Convert (most) functions in src to standard C.

[bpt/emacs.git] / src / ecrt0.c

/* C code startup routine.
   Copyright (C) 1985, 1986, 1992, 2001, 2002, 2003, 2004,
                 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.

This file is part of GNU Emacs.

GNU Emacs is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

GNU Emacs is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */


/* The standard Vax 4.2 Unix crt0.c cannot be used for Emacs
   because it makes `environ' an initialized variable.
   It is easiest to have a special crt0.c on all machines
   though I don't know whether other machines actually need it.  */

/* On the vax and 68000, in BSD4.2 and USG5.2,
   this is the data format on startup:
  (vax) ap and fp are unpredictable as far as I know; don't use them.
  sp ->  word containing argc
         word pointing to first arg string
	 [word pointing to next arg string]... 0 or more times
	 0
Optionally:
	 [word pointing to environment variable]... 1 or more times
	 ...
	 0
And always:
	 first arg string
	 [next arg string]... 0 or more times
*/

#ifdef emacs
#include <config.h>
#endif

/*		********  WARNING ********
    Do not insert any data definitions before data_start!
    Since this is the first file linked, the address of the following
    variable should correspond to the start of initialized data space.
    On some systems this is a constant that is independent of the text
    size for shared executables.  On others, it is a function of the
    text size. In short, this seems to be the most portable way to
    discover the start of initialized data space dynamically at runtime,
    for either shared or unshared executables, on either swapping or
    virtual systems.  It only requires that the linker allocate objects
    in the order encountered, a reasonable model for most Unix systems.
    Similarly, note that the address of _start() should be the start
    of text space.   Fred Fish, UniSoft Systems Inc.  */

int data_start = 0;

char **environ;

static start1 (int bogus_fp, int argc, char *xargv);

/* Define symbol "start": here; some systems want that symbol.  */
asm("	.text		");
asm("	.globl start	");
asm("	start:		");

_start (void)
{
/* On vax, nothing is pushed here  */
  start1 ();
}

static
start1 (int bogus_fp, int argc, char *xargv)
{
  register char **argv = &xargv;
  environ = argv + argc + 1;

  if ((char *)environ == xargv)
    environ--;
  exit (main (argc, argv, environ));

  /* Refer to `start1' so GCC will not think it is never called
     and optimize it out.  */
  (void) &start1;
}

/* arch-tag: 4025c2fb-d6b1-4d29-b1b6-8100b6bd1e74
   (do not change this comment) */