Index: clang/include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -8672,6 +8672,8 @@
     "invalid lvalue in asm input for constraint '%0'">;
   def err_asm_invalid_input_constraint : Error<
     "invalid input constraint '%0' in asm">;
+  def err_asm_immediate_expected : Error<"constraint '%0' expects "
+    "an integer constant expression">;
   def err_asm_tying_incompatible_types : Error<
     "unsupported inline asm: input with type "
     "%diff{$ matching output with type $|}0,1">;
Index: clang/lib/Sema/SemaStmtAsm.cpp
===================================================================
--- clang/lib/Sema/SemaStmtAsm.cpp
+++ clang/lib/Sema/SemaStmtAsm.cpp
@@ -394,6 +394,11 @@
                          << Info.getConstraintStr()
                          << InputExpr->getSourceRange());
     } else if (Info.requiresImmediateConstant() && !Info.allowsRegister()) {
+      if (InputExpr->getType()->isFunctionType()) {
+        return StmtError(
+             Diag(InputExpr->getBeginLoc(), diag::err_asm_immediate_expected)
+             << Info.getConstraintStr() << InputExpr->getSourceRange()); 
+      }
       if (!InputExpr->isValueDependent()) {
         Expr::EvalResult EVResult;
         if (InputExpr->EvaluateAsRValue(EVResult, Context, true)) {
@@ -410,7 +415,6 @@
                                << InputExpr->getSourceRange());
         }
       }
-
     } else {
       ExprResult Result = DefaultFunctionArrayLvalueConversion(Exprs[i]);
       if (Result.isInvalid())
Index: clang/test/Sema/inline-asm-validate-x86.c
===================================================================
--- clang/test/Sema/inline-asm-validate-x86.c
+++ clang/test/Sema/inline-asm-validate-x86.c
@@ -130,3 +130,8 @@
   __asm__ __volatile__("\n#define BEEF abcd%0\n" : : "n"((int*)0xdeadbeeeeeef));
 #endif
 }
+
+void callee(void);
+void caller(void) {
+  asm("call %0"::"n"(callee)); // expected-error{{constraint 'n' expects an integer constant expression}}
+}