* Programming Language Design and Implementation, June 1993
* ftp://ftp.cs.indiana.edu/pub/scheme-repository/doc/pubs/guardians.ps.gz
*
- * Author: Michael N. Livshin
- * Modified by: Mikael Djurfeldt
+ * By this point, the semantics are actually quite different from
+ * those described in the abovementioned paper. The semantic changes
+ * are there to improve safety and intuitiveness. The interface is
+ * still (mostly) the one described by the paper, however.
+ *
+ * Original design: Mikael Djurfeldt
+ * Original implementation: Michael Livshin
+ * Hacked on since by: everybody
*/
-#include <stdio.h>
-#include <assert.h>
#include "libguile/_scm.h"
#include "libguile/ports.h"
#include "libguile/print.h"
#include "libguile/smob.h"
-#include "libguile/vectors.h"
-
#include "libguile/validate.h"
+#include "libguile/root.h"
+#include "libguile/hashtab.h"
+#include "libguile/weaks.h"
+
#include "libguile/guardians.h"
-static long scm_tc16_guardian;
/* The live and zombies FIFOs are implemented as tconcs as described
in Dybvig's paper. This decouples addition and removal of elements
so that no synchronization between these needs to take place.
*/
+
+typedef struct tconc_t
+{
+ SCM head;
+ SCM tail;
+} tconc_t;
+
+#define TCONC_EMPTYP(tc) (SCM_EQ_P ((tc).head, (tc).tail))
+
#define TCONC_IN(tc, obj, pair) \
do { \
SCM_SETCAR ((tc).tail, obj); \
(tc).head = SCM_CDR ((tc).head); \
} while (0)
-#define TCONC_EMPTYP(tc) (SCM_EQ_P ((tc).head, (tc).tail))
-typedef struct tconc_t
-{
- SCM head;
- SCM tail;
-} tconc_t;
+static scm_bits_t tc16_guardian;
typedef struct guardian_t
{
tconc_t live;
tconc_t zombies;
struct guardian_t *next;
+ unsigned long flags;
} guardian_t;
+#define GUARDIAN_P(x) SCM_SMOB_PREDICATE(tc16_guardian, x)
#define GUARDIAN(x) ((guardian_t *) SCM_CELL_WORD_1 (x))
-#define GUARDIAN_LIVE(x) (GUARDIAN (x)->live)
-#define GUARDIAN_ZOMBIES(x) (GUARDIAN (x)->zombies)
-#define GUARDIAN_NEXT(x) (GUARDIAN (x)->next)
-#define CCLO_G(cclo) (SCM_VELTS (cclo)[1])
+#define F_GREEDY 1L
+#define F_LISTED (1L << 1)
+#define F_DESTROYED (1L << 2)
-/* subr constructed from guard below. */
-static SCM guard1;
+#define GREEDY_P(x) (((x)->flags & F_GREEDY) != 0)
+#define SET_GREEDY(x) ((x)->flags |= F_GREEDY)
-/* this is wrapped in a compiled closure and is the Scheme entry point
- for each guardian: if arg is an object, it's added to the
- guardian's live list. if arg is unbound, the next available
- zombified object (or #f if none) is returned. */
-static SCM
-guard (SCM cclo, SCM arg)
+#define LISTED_P(x) (((x)->flags & F_LISTED) != 0)
+#define SET_LISTED(x) ((x)->flags |= F_LISTED)
+#define CLR_LISTED(x) ((x)->flags &= ~F_LISTED)
+
+#define DESTROYED_P(x) (((x)->flags & F_DESTROYED) != 0)
+#define SET_DESTROYED(x) ((x)->flags |= F_DESTROYED)
+
+/* during the gc mark phase, live guardians are linked into the lists
+ here. */
+static guardian_t *greedy_guardians = NULL;
+static guardian_t *sharing_guardians = NULL;
+
+static SCM greedily_guarded_whash = SCM_EOL;
+
+/* this is the list of guarded objects that are parts of cycles. we
+ don't know in which order to return them from guardians, so we just
+ unguard them and whine about it in after-gc-hook */
+static SCM self_centered_zombies = SCM_EOL;
+
+
+static void
+add_to_live_list (guardian_t *g)
{
- if (!SCM_UNBNDP (arg))
+ if (LISTED_P (g))
+ return;
+
+ if (GREEDY_P (g))
{
- scm_guard (cclo, arg);
- return SCM_UNSPECIFIED;
+ g->next = greedy_guardians;
+ greedy_guardians = g;
}
else
- return scm_get_one_zombie (cclo);
+ {
+ g->next = sharing_guardians;
+ sharing_guardians = g;
+ }
+
+ SET_LISTED (g);
}
-void
-scm_guard (SCM guardian, SCM obj)
+/* mark a guardian by adding it to the live guardian list. */
+static SCM
+guardian_mark (SCM ptr)
+{
+ add_to_live_list (GUARDIAN (ptr));
+
+ /* the objects protected by the guardian are not marked here: that
+ would prevent them from ever getting collected. instead marking
+ is done at the end of the mark phase by guardian_zombify. */
+ return SCM_BOOL_F;
+}
+
+
+static scm_sizet
+guardian_free (SCM ptr)
+{
+ scm_must_free (GUARDIAN (ptr));
+ return sizeof (guardian_t);
+}
+
+
+static int
+guardian_print (SCM guardian, SCM port, scm_print_state *pstate)
{
- SCM g = CCLO_G (guardian);
+ guardian_t *g = GUARDIAN (guardian);
+
+ scm_puts ("#<", port);
+
+ if (DESTROYED_P (g))
+ scm_puts ("destroyed ", port);
+
+ if (GREEDY_P (g))
+ scm_puts ("greedy", port);
+ else
+ scm_puts ("sharing", port);
+
+ scm_puts (" guardian 0x", port);
+ scm_intprint ((long) g, 16, port);
- if (SCM_NIMP (obj))
+ if (! DESTROYED_P (g))
+ {
+ scm_puts (" (reachable: ", port);
+ scm_display (scm_length (SCM_CDR (g->live.head)), port);
+ scm_puts (" unreachable: ", port);
+ scm_display (scm_length (SCM_CDR (g->zombies.head)), port);
+ scm_puts (")", port);
+ }
+
+ scm_puts (">", port);
+
+ return 1;
+}
+
+
+/* This is the Scheme entry point for each guardian: If OBJ is an
+ * object, it's added to the guardian's live list. If OBJ is unbound,
+ * the next available unreachable object (or #f if none) is returned.
+ *
+ * If the second optional argument THROW_P is true (the default), then
+ * an error is raised if GUARDIAN is greedy and OBJ is already greedily
+ * guarded. If THROW_P is false, #f is returned instead of raising the
+ * error, and #t is returned if everything is fine.
+ */
+static SCM
+guardian_apply (SCM guardian, SCM obj, SCM throw_p)
+{
+ if (DESTROYED_P (GUARDIAN (guardian)))
+ scm_misc_error ("guard", "attempted use of destroyed guardian: ~A",
+ SCM_LIST1 (guardian));
+
+ if (!SCM_UNBNDP (obj))
+ return scm_guard (guardian, obj,
+ (SCM_UNBNDP (throw_p)
+ ? 1
+ : SCM_NFALSEP (throw_p)));
+ else
+ return scm_get_one_zombie (guardian);
+}
+
+
+SCM
+scm_guard (SCM guardian, SCM obj, int throw_p)
+{
+ guardian_t *g = GUARDIAN (guardian);
+
+ if (!SCM_IMP (obj))
{
SCM z;
-
- SCM_NEWCELL (z);
+ SCM_NEWCELL (z);
+
/* This critical section barrier will be replaced by a mutex. */
SCM_DEFER_INTS;
- TCONC_IN (GUARDIAN_LIVE (g), obj, z);
+
+ if (GREEDY_P (g))
+ {
+ if (SCM_NFALSEP (scm_hashq_get_handle
+ (greedily_guarded_whash, obj)))
+ {
+ SCM_ALLOW_INTS;
+
+ if (throw_p)
+ scm_misc_error ("guard",
+ "object is already greedily guarded: ~A",
+ SCM_LIST1 (obj));
+ else
+ return SCM_BOOL_F;
+ }
+ else
+ scm_hashq_create_handle_x (greedily_guarded_whash,
+ obj, guardian);
+ }
+
+ TCONC_IN (g->live, obj, z);
+
SCM_ALLOW_INTS;
}
+
+ return throw_p ? SCM_UNSPECIFIED : SCM_BOOL_T;
+
}
+
SCM
scm_get_one_zombie (SCM guardian)
{
- SCM g = CCLO_G (guardian);
+ guardian_t *g = GUARDIAN (guardian);
SCM res = SCM_BOOL_F;
/* This critical section barrier will be replaced by a mutex. */
SCM_DEFER_INTS;
- if (!TCONC_EMPTYP (GUARDIAN_ZOMBIES (g)))
- TCONC_OUT (GUARDIAN_ZOMBIES (g), res);
+
+ if (!TCONC_EMPTYP (g->zombies))
+ TCONC_OUT (g->zombies, res);
+
+ if (SCM_NFALSEP (res)
+ && GREEDY_P (g))
+ scm_hashq_remove_x (greedily_guarded_whash, res);
+
SCM_ALLOW_INTS;
+
return res;
}
-SCM_DEFINE (scm_make_guardian, "make-guardian", 0, 0, 0,
- (),
+
+SCM_DEFINE (scm_make_guardian, "make-guardian", 0, 1, 0,
+ (SCM greedy_p),
"Create a new guardian.\n"
"A guardian protects a set of objects from garbage collection,\n"
"allowing a program to apply cleanup or other actions.\n\n"
"one of the protected objects which are ready for garbage\n"
"collection or @code{#f} if no such object is available.\n"
"Objects which are returned in this way are removed from\n"
- "the guardian.\n\n".
+ "the guardian.\n\n"
+
+ "make-guardian takes one optional argument that says whether the\n"
+ "new guardian should be greedy or sharing. if there is any chance\n"
+ "that any object protected by the guardian may be resurrected,\n"
+ "then you should make the guardian greedy (this is the default).\n\n"
"See R. Kent Dybvig, Carl Bruggeman, and David Eby (1993)\n"
"\"Guardians in a Generation-Based Garbage Collector\".\n"
"ACM SIGPLAN Conference on Programming Language Design\n"
- "and Implementation, June 1993.")
+ "and Implementation, June 1993.\n\n"
+
+ "(the semantics are slightly different at this point, but the\n"
+ "paper still (mostly) accurately describes the interface).")
#define FUNC_NAME s_scm_make_guardian
{
- SCM cclo = scm_makcclo (guard1, 2L);
- guardian_t *g = SCM_MUST_MALLOC_TYPE(guardian_t);
+ guardian_t *g = SCM_MUST_MALLOC_TYPE (guardian_t);
SCM z1 = scm_cons (SCM_BOOL_F, SCM_EOL);
SCM z2 = scm_cons (SCM_BOOL_F, SCM_EOL);
SCM z;
g->live.head = g->live.tail = z1;
g->zombies.head = g->zombies.tail = z2;
- SCM_NEWSMOB (z, scm_tc16_guardian, g);
+ g->next = NULL;
+ g->flags = 0L;
- CCLO_G (cclo) = z;
+ /* [cmm] the UNBNDP check below is redundant but I like it. */
+ if (SCM_UNBNDP (greedy_p) || SCM_NFALSEP (greedy_p))
+ SET_GREEDY (g);
+
+ SCM_NEWSMOB (z, tc16_guardian, g);
- return cclo;
+ return z;
}
#undef FUNC_NAME
-/* during the gc mark phase, live guardians are linked into a list
- here. */
-static guardian_t *first_live_guardian = NULL;
-static guardian_t **current_link_field = NULL;
-/* called before gc mark phase begins to initialise the live guardian
- list. */
-void
-scm_guardian_gc_init()
+SCM_DEFINE (scm_guardian_destroyed_p, "guardian-destroyed?", 1, 0, 0,
+ (SCM guardian),
+ "Is @var{guardian} destroyed?")
+#define FUNC_NAME s_scm_guardian_destroyed_p
+{
+ SCM res = SCM_BOOL_F;
+
+ /* This critical section barrier will be replaced by a mutex. */
+ SCM_DEFER_INTS;
+
+ res = SCM_BOOL (DESTROYED_P (GUARDIAN (guardian)));
+
+ SCM_ALLOW_INTS;
+
+ return res;
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_guardian_greedy_p, "guardian_greedy?", 1, 0, 0,
+ (SCM guardian),
+ "Is @var{guardian} greedy?")
+#define FUNC_NAME s_scm_guardian_greedy_p
{
- current_link_field = &first_live_guardian;
- first_live_guardian = NULL;
+ return SCM_BOOL (GREEDY_P (GUARDIAN (guardian)));
}
+#undef FUNC_NAME
-/* mark a guardian by adding it to the live guardian list. */
-static SCM
-g_mark (SCM ptr)
+SCM_DEFINE (scm_destroy_guardian_x, "destroy-guardian!", 1, 0, 0,
+ (SCM guardian),
+ "Destroys @var{guardian}, by making it impossible to put any more\n"
+ "objects in it or get any objects from it. It also unguards any\n"
+ "objects guarded by @var{guardian}.")
+#define FUNC_NAME s_scm_destroy_guardian_x
{
- *current_link_field = GUARDIAN (ptr);
- current_link_field = &GUARDIAN_NEXT (ptr);
- GUARDIAN_NEXT (ptr) = NULL;
+ guardian_t *g = GUARDIAN (guardian);
- /* the objects protected by the guardian are not marked here: that
- would prevent them from ever getting collected. instead marking
- is done at the end of the mark phase by scm_guardian_zombify. */
- return SCM_BOOL_F;
+ /* This critical section barrier will be replaced by a mutex. */
+ SCM_DEFER_INTS;
+
+ if (DESTROYED_P (g))
+ {
+ SCM_ALLOW_INTS;
+ SCM_MISC_ERROR ("guardian is already destroyed: ~A", SCM_LIST1 (guardian));
+ }
+
+ if (GREEDY_P (g))
+ {
+ /* clear the "greedily guarded" property of the objects */
+ SCM pair;
+ for (pair = g->live.head; pair != g->live.tail; pair = SCM_CDR (pair))
+ scm_hashq_remove_x (greedily_guarded_whash, SCM_CAR (pair));
+ for (pair = g->zombies.head; pair != g->zombies.tail; pair = SCM_CDR (pair))
+ scm_hashq_remove_x (greedily_guarded_whash, SCM_CAR (pair));
+ }
+
+ /* empty the lists */
+ g->live.head = g->live.tail;
+ g->zombies.head = g->zombies.tail;
+
+ SET_DESTROYED (g);
+
+ SCM_ALLOW_INTS;
+
+ return SCM_UNSPECIFIED;
+}
+#undef FUNC_NAME
+
+/* called before gc mark phase begins to initialise the live guardian list. */
+static void *
+guardian_gc_init (void *dummy1, void *dummy2, void *dummy3)
+{
+ greedy_guardians = sharing_guardians = NULL;
+
+ return 0;
}
+static void
+mark_dependencies_in_tconc (tconc_t *tc)
+{
+ SCM pair, next_pair;
+ SCM *prev_ptr;
+
+ /* scan the list for unmarked objects, and mark their
+ dependencies */
+ for (pair = tc->head, prev_ptr = &tc->head;
+ ! SCM_EQ_P (pair, tc->tail);
+ pair = next_pair)
+ {
+ SCM obj = SCM_CAR (pair);
+ next_pair = SCM_CDR (pair);
+
+ if (! SCM_MARKEDP (obj))
+ {
+ /* a candidate for finalizing */
+ scm_gc_mark_dependencies (obj);
+
+ if (SCM_MARKEDP (obj))
+ {
+ /* uh oh. a cycle. transfer this object (the
+ spine cell, to be exact) to
+ self_centered_zombies, so we'll be able to
+ complain about it later. */
+ *prev_ptr = next_pair;
+ SCM_SETGCMARK (pair);
+ SCM_SETCDR (pair, SCM_CDR (self_centered_zombies));
+ SCM_SETCDR (self_centered_zombies, pair);
+ }
+ else
+ {
+ /* see if this is a guardian. if yes, list it (but don't
+ mark it yet). */
+ if (GUARDIAN_P (obj))
+ add_to_live_list (GUARDIAN (obj));
+
+ prev_ptr = SCM_CDRLOC (pair);
+ }
+ }
+ }
+}
+
+static void
+mark_dependencies (guardian_t *g)
+{
+ mark_dependencies_in_tconc (&g->zombies);
+ mark_dependencies_in_tconc (&g->live);
+}
+
+static void
+mark_and_zombify (guardian_t *g)
+{
+ SCM tconc_tail = g->live.tail;
+ SCM *prev_ptr = &g->live.head;
+ SCM pair = g->live.head;
+
+ while (! SCM_EQ_P (pair, tconc_tail))
+ {
+ SCM next_pair = SCM_CDR (pair);
+
+ if (SCM_NMARKEDP (SCM_CAR (pair)))
+ {
+ /* got you, zombie! */
+
+ /* out of the live list! */
+ *prev_ptr = next_pair;
+
+ if (GREEDY_P (g))
+ /* if the guardian is greedy, mark this zombie now. this
+ way it won't be zombified again this time around. */
+ SCM_SETGCMARK (SCM_CAR (pair));
+
+ /* into the zombie list! */
+ TCONC_IN (g->zombies, SCM_CAR (pair), pair);
+ }
+ else
+ prev_ptr = SCM_CDRLOC (pair);
+
+ pair = next_pair;
+ }
+
+ /* Mark the cells of the live list (yes, the cells in the list, we
+ don't care about objects pointed to by the list cars, since we
+ know they are already marked). */
+ for (pair = g->live.head; !SCM_NULLP (pair); pair = SCM_CDR (pair))
+ SCM_SETGCMARK (pair);
+}
+
+
/* this is called by the garbage collector between the mark and sweep
phases. for each marked guardian, it moves any unmarked object in
its live list (tconc) to its zombie list (tconc). */
-void scm_guardian_zombify (void)
+static void *
+guardian_zombify (void *dummy1, void *dummy2, void *dummy3)
{
- guardian_t *first_guardian;
- guardian_t **link_field = &first_live_guardian;
-
- /* Note that new guardians may be stuck on the end of the live
- guardian list as we run this loop. As we move unmarked objects
- to the zombie list and mark them, we may find some guarded
- guardians. The guardian mark function will stick them on the end
- of this list, so they'll be processed properly. */
+ guardian_t *last_greedy_guardian = NULL;
+ guardian_t *last_sharing_guardian = NULL;
+ guardian_t *first_greedy_guardian = NULL;
+ guardian_t *first_sharing_guardian = NULL;
+ guardian_t *g;
+
+ /* First, find all newly unreachable objects and mark their
+ dependencies.
+
+ Note that new guardians may be stuck on the end of the live
+ guardian lists as we run this loop, since guardians might be
+ guarded too. When we mark a guarded guardian, its mark function
+ sticks in the appropriate live guardian list. The loop
+ terminates when no new guardians are found. */
do {
- guardian_t *g;
-
- first_guardian = *link_field;
- link_field = current_link_field;
-
- /* first, scan all the guardians that are currently known to be live
- and move their unmarked objects to zombie lists. */
-
- for (g = first_guardian; g; g = g->next)
- {
- SCM tconc_tail = g->live.tail;
- SCM *prev_ptr = &g->live.head;
- SCM pair = g->live.head;
-
- while (! SCM_EQ_P (pair, tconc_tail))
- {
- SCM next_pair = SCM_CDR (pair);
-
- if (SCM_NMARKEDP (SCM_CAR (pair)))
- {
- /* got you, zombie! */
-
- /* out of the live list! */
- *prev_ptr = next_pair;
-
- /* into the zombie list! */
- TCONC_IN (g->zombies, SCM_CAR (pair), pair);
- }
- else
- prev_ptr = SCM_CDRLOC (pair);
+ first_greedy_guardian = greedy_guardians;
+ first_sharing_guardian = sharing_guardians;
- pair = next_pair;
- }
-
- /* Mark the cells of the live list (yes, the cells in the list,
- even though we don't care about objects pointed to by the list
- cars, since we know they are already marked). */
- for (pair = g->live.head; SCM_NIMP (pair); pair = SCM_GCCDR (pair))
- SCM_SETGCMARK (pair);
- }
-
- /* ghouston: Doesn't it seem a bit disturbing that if a zombie
- is returned to full life after getting returned from the
- guardian procedure, it may reference objects which are in a
- guardian's zombie list? Is it not necessary to move such
- zombies back to the live list, to avoid allowing the
- guardian procedure to return an object which is referenced,
- so not collectable? The paper doesn't give this
- impression.
-
- cmm: the paper does explicitly say that an object that is
- guarded more than once should be returned more than once.
- I believe this covers the above scenario. */
-
- /* Preserve the zombies in their undead state, by marking to
- prevent collection. Note that this may uncover zombified
- guardians -- if so, they'll be processed in the next loop. */
-
- for (g = first_guardian; g && (!*link_field || g != *link_field); g = g->next)
- scm_gc_mark (g->zombies.head);
-
- } while (current_link_field != link_field);
+ for (g = greedy_guardians; g != last_greedy_guardian;
+ g = g->next)
+ mark_dependencies (g);
+ for (g = sharing_guardians; g != last_sharing_guardian;
+ g = g->next)
+ mark_dependencies (g);
+
+ last_greedy_guardian = first_greedy_guardian;
+ last_sharing_guardian = first_sharing_guardian;
+ } while (first_greedy_guardian != greedy_guardians
+ || first_sharing_guardian != sharing_guardians);
+
+ /* now, scan all the guardians that are currently known to be live
+ and move their unmarked objects to zombie lists. */
+
+ for (g = greedy_guardians; g; g = g->next)
+ {
+ mark_and_zombify (g);
+ CLR_LISTED (g);
+ }
+ for (g = sharing_guardians; g; g = g->next)
+ {
+ mark_and_zombify (g);
+ CLR_LISTED (g);
+ }
+
+ /* Preserve the zombies in their undead state, by marking to prevent
+ collection. */
+ for (g = greedy_guardians; g; g = g->next)
+ scm_gc_mark (g->zombies.head);
+ for (g = sharing_guardians; g; g = g->next)
+ scm_gc_mark (g->zombies.head);
+
+ return 0;
}
-/* not generally used, since guardian smob is wrapped in a closure.
- maybe useful for debugging. */
-static int
-g_print (SCM exp, SCM port, scm_print_state *pstate)
+static void *
+whine_about_self_centered_zombies (void *dummy1, void *dummy2, void *dummy3)
{
- char buf[256];
- sprintf (buf, "#<guardian live objs: %lu zombies: %lu>",
- scm_ilength (SCM_CDR (GUARDIAN_LIVE (exp).head)),
- scm_ilength (SCM_CDR (GUARDIAN_ZOMBIES (exp).head)));
- scm_puts (buf, port);
-
- return 1;
+ if (! SCM_NULLP (SCM_CDR (self_centered_zombies)))
+ {
+ SCM pair;
+
+ scm_puts ("** WARNING: the following guarded objects were unguarded due to cycles:",
+ scm_cur_errp);
+ scm_newline (scm_cur_errp);
+ for (pair = SCM_CDR (self_centered_zombies);
+ ! SCM_NULLP (pair); pair = SCM_CDR (pair))
+ {
+ scm_display (SCM_CAR (pair), scm_cur_errp);
+ scm_newline (scm_cur_errp);
+ }
+
+ SCM_SETCDR (self_centered_zombies, SCM_EOL);
+ }
+
+ return 0;
}
void
-scm_init_guardian()
+scm_init_guardians ()
{
- scm_tc16_guardian = scm_make_smob_type_mfpe ("guardian", sizeof (guardian_t),
- g_mark, NULL, g_print, NULL);
- guard1 = scm_make_subr_opt ("guardian", scm_tc7_subr_2o, guard, 0);
+ tc16_guardian = scm_make_smob_type ("guardian", 0);
+ scm_set_smob_mark (tc16_guardian, guardian_mark);
+ scm_set_smob_free (tc16_guardian, guardian_free);
+ scm_set_smob_print (tc16_guardian, guardian_print);
+ scm_set_smob_apply (tc16_guardian, guardian_apply, 0, 2, 0);
+
+ scm_c_hook_add (&scm_before_mark_c_hook, guardian_gc_init, 0, 0);
+ scm_c_hook_add (&scm_before_sweep_c_hook, guardian_zombify, 0, 0);
+
+ self_centered_zombies =
+ scm_permanent_object (scm_cons (SCM_UNDEFINED, SCM_EOL));
+ scm_c_hook_add (&scm_after_gc_c_hook,
+ whine_about_self_centered_zombies, 0, 0);
+
+ greedily_guarded_whash =
+ scm_permanent_object (scm_make_doubly_weak_hash_table (SCM_MAKINUM (31)));
+#ifndef SCM_MAGIC_SNARFER
#include "libguile/guardians.x"
+#endif
}
/*
HCoop / bpt / guile.git / blobdiff