Index: include/llvm/MC/MCContext.h
===================================================================
--- include/llvm/MC/MCContext.h
+++ include/llvm/MC/MCContext.h
@@ -17,6 +17,7 @@
 #include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/MC/MCDwarf.h"
+#include "llvm/MC/MCParser/MCAsmParser.h"
 #include "llvm/MC/MCSubtargetInfo.h"
 #include "llvm/MC/SectionKind.h"
 #include "llvm/Support/Allocator.h"
@@ -302,6 +303,9 @@
     /// Get the symbol for \p Name, or null.
     MCSymbol *lookupSymbol(const Twine &Name) const;
 
+    /// Set value for a symbol.
+    int setSymbolValue(MCAsmParser &Parser, std::string &I);
+
     /// getSymbols - Get a reference for the symbol table for clients that
     /// want to, for example, iterate over all symbols. 'const' because we
     /// still want any modifications to the table itself to use the MCContext
Index: lib/MC/MCContext.cpp
===================================================================
--- lib/MC/MCContext.cpp
+++ lib/MC/MCContext.cpp
@@ -260,6 +260,23 @@
   return Symbols.lookup(NameRef);
 }
 
+int MCContext::setSymbolValue(MCAsmParser &Parser, std::string &I) {
+    auto Pair = StringRef(I).split('=');
+    if (Pair.second.empty()) {
+      errs() << "error: defsym must be of the form: sym=value: " << I << "\n";
+      return 1;
+    }
+    int64_t Value;
+    if (Pair.second.getAsInteger(0, Value)) {
+      errs() << "error: Value is not an integer: " << Pair.second << "\n";
+      return 1;
+    }
+    auto Symbol = getOrCreateSymbol(Pair.first);
+    Parser.getStreamer().EmitAssignment(Symbol,
+                                        MCConstantExpr::create(Value, *this));
+    return 0;
+}
+
 //===----------------------------------------------------------------------===//
 // Section Management
 //===----------------------------------------------------------------------===//
Index: tools/llvm-mc/llvm-mc.cpp
===================================================================
--- tools/llvm-mc/llvm-mc.cpp
+++ tools/llvm-mc/llvm-mc.cpp
@@ -394,22 +394,9 @@
 }
 
 static int fillCommandLineSymbols(MCAsmParser &Parser){
-  for(auto &I: DefineSymbol){
-    auto Pair = StringRef(I).split('=');
-    if(Pair.second.empty()){
-      errs() << "error: defsym must be of the form: sym=value: " << I;
+  for (auto &I: DefineSymbol)
+    if (Parser.getContext().setSymbolValue(Parser, I))
       return 1;
-    }
-    int64_t Value;
-    if(Pair.second.getAsInteger(0, Value)){
-      errs() << "error: Value is not an integer: " << Pair.second;
-      return 1;
-    }
-    auto &Context = Parser.getContext();
-    auto Symbol = Context.getOrCreateSymbol(Pair.first);
-    Parser.getStreamer().EmitAssignment(Symbol,
-                                        MCConstantExpr::create(Value, Context));
-  }
   return 0;
 }