mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-15 07:30:13 +00:00
dc27836e6b
* csu/initfini.c: Don't define __gmon_start__ if WEAK_GMON_START is defined. * sysdeps/unix/sysv/linux/i386/Makefile [subdir==csu]: Add -DWEAK_GMON_START to CFLAGS-initfini.s.
139 lines
4.3 KiB
C
139 lines
4.3 KiB
C
/* Special .init and .fini section support.
|
|
Copyright (C) 1995, 1996, 1997 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 Library General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2 of the License, or (at your option) any later version.
|
|
|
|
In addition to the permissions in the GNU Library General Public
|
|
License, the Free Software Foundation gives you unlimited
|
|
permission to link the compiled version of this file with other
|
|
programs, and to distribute those programs without any restriction
|
|
coming from the use of this file. (The Library General Public
|
|
License restrictions do apply in other respects; for example, they
|
|
cover modification of the file, and distribution when not linked
|
|
into another program.)
|
|
|
|
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 Library General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Library General Public
|
|
License along with the GNU C Library; see the file COPYING.LIB. If not,
|
|
write to the Free Software Foundation, 59 Temple Place - Suite 330,
|
|
Boston, MA 02111-1307, USA. */
|
|
|
|
/* This file is compiled into assembly code which is then munged by a sed
|
|
script into two files: crti.s and crtn.s.
|
|
|
|
* crti.s puts a function prologue at the beginning of the
|
|
.init and .fini sections and defines global symbols for
|
|
those addresses, so they can be called as functions.
|
|
|
|
* crtn.s puts the corresponding function epilogues
|
|
in the .init and .fini sections. */
|
|
|
|
#include <stdlib.h>
|
|
|
|
/* We use embedded asm for .section unconditionally, as this makes it
|
|
easier to insert the necessary directives into crtn.S. */
|
|
#define SECTION(x) asm (".section " x );
|
|
|
|
/* Embed an #include to pull in the alignment and .end directives. */
|
|
asm ("\n#include \"defs.h\"");
|
|
|
|
/* The initial common code ends here. */
|
|
asm ("\n/*@HEADER_ENDS*/");
|
|
|
|
/* To determine whether we need .end and .align: */
|
|
asm ("\n/*@TESTS_BEGIN*/");
|
|
void
|
|
dummy (void (*foo) (void))
|
|
{
|
|
if (foo)
|
|
(*foo) ();
|
|
}
|
|
asm ("\n/*@TESTS_END*/");
|
|
|
|
/* The beginning of _init: */
|
|
asm ("\n/*@_init_PROLOG_BEGINS*/");
|
|
|
|
SECTION (".init")
|
|
void
|
|
_init (void)
|
|
{
|
|
/* We cannot use the normal constructor mechanism in gcrt1.o because it
|
|
appears before crtbegin.o in the link, so the header elt of .ctors
|
|
would come after the elt for __gmon_start__. One approach is for
|
|
gcrt1.o to reference a symbol which would be defined by some library
|
|
module which has a constructor; but then user code's constructors
|
|
would come first, and not be profiled. */
|
|
extern void __gmon_start__ (void) __attribute__ ((weak)); /*weak_extern (__gmon_start__);*/
|
|
|
|
#ifndef WEAK_GMON_START
|
|
__gmon_start__ ();
|
|
#else
|
|
if (__gmon_start__)
|
|
__gmon_start__ ();
|
|
#endif
|
|
|
|
asm ("ALIGN");
|
|
asm("END_INIT");
|
|
/* Now the epilog. */
|
|
asm ("\n/*@_init_PROLOG_ENDS*/");
|
|
asm ("\n/*@_init_EPILOG_BEGINS*/");
|
|
SECTION(".init");
|
|
}
|
|
asm ("END_INIT");
|
|
#ifndef WEAK_GMON_START
|
|
SECTION(".text");
|
|
|
|
/* This version of __gmon_start__ is used if no other is found. By providing
|
|
a default function we avoid the need to test whether the pointer is NULL,
|
|
which can be painful on some machines. */
|
|
|
|
void __attribute__ ((weak))
|
|
__gmon_start__ (void)
|
|
{
|
|
/* do nothing */
|
|
}
|
|
#endif
|
|
|
|
/* End of the _init epilog, beginning of the _fini prolog. */
|
|
asm ("\n/*@_init_EPILOG_ENDS*/");
|
|
asm ("\n/*@_fini_PROLOG_BEGINS*/");
|
|
|
|
SECTION (".fini")
|
|
void
|
|
_fini (void)
|
|
{
|
|
|
|
/* End of the _fini prolog. */
|
|
asm ("ALIGN");
|
|
asm ("END_FINI");
|
|
asm ("\n/*@_fini_PROLOG_ENDS*/");
|
|
|
|
{
|
|
/* Let GCC know that _fini is not a leaf function by having a dummy
|
|
function call here. We arrange for this call to be omitted from
|
|
either crt file. */
|
|
extern void i_am_not_a_leaf (void);
|
|
i_am_not_a_leaf ();
|
|
}
|
|
|
|
/* Beginning of the _fini epilog. */
|
|
asm ("\n/*@_fini_EPILOG_BEGINS*/");
|
|
SECTION (".fini");
|
|
}
|
|
asm ("END_FINI");
|
|
|
|
/* End of the _fini epilog. Any further generated assembly (e.g. .ident)
|
|
is shared between both crt files. */
|
|
asm ("\n/*@_fini_EPILOG_ENDS*/");
|
|
asm ("\n/*@TRAILER_BEGINS*/");
|
|
|
|
/* End of file. */
|