[WebAssembly] Add symbol flag to the binary format llvm.used

Summary:
Rather than add a new attribute
See https://github.com/WebAssembly/tool-conventions/issues/64

Subscribers: dschuff, jgravelle-google, aheejin, sunfish, rupprecht, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D57864

llvm-svn: 353360

2 files changed, 8 insertions, 0 deletions

diff --git a/llvm/include/llvm/BinaryFormat/Wasm.h b/llvm/include/llvm/BinaryFormat/Wasm.h
index 84832766858..348fa11542f 100644
--- a/llvm/include/llvm/BinaryFormat/Wasm.h
+++ b/llvm/include/llvm/BinaryFormat/Wasm.h
@@ -289,6 +289,7 @@ const unsigned WASM_SYMBOL_BINDING_LOCAL = 0x2;
 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,
 
diff --git a/llvm/include/llvm/MC/MCSymbolWasm.h b/llvm/include/llvm/MC/MCSymbolWasm.h
index a39d1ce4b77..88759fe4d9e 100644
--- a/llvm/include/llvm/MC/MCSymbolWasm.h
+++ b/llvm/include/llvm/MC/MCSymbolWasm.h
@@ -46,6 +46,13 @@ public:
   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; }