https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118671
--- Comment #3 from GCC 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:a64d9c96d8ebb0ba2a52daec85779b1a99c2f7fd commit r15-7360-ga64d9c96d8ebb0ba2a52daec85779b1a99c2f7fd Author: Jakub Jelinek <ja...@redhat.com> Date: Tue Feb 4 21:16:57 2025 +0100 c++: Fix ICE with #embed/RAW_DATA_CST after list conversion [PR118671] The following testcases ICE with RAW_DATA_CSTs (so the first one since introduction of #embed C++ optimizations and the latter since optimization of large sequences of comma separated literals). I've missed the fact that implicit_conversion can embed the exact expression passed to it into stuff pointed out by conversion * (e.g. for user conversions in sub->cand->args). So, it isn't enough in convert_like_internal to pass the right INTEGER_CST for each element of the RAW_DATA_CST because the whole RAW_DATA_CST might be in sub->cand->args etc. Either I'd need to chase for wherever the RAW_DATA_CST is found and update those for each element processed, or, as implemented in the following patch, build_list_conv detects the easy optimizable case where convert_like_internal can be kept as the whole RAW_DATA_CST with changed type and possibly narrowing diagnostics, and otherwise instead of having a single subconversion it has RAW_DATA_CST separate subconversions. Instead of trying to reallocate the subconvs array when we detect that case, the patch instead uses an artificial ck_list inside of the u.list array to hold the individual subconversions. Seems the only places where u.list is used are build_list_conv and convert_like_internal. 2025-02-04 Jakub Jelinek <ja...@redhat.com> PR c++/118671 * call.cc (build_list_conv): For RAW_DATA_CST, call implicit_conversion with INTEGER_CST representing first byte instead of the whole RAW_DATA_CST. If it is an optimizable trivial conversion, just save that to subconvs, otherwise allocate an artificial ck_list for all the RAW_DATA_CST bytes and create subsubconv for each of them. (convert_like_internal): For ck_list with RAW_DATA_CST, instead of doing all the checks for optimizable conversion just check kind and assert everything else, otherwise use subsubconversions instead of the subconversion for each element. * g++.dg/cpp/embed-25.C: New test. * g++.dg/cpp0x/pr118671.C: New test.
