[Bug tree-optimization/86850] ubsan: runtime error: member call on null pointer

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86850

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |rguenth at gcc dot 
gnu.org

--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> ---
So the suggested assert is bogus.  But indeed the issue is that
vect_create_new_slp_node eventually uses .create (0) which does nothing
and then splice does

template<typename T>
inline void
vec<T, va_heap, vl_ptr>::splice (const vec<T, va_heap, vl_ptr> &src)
{
  if (src.m_vec)
    m_vec->splice (*(src.m_vec));
}

which for m_vec == NULL is doing the reported.  I guess replacing
if (src.m_vec) with if (src.length ()) would fix this.

diff --git a/gcc/vec.h b/gcc/vec.h
index f8c039754d2..407269c5ad3 100644
--- a/gcc/vec.h
+++ b/gcc/vec.h
@@ -1688,7 +1688,7 @@ template<typename T>
 inline void
 vec<T, va_heap, vl_ptr>::splice (const vec<T, va_heap, vl_ptr> &src)
 {
-  if (src.m_vec)
+  if (src.length ())
     m_vec->splice (*(src.m_vec));
 }