-/* Copyright (C) 2010, 2011 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
- */
-
-#if HAVE_CONFIG_H
-# include <config.h>
-#endif
-
-#include <alloca.h>
-
-#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 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;
-
- 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 vm)
-{
- size_t i, n;
- SCM vals = SCM_EOL;
-
- n = scm_to_size_t (SCM_VM_DATA (vm)->sp[0]);
- for (i = 0; i < n; i++)
- vals = scm_cons (SCM_VM_DATA (vm)->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 (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_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_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 */
-
- /* 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_UNPACK (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;
-}
-
-void
-scm_c_abort (SCM vm, SCM tag, size_t n, SCM *argv, scm_t_int64 cookie)
-{
- SCM cont, winds, prompt = SCM_BOOL_F;
- long delta;
- 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))
- 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++;
-
- /* Unwind */
- scm_dowinds (winds, delta);
-
- /* 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;
-
- /* 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 ();
-
- /* Push vals */
- *(++(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 */
-
- /* Jump! */
- SCM_I_LONGJMP (SCM_PROMPT_REGISTERS (prompt)->regs, 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 *argv;
- 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);
-
- /* 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_i_prompt_print (SCM exp, SCM port, scm_print_state *pstate SCM_UNUSED)
-{
- scm_puts_unlocked ("#<prompt ", port);
- scm_intprint (SCM_UNPACK (exp), 16, port);
- scm_putc_unlocked ('>', port);
-}
-
-void
-scm_init_control (void)
-{
-#include "libguile/control.x"
-}
-
-/*
- Local Variables:
- c-file-style: "gnu"
- End:
-*/
+/* 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
+ * 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
+ */
+
+#if HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <alloca.h>
+
+#include "libguile/_scm.h"
+#include "libguile/control.h"
+#include "libguile/programs.h"
+#include "libguile/instructions.h"
+#include "libguile/vm.h"
+
+\f
+
+#define PROMPT_ESCAPE_P(p) \
+ (SCM_DYNSTACK_TAG_FLAGS (SCM_DYNSTACK_TAG (p)) \
+ & SCM_F_DYNSTACK_PROMPT_ESCAPE_ONLY)
+
+\f
+
+
+/* Only to be called if the SCM_I_SETJMP returns 1 */
+SCM
+scm_i_prompt_pop_abort_args_x (SCM vm)
+{
+ size_t i, n;
+ SCM vals = SCM_EOL;
+
+ n = scm_to_size_t (SCM_VM_DATA (vm)->sp[0]);
+ for (i = 0; i < n; i++)
+ vals = scm_cons (SCM_VM_DATA (vm)->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 (vm)->sp -= n + 1;
+ /* FIXME NULLSTACK */
+
+ return vals;
+}
+
+
+static const scm_t_uint32 compose_continuation_code[] =
+ {
+ SCM_PACK_RTL_24 (scm_rtl_op_compose_continuation, 0)
+ };
+
+
+static SCM
+make_partial_continuation (SCM vm_cont)
+{
+ scm_t_bits nfree = 1;
+ scm_t_bits flags = SCM_F_PROGRAM_IS_PARTIAL_CONTINUATION;
+ SCM ret;
+
+ ret = scm_words (scm_tc7_rtl_program | (nfree << 16) | flags, nfree + 2);
+ SCM_SET_CELL_WORD_1 (ret, compose_continuation_code);
+ SCM_RTL_PROGRAM_FREE_VARIABLE_SET (ret, 0, vm_cont);
+
+ return ret;
+}
+
+static SCM
+reify_partial_continuation (SCM vm,
+ SCM *saved_fp,
+ SCM *saved_sp,
+ scm_t_uint32 *saved_ip,
+ scm_i_jmp_buf *saved_registers,
+ scm_t_dynstack *dynstack,
+ scm_i_jmp_buf *current_registers)
+{
+ SCM vm_cont;
+ scm_t_uint32 flags;
+ SCM *bottom_fp;
+
+ flags = SCM_F_VM_CONT_PARTIAL;
+ /* 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;
+
+ /* Walk the stack down until we find the first frame after saved_fp.
+ We will save the stack down to that frame. It used to be that we
+ could determine the stack bottom in O(1) time, but that's no longer
+ the case, since the thunk application doesn't occur where the
+ prompt is saved. */
+ for (bottom_fp = SCM_VM_DATA (vm)->fp;
+ SCM_FRAME_DYNAMIC_LINK (bottom_fp) > saved_fp;
+ bottom_fp = SCM_FRAME_DYNAMIC_LINK (bottom_fp));
+
+ if (SCM_FRAME_DYNAMIC_LINK (bottom_fp) != saved_fp)
+ abort();
+
+ /* Capture from the top of the thunk application frame up to the end. */
+ vm_cont = scm_i_vm_capture_stack (&SCM_FRAME_LOCAL (bottom_fp, 0),
+ SCM_VM_DATA (vm)->fp,
+ SCM_VM_DATA (vm)->sp,
+ SCM_VM_DATA (vm)->ip,
+ dynstack,
+ flags);
+
+ return make_partial_continuation (vm_cont);
+}
+
+void
+scm_c_abort (SCM vm, SCM tag, size_t n, SCM *argv,
+ scm_i_jmp_buf *current_registers)
+{
+ 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_uint32 *ip;
+ scm_i_jmp_buf *registers;
+ size_t i;
+
+ 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));
+
+ /* 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;
+
+ captured = scm_dynstack_capture (dynstack, SCM_DYNSTACK_NEXT (prompt));
+ cont = reify_partial_continuation (vm, fp, sp, ip, registers, captured,
+ current_registers);
+ }
+
+ /* 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 = fp;
+ SCM_VM_DATA (vm)->sp = sp;
+ SCM_VM_DATA (vm)->ip = ip;
+
+ /* 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 ();
+
+ /* Push vals */
+ *(++(SCM_VM_DATA (vm)->sp)) = cont;
+ for (i = 0; i < n; i++)
+ *(++(SCM_VM_DATA (vm)->sp)) = argv[i];
+ if (flags & SCM_F_DYNSTACK_PROMPT_PUSH_NARGS)
+ *(++(SCM_VM_DATA (vm)->sp)) = scm_from_size_t (n+1); /* +1 for continuation */
+
+ /* Jump! */
+ SCM_I_LONGJMP (*registers, 1);
+
+ /* Shouldn't get here */
+ 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;
+ 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, 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...
+ abort! */
+
+ abort ();
+}
+#undef FUNC_NAME
+
+void
+scm_init_control (void)
+{
+#include "libguile/control.x"
+}
+
+/*
+ Local Variables:
+ c-file-style: "gnu"
+ End:
+*/
HCoop / bpt / guile.git / blobdiff