1 files changed, 22 insertions, 21 deletions

diff --git a/llvm/lib/MC/WasmObjectWriter.cpp b/llvm/lib/MC/WasmObjectWriter.cpp
index d16be49..b2c8c02 100644
--- a/llvm/lib/MC/WasmObjectWriter.cpp
+++ b/llvm/lib/MC/WasmObjectWriter.cpp
@@ -405,12 +405,17 @@ void WasmObjectWriter::writeHeader(const MCAssembler &Asm) {
 
 void WasmObjectWriter::executePostLayoutBinding(MCAssembler &Asm,
                                                 const MCAsmLayout &Layout) {
-  // As a stopgap measure until call_indirect instructions start explicitly
-  // referencing the indirect function table via TABLE_NUMBER relocs, ensure
-  // that the indirect function table import makes it to the output if anything
-  // in the compilation unit has caused it to be present.
-  if (auto *Sym = Asm.getContext().lookupSymbol("__indirect_function_table"))
-    Asm.registerSymbol(*Sym);
+  // Some compilation units require the indirect function table to be present
+  // but don't explicitly reference it.  This is the case for call_indirect
+  // without the reference-types feature, and also function bitcasts in all
+  // cases.  In those cases the __indirect_function_table has the
+  // WASM_SYMBOL_NO_STRIP attribute.  Here we make sure this symbol makes it to
+  // the assembler, if needed.
+  if (auto *Sym = Asm.getContext().lookupSymbol("__indirect_function_table")) {
+    const auto *WasmSym = static_cast<const MCSymbolWasm *>(Sym);
+    if (WasmSym->isNoStrip())
+      Asm.registerSymbol(*Sym);
+  }
 
   // Build a map of sections to the function that defines them, for use
   // in recordRelocation.
@@ -509,21 +514,18 @@ void WasmObjectWriter::recordRelocation(MCAssembler &Asm,
       Type == wasm::R_WASM_TABLE_INDEX_I32 ||
       Type == wasm::R_WASM_TABLE_INDEX_I64) {
     // TABLE_INDEX relocs implicitly use the default indirect function table.
+    // We require the function table to have already been defined.
     auto TableName = "__indirect_function_table";
     MCSymbolWasm *Sym = cast_or_null<MCSymbolWasm>(Ctx.lookupSymbol(TableName));
-    if (Sym) {
-      if (!Sym->isFunctionTable())
-        Ctx.reportError(
-            Fixup.getLoc(),
-            "symbol '__indirect_function_table' is not a function table");
+    if (!Sym || !Sym->isFunctionTable()) {
+      Ctx.reportError(
+          Fixup.getLoc(),
+          "symbol '__indirect_function_table' is not a function table");
     } else {
-      Sym = cast<MCSymbolWasm>(Ctx.getOrCreateSymbol(TableName));
-      Sym->setFunctionTable();
-      // The default function table is synthesized by the linker.
-      Sym->setUndefined();
+      // Ensure that __indirect_function_table reaches the output.
+      Sym->setNoStrip();
+      Asm.registerSymbol(*Sym);
     }
-    Sym->setUsedInReloc();
-    Asm.registerSymbol(*Sym);
   }
 
   // Relocation other than R_WASM_TYPE_INDEX_LEB are required to be
@@ -1211,6 +1213,9 @@ static bool isInSymtab(const MCSymbolWasm &Sym) {
   if (Sym.isSection())
     return false;
 
+  if (Sym.omitFromLinkingSection())
+    return false;
+
   return true;
 }
 
@@ -1674,10 +1679,6 @@ uint64_t WasmObjectWriter::writeOneObject(MCAssembler &Asm,
       WS.setIndex(InvalidIndex);
       continue;
     }
-    if (WS.isTable() && WS.getName() == "__indirect_function_table") {
-      // For the moment, don't emit table symbols -- wasm-ld can't handle them.
-      continue;
-    }
     LLVM_DEBUG(dbgs() << "adding to symtab: " << WS << "\n");
 
     uint32_t Flags = 0;