1 files changed, 17 insertions, 2 deletions
diff --git a/llvm/lib/MC/WasmObjectWriter.cpp b/llvm/lib/MC/WasmObjectWriter.cpp
index 1ef6567555d..c47c014467a 100644
--- a/llvm/lib/MC/WasmObjectWriter.cpp
+++ b/llvm/lib/MC/WasmObjectWriter.cpp
@@ -355,6 +355,10 @@ void WasmObjectWriter::recordRelocation(MCAssembler &Asm,
   if (FixupSection.getSectionName().startswith(".init_array"))
     return;
 
+  // TODO(sbc): Add support for debug sections.
+  if (FixupSection.getKind().isMetadata())
+    return;
+
   if (const MCSymbolRefExpr *RefB = Target.getSymB()) {
     assert(RefB->getKind() == MCSymbolRefExpr::VK_None &&
            "Should not have constructed this");
@@ -423,12 +427,20 @@ void WasmObjectWriter::recordRelocation(MCAssembler &Asm,
   WasmRelocationEntry Rec(FixupOffset, SymA, C, Type, &FixupSection);
   DEBUG(dbgs() << "WasmReloc: " << Rec << "\n");
 
+  // Relocation other than R_WEBASSEMBLY_TYPE_INDEX_LEB are currently required
+  // to be against a named symbol.
+  // TODO(sbc): Add support for relocations against unnamed temporaries such
+  // as those generated by llvm's `blockaddress`.
+  // See: test/MC/WebAssembly/blockaddress.ll
+  if (SymA->getName().empty() && Type != wasm::R_WEBASSEMBLY_TYPE_INDEX_LEB)
+    report_fatal_error("relocations against un-named temporaries are not yet "
+                       "supported by wasm");
+
   if (FixupSection.isWasmData())
     DataRelocations.push_back(Rec);
   else if (FixupSection.getKind().isText())
     CodeRelocations.push_back(Rec);
-  else if (!FixupSection.getKind().isMetadata())
-    // TODO(sbc): Add support for debug sections.
+  else
     llvm_unreachable("unexpected section type");
 }
 
@@ -496,6 +508,9 @@ WasmObjectWriter::getProvisionalValue(const WasmRelocationEntry &RelEntry) {
     if (!Sym->isDefined())
       return 0;
 
+    if (!SymbolIndices.count(Sym))
+      report_fatal_error("symbol not found in function/global index space: " +
+                         Sym->getName());
     uint32_t GlobalIndex = SymbolIndices[Sym];
     const WasmGlobal& Global = Globals[GlobalIndex - NumGlobalImports];
     uint64_t Address = Global.InitialValue + RelEntry.Addend;