Skip the aelemfast size comparison test for perls which predate the code change.

[p5sagit/Devel-Size.git] / Size.xs

diff --git a/Size.xs b/Size.xs
index 9a54522..a3f6eed 100644 (file)
--- a/Size.xs
+++ b/Size.xs
@@ -46,7 +46,6 @@
    without excessive memory needs. The assumption is that your CPU cache
    works :-) (And that we're not going to bust it)  */
 
-#define ALIGN_BITS  ( sizeof(void*) >> 1 )
 #define BYTE_BITS    3
 #define LEAF_BITS   (16 - BYTE_BITS)
 #define LEAF_MASK   0x1FFF
@@ -78,7 +77,7 @@ check_new(struct state *st, const void *const p) {
        (and hence hot in the cache) but we can still deal with any unaligned
        pointers.  */
     const size_t cooked_p
-       = (raw_p >> ALIGN_BITS) | (raw_p << (bits - BYTE_BITS));
+       = (raw_p >> ALIGN_BITS) | (raw_p << (bits - ALIGN_BITS));
     const U8 this_bit = 1 << (cooked_p & 0x7);
     U8 **leaf_p;
     U8 *leaf;
@@ -668,8 +667,16 @@ sv_size(pTHX_ struct state *const st, const SV * const orig_thing,
     if(isGV_with_GP(thing)) {
        st->total_size += GvNAMELEN(thing);
 #ifdef GvFILE
-       /* Is there a file? */
+#  if !defined(USE_ITHREADS) || (PERL_VERSION > 8 || (PERL_VERSION == 8 && PERL_SUBVERSION > 8))
+       /* With itreads, before 5.8.9, this can end up pointing to freed memory
+          if the GV was created in an eval, as GvFILE() points to CopFILE(),
+          and the relevant COP has been freed on scope cleanup after the eval.
+          5.8.9 adds a binary compatible fudge that catches the vast majority
+          of cases. 5.9.something added a proper fix, by converting the GP to
+          use a shared hash key (porperly reference counted), instead of a
+          char * (owned by who knows? possibly no-one now) */
        check_new_and_strlen(st, GvFILE(thing));
+#  endif
 #endif
        /* Is there something hanging off the glob? */
        if (check_new(st, GvGP(thing))) {