diff --git a/lld/wasm/InputFiles.h b/lld/wasm/InputFiles.h
--- a/lld/wasm/InputFiles.h
+++ b/lld/wasm/InputFiles.h
@@ -154,7 +154,7 @@
   Symbol *createDefined(const WasmSymbol &sym);
   Symbol *createUndefined(const WasmSymbol &sym, bool isCalledDirectly);
 
-  bool isExcludedByComdat(InputChunk *chunk) const;
+  bool isExcludedByComdat(const InputChunk *chunk) const;
   void addLegacyIndirectFunctionTableIfNeeded(uint32_t tableSymbolCount);
 
   std::unique_ptr<WasmObjectFile> wasmObj;
diff --git a/lld/wasm/InputFiles.cpp b/lld/wasm/InputFiles.cpp
--- a/lld/wasm/InputFiles.cpp
+++ b/lld/wasm/InputFiles.cpp
@@ -496,12 +496,11 @@
 
   // Populate `Functions`.
   ArrayRef<WasmFunction> funcs = wasmObj->functions();
-  ArrayRef<uint32_t> funcTypes = wasmObj->functionTypes();
   ArrayRef<WasmSignature> types = wasmObj->types();
   functions.reserve(funcs.size());
 
-  for (size_t i = 0, e = funcs.size(); i != e; ++i) {
-    auto* func = make<InputFunction>(types[funcTypes[i]], &funcs[i], this);
+  for (auto &f : funcs) {
+    auto *func = make<InputFunction>(types[f.SigIndex], &f, this);
     func->discarded = isExcludedByComdat(func);
     functions.emplace_back(func);
   }
@@ -541,7 +540,7 @@
   addLegacyIndirectFunctionTableIfNeeded(tableSymbolCount);
 }
 
-bool ObjFile::isExcludedByComdat(InputChunk *chunk) const {
+bool ObjFile::isExcludedByComdat(const InputChunk *chunk) const {
   uint32_t c = chunk->getComdat();
   if (c == UINT32_MAX)
     return false;
diff --git a/llvm/include/llvm/BinaryFormat/Wasm.h b/llvm/include/llvm/BinaryFormat/Wasm.h
--- a/llvm/include/llvm/BinaryFormat/Wasm.h
+++ b/llvm/include/llvm/BinaryFormat/Wasm.h
@@ -139,6 +139,7 @@
 
 struct WasmFunction {
   uint32_t Index;
+  uint32_t SigIndex;
   std::vector<WasmLocalDecl> Locals;
   ArrayRef<uint8_t> Body;
   uint32_t CodeSectionOffset;
diff --git a/llvm/include/llvm/Object/Wasm.h b/llvm/include/llvm/Object/Wasm.h
--- a/llvm/include/llvm/Object/Wasm.h
+++ b/llvm/include/llvm/Object/Wasm.h
@@ -138,7 +138,6 @@
     return TargetFeatures;
   }
   ArrayRef<wasm::WasmSignature> types() const { return Signatures; }
-  ArrayRef<uint32_t> functionTypes() const { return FunctionTypes; }
   ArrayRef<wasm::WasmImport> imports() const { return Imports; }
   ArrayRef<wasm::WasmTable> tables() const { return Tables; }
   ArrayRef<wasm::WasmLimits> memories() const { return Memories; }
diff --git a/llvm/lib/Object/WasmObjectFile.cpp b/llvm/lib/Object/WasmObjectFile.cpp
--- a/llvm/lib/Object/WasmObjectFile.cpp
+++ b/llvm/lib/Object/WasmObjectFile.cpp
@@ -412,7 +412,7 @@
   llvm::DenseSet<uint64_t> SeenFunctions;
   llvm::DenseSet<uint64_t> SeenGlobals;
   llvm::DenseSet<uint64_t> SeenSegments;
-  if (FunctionTypes.size() && !SeenCodeSection) {
+  if (Functions.size() && !SeenCodeSection) {
     return make_error<GenericBinaryError>("names must come after code section",
                                           object_error::parse_failed);
   }
@@ -480,7 +480,7 @@
 
 Error WasmObjectFile::parseLinkingSection(ReadContext &Ctx) {
   HasLinkingSection = true;
-  if (FunctionTypes.size() && !SeenCodeSection) {
+  if (Functions.size() && !SeenCodeSection) {
     return make_error<GenericBinaryError>(
         "linking data must come after code section",
         object_error::parse_failed);
@@ -598,8 +598,8 @@
       if (IsDefined) {
         Info.Name = readString(Ctx);
         unsigned FuncIndex = Info.ElementIndex - NumImportedFunctions;
-        Signature = &Signatures[FunctionTypes[FuncIndex]];
         wasm::WasmFunction &Function = Functions[FuncIndex];
+        Signature = &Signatures[Function.SigIndex];
         if (Function.SymbolName.empty())
           Function.SymbolName = Info.Name;
       } else {
@@ -1140,15 +1140,16 @@
 
 Error WasmObjectFile::parseFunctionSection(ReadContext &Ctx) {
   uint32_t Count = readVaruint32(Ctx);
-  FunctionTypes.reserve(Count);
-  Functions.resize(Count);
+  Functions.reserve(Count);
   uint32_t NumTypes = Signatures.size();
   while (Count--) {
     uint32_t Type = readVaruint32(Ctx);
     if (Type >= NumTypes)
       return make_error<GenericBinaryError>("invalid function type",
                                             object_error::parse_failed);
-    FunctionTypes.push_back(Type);
+    wasm::WasmFunction F;
+    F.SigIndex = Type;
+    Functions.push_back(F);
   }
   if (Ctx.Ptr != Ctx.End)
     return make_error<GenericBinaryError>("function section ended prematurely",
@@ -1272,7 +1273,7 @@
 }
 
 bool WasmObjectFile::isValidFunctionIndex(uint32_t Index) const {
-  return Index < NumImportedFunctions + FunctionTypes.size();
+  return Index < NumImportedFunctions + Functions.size();
 }
 
 bool WasmObjectFile::isDefinedFunctionIndex(uint32_t Index) const {
@@ -1360,7 +1361,7 @@
   SeenCodeSection = true;
   CodeSection = Sections.size();
   uint32_t FunctionCount = readVaruint32(Ctx);
-  if (FunctionCount != FunctionTypes.size()) {
+  if (FunctionCount != Functions.size()) {
     return make_error<GenericBinaryError>("invalid function count",
                                           object_error::parse_failed);
   }
diff --git a/llvm/tools/obj2yaml/wasm2yaml.cpp b/llvm/tools/obj2yaml/wasm2yaml.cpp
--- a/llvm/tools/obj2yaml/wasm2yaml.cpp
+++ b/llvm/tools/obj2yaml/wasm2yaml.cpp
@@ -260,8 +260,8 @@
     }
     case wasm::WASM_SEC_FUNCTION: {
       auto FuncSec = std::make_unique<WasmYAML::FunctionSection>();
-      for (const auto &Func : Obj.functionTypes()) {
-        FuncSec->FunctionTypes.push_back(Func);
+      for (const auto &Func : Obj.functions()) {
+        FuncSec->FunctionTypes.push_back(Func.SigIndex);
       }
       S = std::move(FuncSec);
       break;