Sanity check for BYTEORDER.

[perl5.git] / av.h

diff --git a/av.h b/av.h
index 93dcc0c..d177122 100644 (file)
--- a/av.h
+++ b/av.h
@@ -1,6 +1,7 @@
 /*    av.h
  *
- *    Copyright (c) 1991-1994, Larry Wall
+ *    Copyright (C) 1991, 1992, 1993, 1995, 1996, 1997, 1998, 1999,
+ *    2000, 2001, 2002, by Larry Wall and others
  *
  *    You may distribute under the terms of either the GNU General Public
  *    License or the Artistic License, as specified in the README file.
@@ -8,29 +9,63 @@
  */
 
 struct xpvav {
-    char*      xav_array;      /* pointer to malloced string */
-    SSize_t    xav_fill;
-    SSize_t    xav_max;
+    char*      xav_array;      /* pointer to first array element */
+    SSize_t    xav_fill;       /* Index of last element present */
+    SSize_t    xav_max;        /* max index for which array has space */
     IV         xof_off;        /* ptr is incremented by offset */
-    double     xnv_nv;         /* numeric value, if any */
+    NV         xnv_nv;         /* numeric value, if any */
     MAGIC*     xmg_magic;      /* magic for scalar array */
     HV*                xmg_stash;      /* class package */
 
-    SV**       xav_alloc;
+    SV**       xav_alloc;      /* pointer to beginning of C array of SVs */
     SV*                xav_arylen;
     U8         xav_flags;
 };
 
+
+/* AVf_REAL is set for all AVs whose xav_array contents are refcounted.
+ * Some things like "@_" and the scratchpad list do not set this, to
+ * indicate that they are cheating (for efficiency) by not refcounting
+ * the AV's contents.
+ * 
+ * AVf_REIFY is only meaningful on such "fake" AVs (i.e. where AVf_REAL
+ * is not set).  It indicates that the fake AV is capable of becoming
+ * real if the array needs to be modified in some way.  Functions that
+ * modify fake AVs check both flags to call av_reify() as appropriate.
+ *
+ * Note that the Perl stack and @DB::args have neither flag set. (Thus,
+ * items that go on the stack are never refcounted.)
+ *
+ * These internal details are subject to change any time.  AV
+ * manipulations external to perl should not care about any of this.
+ * GSAR 1999-09-10
+ */
 #define AVf_REAL 1     /* free old entries */
 #define AVf_REIFY 2    /* can become real */
+
+/* XXX this is not used anywhere */
 #define AVf_REUSED 4   /* got undeffed--don't turn old memory into SVs now */
 
+/*
+=head1 Handy Values
+
+=for apidoc AmU||Nullav
+Null AV pointer.
+
+=head1 Array Manipulation Functions
+
+=for apidoc Am|int|AvFILL|AV* av
+Same as C<av_len()>.  Deprecated, use C<av_len()> instead.
+
+=cut
+*/
+
 #define Nullav Null(AV*)
 
 #define AvARRAY(av)    ((SV**)((XPVAV*)  SvANY(av))->xav_array)
 #define AvALLOC(av)    ((XPVAV*)  SvANY(av))->xav_alloc
 #define AvMAX(av)      ((XPVAV*)  SvANY(av))->xav_max
-#define AvFILL(av)     ((XPVAV*)  SvANY(av))->xav_fill
+#define AvFILLp(av)    ((XPVAV*)  SvANY(av))->xav_fill
 #define AvARYLEN(av)   ((XPVAV*)  SvANY(av))->xav_arylen
 #define AvFLAGS(av)    ((XPVAV*)  SvANY(av))->xav_flags
 
@@ -44,5 +79,9 @@ struct xpvav {
 #define AvREUSED_on(av)        (AvFLAGS(av) |= AVf_REUSED)
 #define AvREUSED_off(av) (AvFLAGS(av) &= ~AVf_REUSED)
 
-#define AvREALISH(av)  AvFLAGS(av)     /* REAL or REIFY -- shortcut */
+#define AvREALISH(av)  (AvFLAGS(av) & (AVf_REAL|AVf_REIFY))
+                                          
+#define AvFILL(av)     ((SvRMAGICAL((SV *) (av))) \
+                         ? mg_size((SV *) av) : AvFILLp(av))
 
+#define NEGATIVE_INDICES_VAR "NEGATIVE_INDICES"