[PATCH] D149541: [JITLink] Process null symbols

[Job Noorman via Phabricator via llvm-commits]

jobnoorman added inline comments.


================
Comment at: llvm/lib/ExecutionEngine/JITLink/ELFLinkGraphBuilder.h:552-553
+
+      auto &GSym = G->addAbsoluteSymbol(*Name, orc::ExecutorAddr(0), 0,
+                                        Linkage::Strong, Scope::Local, false);
+      setGraphSymbol(SymIndex, GSym);
----------------
lhames wrote:
> Let's name these `__jitlink_ELF_SYM_UND_<st_value>` -- it'll make them easy to spot when debugging, and allow us to keep the invariant that all absolute symbols are named (which means that the change to `JITLink.cpp` would no longer be needed).
> 
> Side note: We should probably change `Symbol::hasName` so that empty symbols still count as valid names, but that's outside the scope of this patch.
> Let's name these `__jitlink_ELF_SYM_UND_<st_value>` -- it'll make them easy to spot when debugging

Should we maybe go for `__jitlink_ELF_SYM_UND_<SymIndex>` to make sure the name is always unique? `st_value` will always be 0 in this case.

> and allow us to keep the invariant that all absolute symbols are named (which means that the change to `JITLink.cpp` would no longer be needed).

I might be missing something here but wouldn't this change still be needed? It handles printing edges with targets that are `!isDefined()` rather than `!hasName()`.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D149541/new/

https://reviews.llvm.org/D149541