Tell valgrind about conservative GC regions and suppress spurious

warings.

* alloc.c (USE_VALGRIND): New macro; on by default
when ENABLE_CHECKING.
(mark_maybe_object,mark_maybe_pointer)
[USE_VALGRIND]: Mark conservatively-scanned regions valid for
valgrind purposes.
(valgrind_p) [USE_VALGRIND]: New variable.
(init_alloc) [USE_VALGRIND]: Initialize valgrind_p.

1 files changed, 26 insertions, 0 deletions

diff --git a/src/alloc.c b/src/alloc.c
index 847b3c88bbe..564faa18aa8 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -45,6 +45,18 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include <verify.h>
 
+#if (defined ENABLE_CHECKING &&               \
+     defined HAVE_VALGRIND_VALGRIND_H &&      \
+     !defined USE_VALGRIND)
+# define USE_VALGRIND 1
+#endif
+
+#if USE_VALGRIND
+#include <valgrind/valgrind.h>
+#include <valgrind/memcheck.h>
+static int valgrind_p;
+#endif
+
 /* GC_CHECK_MARKED_OBJECTS means do sanity checks on allocated objects.
    Doable only if GC_MARK_STACK.  */
 #if ! GC_MARK_STACK
@@ -4327,6 +4339,11 @@ mark_maybe_object (Lisp_Object obj)
   void *po;
   struct mem_node *m;
 
+#if USE_VALGRIND
+  if (valgrind_p)
+    VALGRIND_MAKE_MEM_DEFINED (&obj, sizeof (obj));
+#endif
+
   if (INTEGERP (obj))
     return;
 
@@ -4395,6 +4412,11 @@ mark_maybe_pointer (void *p)
 {
   struct mem_node *m;
 
+#if USE_VALGRIND
+  if (valgrind_p)
+    VALGRIND_MAKE_MEM_DEFINED (&p, sizeof (p));
+#endif
+
   /* Quickly rule out some values which can't point to Lisp data.
      USE_LSB_TAG needs Lisp data to be aligned on multiples of GCALIGNMENT.
      Otherwise, assume that Lisp data is aligned on even addresses.  */
@@ -6643,6 +6665,10 @@ init_alloc (void)
 #endif
   Vgc_elapsed = make_float (0.0);
   gcs_done = 0;
+
+#if USE_VALGRIND
+  valgrind_p = RUNNING_ON_VALGRIND;
+#endif
 }
 
 void