https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117023
--- Comment #8 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:206cb6c10589bef4afc90f4df993fc3bdb031e27 commit r15-7682-g206cb6c10589bef4afc90f4df993fc3bdb031e27 Author: Jakub Jelinek <ja...@redhat.com> Date: Mon Feb 24 09:18:27 2025 +0100 analyzer: Handle nonnull_if_nonzero attribute [PR117023] On top of the https://gcc.gnu.org/pipermail/gcc-patches/2024-November/668554.html patch which introduces the nonnull_if_nonzero attribute (because C2Y is allowing NULL arguments on various calls like memcpy, memset, strncpy etc. as long as the count is 0) the following patch adds just limited handling of the attribute in the analyzer. For nonnull attribute(s) we have the get_nonnull_args helper which returns a bitmap, for nonnull_if_nonzero a function would need to return a hash_map or something similar, I think it is better to handle the attributes one by one. This patch just handles the non-zero INTEGER_CST (integer_nonzerop) count arguments, in other places the above patch uses ranger to some extent, but I'm not familiar enough with the analyzer to know if one can use the ranger, or should somehow explain in data structures the conditional nature of the nonnull property, the argument is nonnull only if some other argument is nonzero. Also, analyzer uses get_nonnull_args in another spot when entering a frame, not sure if anything can be done there (note the conditional nonnull somehow, pass from callers if the argument is nonzero, ...). Note, the testsuite changes aren't strictly necessary with just the above and this patch, but will be with a patch I'm going to post soon. 2025-02-24 Jakub Jelinek <ja...@redhat.com> PR c/117023 gcc/analyzer/ * sm-malloc.cc (malloc_state_machine::handle_nonnull): New private method. (malloc_state_machine::on_stmt): Use it for nonnull attribute arguments. Handle also nonnull_if_nonzero attributes. gcc/testsuite/ * c-c++-common/analyzer/call-summaries-malloc.c (test_use_without_check): Pass 4 rather than sz to memset. * c-c++-common/analyzer/strncpy-1.c (test_null_dst, test_null_src): Pass 42 rather than count to strncpy.
