lib/csu/x86_64/crt1.c

   1 /*-
   2  * Copyright 1996-1998 John D. Polstra.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #ifndef __GNUC__
  27 #error "GCC is needed to compile this file"
  28 #endif
  29
  30 #include <machine/tls.h>
  31 #include <stdlib.h>
  32
  33 #include "libc_private.h"
  34 #include "initfini.c"
  35 #include "crtbrand.c"
  36
  37 typedef void (*fptr)(void);
  38
  39 #ifdef GCRT
  40 extern void _mcleanup(void);
  41 extern void monstartup(void *, void *);
  42 extern int eprol;
  43 extern int etext;
  44 #endif
  45
  46 void _start(char **, void (*)(void));
  47
  48 /* The entry function. */
  49 void
  50 _start(char **ap, void (*cleanup)(void))
  51 {
  52         int argc;
  53         char **argv;
  54         char **env;
  55
  56         argc = *(long *)(void *)ap;
  57         argv = ap + 1;
  58         env = ap + 2 + argc;
  59         handle_argv(argc, argv, env);
  60
  61         /*
  62          * Setup the initial TLS space.  The RTLD does not set up our TLS
  63          * (it can't, it doesn't know how our errno is declared).  It simply
  64          * does all the groundwork required so that we can call
  65          * _rtld_allocate_tls().
  66          */
  67         _init_tls();
  68         _rtld_call_init();
  69
  70         if (&_DYNAMIC != NULL)
  71                 atexit(cleanup);
  72
  73 #ifdef GCRT
  74         atexit(_mcleanup);
  75         monstartup(&eprol, &etext);
  76 #endif
  77
  78         handle_static_init(argc, argv, env);
  79 #ifdef GCRT
  80         /*
  81          * This label was previously located just after the monstartup
  82          * function.  It was relocated after the handle_static_init function
  83          * to avoid an alternative conditional optimization performed by
  84          * clang.  The optimization cause the compilation to fail with a
  85          * label redefinition error.  The impact of the label relocation is
  86          * the loss of profiling of handle_static_init function.
  87          */
  88 __asm__("eprol:");
  89 #endif
  90         exit(main(argc, argv, env));
  91 }