[Bug middle-end/67649] trunk build with valgrind fail in get_def_blocks_for

[miyuki at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67649

Mikhail Maltsev <miyuki at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|unassigned at gcc dot gnu.org      |miyuki at gcc dot 
gnu.org

--- Comment #9 from Mikhail Maltsev <miyuki at gcc dot gnu.org> ---
I think, this patch falls under obvious, but I'll need to configure valgrind
build on my (sort of) CI server, and testing might take some time.

diff --git a/gcc/memory-block.h b/gcc/memory-block.h
index 1a495ea..8b1202b 100644
--- a/gcc/memory-block.h
+++ b/gcc/memory-block.h
@@ -57,6 +57,7 @@ memory_block_pool::allocate ()

   void *result = instance.m_blocks;
   instance.m_blocks = instance.m_blocks->m_next;
+  VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (result, block_size));
   return result;
 }