glibc/csu/gmon-start.c
2012-02-09 23:18:22 +00:00

69 lines
2.1 KiB
C

/* Code to enable profiling at program startup.
Copyright (C) 1995,1996,1997,2000,2001,2002,2012 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 Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <sys/types.h>
#include <sys/gmon.h>
#include <stdlib.h>
#include <unistd.h>
#define __ASSEMBLY__
#include <entry.h>
/* Beginning and end of our code segment. We cannot declare them
as the external functions since we want the addresses of those
labels. Taking the address of a function may have different
meanings on different platforms. */
#ifdef ENTRY_POINT_DECL
ENTRY_POINT_DECL(extern)
#else
extern char ENTRY_POINT[];
#endif
extern char etext[];
#ifndef TEXT_START
# ifdef ENTRY_POINT_DECL
# define TEXT_START ENTRY_POINT
# else
# define TEXT_START &ENTRY_POINT
# endif
#endif
/* We cannot use the normal constructor mechanism to call
__gmon_start__ because gcrt1.o appears before crtbegin.o in the link.
Instead crti.o calls it specially. */
extern void __gmon_start__ (void);
void
__gmon_start__ (void)
{
/* Protect from being called more than once. Since crti.o is linked
into every shared library, each of their init functions will call us. */
static int called;
if (called)
return;
called = 1;
/* Start keeping profiling records. */
__monstartup ((u_long) TEXT_START, (u_long) &etext);
/* Call _mcleanup before exiting; it will write out gmon.out from the
collected data. */
atexit (&_mcleanup);
}