https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97273
--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-10 branch has been updated by Patrick Palka <ppa...@gcc.gnu.org>: https://gcc.gnu.org/g:aeb69dda51e93379fce10fb03ec57650fbf73f31 commit r10-8872-gaeb69dda51e93379fce10fb03ec57650fbf73f31 Author: Patrick Palka <ppa...@redhat.com> Date: Thu Oct 8 19:31:57 2020 -0400 c++: Distinguish alignof and __alignof__ in cp_tree_equal [PR97273] cp_tree_equal currently considers alignof the same as __alignof__, but these operators are semantically different ever since r8-7957. In the testcase below, this causes the second static_assert to fail on targets where alignof(double) != __alignof__(double) because the specialization table (which uses cp_tree_equal as its equality predicate) conflates the two dependent specializations integral_constant<__alignof__(T)> and integral_constant<alignof(T)>. This patch makes cp_tree_equal distinguish between these two operators by inspecting the ALIGNOF_EXPR_STD_P flag. gcc/cp/ChangeLog: PR c++/88115 PR libstdc++/97273 * tree.c (cp_tree_equal) <case ALIGNOF_EXPR>: Return false if ALIGNOF_EXPR_STD_P differ. gcc/testsuite/ChangeLog: PR c++/88115 PR libstdc++/97273 * g++.dg/template/alignof3.C: New test. (cherry picked from commit 592fe221735bdaa375b1834dd49ce125d0b600d8)
