From 57662048f3b5340f174f51c4f7d9921968aa6a1a Mon Sep 17 00:00:00 2001
From: Kaz Kylheku <kaz@kylheku.com>
Date: Sat, 16 Apr 2016 17:12:56 -0700
Subject: 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.
---
 unwind.c | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

(limited to 'unwind.c')

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);
-- 
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