On Wed, 2023-10-04 at 23:19 +0100, Roger Sayle wrote: > > The recent patch to remove poly_int_pod triggers a bug in g++ 4.8.5's > C++ 11 support which mistakenly believes poly_uint16 has a non-trivial > constructor. This in turn prohibits it from being used as a member in > a union (rtxunion) that constructed statically, resulting in a (fatal) > error during stage 1. A workaround is to add an explicit constructor > to the problematic union, which allows mainline to be bootstrapped with > the system compiler on older RedHat 7 systems. > > This patch has been tested on x86_64-pc-linux-gnu where it allows a > bootstrap to complete when using g++ 4.8.5 as the host compiler. > Ok for mainline? > > > 2023-10-04 Roger Sayle <ro...@nextmovesoftware.com> > > gcc/ChangeLog > * rtl.h (rtx_def::u): Add explicit constructor to workaround > issue using g++ 4.8 as a host compiler.
AFAIK G++ 5.1 also has a bug (https://gcc.gnu.org/PR65801) breaking building recent GCC. I don't think it's really "maintainable" to ensure current GCC able to be built with a buggy host compiler. -- Xi Ruoyao <xry...@xry111.site> School of Aerospace Science and Technology, Xidian University
