+#if defined(PERL_TRACK_MEMPOOL) && defined(PERL_DEBUG_READONLY_COW)
+static void
+S_maybe_protect_rw(pTHX_ struct perl_memory_debug_header *header)
+{
+ if (header->readonly
+ && mprotect(header, header->size, PROT_READ|PROT_WRITE))
+ Perl_warn(aTHX_ "mprotect for COW string %p %lu failed with %d",
+ header, header->size, errno);
+}
+
+static void
+S_maybe_protect_ro(pTHX_ struct perl_memory_debug_header *header)
+{
+ if (header->readonly
+ && mprotect(header, header->size, PROT_READ))
+ Perl_warn(aTHX_ "mprotect RW for COW string %p %lu failed with %d",
+ header, header->size, errno);
+}
+# define maybe_protect_rw(foo) S_maybe_protect_rw(aTHX_ foo)
+# define maybe_protect_ro(foo) S_maybe_protect_ro(aTHX_ foo)
+#else
+# define maybe_protect_rw(foo) NOOP
+# define maybe_protect_ro(foo) NOOP
+#endif
+