-/* Copyright (C) 2010, 2011 Free Software Foundation, Inc.
+/* Copyright (C) 2010, 2011, 2012, 2013 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
\f
+#define PROMPT_ESCAPE_P(p) \
+ (SCM_DYNSTACK_TAG_FLAGS (SCM_DYNSTACK_TAG (p)) \
+ & SCM_F_DYNSTACK_PROMPT_ESCAPE_ONLY)
-SCM
-scm_c_make_prompt (SCM k, SCM *fp, SCM *sp, scm_t_uint8 *abort_ip,
- scm_t_uint8 escape_only_p, scm_t_int64 vm_cookie,
- SCM winds)
-{
- scm_t_bits tag;
- struct scm_prompt_registers *regs;
-
- tag = scm_tc7_prompt;
- if (escape_only_p)
- tag |= (SCM_F_PROMPT_ESCAPE<<8);
-
- regs = scm_gc_malloc_pointerless (sizeof (*regs), "prompt registers");
- regs->fp = fp;
- regs->sp = sp;
- regs->ip = abort_ip;
- regs->cookie = vm_cookie;
+\f
- return scm_double_cell (tag, SCM_UNPACK (k), (scm_t_bits)regs,
- SCM_UNPACK (winds));
-}
-/* Only to be called if the SCM_PROMPT_SETJMP returns 1 */
+/* Only to be called if the SCM_I_SETJMP returns 1 */
SCM
scm_i_prompt_pop_abort_args_x (SCM vm)
{
#define META_HEADER(meta) meta, 0, 0, 0, 0, 0, 0, 0
#endif
-#define ALIGN_PTR(type,p,align) (type*)(ROUND_UP (((scm_t_bits)p), align))
+#define OBJCODE_TAG SCM_MAKE_OBJCODE_TAG (SCM_OBJCODE_TYPE_STATIC, 0)
-#ifdef SCM_ALIGNED
+#if defined (SCM_ALIGNED)
#define SCM_DECLARE_STATIC_ALIGNED_ARRAY(type, sym) \
static const type sym[]
#define SCM_STATIC_ALIGNED_ARRAY(alignment, type, sym) \
static SCM_ALIGNED (alignment) const type sym[]
-#else
-#define SCM_DECLARE_STATIC_ALIGNED_ARRAY(type, sym) \
-static type *sym
-#define SCM_STATIC_ALIGNED_ARRAY(alignment, type, sym) \
-SCM_SNARF_INIT(sym = scm_malloc_pointerless (sizeof(sym##__unaligned); \
- memcpy (sym, sym##__unaligned, sizeof(sym##__unaligned));) \
-static type *sym = NULL; \
-static const type sym##__unaligned[]
-#endif
-
-#define STATIC_OBJCODE_TAG \
- SCM_PACK (SCM_MAKE_OBJCODE_TAG (SCM_OBJCODE_TYPE_STATIC, 0))
-
#define SCM_STATIC_OBJCODE(sym) \
SCM_DECLARE_STATIC_ALIGNED_ARRAY (scm_t_uint8, sym##__bytecode); \
SCM_STATIC_ALIGNED_ARRAY (8, scm_t_cell, sym##__cells) = { \
- { STATIC_OBJCODE_TAG, SCM_PACK (sym##__bytecode) }, \
+ { SCM_PACK (OBJCODE_TAG), SCM_PACK (sym##__bytecode) }, \
{ SCM_BOOL_F, SCM_PACK (0) } \
}; \
static const SCM sym = SCM_PACK (sym##__cells); \
SCM_STATIC_ALIGNED_ARRAY (8, scm_t_uint8, sym##__bytecode)
+#else
+#define SCM_STATIC_OBJCODE(sym) \
+static SCM sym; \
+static scm_t_uint8 *sym##_bytecode; \
+SCM_SNARF_INIT(sym##_bytecode = scm_gc_malloc_pointerless (sizeof(sym##_bytecode__unaligned), "partial continuation stub"); \
+ memcpy (sym##_bytecode, sym##_bytecode__unaligned, sizeof(sym##_bytecode__unaligned));) \
+SCM_SNARF_INIT(sym = scm_double_cell (OBJCODE_TAG, \
+ (scm_t_bits)sym##_bytecode, \
+ SCM_UNPACK (SCM_BOOL_F), \
+ 0);) \
+static const scm_t_uint8 sym##_bytecode__unaligned[]
+#endif
+
-
SCM_STATIC_OBJCODE (cont_objcode) = {
/* Like in continuations.c, but with partial-cont-call. */
OBJCODE_HEADER (8, 19),
/* leave args on the stack */
/* 0 */ scm_op_object_ref, 0, /* push scm_vm_cont object */
- /* 2 */ scm_op_object_ref, 1, /* push internal winds */
- /* 4 */ scm_op_partial_cont_call, /* and go! */
- /* 5 */ scm_op_nop, scm_op_nop, scm_op_nop, /* pad to 8 bytes */
+ /* 2 */ scm_op_partial_cont_call, /* and go! */
+ /* 3 */ scm_op_nop,
+ /* 4 */ scm_op_nop, scm_op_nop, scm_op_nop, scm_op_nop, /* pad to 8 bytes */
/* 8 */
/* We could put some meta-info to say that this proc is a continuation. Not sure
META_HEADER (19),
/* 0 */ scm_op_make_eol, /* bindings */
/* 1 */ scm_op_make_eol, /* sources */
- /* 2 */ scm_op_make_int8, 0, scm_op_make_int8, 5, /* arity: from ip 0 to ip 7 */
+ /* 2 */ scm_op_make_int8, 0, scm_op_make_int8, 3, /* arity: from ip 0 to ip 3 */
/* 6 */ scm_op_make_int8_0, /* the arity is 0 required args */
/* 7 */ scm_op_make_int8_0, /* 0 optionals */
/* 8 */ scm_op_make_true, /* and a rest arg */
static SCM
-reify_partial_continuation (SCM vm, SCM prompt, SCM extwinds,
- scm_t_int64 cookie)
+reify_partial_continuation (SCM vm,
+ SCM *saved_fp, SCM *saved_sp, scm_t_uint8 *saved_ip,
+ scm_i_jmp_buf *saved_registers,
+ scm_t_dynstack *dynstack,
+ scm_i_jmp_buf *current_registers)
{
- SCM vm_cont, dynwinds, intwinds = SCM_EOL, ret;
+ SCM vm_cont, ret;
scm_t_uint32 flags;
- /* No need to reify if the continuation is never referenced in the handler. */
- if (SCM_PROMPT_ESCAPE_P (prompt))
- return SCM_BOOL_F;
-
- dynwinds = scm_i_dynwinds ();
- while (!scm_is_eq (dynwinds, extwinds))
- {
- intwinds = scm_cons (scm_car (dynwinds), intwinds);
- dynwinds = scm_cdr (dynwinds);
- }
-
flags = SCM_F_VM_CONT_PARTIAL;
- if (cookie >= 0 && SCM_PROMPT_REGISTERS (prompt)->cookie == cookie)
+ /* If we are aborting to a prompt that has the same registers as those
+ of the abort, it means there are no intervening C frames on the
+ stack, and so the continuation can be relocated elsewhere on the
+ stack: it is rewindable. */
+ if (saved_registers && saved_registers == current_registers)
flags |= SCM_F_VM_CONT_REWINDABLE;
/* Since non-escape continuations should begin with a thunk application, the
first bit of the stack should be a frame, with the saved fp equal to the fp
that was current when the prompt was made. */
- if ((SCM*)SCM_UNPACK (SCM_PROMPT_REGISTERS (prompt)->sp[1])
- != SCM_PROMPT_REGISTERS (prompt)->fp)
+ if ((SCM*)SCM_UNPACK (saved_sp[1]) != saved_fp)
abort ();
/* Capture from the top of the thunk application frame up to the end. Set an
MVRA only, as the post-abort code is in an MV context. */
- vm_cont = scm_i_vm_capture_stack (SCM_PROMPT_REGISTERS (prompt)->sp + 4,
+ vm_cont = scm_i_vm_capture_stack (saved_sp + 4,
SCM_VM_DATA (vm)->fp,
SCM_VM_DATA (vm)->sp,
NULL,
SCM_VM_DATA (vm)->ip,
+ dynstack,
flags);
ret = scm_make_program (cont_objcode,
- scm_vector (scm_list_2 (vm_cont, intwinds)),
+ scm_c_make_vector (1, vm_cont),
SCM_BOOL_F);
SCM_SET_CELL_WORD_0 (ret,
SCM_CELL_WORD_0 (ret) | SCM_F_PROGRAM_IS_PARTIAL_CONTINUATION);
}
void
-scm_c_abort (SCM vm, SCM tag, size_t n, SCM *argv, scm_t_int64 cookie)
+scm_c_abort (SCM vm, SCM tag, size_t n, SCM *argv,
+ scm_i_jmp_buf *current_registers)
{
- SCM cont, winds, prompt = SCM_BOOL_F;
- long delta;
+ SCM cont;
+ scm_t_dynstack *dynstack = &SCM_I_CURRENT_THREAD->dynstack;
+ scm_t_bits *prompt;
+ scm_t_dynstack_prompt_flags flags;
+ SCM *fp, *sp;
+ scm_t_uint8 *ip;
+ scm_i_jmp_buf *registers;
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, raise an error. */
- if (scm_is_false (prompt))
+ prompt = scm_dynstack_find_prompt (dynstack, tag,
+ &flags, &fp, &sp, &ip, ®isters);
+
+ if (!prompt)
scm_misc_error ("abort", "Abort to unknown prompt", scm_list_1 (tag));
- cont = reify_partial_continuation (vm, prompt, winds, cookie);
+ /* Only reify if the continuation referenced in the handler. */
+ if (flags & SCM_F_DYNSTACK_PROMPT_ESCAPE_ONLY)
+ cont = SCM_BOOL_F;
+ else
+ {
+ scm_t_dynstack *captured;
- /* Unwind once more, beyond the prompt. */
- winds = SCM_CDR (winds), delta++;
+ captured = scm_dynstack_capture (dynstack, SCM_DYNSTACK_NEXT (prompt));
+ cont = reify_partial_continuation (vm, fp, sp, ip, registers, captured,
+ current_registers);
+ }
- /* Unwind */
- scm_dowinds (winds, delta);
+ /* Unwind. */
+ scm_dynstack_unwind (dynstack, prompt);
/* Unwinding may have changed the current thread's VM, so use the
new one. */
vm = scm_the_vm ();
/* 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;
+ SCM_VM_DATA (vm)->fp = fp;
+ SCM_VM_DATA (vm)->sp = sp;
+ SCM_VM_DATA (vm)->ip = ip;
- /* Since we're jumping down, we should always have enough space */
+ /* 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 ();
*(++(SCM_VM_DATA (vm)->sp)) = scm_from_size_t (n+1); /* +1 for continuation */
/* Jump! */
- SCM_I_LONGJMP (SCM_PROMPT_REGISTERS (prompt)->regs, 1);
+ SCM_I_LONGJMP (*registers, 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_DEFINE (scm_abort_to_prompt_star, "abort-to-prompt*", 2, 0, 0,
+ (SCM tag, SCM args),
+ "Abort to the nearest prompt with tag @var{tag}, yielding the\n"
+ "values in the list, @var{args}.")
+#define FUNC_NAME s_scm_abort_to_prompt_star
{
SCM *argv;
- size_t i, n;
+ size_t i;
+ long 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, -1);
+ scm_c_abort (scm_the_vm (), tag, n, argv, NULL);
/* 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...
}
#undef FUNC_NAME
-void
-scm_i_prompt_print (SCM exp, SCM port, scm_print_state *pstate SCM_UNUSED)
-{
- scm_puts ("#<prompt ", port);
- scm_intprint (SCM_UNPACK (exp), 16, port);
- scm_putc ('>', port);
-}
-
void
scm_init_control (void)
{
HCoop / bpt / guile.git / blobdiff