https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100532
--- Comment #10 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The trunk branch has been updated by Andrew Pinski <pins...@gcc.gnu.org>: https://gcc.gnu.org/g:2454ba9e2d1ce2d1b9b2b46f6111e022364bf9b5 commit r14-4759-g2454ba9e2d1ce2d1b9b2b46f6111e022364bf9b5 Author: Andrew Pinski <pins...@gmail.com> Date: Thu Oct 19 05:42:02 2023 +0000 c: Fix ICE when an argument was an error mark [PR100532] In the case of convert_argument, we would return the same expression back rather than error_mark_node after the error message about trying to convert to an incomplete type. This causes issues in the gimplfier trying to see if another conversion is needed. The code here dates back to before the revision history too so it might be the case it never noticed we should return an error_mark_node. Bootstrapped and tested on x86_64-linux-gnu with no regressions. PR c/100532 gcc/c/ChangeLog: * c-typeck.cc (convert_argument): After erroring out about an incomplete type return error_mark_node. gcc/testsuite/ChangeLog: * gcc.dg/pr100532-1.c: New test.