https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99062
--- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Marek Polacek <mpola...@gcc.gnu.org>: https://gcc.gnu.org/g:30a4d95bf76b0a0fdb66ac0211589a4434c83af3 commit r11-7259-g30a4d95bf76b0a0fdb66ac0211589a4434c83af3 Author: Marek Polacek <pola...@redhat.com> Date: Wed Feb 10 15:24:25 2021 -0500 c-family: ICE with assume_aligned attribute [PR99062] We ICE in handle_assume_aligned_attribute since r271338 which added @@ -2935,8 +2936,8 @@ handle_assume_aligned_attribute (tree *node, tree name, tree args, int, /* The misalignment specified by the second argument must be non-negative and less than the alignment. */ warning (OPT_Wattributes, - "%qE attribute argument %E is not in the range [0, %E)", - name, val, align); + "%qE attribute argument %E is not in the range [0, %wu]", + name, val, tree_to_uhwi (align) - 1); *no_add_attrs = true; return NULL_TREE; } because align is INT_MIN and tree_to_uhwi asserts tree_fits_uhwi_p -- which ALIGN does not and the prior tree_fits_shwi_p check is fine with it, as well as the integer_pow2p check. Since neither of the arguments to assume_aligned can be negative, I've hoisted the tree_int_cst_sgn check. And add the missing "argument" word to an existing warning. gcc/c-family/ChangeLog: PR c++/99062 * c-attribs.c (handle_assume_aligned_attribute): Check that the alignment argument is non-negative. Tweak a warning message. gcc/testsuite/ChangeLog: PR c++/99062 * gcc.dg/attr-assume_aligned-4.c: Adjust dg-warning. * g++.dg/ext/attr-assume-aligned.C: New test.