[Bug c++/68978] [6 Regression] bogus error: lvalue required as left operand of assignment

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68978

Patrick Palka <ppalka at gcc dot gnu.org> changed:

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

--- Comment #2 from Patrick Palka <ppalka at gcc dot gnu.org> ---
It looks like lvalue_kind() does not handle MODOP_EXPRs correctly.  It does not
consider (i *= radix) (encoded at that point as an unlowered MODOP_EXPR) to be
an lvalue.  I am testing this fix:

diff --git a/gcc/cp/tree.c b/gcc/cp/tree.c
index ae176d0..ac22e45 100644
--- a/gcc/cp/tree.c
+++ b/gcc/cp/tree.c
@@ -186,6 +186,7 @@ lvalue_kind (const_tree ref)
       break;

     case MODIFY_EXPR:
+    case MODOP_EXPR:
     case TYPEID_EXPR:
       return clk_ordinary;