1/* Code to enable profiling at program startup.
2 Copyright (C) 1995-2017 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 In addition to the permissions in the GNU Lesser General Public
11 License, the Free Software Foundation gives you unlimited
12 permission to link the compiled version of this file with other
13 programs, and to distribute those programs without any restriction
14 coming from the use of this file. (The GNU Lesser General Public
15 License restrictions do apply in other respects; for example, they
16 cover modification of the file, and distribution when not linked
17 into another program.)
18
19 Note that people who make modified versions of this file are not
20 obligated to grant this special exception for their modified
21 versions; it is their choice whether to do so. The GNU Lesser
22 General Public License gives permission to release a modified
23 version without this exception; this exception also makes it
24 possible to release a modified version which carries forward this
25 exception.
26
27 The GNU C Library is distributed in the hope that it will be useful,
28 but WITHOUT ANY WARRANTY; without even the implied warranty of
29 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
30 Lesser General Public License for more details.
31
32 You should have received a copy of the GNU Lesser General Public
33 License along with the GNU C Library; if not, see
34 <http://www.gnu.org/licenses/>. */
35
36#include <sys/types.h>
37#include <sys/gmon.h>
38#include <stdlib.h>
39#include <unistd.h>
40#define __ASSEMBLY__
41#include <entry.h>
42
43/* Beginning and end of our code segment. We cannot declare them
44 as the external functions since we want the addresses of those
45 labels. Taking the address of a function may have different
46 meanings on different platforms. */
47#ifdef ENTRY_POINT_DECL
48ENTRY_POINT_DECL(extern)
49#else
50extern char ENTRY_POINT[];
51#endif
52extern char etext[];
53
54#ifndef TEXT_START
55# ifdef ENTRY_POINT_DECL
56# define TEXT_START ENTRY_POINT
57# else
58# define TEXT_START &ENTRY_POINT
59# endif
60#endif
61
62#ifdef GMON_START_ARRAY_SECTION
63static void __gmon_start__ (void);
64static void (*const gmon_start_initializer) (void)
65 __attribute__ ((used, section (GMON_START_ARRAY_SECTION))) = &__gmon_start__;
66static
67#else
68/* We cannot use the normal constructor mechanism to call
69 __gmon_start__ because gcrt1.o appears before crtbegin.o in the link.
70 Instead crti.o calls it specially. */
71extern void __gmon_start__ (void);
72#endif
73
74void
75__gmon_start__ (void)
76{
77 /* Protect from being called more than once. Since crti.o is linked
78 into every shared library, each of their init functions will call us. */
79 static int called;
80
81 if (called)
82 return;
83
84 called = 1;
85
86 /* Start keeping profiling records. */
87 __monstartup ((u_long) TEXT_START, (u_long) &etext);
88
89 /* Call _mcleanup before exiting; it will write out gmon.out from the
90 collected data. */
91 atexit (&_mcleanup);
92}
93