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/* Copyright (C) 2010 Free Software Foundation, Inc.
*
* This 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 3 of
* the License, or (at your option) any later version.
*
* This 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 this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301 USA
*/
#if HAVE_CONFIG_H
# include <config.h>
#endif
#include "libguile/_scm.h"
#include "libguile/control.h"
#include "libguile/vm.h"
SCM
scm_c_make_prompt (SCM vm, SCM k, scm_t_uint8 escape_only_p,
scm_t_int64 vm_cookie)
{
scm_t_bits tag;
SCM ret;
struct scm_prompt_registers *regs;
tag = scm_tc7_prompt;
if (escape_only_p)
tag |= SCM_F_PROMPT_ESCAPE;
ret = scm_words (tag, 5);
regs = scm_gc_malloc_pointerless (sizeof (*regs), "prompt registers");
regs->fp = SCM_VM_DATA (vm)->fp;
regs->sp = SCM_VM_DATA (vm)->sp;
regs->ip = SCM_VM_DATA (vm)->ip;
regs->cookie = vm_cookie;
SCM_SET_CELL_OBJECT (ret, 1, k);
SCM_SET_CELL_WORD (ret, 2, (scm_t_bits)regs);
SCM_SET_CELL_OBJECT (ret, 3, scm_i_dynwinds ());
return ret;
}
SCM
scm_c_abort (SCM vm, SCM tag, size_t n, SCM *argv)
{
SCM winds, prompt = SCM_BOOL_F;
long delta;
size_t i;
/* Search the wind list for an appropriate prompt.
"Waiter, please bring us the wind list." */
for (winds = scm_i_dynwinds (), delta = 0;
scm_is_pair (winds);
winds = SCM_CDR (winds), delta++)
{
SCM elt = SCM_CAR (winds);
if (SCM_PROMPT_P (elt) && scm_is_eq (SCM_PROMPT_TAG (elt), tag))
{
prompt = elt;
break;
}
}
/* If we didn't find anything, print a message and abort the process
right here. If you don't want this, establish a catch-all around
any code that might throw up. */
if (scm_is_false (prompt))
{
/* FIXME: jump to default */
/* scm_handle_by_message (NULL, key, args); */
abort ();
}
/* Unwind once more, beyond the prompt. */
winds = SCM_CDR (winds), delta++;
/* Unwind */
scm_dowinds (winds, delta);
/* Restore VM regs */
SCM_VM_DATA (vm)->fp = SCM_PROMPT_REGISTERS (prompt)->fp;
SCM_VM_DATA (vm)->sp = SCM_PROMPT_REGISTERS (prompt)->sp;
SCM_VM_DATA (vm)->ip = SCM_PROMPT_REGISTERS (prompt)->ip;
/* Since we're jumping down, we should always have enough space */
if (SCM_VM_DATA (vm)->sp + n + 1 >= SCM_VM_DATA (vm)->stack_limit)
abort ();
/* Push vals */
*(++(SCM_VM_DATA (vm)->sp)) = SCM_BOOL_F; /* the continuation */
for (i = 0; i < n; i++)
*(++(SCM_VM_DATA (vm)->sp)) = argv[i];
*(++(SCM_VM_DATA (vm)->sp)) = scm_from_size_t (n+1); /* +1 for continuation */
/* Jump! */
SCM_I_LONGJMP (SCM_PROMPT_REGISTERS (prompt)->regs, 1);
/* Shouldn't get here */
abort ();
}
SCM_DEFINE (scm_at_abort, "@abort", 2, 0, 0, (SCM tag, SCM args),
"Abort to the nearest prompt with tag @var{tag}.")
#define FUNC_NAME s_scm_at_abort
{
SCM *argv;
size_t i, n;
SCM_VALIDATE_LIST_COPYLEN (SCM_ARG2, args, n);
argv = alloca (sizeof (SCM)*n);
for (i = 0; i < n; i++, args = scm_cdr (args))
argv[i] = scm_car (args);
scm_c_abort (scm_the_vm (), tag, n, argv);
/* Oh, what, you're still here? The abort must have been reinstated. Actually,
that's quite impossible, given that we're already in C-land here, so...
abort! */
abort ();
}
#undef FUNC_NAME
void scm_init_control (void)
{
#include "control.x"
}
/*
Local Variables:
c-file-style: "gnu"
End:
*/
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