[WebAssembly] Model weakly defined symbols as wasm exports

Previously these were being included as both imports and
exports, with the import being satisfied by the export
(or some strong symbol) at runtime.  However proved
unnecessary and actually complicated linking as it meant
there was not a 1-to-1 mapping between a wasm function
/global index and a linker symbol.

Differential Revision: https://reviews.llvm.org/D38246

llvm-svn: 314245

1 files changed, 5 insertions, 13 deletions

diff --git a/llvm/lib/Object/WasmObjectFile.cpp b/llvm/lib/Object/WasmObjectFile.cpp
index c320b91..1954335 100644
--- a/llvm/lib/Object/WasmObjectFile.cpp
+++ b/llvm/lib/Object/WasmObjectFile.cpp
@@ -337,19 +337,11 @@ void WasmObjectFile::populateSymbolTable() {
           Export.Kind == wasm::WASM_EXTERNAL_FUNCTION
               ? WasmSymbol::SymbolType::FUNCTION_EXPORT
               : WasmSymbol::SymbolType::GLOBAL_EXPORT;
-      auto Pair = SymbolMap.try_emplace(Export.Name, Symbols.size());
-      if (Pair.second) {
-        Symbols.emplace_back(Export.Name, ExportType,
-                             ExportSection, Export.Index);
-        DEBUG(dbgs() << "Adding export: " << Symbols.back()
-                     << " sym index:" << Symbols.size() << "\n");
-      } else {
-        uint32_t SymIndex = Pair.first->second;
-        Symbols[SymIndex] =
-            WasmSymbol(Export.Name, ExportType, ExportSection, Export.Index);
-        DEBUG(dbgs() << "Replacing existing symbol:  " << Symbols[SymIndex]
-                     << " sym index:" << SymIndex << "\n");
-      }
+      SymbolMap.try_emplace(Export.Name, Symbols.size());
+      Symbols.emplace_back(Export.Name, ExportType,
+                           ExportSection, Export.Index);
+      DEBUG(dbgs() << "Adding export: " << Symbols.back()
+                   << " sym index:" << Symbols.size() << "\n");
     }
   }
 }