https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117178
--- Comment #32 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:1301e18f69ced6a14a7648a24d1eb3addd836b6c commit r15-7921-g1301e18f69ced6a14a7648a24d1eb3addd836b6c Author: Jakub Jelinek <ja...@redhat.com> Date: Mon Mar 10 09:31:41 2025 +0100 gimple-ssa-warn-access: Adjust maybe_warn_nonstring_arg for nonstring multidimensional arrays [PR117178] The following patch fixes 4 xfails in attr-nonstring-11.c (and results in 2 false positive warnings in attr-nonstring-12.c not being produced either). The thing is that maybe_warn_nonstring_arg simply assumed that nonstring arrays must be single-dimensional, so when it sees a nonstring decl with ARRAY_TYPE, it just used its dimension. With multi-dimensional arrays that is not the right dimension to use though, it can be dimension of some outer dimension, e.g. if we have char a[5][6][7] __attribute__((nonstring)) if decl is a[5] it would assume maximum non-NUL terminated string length of 5 rather than 7, if a[5][6] it would assume 6 and only for a[5][6][0] it would assume the correct 7. So, the following patch looks through all the outer dimensions to reach the innermost one (which for attribute nonstring is guaranteed to have char/unsigned char/signed char element type). 2025-03-10 Jakub Jelinek <ja...@redhat.com> PR c/117178 * gimple-ssa-warn-access.cc (maybe_warn_nonstring_arg): Look through multi-dimensional array types, stop at the innermost ARRAY_TYPE. * c-c++-common/attr-nonstring-11.c: Remove xfails. * c-c++-common/attr-nonstring-12.c (warn_strcmp_cst_1, warn_strcmp_cst_2): Don't expect any warnings here. (warn_strcmp_cst_3, warn_strcmp_cst_4): New functions with expected warnings.
