I've posted an update to PR 66014 regarding mingw64 slim LTO bootstrap errors I had been getting I was hoping to get some comments on. Though this resolves the problem for me, I'm wondering what other potential issues similar to it may spring up and was hoping to get some feedback.
In addition, there is another related failure when doing bootstrap-lto or bootstrap-lto-noplugin (slim or fat) in mingw64 relating to sys_siglist. mingw64 (as far as I know) does not have an implementation for it. The issue is as follows: 1. stage1 completes bootstrapping. strsignal and sys_siglist are undetected resulting in HAVE_STRSIGNAL and HAVE_SYS_SIGLIST. 2. stage2 (or stagefeedback) detects strsignal but not sys_siglist leaving HAVE_SYS_SIGLIST defined. This causes libiberty to define strsignal but skips sys_siglist during the build leaving an undefined reference to sys_siglist. 3. Build fails when attempting to link against the new LTO libiberty.a(strsignal.o) when building gcc-nm, gcc-ar, etc. Non-LTO builds suffer neither problem and fat bootstraps only suffer from the issue above which I have worked around by passing in "libiberty_cv_var_sys_siglist=no" during configuration. Combined with building libiberty with "-fno-builtin-stpcpy" (PR 66014), I have gotten all builds to finally succeed. I could use some guidance on where to go from here, however. Thanks, Matt
