https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108702
--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jakub Jelinek <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:9d5730dee4f42e94004b38f8f4862c0b1f4d964c commit r13-6473-g9d5730dee4f42e94004b38f8f4862c0b1f4d964c Author: Jakub Jelinek <ja...@redhat.com> Date: Sat Mar 4 09:51:31 2023 +0100 c++: Don't defer local statics initialized with constant expressions [PR108702] The stmtexpr19.C testcase used to be rejected as it has a static variable in statement expression in constexpr context, but as that static variable is initialized by constant expression, when P2647R1 was implemented we agreed to make it valid. Now, as reported, the testcase compiles fine, but doesn't actually link because the static variable isn't defined anywhere, and with -flto ICEs because of this problem. This is because we never varpool_node::finalize_decl those vars, the constant expression in which the DECL_EXPR is present for the static VAR_DECL is folded (constant evaluated) into just the address of the VAR_DECL. Now, similar testcase included below (do we want to include it in the testsuite too?) works fine, because in cp_finish_decl -> make_rtl_for_nonlocal_decl we have since PR70353 fix: /* We defer emission of local statics until the corresponding DECL_EXPR is expanded. But with constexpr its function might never be expanded, so go ahead and tell cgraph about the variable now. */ defer_p = ((DECL_FUNCTION_SCOPE_P (decl) && !var_in_maybe_constexpr_fn (decl)) || DECL_VIRTUAL_P (decl)); and so don't defer them in constexpr/consteval functions. The following patch calls rest_of_decl_compilation which make_rtl_for_nonlocal_decl didn't call when encountering DECL_EXPRs of such vars during constant evaluation if they weren't finalized yet. 2023-03-04 Jakub Jelinek <ja...@redhat.com> PR c++/108702 * constexpr.cc: Include toplev.h. (cxx_eval_constant_expression) <case DECL_EXPR>: When seeing a local static initialized by constant expression outside of a constexpr function which has been deferred by make_rtl_for_nonlocal_decl, call rest_of_decl_compilation on it. * g++.dg/ext/stmtexpr19.C: Use dg-do link rather than dg-do compile.
