[PATCH] D59709: [ThinLTO] Auto-hide prevailing linkonce_odr only when all copies eligible

[Steven Wu via Phabricator via llvm-commits]

steven_wu added a comment.

Hi Teresa, I am seeing some regressions because of this commit. ThinLTO is now producing more weak symbols than before and I am looking for a good fix. See inline comments for details.



================
Comment at: llvm/trunk/lib/LTO/LTO.cpp:334
+        S->setCanAutoHide(VI.canAutoHide() &&
+                          !GUIDPreservedSymbols.count(VI.getGUID()));
+      }
----------------
The regression I saw is exactly the situation mentioned in the comments but I am not so sure about the conclusion here. For ld64, it can see whether a symbol can be auto hide or not, and it prefers the one that is not auto hide. This means if there are other copies of the symbol that is not autohide outside the summary and not autohide, the one can be autohide should never be prevailing.

Is that the case for other linker?


Repository:
  rL LLVM

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D59709/new/

https://reviews.llvm.org/D59709