[PATCH] D142188: [ORC] Fix in-process lookup of symbols without GlobalPrefix

[Lang Hames via Phabricator via llvm-commits]

lhames added a comment.

This change won't work for other platforms at the moment. E.g. On Darwin where the global prefix is `_` an ORC lookup (which uses mangled names) for `[ "foo", "_foo" ]` should return `[ nullptr, <addr of _foo> ]`, but with this patch it will return `[ <addr of foo>, <addr of foo> ]`.

`GlobalPrefix` was always a bit of a hack -- I think we want to make this a generalized demangle function that returns a `std::optional<std::string>`, then we can write:

  for (auto &KV : Symbols) {
    auto &Name = KV.first;
  
    if ((*Name).empty())
      continue;
  
    if (Allow && !Allow(Name))
      continue;
  
    auto DemangledName = Demangle(Name);
    if (!DemangledName)
      continue;
  
    if (void *Addr = Dylib.getAddressOfSymbol(DemangledName->c_str())) {
      NewSymbols[Name] = JITEvaluatedSymbol(
          static_cast<JITTargetAddress>(reinterpret_cast<uintptr_t>(Addr)),
          JITSymbolFlags::Exported);
    }
  }

On windows the demangler can conditionally drop the `?`, and on Darwin it can require the `_` prefix (returning std::noneopt` when it's not present.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D142188/new/

https://reviews.llvm.org/D142188