Valgrind support in continuations.

* unwind.c (revive_cont): When scanning the stack of the
revived continuation to fix up pointers, we can save the
Valgrind validity bits of each word, mark it defined, and then
restore the validity bits.

1 files changed, 18 insertions, 1 deletions

diff --git a/unwind.c b/unwind.c
index a521c732..7495be1e 100644
--- a/unwind.c
+++ b/unwind.c
@@ -33,6 +33,9 @@
 #include <stdarg.h>
 #include <signal.h>
 #include "config.h"
+#if HAVE_VALGRIND
+#include <valgrind/memcheck.h>
+#endif
 #include "lib.h"
 #include "gc.h"
 #include "args.h"
@@ -754,11 +757,25 @@ static val revive_cont(val dc, val arg)
     for (ptr = space; ptr < space + cont->size; ptr += sizeof (cnum))
     {
       uint_ptr_t *wordptr = coerce(uint_ptr_t *, ptr);
-      uint_ptr_t word = *wordptr;
+      uint_ptr_t word;
+#if HAVE_VALGRIND
+      uint_ptr_t vbits = 0;
+
+      if (opt_vg_debug) {
+        VALGRIND_GET_VBITS(wordptr, &vbits, sizeof *wordptr);
+        VALGRIND_MAKE_MEM_DEFINED(wordptr, sizeof *wordptr);
+      }
+#endif
+      word = *wordptr;
 
       if (word >= orig_start - frame_slack &&
           word < orig_end && is_ptr(coerce(val, word)))
         *wordptr = word + delta;
+
+#if HAVE_VALGRIND
+      if (opt_vg_debug)
+        VALGRIND_SET_VBITS(wordptr, &vbits, sizeof *wordptr);
+#endif
     }
 
     uw_block_begin (cont->tag, result);