https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97975
--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-10 branch has been updated by Marek Polacek <mpola...@gcc.gnu.org>: https://gcc.gnu.org/g:d0684e49ee8d859fc527b22aaaaed206930371a3 commit r10-9207-gd0684e49ee8d859fc527b22aaaaed206930371a3 Author: Marek Polacek <pola...@redhat.com> Date: Tue Dec 1 10:39:08 2020 -0500 c++: Fix ICE with inline variable in template [PR97975] In this test, we have static inline const int c = b; in a class template, and we call store_init_value as usual. There, the value is IMPLICIT_CONV_EXPR<const float>(b) which is is_nondependent_static_init_expression but isn't is_nondependent_constant_expression (they only differ in STRICT). We call fold_non_dependent_expr, but that just returns the expression because it only instantiates is_nondependent_constant_expression expressions. Since we're not checking the initializer of a constexpr variable, we go on to call maybe_constant_init, whereupon we crash because it tries to evaluate all is_nondependent_static_init_expression expressions, which our value is, but it still contains a template code. I think the fix is to call fold_non_dependent_init instead of maybe_constant_init, and only call fold_non_dependent_expr on the "this is a constexpr variable" path so as to avoid instantiating twice in a row. Outside a template this should also avoid evaluating the value twice. gcc/cp/ChangeLog: PR c++/97975 * constexpr.c (fold_non_dependent_init): Add a tree parameter. Use it. * cp-tree.h (fold_non_dependent_init): Add a tree parameter with a default value. * typeck2.c (store_init_value): Call fold_non_dependent_expr only when checking the initializer for constexpr variables. Call fold_non_dependent_init instead of maybe_constant_init. gcc/testsuite/ChangeLog: PR c++/97975 * g++.dg/cpp1z/inline-var8.C: New test. (cherry picked from commit 69bf1c7d5ee21392334f1982d1b40c38e103bbd4)
