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/*
Copyright (C) 1994 M. Hagiya, W. sLchelter, T. Yuasa
This file is part of GNU Common Lisp, herein referred to as GCL
GCL 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, or (at your option)
any later version.
GCL 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 GCL; see the file COPYING. If not, write to the Free Software
Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/*
block.c
blocks and exits
*/
#include "include.h"
static void
FFN(Fblock)(VOL object args)
{
object *oldlex = lex_env;
object id;
object body;
object *top;
if(endp(args))
FEtoo_few_argumentsF(args);
lex_copy();
id = alloc_frame_id();
vs_push(id);
lex_block_bind(MMcar(args), id);
vs_popp;
frs_push(FRS_CATCH, id);
if (nlj_active)
nlj_active = FALSE;
else {
body = MMcdr(args);
if (endp(body)) {
vs_base = vs_top;
vs_push(Cnil);
} else {
top = vs_top;
do {
vs_top = top;
eval(MMcar(body));
body = MMcdr(body);
} while (!endp(body));
}
}
frs_pop();
lex_env = oldlex;
}
static void
FFN(Freturn_from)(object args)
{
object lex_block;
frame_ptr fr;
if (endp(args))
FEtoo_few_argumentsF(args);
if (!endp(MMcdr(args)) && !endp(MMcddr(args)))
FEtoo_many_argumentsF(args);
lex_block = lex_block_sch(MMcar(args));
if (MMnull(lex_block))
FEerror("The block name ~S is undefined.", 1, MMcar(args));
fr = frs_sch(MMcaddr(lex_block));
if(fr == NULL)
FEerror("The block ~S is missing.", 1, MMcar(args));
if(endp(MMcdr(args))) {
vs_base = vs_top;
vs_push(Cnil);
}
else
eval(MMcadr(args));
unwind(fr, MMcaddr(lex_block));
/* never reached */
}
static void
FFN(Freturn)(object args)
{
object lex_block;
frame_ptr fr;
if(!endp(args) && !endp(MMcdr(args)))
FEtoo_many_argumentsF(args);
lex_block = lex_block_sch(Cnil);
if (MMnull(lex_block))
FEerror("The block name ~S is undefined.", 1, Cnil);
fr = frs_sch(MMcaddr(lex_block));
if (fr == NULL)
FEerror("The block ~S is missing.", 1, Cnil);
if(endp(args)) {
vs_base = vs_top;
vs_push(Cnil);
} else
eval(MMcar(args));
unwind(fr, MMcaddr(lex_block));
/* never reached */
}
void
gcl_init_block(void)
{
sLblock = make_special_form("BLOCK", Fblock);
enter_mark_origin(&sLblock);
make_special_form("RETURN-FROM", Freturn_from);
make_special_form("RETURN", Freturn);
}
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