https://gcc.gnu.org/g:059231fb8a42eaeac8880c5d207249b46757767c
commit r17-4537-g059231fb8a42eaeac8880c5d207249b46757767c Author: Léo Hardt <[email protected]> Date: Mon Sep 21 12:41:35 2026 -0600 [PATCH][PR preprocessor/121508] fix(libcpp): Don't ICE parsing __has_include outside directive. fix(libcpp): Don't ICE parsing __has_include outside directive. cc: libcpp maintainers. Fixes an ICE wherein 'glue_header_name' is called outside parsing a preprocessor directive, causing an entire file to be read and presumed to be a header name. Then, on the next read (the closing '>' or ')'), the parser ICEs since the input has already come to an end. Affects __has_include and __has_embed when used outside directives. Minimal reproducible crash has two tokens (both gcc and g++): __has_include< Given glue_header_name was written for usage inside preprocessor parsing, we could either change it or not call it in case of errors. I opted to bail out early on an error case, since there is no chance it could influence valid code parsing. See more on https://gcc.gnu.org/PR121508. PR preprocessor/121508 PR preprocessor/123339 libcpp/ChangeLog: * macro.cc (builtin_has_include_1): Bail early if not on a preprocessor directive. Signed-off-by: Léo Hardt <[email protected]> Diff: --- libcpp/macro.cc | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/libcpp/macro.cc b/libcpp/macro.cc index 736c360336d0..24493a45f860 100644 --- a/libcpp/macro.cc +++ b/libcpp/macro.cc @@ -392,8 +392,11 @@ builtin_has_include_1 (cpp_reader *pfile, const char *name, bool *paren, bool *bracket, location_t *loc) { if (!pfile->state.in_directive) - cpp_error (pfile, CPP_DL_ERROR, - "%qs used outside of preprocessing directive", name); + { + cpp_error (pfile, CPP_DL_ERROR, + "%qs used outside of preprocessing directive", name); + return NULL; + } pfile->state.angled_headers = true; const auto sav_padding = pfile->state.directive_wants_padding;
