd, _position, L_SET) != _position) \
	  fatal(_error_message, _error_arg);

struct headers {
    struct filehdr fhdr;
    struct aouthdr aout;
    struct scnhdr text_section;
    struct scnhdr rdata_section;
    struct scnhdr data_section;
    struct scnhdr sdata_section;
    struct scnhdr sbss_section;
    struct scnhdr bss_section;
};

unexec (new_name, a_name, data_start, bss_start, entry_address)
     char *new_name, *a_name;
     unsigned data_start, bss_start, entry_address;
{
  int new, old;
  int pagesize, brk;
  int newsyms, symrel;
  int nread;
  struct headers hdr;
#define BUFSIZE 8192
  char buffer[BUFSIZE];

  old = open (a_name, O_RDONLY, 0);
  if (old < 0) fatal("openning %s", a_name);

  new = creat (new_name, 0666);
  if (new < 0) fatal("creating %s", new_name);

  hdr = *((struct headers *)TEXT_START);
  if (hdr.fhdr.f_magic != MIPSELMAGIC
      && hdr.fhdr.f_magic != MIPSEBMAGIC) {
      fprintf(stderr, "unexec: input file magic number is %x, not %x or %x.\n",
	      hdr.fhdr.f_magic, MIPSELMAGIC, MIPSEBMAGIC);
      exit(1);
  }
  if (hdr.fhdr.f_opthdr != sizeof(hdr.aout)) {
      fprintf(stderr, "unexec: input a.out header is %d bytes, not %d.\n",
	      hdr.fhdr.f_opthdr, sizeof(hdr.aout));
      exit(1);
  }
#if 0
  if (hdr.aout.magic != ZMAGIC
      && hdr.aout.magic != NMAGIC
      && hdr.aout.magic != OMAGIC) {
      fprintf(stderr, "unexec: input file a.out magic number is %o, not %o, %o, or %o.\n",
	      hdr.aout.magic, ZMAGIC, NMAGIC, OMAGIC);
      exit(1);
  }
#else
  if (hdr.aout.magic != ZMAGIC) {
      fprintf(stderr, "unexec: input file a.out magic number is %o, not %o.\n",
	      hdr.aout.magic, ZMAGIC);
      exit(1);
  }
#endif
  if (hdr.fhdr.f_nscns != 6) {
      fprintf(stderr, "unexec: %d sections instead of 6.\n", hdr.fhdr.f_nscns);
  }
#define CHECK_SCNHDR(field, name, flags) \
  if (strcmp(hdr.field.s_name, name) != 0) { \
      fprintf(stderr, "unexec: %s section where %s expected.\n", \
	      hdr.field.s_name, name); \
      exit(1); \
  } \
  else if (hdr.field.s_flags != flags) { \
      fprintf(stderr, "unexec: %x flags where %x expected in %s section.\n", \
	      hdr.field.s_flags, flags, name); \
  }
  CHECK_SCNHDR(text_section,  _TEXT,  STYP_TEXT);
  CHECK_SCNHDR(rdata_section, _RDATA, STYP_RDATA);
  CHECK_SCNHDR(data_section,  _DATA,  STYP_DATA);
  CHECK_SCNHDR(sdata_section, _SDATA, STYP_SDATA);
  CHECK_SCNHDR(sbss_section,  _SBSS,  STYP_SBSS);
  CHECK_SCNHDR(bss_section,   _BSS,   STYP_BSS);

  pagesize = getpagesize();
  brk = (sbrk(0) + pagesize - 1) & (-pagesize);
  hdr.aout.dsize = brk - DATA_START;
  hdr.aout.bsize = 0;
  if (entry_address == 0) {
    extern __start();
    hdr.aout.entry = (unsigned)__start;
  }
  else {
    hdr.aout.entry = entry_address;
  }
  hdr.aout.bss_start = hdr.aout.data_start + hdr.aout.dsize;
  hdr.rdata_section.s_size = data_start - DATA_START;
  hdr.data_section.s_vaddr = data_start;
  hdr.data_section.s_paddr = data_start;
  hdr.data_section.s_size = brk - DATA_START;
  hdr.data_section.s_scnptr = hdr.rdata_section.s_scnptr
				+ hdr.rdata_section.s_size;
  hdr.sdata_section.s_vaddr = hdr.data_section.s_vaddr
				+ hdr.data_section.s_size;
  hdr.sdata_section.s_paddr = hdr.sdata_section.s_paddr;
  hdr.sdata_section.s_size = 0;
  hdr.sdata_section.s_scnptr = hdr.data_section.s_scnptr
				+ hdr.data_section.s_size;
  hdr.sbss_section.s_vaddr = hdr.sdata_section.s_vaddr
				+ hdr.sdata_section.s_size;
  hdr.sbss_section.s_paddr = hdr.sbss_section.s_vaddr;
  hdr.sbss_section.s_size = 0;
  hdr.sbss_section.s_scnptr = hdr.sdata_section.s_scnptr
				+ hdr.sdata_section.s_size;
  hdr.bss_section.s_vaddr = hdr.sbss_section.s_vaddr
				+ hdr.sbss_section.s_size;
  hdr.bss_section.s_paddr = hdr.bss_section.s_vaddr;
  hdr.bss_section.s_size = 0;
  hdr.bss_section.s_scnptr = hdr.sbss_section.s_scnptr
				+ hdr.sbss_section.s_size;

  WRITE(new, TEXT_START, hdr.aout.tsize,
	"writing text section to %s", new_name);
  WRITE(new, DATA_START, hdr.aout.dsize,
	"writing text section to %s", new_name);

  SEEK(old, hdr.fhdr.f_symptr, "seeking to start of symbols in %s", a_name);
  errno = EEOF;
  nread = read(old, buffer, BUFSIZE);
  if (nread < sizeof(HDRR)) fatal("reading symbols from %s", a_name);
#define symhdr ((pHDRR)buffer)
  newsyms = hdr.aout.tsize + hdr.aout.dsize;
  symrel = newsyms - hdr.fhdr.f_symptr;
  hdr.fhdr.f_symptr = newsyms;
  symhdr->cbLineOffset += symrel;
  symhdr->cbDnOffset += symrel;
  symhdr->cbPdOffset += symrel;
  symhdr->cbSymOffset += symrel;
  symhdr->cbOptOffset += symrel;
  symhdr->cbAuxOffset += symrel;
  symhdr->cbSsOffset += symrel;
  symhdr->cbSsExtOffset += symrel;
  symhdr->cbFdOffset += symrel;
  symhdr->cbRfdOffset += symrel;
  symhdr->cbExtOffset += symrel;
#undef symhdr
  do {
      if (write(new, buffer, nread) != nread)
	fatal("writing symbols to %s", new_name);
      nread = read(old, buffer, BUFSIZE);
      if (nread < 0) fatal("reading symbols from %s", a_name);
#undef BUFSIZE
  } while (nread != 0);

  SEEK(new, 0, "seeking to start of header in %s", new_name);
  WRITE(new, &hdr, sizeof(hdr),
	"writing header of %s", new_name);

  close(old);
  close(new);
  mark_x(new_name);
}

/*
 * mark_x
 *
 * After succesfully building the new a.out, mark it executable
 */
static
mark_x (name)
     char *name;
{
  struct stat sbuf;
  int um = umask (777);
  umask (um);
  if (stat(name, &sbuf) < 0)
    fatal("getting protection on %s", name);
  sbuf.st_mode |= 0111 & ~um;
  if (chmod(name, sbuf.st_mode) < 0)
    fatal("setting protection on %s", name);
}

#endif /* mips */

#else /* CANNOT_UNEXEC */
/* This is used by Apollo sysems running release 9.5
   It is similar to the VMS code in vmsmap.c */

extern char * _malloc_base;
extern int my_edata;

/* Structure to write into first block of map file. */

struct map_data
 {
   char * sdata;		/* Start of data area */
   char * edata;		/* End of data area */
   char * smalloc;		/* Start of malloc area */
   char * emalloc;		/* End of malloc area */
 };

static int write_data ();

/* Maps in the data and alloc area from the map file. */

int
mapin_data (name)
     char * name;
{
  int fd;
  struct map_data map_data;
  char * sbrk ();
  
  _malloc_base = sbrk (0);

  /* Open map file. */
  if ((fd = open (name, O_RDONLY)) < 0)
    {
      printf ("Map file not available, running bare Emacs...\n");
      return (0);		/* Map file not available */
    }

  /* Read the header data */
  if (read (fd, &map_data, sizeof (map_data)) != sizeof (map_data))
    {
      printf ("Map file not correct format, running bare Emacs...\n");
      return (0);		/* Map file not available */
    }

  if (map_data.sdata != start_of_data ())
    {
      printf ("Start of data area has moved: cannot map in data.\n");
      return (0);
    }
  if (map_data.edata != (char *) &my_edata)
    {
      printf ("End of data area has moved: cannot map in data.\n");
      return (0);
    }
  /* Extend virtual address space to end of previous malloc area. */
  if (brk (map_data.emalloc))
    {
      printf ("Couldn't set brk.\n");
      return (0);
    }

  /* Open the file for mapping now. */
  if (read (fd, map_data.sdata, 1 + map_data.edata - map_data.sdata) < 0)
    {
      printf ("Couldn't read data section.\n");
      exit (1);
    }

  /* Check mapping. */
  if (_malloc_base != map_data.smalloc)
    {
      printf ("Data area mapping invalid.\n");
      exit (1);
    }
  /* Map malloc area. */
  if (read (fd, map_data.smalloc, 1 + map_data.emalloc - map_data.smalloc) < 0)
    exit (1);

  close (fd);

  return (1);
}

/* Writes the data and alloc area to the map file. */

mapout_data (into)
     char * into;
{
  int fd;
  struct map_data map_data;
  char * sbrk ();
  
  map_data.sdata = start_of_data ();
  map_data.edata = (char *) &my_edata;
  map_data.smalloc = _malloc_base;
  map_data.emalloc = sbrk (0) - 1;
  /* Create map file. */
  fd = open (into, O_WRONLY | O_CREAT, 0666);
  write (fd, &map_data, sizeof (map_data));
  write (fd, map_data.sdata, 1+map_data.edata-map_data.sdata);
  write (fd, map_data.smalloc, 1+map_data.emalloc-map_data.smalloc);
  close (fd);
  return (1);
}

#endif /* CANNOT_UNEXEC */

#endif /* not CANNOT_DUMP */

	 	



-- 
Jim Thompson		 		Convex Computer Corporation
(214) 952-0536		 		701 N. Plano Road
"panic: getfs: bad magic"		Richardson, Texas 75081
{uiucdcs,ihnp4,sun,allegra,harvard,killer,usenix}!convex!jthomp

rbj@ICST-CMR.ARPA (Root Boy Jim) (03/24/88)

   I actually have the [microemacs] 3.9i version which is labelled as
   3.9e with bugfixes.  The "i" stands for interim.

I had always wondered about those BMW's and the Varian 620i :-)

	(Root Boy) Jim Cottrell	<rbj@icst-cmr.arpa>
	National Bureau of Standards
	Flamer's Hotline: (301) 975-5688
Somewhere in suburban Honolulu, an unemployed bellhop is whipping up
 a batch of illegal psilocybin chop suey!!