freebsd-nq/lib/csu/i386/c++rt0.c
Doug Rabson 82aaeb09ad Change ld.so to correctly load dependant libraries for dlopen and unload them
on dlclose.  Also correctly call constructors and destructors for libraries
linked with /usr/lib/c++rt0.o.
Change interpretation of dlopen manpage to call _init() rather than init()
for dlopened objects.
Change c++rt0.o to avoid using atexit to call destructors, allowing dlclose to
call destructors when an object is unloaded.
Change interface between crt0 and ld.so to allow crt0 to call a function on
exit to call destructors for shared libraries explicitly.

These changes are backwards compatible.  Old binaries will work with the new
ld.so and new binaries will work with the old ld.so.  A version number has
been introduced in the crt0-ld.so interface to allow for future changes.

Reviewed by:	GAWollman, Craig Struble <cstruble@singularity.bevc.blacksburg.va.us>
1995-06-27 09:53:27 +00:00

87 lines
2.5 KiB
C

/*
* Copyright (c) 1993 Paul Kranenburg
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Paul Kranenburg.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $Id: c++rt0.c,v 1.2 1995/05/30 05:39:36 rgrimes Exp $
*/
/*
* Run-time module for GNU C++ compiled shared libraries.
*
* The linker constructs the following arrays of pointers to global
* constructors and destructors. The first element contains the
* number of pointers in each.
* The tables are also null-terminated.
*/
void (*__CTOR_LIST__[0])(void);
void (*__DTOR_LIST__[0])(void);
static void
__dtors(void)
{
unsigned long i = (unsigned long) __DTOR_LIST__[0];
void (**p)(void) = __DTOR_LIST__ + i;
while (i--)
(**p--)();
}
static void
__ctors(void)
{
void (**p)(void) = __CTOR_LIST__ + 1;
while (*p)
(**p++)();
}
extern void __init() asm(".init");
extern void __fini() asm(".fini");
void
__init(void)
{
static int initialized = 0;
/*
* Call global constructors.
* Arrange to call global destructors at exit.
*/
if (!initialized) {
initialized = 1;
__ctors();
}
}
void
__fini(void)
{
__dtors();
}