On Feb 16, 2024, Jason Merrill <ja...@redhat.com> wrote: > So, for stage2+, let's add just prev- libgcc.
I'm pretty sure this will break bootstrap-lean where libgcc_s isn't a system library, and we're building post-bootstrap host tools :-( We need the current stage lib after the prev stage is removed. I also doubt that TARGET_LIB_PATH was defined and used for no reason. My hunch is that bootstrap options and/or targets that don't have these libraries as system libraries will break in some obscure way without it. But I don't have the bandwidth to track down the history behind their inclusion. I insist that the entire approach of choosing the same set of target library directories regardless of the freshness relationship between e.g. a system libstdc++ and the one we're building can't possibly be an overall improvement, it's only trading problems in some scenarios (where we're building an older libstdc++) for problems in other scenarios (where we're building a newer libstdc++). The latter is unfortunately far more likely, which is reason enough for the current arrangement, but libstdc++ problems will likely only hit if the gap between system and being-built libraries is large enough (say, new symbols in the newer libstdc++ used by the compiler, but not available in the system library). I'm really uncomfortable with this change, especially at this stage. I'd much rather have a relatively obscure workaround for this relatively obscure problem, while keeping the defaults that have accumulated lots of testing on lots of configurations. An idea that occurred to me is to have some configure option or just a make variable that would be prepended to RPATH_ENVVAR, so that it would preempt TARGET_LIB_PATH. That would be a far more conservative change, that I think we could make even at this stage. WDYT? -- Alexandre Oliva, happy hacker https://FSFLA.org/blogs/lxo/ Free Software Activist GNU Toolchain Engineer More tolerance and less prejudice are key for inclusion and diversity Excluding neuro-others for not behaving ""normal"" is *not* inclusive
