https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100152
--- Comment #40 from Richard Biener <rguenth at gcc dot gnu.org> --- (In reply to Richard Biener from comment #39) > (In reply to Iain Sandoe from comment #38) > > (In reply to Richard Biener from comment #37) > > > Oh, and FYI a cc1 cross from x86_64 to x86_64-apple-darwin19.6.0 doesn't > > > seem > > > to reproduce the issue with the reduced testcase (I seee no call to > > > ___UTF_8_put remaining with -O3 -fPIC -fno-strict-aliasing -fwrapv). > > > > I think my interestingness test isn't strict enough - the creduced code > > resulting doesn't have an extern for ___UTF_8_put and only seems to not > > inline that fn because the interface has been mangled. [ so that the fn is > > legitimately binds_localP as the pasted case ]. > > > > if you still have the build around, out of curiosity, does it fail on the > > original .i file attached here? > > > > and with -fno-trapping-math -fno-math-errno -fschedule-insns2 > > -fomit-frame-pointer > > > > ( I only need O2 to get a fail ). > > Yes, with -O2 -fno-trapping-math -fno-math-errno -fschedule-insns2 > -fomit-frame-pointer it produces the problematical > > .align 4,0x90 > L945: > movl 0(%rbp,%r10,4), %esi > call ____UTF_8_put > movq %r10, %rax > addq $1, %r10 > cmpq %rax, %r12 > jne L945 > > code. But then ___UTF_8_put isn't interposable so I wonder why the linker > even has to resolve anything. Adding -fPIC OTOH should definitely make the > symbol interposable but the same code is still generated ... > > Note the 'extern' declaration shouldn't change anything, only that we > see a definition is relevant. > > breaking on darwin_binds_local_p I see ___UTF_8_put is considered binding > local even with -fPIC. So GCC thinks there will be no linker stub involved. > > Note 'shlib' is passed as false to default_binds_local_p_3 computed as > > 3140 on earlier system versions, and with a TODO to complete. */ > 3141 bool force_overridable = TARGET_KEXTABI && DARWIN_VTABLE_P (decl); > 3142 return default_binds_local_p_3 (decl, force_overridable /* shlib > */, > 3143 false /* weak dominate */, > > and default_binds_local_p_3 would do > > /* If PIC, then assume that any global name can be overridden by > symbols resolved from other modules. */ > if (shlib) > return false; > > ix86_binds_local_p simply passes flag_shlib != 0 as this argument. So it looks like darwin should pass flag_shlib != 0 || force_overridable instead?
