mirror of
https://git.savannah.gnu.org/git/guile.git
synced 2025-04-30 03:40:34 +02:00
9d381ba478
* libguile/control.h: Remove scm_t_prompt_registers and scm_c_make_prompt_registers. (scm_c_abort): Take a pointer to a jmpbuf instead of a cookie. It will serve the same purpose. * libguile/control.c (reify_partial_continuation, scm_at_abort): Adapt to new prompt representation. * libguile/dynstack.h: * libguile/dynstack.c (scm_dynstack_push_prompt): Prompts now have 5 words instead of 2, as they now push the fp, sp, ip, and jmpbuf on the stack separately. This avoids allocation. (scm_dynstack_find_prompt): Likewise, add return values for fp, sp, etc. (scm_dynstack_wind_prompt): Replaces scm_dynstack_relocate_prompt. * libguile/eval.c (eval): * libguile/stacks.c (find_prompt): * libguile/throw.c (pre_init_catch): Adapt to the new prompt mechanism. * libguile/vm-engine.c (vm_engine): Setjmp an on-stack jmpbuf every time the VM enters. We can then re-use that jmpbuf for all prompts in that invocation. * libguile/vm-i-system.c (partial_cont_call): Adapt to change in prompt representation. We don't need to wind here any more, since we pass in the prompt's jmpbuf. (prompt): Adapt to scm_dynstack_push_prompt change. (abort): Adapt to vm_abort change. * libguile/vm.h (struct scm_vm): No more cookie. * libguile/vm.c (vm_abort): Adapt to scm_c_abort change. (vm_reinstate_partial_continuation): Rewind the dynamic stack here, now that we do have a valid jmpbuf. (make_vm): No need to initialize a cookie.
208 lines
7.6 KiB
C
208 lines
7.6 KiB
C
/* classes: h_files */
|
||
|
||
#ifndef SCM_DYNSTACK_H
|
||
#define SCM_DYNSTACK_H
|
||
|
||
/* Copyright (C) 2012 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
|
||
*/
|
||
|
||
|
||
|
||
#include "libguile/__scm.h"
|
||
#include "libguile/control.h"
|
||
|
||
|
||
|
||
typedef struct
|
||
{
|
||
scm_t_bits *base;
|
||
scm_t_bits *top;
|
||
scm_t_bits *limit;
|
||
} scm_t_dynstack;
|
||
|
||
|
||
|
||
/* Items on the dynstack are preceded by two-word headers, giving the
|
||
offset of the preceding item (or 0 if there is none) and the type,
|
||
flags, and length of the following dynstack entry, in words. In
|
||
addition, there is a "null header" at the top of the stack,
|
||
indicating the length of the previous item, but with a tag of zero.
|
||
|
||
For example, consider an empty dynstack, with a capacity of 6 words:
|
||
|
||
+----------+----------+ +
|
||
|prev=0 |tag=0 | |
|
||
+----------+----------+ +
|
||
^base ^top limit^
|
||
|
||
Now we evaluate (dynamic-wind enter thunk leave). That will result
|
||
in a dynstack of:
|
||
|
||
/ the len=2 words \
|
||
+----------+----------+----------+----------+----------+----------+
|
||
|prev=0 |tag:len=2 |enter |leave |prev=4 |tag=0 |
|
||
+----------+----------+----------+----------+----------+----------+
|
||
^base top,limit^
|
||
|
||
The tag is a combination of the type of the dynstack item, some flags
|
||
associated with the item, and the length of the item. See
|
||
SCM_MAKE_DYNSTACK_TAG below for the details.
|
||
|
||
This arrangement makes it possible to have variable-length dynstack
|
||
items, and yet be able to traverse them forwards or backwards. */
|
||
|
||
#define SCM_DYNSTACK_HEADER_LEN 2
|
||
|
||
#define SCM_DYNSTACK_PREV_OFFSET(top) ((top)[-2])
|
||
#define SCM_DYNSTACK_SET_PREV_OFFSET(top, offset) (top)[-2] = (offset)
|
||
|
||
#define SCM_DYNSTACK_TAG(top) ((top)[-1])
|
||
#define SCM_DYNSTACK_SET_TAG(top, tag) (top)[-1] = (tag)
|
||
|
||
typedef enum {
|
||
SCM_DYNSTACK_TYPE_NONE = 0,
|
||
SCM_DYNSTACK_TYPE_FRAME,
|
||
SCM_DYNSTACK_TYPE_UNWINDER,
|
||
SCM_DYNSTACK_TYPE_REWINDER,
|
||
SCM_DYNSTACK_TYPE_WITH_FLUIDS,
|
||
SCM_DYNSTACK_TYPE_PROMPT,
|
||
SCM_DYNSTACK_TYPE_DYNWIND,
|
||
} scm_t_dynstack_item_type;
|
||
|
||
#define SCM_DYNSTACK_TAG_TYPE_MASK 0xf
|
||
#define SCM_DYNSTACK_TAG_FLAGS_MASK 0xf0
|
||
#define SCM_DYNSTACK_TAG_FLAGS_SHIFT 4
|
||
#define SCM_DYNSTACK_TAG_LEN_SHIFT 8
|
||
|
||
#define SCM_MAKE_DYNSTACK_TAG(type, flags, len) \
|
||
((type) | (flags) | ((len) << SCM_DYNSTACK_TAG_LEN_SHIFT))
|
||
|
||
#define SCM_DYNSTACK_TAG_TYPE(tag) \
|
||
((tag) & SCM_DYNSTACK_TAG_TYPE_MASK)
|
||
#define SCM_DYNSTACK_TAG_FLAGS(tag) \
|
||
((tag) & SCM_DYNSTACK_TAG_FLAGS_MASK)
|
||
#define SCM_DYNSTACK_TAG_LEN(tag) \
|
||
((tag) >> SCM_DYNSTACK_TAG_LEN_SHIFT)
|
||
|
||
#define SCM_DYNSTACK_PREV(top) \
|
||
(SCM_DYNSTACK_PREV_OFFSET (top) \
|
||
? ((top) - SCM_DYNSTACK_PREV_OFFSET (top)) : NULL)
|
||
#define SCM_DYNSTACK_NEXT(top) \
|
||
(SCM_DYNSTACK_TAG (top) \
|
||
? ((top) + SCM_DYNSTACK_TAG_LEN (SCM_DYNSTACK_TAG (top)) \
|
||
+ SCM_DYNSTACK_HEADER_LEN) \
|
||
: NULL)
|
||
|
||
#define SCM_DYNSTACK_FIRST(dynstack) \
|
||
((dynstack)->base + SCM_DYNSTACK_HEADER_LEN)
|
||
|
||
#define SCM_DYNSTACK_CAPACITY(dynstack) \
|
||
((dynstack)->limit - (dynstack)->base)
|
||
#define SCM_DYNSTACK_SPACE(dynstack) \
|
||
((dynstack)->limit - (dynstack)->top)
|
||
#define SCM_DYNSTACK_HEIGHT(dynstack) \
|
||
((dynstack)->top - (dynstack)->base)
|
||
|
||
#define SCM_DYNSTACK_HAS_SPACE(dynstack, n) \
|
||
(SCM_DYNSTACK_SPACE (dynstack) >= n + SCM_DYNSTACK_HEADER_LEN)
|
||
|
||
typedef enum {
|
||
SCM_F_DYNSTACK_FRAME_REWINDABLE = (1 << SCM_DYNSTACK_TAG_FLAGS_SHIFT)
|
||
} scm_t_dynstack_frame_flags;
|
||
|
||
typedef enum {
|
||
SCM_F_DYNSTACK_WINDER_EXPLICIT = (1 << SCM_DYNSTACK_TAG_FLAGS_SHIFT)
|
||
} scm_t_dynstack_winder_flags;
|
||
|
||
typedef enum {
|
||
SCM_F_DYNSTACK_PROMPT_ESCAPE_ONLY = (1 << SCM_DYNSTACK_TAG_FLAGS_SHIFT)
|
||
} scm_t_dynstack_prompt_flags;
|
||
|
||
typedef void (*scm_t_guard) (void *);
|
||
|
||
|
||
|
||
|
||
/* Pushing and popping entries on the dynamic stack. */
|
||
|
||
SCM_INTERNAL void scm_dynstack_push_frame (scm_t_dynstack *,
|
||
scm_t_dynstack_frame_flags);
|
||
SCM_INTERNAL void scm_dynstack_push_rewinder (scm_t_dynstack *,
|
||
scm_t_dynstack_winder_flags,
|
||
scm_t_guard, void *);
|
||
SCM_INTERNAL void scm_dynstack_push_unwinder (scm_t_dynstack *,
|
||
scm_t_dynstack_winder_flags,
|
||
scm_t_guard, void *);
|
||
SCM_INTERNAL void scm_dynstack_push_fluids (scm_t_dynstack *,
|
||
size_t,
|
||
SCM *fluids,
|
||
SCM *values,
|
||
SCM dynamic_state);
|
||
SCM_INTERNAL void scm_dynstack_push_prompt (scm_t_dynstack *,
|
||
scm_t_dynstack_prompt_flags,
|
||
SCM key,
|
||
SCM *fp, SCM *sp, scm_t_uint8 *ip,
|
||
scm_i_jmp_buf *registers);
|
||
SCM_INTERNAL void scm_dynstack_push_dynwind (scm_t_dynstack *,
|
||
SCM enter, SCM leave);
|
||
|
||
SCM_INTERNAL void scm_dynstack_pop (scm_t_dynstack *);
|
||
|
||
|
||
|
||
|
||
/* Capturing, winding, and unwinding. */
|
||
|
||
SCM_INTERNAL scm_t_dynstack* scm_dynstack_capture_all (scm_t_dynstack *dynstack);
|
||
SCM_INTERNAL scm_t_dynstack* scm_dynstack_capture (scm_t_dynstack *dynstack,
|
||
scm_t_bits *item);
|
||
|
||
SCM_INTERNAL void scm_dynstack_wind_1 (scm_t_dynstack *, scm_t_bits *);
|
||
SCM_INTERNAL scm_t_bits scm_dynstack_unwind_1 (scm_t_dynstack *);
|
||
|
||
SCM_INTERNAL void scm_dynstack_wind (scm_t_dynstack *, scm_t_bits *);
|
||
SCM_INTERNAL void scm_dynstack_unwind (scm_t_dynstack *, scm_t_bits *);
|
||
|
||
|
||
|
||
|
||
/* Miscellany. */
|
||
|
||
SCM_INTERNAL scm_t_bits* scm_dynstack_unwind_fork (scm_t_dynstack *,
|
||
scm_t_dynstack *);
|
||
|
||
SCM_INTERNAL void scm_dynstack_unwind_frame (scm_t_dynstack *);
|
||
SCM_INTERNAL void scm_dynstack_unwind_fluids (scm_t_dynstack *dynstack,
|
||
SCM dynamic_state);
|
||
|
||
SCM_INTERNAL scm_t_bits* scm_dynstack_find_prompt (scm_t_dynstack *, SCM,
|
||
scm_t_dynstack_prompt_flags *,
|
||
SCM **, SCM **, scm_t_uint8 **,
|
||
scm_i_jmp_buf **);
|
||
|
||
SCM_INTERNAL void scm_dynstack_wind_prompt (scm_t_dynstack *, scm_t_bits *,
|
||
scm_t_ptrdiff, scm_i_jmp_buf *);
|
||
|
||
|
||
#endif /* SCM_DYNSTACK_H */
|
||
|
||
/*
|
||
Local Variables:
|
||
c-file-style: "gnu"
|
||
End:
|
||
*/
|