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-rw-r--r--libguile/control.c117
1 files changed, 113 insertions, 4 deletions
diff --git a/libguile/control.c b/libguile/control.c
index 371ec2d20..25c95047b 100644
--- a/libguile/control.c
+++ b/libguile/control.c
@@ -22,6 +22,8 @@
#include "libguile/_scm.h"
#include "libguile/control.h"
+#include "libguile/objcodes.h"
+#include "libguile/instructions.h"
#include "libguile/vm.h"
@@ -52,10 +54,115 @@ scm_c_make_prompt (SCM vm, SCM k, scm_t_uint8 escape_only_p,
return ret;
}
+#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 ROUND_UP(len,align) (((len-1)|(align-1))+1)
+#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 (sizeof(sym##__unaligned) + alignment - 1); \
+ sym = ALIGN_PTR (type, sym, alignment); \
+ 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_object_ref, 2, /* push external winds */
+ /* 6 */ scm_op_partial_cont_call, /* and go! */
+ /* 7 */ scm_op_nop, /* pad to 8 bytes */
+ /* 8 */
+
+ /* 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, 7, /* 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;
+
+ /* NULL RA and MVRA, as those get set when the cont is reinstated */
+ vm_cont = scm_i_vm_capture_stack (SCM_PROMPT_REGISTERS (prompt)->sp,
+ SCM_VM_DATA (vm)->fp,
+ SCM_VM_DATA (vm)->sp,
+ NULL, NULL,
+ flags);
+
+ ret = scm_make_program (cont_objcode,
+ scm_vector (scm_list_3 (vm_cont, intwinds, extwinds)),
+ SCM_BOOL_F);
+ SCM_SET_CELL_WORD_0 (ret,
+ SCM_CELL_WORD_0 (ret) | SCM_F_PROGRAM_IS_CONTINUATION);
+ return ret;
+}
+
SCM
-scm_c_abort (SCM vm, SCM tag, size_t n, SCM *argv)
+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;
@@ -83,6 +190,8 @@ scm_c_abort (SCM vm, SCM tag, size_t n, SCM *argv)
abort ();
}
+ cont = reify_partial_continuation (vm, prompt, winds, cookie);
+
/* Unwind once more, beyond the prompt. */
winds = SCM_CDR (winds), delta++;
@@ -99,7 +208,7 @@ scm_c_abort (SCM vm, SCM tag, size_t n, SCM *argv)
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 */
@@ -123,7 +232,7 @@ SCM_DEFINE (scm_at_abort, "@abort", 2, 0, 0, (SCM tag, SCM args),
for (i = 0; i < n; i++, args = scm_cdr (args))
argv[i] = scm_car (args);
- scm_c_abort (scm_the_vm (), tag, n, argv);
+ 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...