https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82336
Paolo Carlini <paolo.carlini at oracle dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC|mukesh.kapoor at oracle dot com |paolo.carlini at oracle
dot com
--- Comment #4 from Paolo Carlini <paolo.carlini at oracle dot com> ---
Just to confirm that Nathan's analysis is correct the below "works".
That said, I don't know how pervasive the problem is, to wit in how many cases
using perform_implicit_conversion_flags - which is supposed to be used only
when we are committed to do the conversion - in check_default_argument actually
causes problems, if we could imagine restricting an unsharing to some kinds of
arguments (in this case it's an *empty* CONSTRUCTOR!), or we really should
write new facilities only for checking purposes, and so on.
Maybe Jason is willing to comment on this, which kind of ways forward he can
see...
------------
Index: decl.c
===================================================================
--- decl.c (revision 258222)
+++ decl.c (working copy)
@@ -12627,6 +12627,8 @@ check_default_argument (tree decl, tree arg, tsubs
further. */
return error_mark_node;
+ tree orig_arg = unshare_expr (arg);
+
/* [dcl.fct.default]
A default argument expression is implicitly converted to the
@@ -12636,6 +12638,8 @@ check_default_argument (tree decl, tree arg, tsubs
LOOKUP_IMPLICIT);
--cp_unevaluated_operand;
+ arg = orig_arg;
+
/* Avoid redundant -Wzero-as-null-pointer-constant warnings at
the call sites. */
if (TYPE_PTR_OR_PTRMEM_P (decl_type)
