https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104016
Bug ID: 104016
Summary: constexpr folding of std::type_info depends on
-fdelete-null-ptr-checks
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Keywords: rejects-valid
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: redi at gcc dot gnu.org
CC: jakub at gcc dot gnu.org
Target Milestone: ---
// { dg-options "-std=gnu++23 -fno-delete-null-pointer-checks" }
// { dg-do compile { target c++23 } }
#include <typeinfo>
static_assert( typeid(int) != typeid(long) );
This compiles with the default flags, but -fno-delete-null-pointer-checks
causes it to fail:
ti.C:4:28: error: non-constant condition for static assertion
4 | static_assert( typeid(int) != typeid(long) );
| ~~~~~~~~~~~~^~~~~~~~~~~~~~~
In file included from ti.C:3:
/home/jwakely/gcc/12/include/c++/12.0.0/typeinfo:196:19: error: '(((const
std::type_info*)(& _ZTIi)) == ((const std::type_info*)(& _ZTIl)))' is not a
constant expression
196 | return this == &__arg;
| ~~~~~^~~~~~~~~
Not a regression, because this code was rejected as ill-formed until very
recently.
Maybe related to PR c++/97913
