*** empty log message ***

[bpt/guile.git] / libguile / pairs.h

diff --git a/libguile/pairs.h b/libguile/pairs.h
index 638e62d..40af8ce 100644 (file)
--- a/libguile/pairs.h
+++ b/libguile/pairs.h
@@ -2,7 +2,7 @@
 
 #ifndef PAIRSH
 #define PAIRSH
-/*     Copyright (C) 1995,1996 Free Software Foundation, Inc.
+/*     Copyright (C) 1995,1996, 2000 Free Software Foundation, Inc.
  * 
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -42,6 +42,10 @@
  * If you write modifications of your own for GUILE, it is your choice
  * whether to permit this exception to apply to your modifications.
  * If you do not wish that, delete this exception notice.  */
+
+/* Software engineering face-lift by Greg J. Badros, 11-Dec-1999,
+   gjb@cs.washington.edu, http://www.cs.washington.edu/homes/gjb */
+
 \f
 
 #include "libguile/__scm.h"
@@ -100,17 +104,21 @@ typedef SCM  huge *SCMPTR;
 
 #define SCM_CAR(x) (((scm_cell *)(SCM2PTR(x)))->car)
 #define SCM_CDR(x) (((scm_cell *)(SCM2PTR(x)))->cdr)
-#define SCM_GCCDR(x) (~1L & SCM_CDR(x))
-#define SCM_SETCAR(x, v) (SCM_CAR(x) = (SCM)(v))
-#define SCM_SETCDR(x, v) (SCM_CDR(x) = (SCM)(v))
+#define SCM_GCCDR(x) SCM_PACK(~1L & SCM_UNPACK (SCM_CDR(x)))
+#define SCM_SETCAR(x, v) (SCM_CAR(x) = SCM_PACK(v))
+#define SCM_SETCDR(x, v) (SCM_CDR(x) = SCM_PACK(v))
 
 #define SCM_CARLOC(x) (&SCM_CAR (x))
 #define SCM_CDRLOC(x) (&SCM_CDR (x))
 
-#define SCM_SETAND_CAR(x, y) (SCM_CAR (x) &= (y))
-#define SCM_SETAND_CDR(x, y) (SCM_CDR (x) &= (y))
-#define SCM_SETOR_CAR(x, y)  (SCM_CAR (x) |= (y))
-#define SCM_SETOR_CDR(x, y)  (SCM_CDR (x) |= (y))
+#define SCM_SETAND_CAR(x, y)\
+  (SCM_CAR (x) = SCM_PACK (SCM_UNPACK (SCM_CAR (x)) & (y)))
+#define SCM_SETAND_CDR(x, y)\
+  (SCM_CDR (x) = SCM_PACK (SCM_UNPACK (SCM_CDR (x)) & (y)))
+#define SCM_SETOR_CAR(x, y)\
+  (SCM_CAR (x) = SCM_PACK (SCM_UNPACK (SCM_CAR (x)) | (y)))
+#define SCM_SETOR_CDR(x, y)\
+  (SCM_CDR (x) = SCM_PACK (SCM_UNPACK (SCM_CDR (x)) | (y)))
 
 #define SCM_CAAR(OBJ)          SCM_CAR (SCM_CAR (OBJ))
 #define SCM_CDAR(OBJ)          SCM_CDR (SCM_CAR (OBJ))
@@ -143,6 +151,11 @@ typedef SCM  huge *SCMPTR;
 #define SCM_CADDDR(OBJ)                SCM_CAR (SCM_CDR (SCM_CDR (SCM_CDR (OBJ))))
 #define SCM_CDDDDR(OBJ)                SCM_CDR (SCM_CDR (SCM_CDR (SCM_CDR (OBJ))))
 
+/* the allocated thing: The car of newcells are set to
+   scm_tc16_allocated to avoid the fragile state of newcells wrt the
+   gc. If it stays as a freecell, any allocation afterwards could
+   cause the cell to go back on the freelist, which will bite you
+   sometime afterwards */
 
 #ifdef GUILE_DEBUG_FREELIST
 #define SCM_NEWCELL(_into) do { _into = scm_debug_newcell (); } while (0)
@@ -155,6 +168,7 @@ typedef SCM  huge *SCMPTR;
            { \
               _into = scm_freelist; \
               scm_freelist = SCM_CDR(scm_freelist);\
+               SCM_SETCAR(_into, scm_tc16_allocated); \
               ++scm_cells_allocated; \
            } \
        } while(0)
@@ -162,11 +176,11 @@ typedef SCM  huge *SCMPTR;
 
 \f
 
-extern SCM scm_cons SCM_P ((SCM x, SCM y));
-extern SCM scm_cons2 SCM_P ((SCM w, SCM x, SCM y));
-extern SCM scm_pair_p SCM_P ((SCM x));
-extern SCM scm_set_car_x SCM_P ((SCM pair, SCM value));
-extern SCM scm_set_cdr_x SCM_P ((SCM pair, SCM value));
-extern void scm_init_pairs SCM_P ((void));
+extern SCM scm_cons (SCM x, SCM y);
+extern SCM scm_cons2 (SCM w, SCM x, SCM y);
+extern SCM scm_pair_p (SCM x);
+extern SCM scm_set_car_x (SCM pair, SCM value);
+extern SCM scm_set_cdr_x (SCM pair, SCM value);
+extern void scm_init_pairs (void);
 
 #endif  /* PAIRSH */