https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99325
--- Comment #5 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:a1b56c3ef70036af6d171d61ea48ad4c368fcb5b commit r11-7511-ga1b56c3ef70036af6d171d61ea48ad4c368fcb5b Author: Jakub Jelinek <ja...@redhat.com> Date: Thu Mar 4 16:02:07 2021 +0100 c-ppoutput: Fix preprocessing ICE on very large line number [PR99325] In libcpp, lines are represented as linenum_type, which is unsigned int. The following testcases ICE because maybe_print_line_1 is sometimes called with UNKNOWN_LOCATION (e.g. at pragma eof) and while most of the time the && src_line >= print.src_line && src_line < print.src_line + 8 check doesn't succeed for the src_line of 0 from UNKNOWN_LOCATION, when print.src_line is from very large line numbers (UINT_MAX - 7 and above) it succeeds (with UB on the compiler side) but src_file is NULL for UNKNOWN_LOCATION and so the strcmp call ICEs. As print.src_line can easily wrap around, this patch changes its type to unsigned int to match libcpp, so that we don't invoke UB in the compiler. For print.src_line of UINT_MAX - 7 and above, src_line from UNKNOWN_LOCATION will not pass that test anymore, but when it wraps around to 0, it can, so I've also added a check for src_loc != UNKNOWN_LOCATION (or, if preferred, could be src_file != NULL). Besides fixing the ICE and UB in the compiler, I believe worst case the patch will cause printing a few more line directives in the preprocessed source around the wrapping from lines UINT_MAX - 7 to 0 (but less around the wrapping from INT_MAX to INT_MAX + 1U), but I think those are exceptional cases (sources with > 2billion lines are rare and we warn or error on #line > INT_MAX). 2021-03-04 Jakub Jelinek <ja...@redhat.com> PR c/99325 * c-ppoutput.c (print): Change src_line type from int to unsigned. (token_streamer::stream) Likewise. (maybe_print_line_1): Likewise. Don't strcmp src_file if src_loc is UNKNOWN_LOCATION. * gcc.dg/cpp/line11.c: New test. * gcc.dg/cpp/line12.c: New test.
