On Tue, Aug 29, 2023 at 18:57:37 +0200, Richard Biener wrote: > I suppose for bootstrapping we could disable ISL during stage1 since > it enables an optional feature only. Other than that GCC only > requires a C++11 compiler for building, so ISL breaks that constraint > with requiring C++17.
Note that it doesn't *require* it per sé; the tests that try it are compiled if C++17 support was detected at all. The headers seem to just have optional header-only `std::any`-using APIs if C++17 is around. `isl` supporting a flag to disable the tests would also work, but that doesn't fix 0.26. It also doesn't mean it won't start requiring C++17 at some point in the future. In light of that, I feel that skipping it for bootstrap is probably the right solution here. Alas, my skill with autotools is closer to the caveman-with-club level rather than that of a surgeon. --Ben
