#include "libguile/_scm.h"
#include "libguile/control.h"
+#include "libguile/objcodes.h"
+#include "libguile/instructions.h"
#include "libguile/vm.h"
\f
+
SCM
-scm_c_make_prompt (SCM vm, SCM k, scm_t_uint8 escape_only_p)
+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;
- 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);
+ tag |= (SCM_F_PROMPT_ESCAPE<<8);
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->fp = fp;
+ regs->sp = sp;
+ regs->ip = abort_ip;
+ regs->cookie = vm_cookie;
+
+ 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 */
+SCM
+scm_i_prompt_pop_abort_args_x (SCM prompt)
+{
+ size_t i, n;
+ SCM vals = SCM_EOL;
+
+ n = scm_to_size_t (SCM_PROMPT_REGISTERS (prompt)->sp[0]);
+ for (i = 0; i < n; i++)
+ vals = scm_cons (SCM_PROMPT_REGISTERS (prompt)->sp[-(i + 1)], vals);
+
+ /* The abort did reset the VM's registers, but then these values
+ were pushed on; so we need to pop them ourselves. */
+ SCM_VM_DATA (scm_the_vm ())->sp -= n + 1;
+ /* FIXME NULLSTACK */
+
+ return vals;
+}
+
+
+#ifdef WORDS_BIGENDIAN
+#define OBJCODE_HEADER(main,meta) 0, 0, 0, main, 0, 0, 0, meta+8
+#define META_HEADER(meta) 0, 0, 0, meta, 0, 0, 0, 0
+#else
+#define OBJCODE_HEADER(main,meta) main, 0, 0, 0, meta+8, 0, 0, 0
+#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))
+
+#ifdef 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_tc7_objcode | (SCM_F_OBJCODE_IS_STATIC << 8))
+
+#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_BOOL_F, SCM_PACK (0) } \
+ }; \
+ static const SCM sym = SCM_PACK (sym##__cells); \
+ SCM_STATIC_ALIGNED_ARRAY (8, scm_t_uint8, sym##__bytecode)
+
+
+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 */
+ /* 8 */
- 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 ());
+ /* We could put some meta-info to say that this proc is a continuation. Not sure
+ how to do that, though. */
+ 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 */
+ /* 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 */
+ /* 9 */ scm_op_list, 0, 5, /* make a list of those 5 vals */
+ /* 12 */ scm_op_list, 0, 1, /* and the arities will be a list of that one list */
+ /* 15 */ scm_op_list, 0, 3, /* pack bindings, sources, and arities into list */
+ /* 18 */ scm_op_return /* and return */
+ /* 19 */
+};
+
+static SCM
+reify_partial_continuation (SCM vm, SCM prompt, SCM extwinds,
+ scm_t_int64 cookie)
+{
+ SCM vm_cont, dynwinds, intwinds = SCM_EOL, 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)
+ 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_PROMPT_REGISTERS (prompt)->sp[1])
+ != SCM_PROMPT_REGISTERS (prompt)->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,
+ SCM_VM_DATA (vm)->fp,
+ SCM_VM_DATA (vm)->sp,
+ NULL,
+ SCM_VM_DATA (vm)->ip,
+ flags);
+
+ ret = scm_make_program (cont_objcode,
+ scm_vector (scm_list_2 (vm_cont, intwinds)),
+ SCM_BOOL_F);
+ SCM_SET_CELL_WORD_0 (ret,
+ SCM_CELL_WORD_0 (ret) | SCM_F_PROGRAM_IS_PARTIAL_CONTINUATION);
return ret;
}
-SCM
-scm_c_abort (SCM vm, SCM tag, size_t n, SCM *argv)
+void
+scm_c_abort (SCM vm, SCM tag, size_t n, SCM *argv, scm_t_int64 cookie)
{
- SCM winds, prompt = SCM_BOOL_F;
+ SCM cont, winds, prompt = SCM_BOOL_F;
long delta;
size_t i;
}
}
- /* 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 we didn't find anything, raise an error. */
if (scm_is_false (prompt))
- {
- /* FIXME: jump to default */
- /* scm_handle_by_message (NULL, key, args); */
- abort ();
- }
+ scm_misc_error ("abort", "Abort to unknown prompt", scm_list_1 (tag));
+
+ cont = reify_partial_continuation (vm, prompt, winds, cookie);
/* Unwind once more, beyond the prompt. */
winds = SCM_CDR (winds), delta++;
abort ();
/* Push vals */
- *(++(SCM_VM_DATA (vm)->sp)) = SCM_BOOL_F; /* the continuation */
+ *(++(SCM_VM_DATA (vm)->sp)) = cont;
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 */
abort ();
}
-SCM_DEFINE (scm_abort, "abort", 1, 0, 1, (SCM tag, SCM args),
+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_abort
+#define FUNC_NAME s_scm_at_abort
{
SCM *argv;
size_t i, 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. OK, pull
- args back from the stack, and keep going... */
-
- {
- SCM vals = SCM_EOL;
- struct scm_vm *vp = SCM_VM_DATA (scm_the_vm ());
- n = scm_to_size_t (vp->sp[0]);
- for (i = 0; i < n; i++)
- vals = scm_cons (vp->sp[-(i + 1)], vals);
- /* The continuation call did reset the VM's registers, but then these values
- were pushed on; so we need to pop them ourselves. */
- vp->sp -= n + 1;
- /* FIXME NULLSTACK */
-
- return (scm_is_pair (vals) && scm_is_null (scm_cdr (vals)))
- ? scm_car (vals) : scm_values (vals);
- }
+ scm_c_abort (scm_the_vm (), tag, n, argv, -1);
+
+ /* 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)
+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)
{
-#include "control.x"
+#include "libguile/control.x"
}
/*
HCoop / bpt / guile.git / blobdiff