mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-25 14:30:06 +00:00
140 lines
4.6 KiB
C
140 lines
4.6 KiB
C
/* Special .init and .fini section support.
|
|
Copyright (C) 1995, 1996, 1997, 2000 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.
|
|
|
|
In addition to the permissions in the GNU Lesser 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 GNU Lesser 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.)
|
|
|
|
Note that people who make modified versions of this file are not
|
|
obligated to grant this special exception for their modified
|
|
versions; it is their choice whether to do so. The GNU Lesser
|
|
General Public License gives permission to release a modified
|
|
version without this exception; this exception also makes it
|
|
possible to release a modified version which carries forward this
|
|
exception.
|
|
|
|
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. */
|
|
|
|
/* 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*/");
|
|
extern void dummy (void (*foo) (void));
|
|
void
|
|
dummy (void (*foo) (void))
|
|
{
|
|
if (foo)
|
|
(*foo) ();
|
|
}
|
|
asm ("\n/*@TESTS_END*/");
|
|
|
|
/* The beginning of _init: */
|
|
asm ("\n/*@_init_PROLOG_BEGINS*/");
|
|
|
|
static void
|
|
call_gmon_start(void)
|
|
{
|
|
extern void __gmon_start__ (void) __attribute__ ((weak)); /*weak_extern (__gmon_start__);*/
|
|
void (*gmon_start) (void) = __gmon_start__;
|
|
|
|
if (gmon_start)
|
|
gmon_start ();
|
|
}
|
|
|
|
SECTION (".init");
|
|
extern void __attribute__ ((section (".init"))) _init (void);
|
|
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. */
|
|
call_gmon_start ();
|
|
|
|
asm ("ALIGN");
|
|
asm("END_INIT");
|
|
/* Now the epilog. */
|
|
asm ("\n/*@_init_PROLOG_ENDS*/");
|
|
asm ("\n/*@_init_EPILOG_BEGINS*/");
|
|
SECTION(".init");
|
|
}
|
|
asm ("END_INIT");
|
|
|
|
/* End of the _init epilog, beginning of the _fini prolog. */
|
|
asm ("\n/*@_init_EPILOG_ENDS*/");
|
|
asm ("\n/*@_fini_PROLOG_BEGINS*/");
|
|
|
|
SECTION (".fini");
|
|
extern void __attribute__ ((section (".fini"))) _fini (void);
|
|
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. */
|