Index: lib/Sema/SemaType.cpp
===================================================================
--- lib/Sema/SemaType.cpp
+++ lib/Sema/SemaType.cpp
@@ -5369,6 +5369,7 @@
   struct FunctionTypeUnwrapper {
     enum WrapKind {
       Desugar,
+      Attributed,
       Parens,
       Pointer,
       BlockPointer,
@@ -5401,6 +5402,9 @@
         } else if (isa<ReferenceType>(Ty)) {
           T = cast<ReferenceType>(Ty)->getPointeeType();
           Stack.push_back(Reference);
+        } else if (isa<AttributedType>(Ty)) {
+          T = cast<AttributedType>(Ty)->getEquivalentType();
+          Stack.push_back(Attributed);
         } else {
           const Type *DTy = Ty->getUnqualifiedDesugaredType();
           if (Ty == DTy) {
@@ -5449,6 +5453,9 @@
         // information.
         return wrap(C, Old->getUnqualifiedDesugaredType(), I);
 
+      case Attributed:
+        return wrap(C, cast<AttributedType>(Old)->getEquivalentType(), I);
+
       case Parens: {
         QualType New = wrap(C, cast<ParenType>(Old)->getInnerType(), I);
         return C.getParenType(New);
Index: test/CodeGen/pr25786.c
===================================================================
--- test/CodeGen/pr25786.c
+++ test/CodeGen/pr25786.c
@@ -0,0 +1,11 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple i686-unknown-linux-gnu -emit-llvm -o - %s | FileCheck %s --check-prefix=CHECK-OK
+
+void (__attribute__((regparm(3), stdcall)) *pf) ();
+void (__attribute__((regparm(2), stdcall)) foo)(int a) {
+}
+// CHECK: @pf = common global void (...)* null
+// CHECK: define void @foo(i32 %a)
+
+// CHECK-OK: @pf = common global void (...)* null
+// CHECK-OK: define x86_stdcallcc void @foo(i32 inreg %a)
Index: test/Sema/pr25786.c
===================================================================
--- test/Sema/pr25786.c
+++ test/Sema/pr25786.c
@@ -0,0 +1,12 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -DTEST -fsyntax-only -verify %s
+// RUN: %clang_cc1 -triple i686-unknown-linux-gnu -fsyntax-only -verify %s
+
+#if TEST
+void (__attribute__((regparm(3), stdcall)) *pf) (); //expected-warning {{calling convention 'stdcall' ignored for this target}}
+void (__attribute__((regparm(2), stdcall)) foo)(int a) { //expected-warning {{calling convention 'stdcall' ignored for this target}}
+}
+#else
+//expected-no-diagnostics
+void (__attribute__((regparm(3), stdcall)) *pf) ();
+void (__attribute__((regparm(2), stdcall)) foo)(int a) {}
+#endif