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/*
* Manuel Novoa III Feb 2001
* Erik Anderseni Mar 2002
*
* __uClibc_main is the routine to be called by all the arch-specific
* versions of crt0.S in uClibc.
*
* It is meant to handle any special initialization needed by the library
* such as setting the global variable(s) __environ (environ) and
* initializing the stdio package. Using weak symbols, the latter is
* avoided in the static library case.
*/
#define _ERRNO_H
#include <stdlib.h>
#include <unistd.h>
#if !defined HAVE_ELF || !defined __UCLIBC_HAS_MMU__
# undef weak_function
# undef weak_const_function
# define weak_function
# define weak_const_function
# define __USE_WEAK_ALIASES
#endif
/*
* Prototypes.
*/
extern int main(int argc, char **argv, char **envp);
extern int weak_function atexit(void (*function)(void));
extern void weak_function _init(void);
extern void weak_function _fini(void);
extern void weak_function _stdio_init(void);
extern void weak_function _stdio_term(void);
extern int *weak_const_function __errno_location(void);
extern int *weak_const_function __h_errno_location(void);
/*
* Declare the __environ global variable and create a weak alias environ.
* Note: Apparently we must initialize __environ for the weak environ
* symbol to be included.
*/
char **__environ = 0;
weak_alias(__environ, environ);
/*
* Now for our main routine.
*/
void __attribute__ ((__noreturn__))
__uClibc_main(int argc, char **argv, char **envp)
{
/*
* Initialize the global variable __environ.
*/
__environ = envp;
#if 0
/* Some security at this point. Prevent starting a SUID binary
* where the standard file descriptors are not opened. We have
* to do this only for statically linked applications since
* otherwise the dynamic loader did the work already. */
if (unlikely (__libc_enable_secure))
__libc_check_standard_fds ();
#endif
/*
* Initialize stdio here. In the static library case, this will
* be bypassed if not needed because of the weak alias above.
*/
if (likely(_stdio_init))
_stdio_init();
/* Arrange for dtors to run at exit. */
atexit (&_fini);
/* Run all ctors now. */
_init();
/*
* Note: It is possible that any initialization done above could
* have resulted in errno being set nonzero, so set it to 0 before
* we call main.
*/
if (likely(__errno_location))
*(__errno_location()) = 0;
/* Set h_errno to 0 as well */
if (likely(__h_errno_location))
*(__h_errno_location()) = 0;
/*
* Finally, invoke application's main and then exit.
*/
exit(main(argc, argv, envp));
}
#ifdef __USE_WEAK_ALIASES
/*
* Define an empty function and use it as a weak alias for the stdio
* initialization routine. That way we don't pull in all the stdio
* code unless we need to. Similarly, do the same for _stdio_term
* so as not to include atexit unnecessarily.
*
* NOTE!!! This is only true for the _static_ case!!!
*/
weak_alias(__environ, environ);
void __uClibc_empty_func(void)
{
}
weak_alias(__uClibc_empty_func, atexit);
weak_alias(__uClibc_empty_func, _init);
weak_alias(__uClibc_empty_func, _fini);
weak_alias(__uClibc_empty_func, __errno_location);
weak_alias(__uClibc_empty_func, __h_errno_location);
weak_alias(__uClibc_empty_func, _stdio_init);
weak_alias(__uClibc_empty_func, _stdio_term);
#endif
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