[WebAssembly] Refactor handling of weak undefined functions. NFC.

Also add to the docs.

This is refactor in preparation for https://reviews.llvm.org/D57909

Differential Revision: https://reviews.llvm.org/D57920

llvm-svn: 353478

1 files changed, 6 insertions, 1 deletions

diff --git a/lld/wasm/SymbolTable.h b/lld/wasm/SymbolTable.h
index 67133cee256..f03980d7066 100644
--- a/lld/wasm/SymbolTable.h
+++ b/lld/wasm/SymbolTable.h
@@ -79,10 +79,15 @@ public:
   DefinedFunction *addSyntheticFunction(StringRef Name, uint32_t Flags,
                                         InputFunction *Function);
 
+  void handleWeakUndefines();
+
 private:
-  std::pair<Symbol *, bool> insert(StringRef Name, InputFile *File);
+  std::pair<Symbol *, bool> insert(StringRef Name, const InputFile *File);
   std::pair<Symbol *, bool> insertName(StringRef Name);
 
+  InputFunction *replaceWithUnreachable(Symbol *Sym, const WasmSignature &Sig,
+                                        StringRef DebugName);
+
   // Maps symbol names to index into the SymVector.  -1 means that symbols
   // is to not yet in the vector but it should have tracing enabled if it is
   // ever added.