=cut
*/
+/* EXTEND_HWM_SET: note the high-water-mark to which the stack has been
+ * requested to be extended (which is likely to be less than PL_stack_max)
+ */
+#if defined DEBUGGING && !defined DEBUGGING_RE_ONLY
+# define EXTEND_HWM_SET(p, n) \
+ STMT_START { \
+ SSize_t ix = (p) - PL_stack_base + (n); \
+ if (ix > PL_curstackinfo->si_stack_hwm) \
+ PL_curstackinfo->si_stack_hwm = ix; \
+ } STMT_END
+#else
+# define EXTEND_HWM_SET(p, n) NOOP
+#endif
+
/* _EXTEND_SAFE_N(n): private helper macro for EXTEND().
* Tests whether the value of n would be truncated when implicitly cast to
* SSize_t as an arg to stack_grow(). If so, sets it to -1 instead to
(sizeof(n) > sizeof(SSize_t) && ((SSize_t)(n) != (n)) ? -1 : (n))
#ifdef STRESS_REALLOC
+# define EXTEND_SKIP(p, n) EXTEND_HWM_SET(p, n)
+
# define EXTEND(p,n) STMT_START { \
sp = stack_grow(sp,p,_EXTEND_SAFE_N(n)); \
PERL_UNUSED_VAR(sp); \
* this just gives a safe false positive
*/
-# define _EXTEND_NEEDS_GROW(p,n) ( (n) < 0 || PL_stack_max - p < (n))
+# define _EXTEND_NEEDS_GROW(p,n) ((n) < 0 || PL_stack_max - (p) < (n))
+
+
+/* EXTEND_SKIP(): used for where you would normally call EXTEND(), but
+ * you know for sure that a previous op will have already extended the
+ * stack sufficiently. For example pp_enteriter ensures that that there
+ * is always at least 1 free slot, so pp_iter can return &PL_sv_yes/no
+ * without checking each time. Calling EXTEND_SKIP() defeats the HWM
+ * debugging mechanism which would otherwise whine
+ */
+
+# define EXTEND_SKIP(p, n) STMT_START { \
+ EXTEND_HWM_SET(p, n); \
+ assert(!_EXTEND_NEEDS_GROW(p,n)); \
+ } STMT_END
+
# define EXTEND(p,n) STMT_START { \
+ EXTEND_HWM_SET(p, n); \
if (UNLIKELY(_EXTEND_NEEDS_GROW(p,n))) { \
sp = stack_grow(sp,p,_EXTEND_SAFE_N(n)); \
PERL_UNUSED_VAR(sp); \
} } STMT_END
/* Same thing, but update mark register too. */
# define MEXTEND(p,n) STMT_START { \
+ EXTEND_HWM_SET(p, n); \
if (UNLIKELY(_EXTEND_NEEDS_GROW(p,n))) { \
const SSize_t markoff = mark - PL_stack_base;\
sp = stack_grow(sp,p,_EXTEND_SAFE_N(n)); \
} } STMT_END
#endif
+
/* set TARG to the IV value i. If do_taint is false,
* assume that PL_tainted can never be true */
#define TARGi(i, do_taint) \