xref: /dragonfly/lib/csu/x86_64/crt1.c (revision 9348a738)
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 }
92