glibc/csu/gmon-start.c
Richard Henderson b1c1949e60 Don't take the address of a void object.
GCC 4.5 warns about "extern void _end; &end;".
Use char[] instead, as that also doesn't fall foul
of a target's .sdata optimizations.

Signed-off-by: Richard Henderson <rth@twiddle.net>
2010-03-26 09:16:21 -07:00

80 lines
2.5 KiB
C

/* Code to enable profiling at program startup.
Copyright (C) 1995,1996,1997,2000,2001,2002 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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#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
#ifndef HAVE_INITFINI
/* This function gets called at startup by the normal constructor
mechanism. We link this file together with start.o to produce gcrt1.o,
so this constructor will be first in the list. */
extern void __gmon_start__ (void) __attribute__ ((constructor));
#else
/* In ELF and COFF, 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 (see initfini.c). */
extern void __gmon_start__ (void);
#endif
void
__gmon_start__ (void)
{
#ifdef HAVE_INITFINI
/* 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;
#endif
/* 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);
}