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/* Copyright (C) 1995,1996 Free Software Foundation, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this software; see the file COPYING. If not, write to
* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
*
* As a special exception, the Free Software Foundation gives permission
* for additional uses of the text contained in its release of GUILE.
*
* The exception is that, if you link the GUILE library with other files
* to produce an executable, this does not by itself cause the
* resulting executable to be covered by the GNU General Public License.
* Your use of that executable is in no way restricted on account of
* linking the GUILE library code into it.
*
* This exception does not however invalidate any other reasons why
* the executable file might be covered by the GNU General Public License.
*
* This exception applies only to the code released by the
* Free Software Foundation under the name GUILE. If you copy
* code from other Free Software Foundation releases into a copy of
* GUILE, as the General Public License permits, the exception does
* not apply to the code that you add in this way. To avoid misleading
* anyone as to the status of such modified files, you must delete
* this exception notice from them.
*
* If you write modifications of your own for GUILE, it is your choice
* whether to permit this exception to apply to your modifications.
* If you do not wish that, delete this exception notice.
*/
#include <stdio.h>
#include "_scm.h"
#include "stackchk.h"
#include "dynwind.h"
#include "eval.h"
#include "genio.h"
#include "smob.h"
#include "pairs.h"
#include "throw.h"
#include "root.h"
SCM scm_sys_protects[SCM_NUM_PROTECTS];
long scm_tc16_root;
#ifndef USE_THREADS
struct scm_root_state *scm_root;
#endif
static SCM mark_root SCM_P ((SCM));
static SCM
mark_root (root)
SCM root;
{
scm_root_state *s = SCM_ROOT_STATE (root);
SCM_SETGC8MARK (root);
scm_gc_mark (s->rootcont);
scm_gc_mark (s->dynwinds);
scm_gc_mark (s->continuation_stack);
scm_gc_mark (s->continuation_stack_ptr);
scm_gc_mark (s->progargs);
scm_gc_mark (s->exitval);
scm_gc_mark (s->cur_inp);
scm_gc_mark (s->cur_outp);
scm_gc_mark (s->cur_errp);
scm_gc_mark (s->def_inp);
scm_gc_mark (s->def_outp);
scm_gc_mark (s->def_errp);
scm_gc_mark (s->top_level_lookup_thunk_var);
scm_gc_mark (s->system_transformer);
return SCM_ROOT_STATE (root) -> parent;
}
static scm_sizet free_root SCM_P ((SCM));
static scm_sizet
free_root (root)
SCM root;
{
scm_must_free ((char *) SCM_ROOT_STATE (root));
return sizeof (scm_root_state);
}
static int print_root SCM_P ((SCM exp, SCM port, scm_print_state *pstate));
static int
print_root (exp, port, pstate)
SCM exp;
SCM port;
scm_print_state *pstate;
{
scm_gen_puts (scm_regular_string, "#<root ", port);
scm_intprint(SCM_SEQ (SCM_ROOT_STATE (exp) -> rootcont), 16, port);
scm_gen_putc('>', port);
return 1;
}
static scm_smobfuns root_smob =
{
mark_root,
free_root,
print_root,
0
};
SCM
scm_make_root (parent)
SCM parent;
{
SCM root;
scm_root_state *root_state;
root_state = (scm_root_state *) scm_must_malloc (sizeof (scm_root_state),
"scm_make_root");
if (SCM_NIMP (parent) && SCM_ROOTP (parent))
{
memcpy (root_state, SCM_ROOT_STATE (parent), sizeof (scm_root_state));
root_state->parent = parent;
}
else
{
root_state->parent = SCM_BOOL_F;
}
SCM_NEWCELL (root);
SCM_REDEFER_INTS;
SCM_SETCAR (root, scm_tc16_root);
SCM_SETCDR (root, root_state);
root_state->handle = root;
SCM_REALLOW_INTS;
return root;
}
/* {call-with-dynamic-root}
*
* Suspending the current thread to evaluate a thunk on the
* same C stack but under a new root.
*
* Calls to call-with-dynamic-root return exactly once (unless
* the process is somehow exitted).
*/
#if 0
SCM scm_exitval; /* INUM with return value */
#endif
static int n_dynamic_roots = 0;
static SCM cwdr SCM_P ((SCM thunk, SCM a1, SCM args, SCM handler, SCM_STACKITEM *stack_start));
/* This is the basic code for new root creation.
*
* WARNING! The order of actions in this routine is in many ways
* critical. E. g., it is essential that an error doesn't leave Guile
* in a messed up state.
*/
static SCM
cwdr (proc, a1, args, handler, stack_start)
SCM proc;
SCM a1;
SCM args;
SCM handler;
SCM_STACKITEM *stack_start;
{
int old_ints_disabled = scm_ints_disabled;
SCM old_rootcont, old_winds;
SCM answer;
/* Create a fresh root continuation.
*/
{
SCM new_rootcont;
SCM_NEWCELL (new_rootcont);
SCM_REDEFER_INTS;
SCM_SETJMPBUF (new_rootcont,
scm_must_malloc ((long) sizeof (regs),
"inferior root continuation"));
SCM_CAR (new_rootcont) = scm_tc7_contin;
SCM_DYNENV (new_rootcont) = SCM_EOL;
SCM_BASE (new_rootcont) = stack_start;
SCM_SEQ (new_rootcont) = ++n_dynamic_roots;
#ifdef DEBUG_EXTENSIONS
SCM_DFRAME (new_rootcont) = 0;
#endif
old_rootcont = scm_rootcont;
scm_rootcont = new_rootcont;
SCM_REALLOW_INTS;
}
/* Exit caller's dynamic state.
*/
old_winds = scm_dynwinds;
scm_dowinds (SCM_EOL, scm_ilength (scm_dynwinds));
#ifdef DEBUG_EXTENSIONS
scm_last_debug_frame = 0;
#endif
/* Catch all errors. */
answer = scm_catch_apply (SCM_BOOL_T, proc, a1, args, handler);
scm_dowinds (old_winds, - scm_ilength (old_winds));
SCM_REDEFER_INTS;
scm_rootcont = old_rootcont;
#ifdef DEBUG_EXTENSIONS
scm_last_debug_frame = SCM_DFRAME (scm_rootcont);
#endif
SCM_REALLOW_INTS;
scm_ints_disabled = old_ints_disabled;
return answer;
}
SCM_PROC(s_call_with_dynamic_root, "call-with-dynamic-root", 2, 0, 0, scm_call_with_dynamic_root);
SCM
scm_call_with_dynamic_root (thunk, handler)
SCM thunk;
SCM handler;
{
SCM_STACKITEM stack_place;
return cwdr (thunk, SCM_EOL, SCM_EOL, handler, &stack_place);
}
SCM_PROC(s_dynamic_root, "dynamic-root", 0, 0, 0, scm_dynamic_root);
SCM
scm_dynamic_root ()
{
return scm_ulong2num (SCM_SEQ (scm_root->rootcont));
}
SCM
scm_apply_with_dynamic_root (proc, a1, args, handler)
SCM proc;
SCM a1;
SCM args;
SCM handler;
{
SCM_STACKITEM stack_place;
return cwdr (proc, a1, args, handler, &stack_place);
}
/* Call thunk(closure) underneath a top-level error handler.
* If an error occurs, pass the exitval through err_filter and return it.
* If no error occurs, return the value of thunk.
*/
#ifdef _UNICOS
typedef int setjmp_type;
#else
typedef long setjmp_type;
#endif
SCM
scm_call_catching_errors (thunk, err_filter, closure)
SCM (*thunk)();
SCM (*err_filter)();
void *closure;
{
SCM answer;
setjmp_type i;
#ifdef DEBUG_EXTENSIONS
SCM_DFRAME (scm_rootcont) = scm_last_debug_frame;
#endif
i = setjmp (SCM_JMPBUF (scm_rootcont));
#ifdef STACK_CHECKING
scm_stack_checking_enabled_p = SCM_STACK_CHECKING_P;
#endif
if (!i)
{
scm_gc_heap_lock = 0;
answer = thunk (closure);
}
else
{
scm_gc_heap_lock = 1;
answer = err_filter (scm_exitval, closure);
}
return answer;
}
void
scm_init_root ()
{
scm_tc16_root = scm_newsmob (&root_smob);
#include "root.x"
}
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