[Bug middle-end/90923] hash_map destroys elements without constructing them

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90923

Martin Sebor <msebor at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |wrong-code
           See Also|                            |https://gcc.gnu.org/bugzill
                   |                            |a/show_bug.cgi?id=90904

--- Comment #1 from Martin Sebor <msebor at gcc dot gnu.org> ---
The otherwise untested patch is enough to fix the test case:

diff --git a/gcc/hash-map.h b/gcc/hash-map.h
index 588dfda04fa..40e5ec5871e 100644
--- a/gcc/hash-map.h
+++ b/gcc/hash-map.h
@@ -177,7 +177,10 @@ public:
                                                   INSERT);
       bool ins = Traits::is_empty (*e);
       if (ins)
-       e->m_key = k;
+       {
+         e->m_key = k;
+         new ((void *)&e->m_value) Value ();
+       }

       if (existed != NULL)
        *existed = !ins;