freebsd-nq/lib/csu/i386/c++rt0.c
1999-08-28 00:22:10 +00:00

108 lines
3.2 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.
*
* $FreeBSD$
*/
/*
* 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.
*/
extern void (*__CTOR_LIST__[])(void);
extern void (*__DTOR_LIST__[])(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();
}
/*
* Make sure there is at least one constructor and one destructor in the
* shared library. Otherwise, the linker does not realize that the
* constructor and destructor lists are linker sets. It treats them as
* commons and resolves them to the lists from the main program. That
* causes multiple invocations of the main program's static constructors
* and destructors, which is very bad.
*/
static void
do_nothing(void)
{
}
/* Linker magic to add an element to a constructor or destructor list. */
#define TEXT_SET(set, sym) \
asm(".stabs \"_" #set "\", 23, 0, 0, _" #sym)
TEXT_SET(__CTOR_LIST__, do_nothing);
TEXT_SET(__DTOR_LIST__, do_nothing);