Index: llvm/trunk/include/llvm/BinaryFormat/Wasm.h
===================================================================
--- llvm/trunk/include/llvm/BinaryFormat/Wasm.h
+++ llvm/trunk/include/llvm/BinaryFormat/Wasm.h
@@ -289,6 +289,7 @@
 const unsigned WASM_SYMBOL_VISIBILITY_DEFAULT = 0x0;
 const unsigned WASM_SYMBOL_VISIBILITY_HIDDEN = 0x4;
 const unsigned WASM_SYMBOL_UNDEFINED = 0x10;
+const unsigned WASM_SYMBOL_EXPORTED = 0x20;
 
 #define WASM_RELOC(name, value) name = value,
 
Index: llvm/trunk/include/llvm/MC/MCSymbolWasm.h
===================================================================
--- llvm/trunk/include/llvm/MC/MCSymbolWasm.h
+++ llvm/trunk/include/llvm/MC/MCSymbolWasm.h
@@ -46,6 +46,13 @@
   wasm::WasmSymbolType getType() const { return Type; }
   void setType(wasm::WasmSymbolType type) { Type = type; }
 
+  bool isExported() const {
+    return getFlags() & wasm::WASM_SYMBOL_EXPORTED;
+  }
+  void setExported() const {
+    modifyFlags(wasm::WASM_SYMBOL_EXPORTED, wasm::WASM_SYMBOL_EXPORTED);
+  }
+
   bool isWeak() const { return IsWeak; }
   void setWeak(bool isWeak) { IsWeak = isWeak; }
 
Index: llvm/trunk/lib/MC/MCAsmInfoWasm.cpp
===================================================================
--- llvm/trunk/lib/MC/MCAsmInfoWasm.cpp
+++ llvm/trunk/lib/MC/MCAsmInfoWasm.cpp
@@ -18,6 +18,7 @@
 
 MCAsmInfoWasm::MCAsmInfoWasm() {
   HasIdentDirective = true;
+  HasNoDeadStrip = true;
   WeakRefDirective = "\t.weak\t";
   PrivateGlobalPrefix = ".L";
   PrivateLabelPrefix = ".L";
Index: llvm/trunk/lib/MC/MCWasmStreamer.cpp
===================================================================
--- llvm/trunk/lib/MC/MCWasmStreamer.cpp
+++ llvm/trunk/lib/MC/MCWasmStreamer.cpp
@@ -121,6 +121,10 @@
   case MCSA_Cold:
     break;
 
+  case MCSA_NoDeadStrip:
+    Symbol->setExported();
+    break;
+
   default:
     // unrecognized directive
     llvm_unreachable("unexpected MCSymbolAttr");
Index: llvm/trunk/lib/MC/WasmObjectWriter.cpp
===================================================================
--- llvm/trunk/lib/MC/WasmObjectWriter.cpp
+++ llvm/trunk/lib/MC/WasmObjectWriter.cpp
@@ -1454,6 +1454,8 @@
       Flags |= wasm::WASM_SYMBOL_BINDING_LOCAL;
     if (WS.isUndefined())
       Flags |= wasm::WASM_SYMBOL_UNDEFINED;
+    if (WS.isExported())
+      Flags |= wasm::WASM_SYMBOL_EXPORTED;
 
     wasm::WasmSymbolInfo Info;
     Info.Name = WS.getName();
Index: llvm/trunk/lib/ObjectYAML/WasmYAML.cpp
===================================================================
--- llvm/trunk/lib/ObjectYAML/WasmYAML.cpp
+++ llvm/trunk/lib/ObjectYAML/WasmYAML.cpp
@@ -486,6 +486,7 @@
   // BCaseMask(VISIBILITY_MASK, VISIBILITY_DEFAULT);
   BCaseMask(VISIBILITY_MASK, VISIBILITY_HIDDEN);
   BCaseMask(UNDEFINED, UNDEFINED);
+  BCaseMask(EXPORTED, EXPORTED);
 #undef BCaseMask
 }
 
Index: llvm/trunk/test/MC/WebAssembly/no-dead-strip.ll
===================================================================
--- llvm/trunk/test/MC/WebAssembly/no-dead-strip.ll
+++ llvm/trunk/test/MC/WebAssembly/no-dead-strip.ll
@@ -0,0 +1,21 @@
+; RUN: llc -filetype=obj -wasm-keep-registers %s -o - | llvm-readobj --symbols | FileCheck %s
+
+target triple = "wasm32-unknown-unknown"
+
+@llvm.used = appending global [1 x i8*] [i8* bitcast (i32 ()* @foo to i8*)], section "llvm.metadata"
+
+define i32 @foo() {
+entry:
+    ret i32 0
+}
+
+; CHECK:      Symbols [
+; CHECK-NEXT:   Symbol {
+; CHECK-NEXT:     Name: foo
+; CHECK-NEXT:     Type: FUNCTION (0x0)
+; CHECK-NEXT:     Flags [ (0x20)
+; CHECK-NEXT:       EXPORTED (0x20)
+; CHECK-NEXT:     ]
+; CHECK-NEXT:     ElementIndex: 0x0
+; CHECK-NEXT:   }
+; CHECK-NEXT: ]
Index: llvm/trunk/tools/llvm-readobj/WasmDumper.cpp
===================================================================
--- llvm/trunk/tools/llvm-readobj/WasmDumper.cpp
+++ llvm/trunk/tools/llvm-readobj/WasmDumper.cpp
@@ -49,6 +49,7 @@
   ENUM_ENTRY(VISIBILITY_DEFAULT),
   ENUM_ENTRY(VISIBILITY_HIDDEN),
   ENUM_ENTRY(UNDEFINED),
+  ENUM_ENTRY(EXPORTED),
 #undef ENUM_ENTRY
 };