glibc/sysdeps/unix/start.c

93 lines
2.5 KiB
C

/* Copyright (C) 1991, 1993, 1995 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
The GNU C Library 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 the GNU C Library; see the file COPYING. If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
#include <ansidecl.h>
#include <errno.h>
#include <stdlib.h>
#include <unistd.h>
#include <sysdep.h> /* In case it wants to define anything. */
/* The first piece of initialized data. */
int __data_start = 0;
#ifdef HAVE_WEAK_SYMBOLS
weak_alias (__data_start, data_start)
#endif
#ifdef DUMMIES
#define ARG_DUMMIES DUMMIES,
#define DECL_DUMMIES int DUMMIES;
#else
#define ARG_DUMMIES
#define DECL_DUMMIES
#endif
#ifndef errno
volatile int errno;
#endif
extern void EXFUN(__libc_init, (int argc, char **argv, char **envp));
extern int EXFUN(main, (int argc, char **argv, char **envp));
/* Not a prototype because it gets called strangely. */
static void start1();
#ifndef HAVE__start
/* N.B.: It is important that this be the first function.
This file is the first thing in the text section. */
void
DEFUN_VOID(_start)
{
start1();
}
#ifndef NO_UNDERSCORES
/* Make an alias called `start' (no leading underscore, so it can't
conflict with C symbols) for `_start'. This is the name vendor crt0.o's
tend to use, and thus the name most linkers expect. */
asm (".set start, __start");
#endif
#endif
/* ARGSUSED */
static void
start1 (ARG_DUMMIES argc, argp)
DECL_DUMMIES
int argc;
char *argp;
{
char **argv = &argp;
/* The environment starts just after ARGV. */
__environ = &argv[argc + 1];
/* If the first thing after ARGV is the arguments
themselves, there is no environment. */
if ((char *) __environ == *argv)
/* The environment is empty. Make __environ
point at ARGV[ARGC], which is NULL. */
--__environ;
/* Do C library initializations. */
__libc_init (argc, argv, __environ);
/* Call the user program. */
exit (main (argc, argv, __environ));
}