Don't dllexport declarations

Fixes PR22488

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228411 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/X86/X86AsmPrinter.cpp

@@ -695,11 +695,11 @@ void X86AsmPrinter::EmitEndOfAsmFile(Module &M) {
     std::vector<const MCSymbol*> DLLExportedFns, DLLExportedGlobals;
 
     for (const auto &Function : M)
-      if (Function.hasDLLExportStorageClass())
+      if (Function.hasDLLExportStorageClass() && !Function.isDeclaration())
         DLLExportedFns.push_back(getSymbol(&Function));
 
     for (const auto &Global : M.globals())
-      if (Global.hasDLLExportStorageClass())
+      if (Global.hasDLLExportStorageClass() && !Global.isDeclaration())
         DLLExportedGlobals.push_back(getSymbol(&Global));
 
     for (const auto &Alias : M.aliases()) {

test/CodeGen/X86/dllexport.ll

@@ -21,6 +21,8 @@ define dllexport void @f2() unnamed_addr {
 	ret void
 }
 
+declare dllexport void @not_defined()
+
 ; CHECK: .globl _stdfun@0
 define dllexport x86_stdcallcc void @stdfun() nounwind {
 	ret void
@@ -86,7 +88,6 @@ define weak_odr dllexport void @weak1() {
 ; CHECK: _weak_alias = _f1
 @weak_alias = weak_odr dllexport alias void()* @f1
 
-
 ; CHECK: .section .drectve
 ; CHECK-CL: " /EXPORT:_Var1,DATA"
 ; CHECK-CL: " /EXPORT:_Var2,DATA"
@@ -95,6 +96,7 @@ define weak_odr dllexport void @weak1() {
 ; CHECK-CL: " /EXPORT:_WeakVar2,DATA"
 ; CHECK-CL: " /EXPORT:_f1"
 ; CHECK-CL: " /EXPORT:_f2"
+; CHECK-CL-NOT: not_exported
 ; CHECK-CL: " /EXPORT:_stdfun@0"
 ; CHECK-CL: " /EXPORT:@fastfun@0"
 ; CHECK-CL: " /EXPORT:_thisfun"
@@ -112,6 +114,7 @@ define weak_odr dllexport void @weak1() {
 ; CHECK-GCC: " -export:WeakVar2,data"
 ; CHECK-GCC: " -export:f1"
 ; CHECK-GCC: " -export:f2"
+; CHECK-CL-NOT: not_exported
 ; CHECK-GCC: " -export:stdfun@0"
 ; CHECK-GCC: " -export:@fastfun@0"
 ; CHECK-GCC: " -export:thisfun"