[PATCH] D44149: [WebAssembly] Use StringSaver to retain ownership of ctor function body. NFC

[Rui Ueyama via Phabricator via llvm-commits]

ruiu added inline comments.


================
Comment at: wasm/Writer.cpp:877
   SyntheticFunction *F = make<SyntheticFunction>(
-      *Sig, std::move(FunctionBody), WasmSym::CallCtors->getName());
+      *Sig, toArrayRef(Saver.save(FunctionBody)),
+      WasmSym::CallCtors->getName());
----------------
I don't think the amount of data we need to copy is large, so it is presumably OK, and I'm not obsessed with micro-optimization, but here we make a copy of std::string here and then immediately discard the original string at the end of the scope. So this makes a redundant copy of a string.

There is a way to avoid unnecessary copying. If you allocate std::string by `make<std::string>()`, then its body will have the same lifetime as the entire linking process.


Repository:
  rLLD LLVM Linker

https://reviews.llvm.org/D44149