yaxunl abandoned this revision. yaxunl added a comment. In D95970#2540669 <https://reviews.llvm.org/D95970#2540669>, @tra wrote:
> In D95970#2540414 <https://reviews.llvm.org/D95970#2540414>, @yaxunl wrote: > >> In D95970#2540303 <https://reviews.llvm.org/D95970#2540303>, @tra wrote: >> >>> What's going to happen if you do have an undefined reference that's *not* >>> to a `__managed__` variable? >> >> By default HIP toolchain uses -fvisibility hidden >> -fapply-global-visibility-to-externs for device compilation. Undefined >> variable symbols have protected visibility. Undefined function symbols have >> hidden visibility. Since they are not allowed to be preempted, lld still >> emits error if they are undefined. `__managed__` variables have default >> visibility, therefore they are allowed to go through. > > Is there a test that verifies/demonstrates how it's handled at compile time? > >> We can let HIP runtime emit an error if there are undefined symbols other >> than managed variables. > > Detecting compilation errors at run-time is not very useful. The end user > would likely have no idea what's going on. > I wonder if we can catch the errors earlier. E.g. w/o RDC, we can probably > catch it in the codegen. > With RDC, only the linker will know it, so you would need some sort of custom > plugin for that. > > What if we actually resolve all `__managed__` references and point them to > some sort of placeholder. > E.g a weak symbol, that would be directed to the real location when the > binary is loaded. > Or, maybe, introduce an indirection and let the runtime handle managed > variables as a special case > and point the indirect links to the right locations. > This way you can still run with `-no-undefined` and find all other unresolved > references that should not be there. Good point. I will try using indirection. This should avoid undefined symbols in device binary. CHANGES SINCE LAST ACTION https://reviews.llvm.org/D95970/new/ https://reviews.llvm.org/D95970 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
