Add a define PERL_POISON which tries to trip up anything accessing

freed or uninitialised memory. Currently only Poison()s freed
pointers.

p4raw-id: //depot/perl@24959

1 files changed, 6 insertions, 0 deletions

diff --git a/handy.h b/handy.h
index 534e92e7b1..0a2c50e26c 100644
--- a/handy.h
+++ b/handy.h
@@ -626,7 +626,13 @@ hopefully catches attempts to access uninitialized memory.
 	  (v = (MEM_WRAP_CHECK_(n,t) (t*)saferealloc((Malloc_t)(v),(MEM_SIZE)((n)*sizeof(t)))))
 #define Renewc(v,n,t,c) \
 	  (v = (MEM_WRAP_CHECK_(n,t) (c*)saferealloc((Malloc_t)(v),(MEM_SIZE)((n)*sizeof(t)))))
+
+#ifdef PERL_POISON
+#define Safefree(d) \
+  (d ? (void)(safefree((Malloc_t)(d)), Poison(&(d), 1, Malloc_t)) : (void) 0)
+#else
 #define Safefree(d)	safefree((Malloc_t)(d))
+#endif
 
 #define Move(s,d,n,t)	(MEM_WRAP_CHECK_(n,t) (void)memmove((char*)(d),(const char*)(s), (n) * sizeof(t)))
 #define Copy(s,d,n,t)	(MEM_WRAP_CHECK_(n,t) (void)memcpy((char*)(d),(const char*)(s), (n) * sizeof(t)))