Index: WebAssemblyAsmPrinter.cpp
===================================================================
--- WebAssemblyAsmPrinter.cpp
+++ WebAssemblyAsmPrinter.cpp
@@ -90,10 +90,12 @@
   }
   for (const auto &G : M.globals()) {
     if (!G.hasInitializer() && G.hasExternalLinkage()) {
-      uint16_t Size = M.getDataLayout().getTypeAllocSize(G.getValueType());
-      getTargetStreamer()->emitGlobalImport(G.getGlobalIdentifier());
-      OutStreamer->emitELFSize(getSymbol(&G),
+      if (G.getValueType()->isSized()) {
+        uint16_t Size = M.getDataLayout().getTypeAllocSize(G.getValueType());
+        getTargetStreamer()->emitGlobalImport(G.getGlobalIdentifier());
+        OutStreamer->emitELFSize(getSymbol(&G),
                                MCConstantExpr::create(Size, OutContext));
+      }
     }
   }
 }