fix __attribute__(format) for struct function pointer fields

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@49938 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 015ba8c..e51b797 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -2268,10 +2268,14 @@
 }
 
 static const FunctionTypeProto *getFunctionProto(Decl *d) {
-  ValueDecl *decl = dyn_cast<ValueDecl>(d);
-  if (!decl) return 0;
+  QualType Ty;
 
-  QualType Ty = decl->getType();
+  if (ValueDecl *decl = dyn_cast<ValueDecl>(d))
+    Ty = decl->getType();
+  else if (FieldDecl *decl = dyn_cast<FieldDecl>(d))
+    Ty = decl->getType();
+  else
+    return 0;
 
   if (Ty->isFunctionPointerType()) {
     const PointerType *PtrTy = Ty->getAsPointerType();
diff --git a/test/Sema/format-attribute.c b/test/Sema/format-attribute.c
index df3e4b5..8eefe3f 100644
--- a/test/Sema/format-attribute.c
+++ b/test/Sema/format-attribute.c
@@ -17,3 +17,8 @@
 
 int (*f_ptr)(char*,...) __attribute__((format(printf, 1,2))); // no-error
 int (*f2_ptr)(double,...) __attribute__((format(printf, 1, 2))); // expected-error {{format argument not a string type}}
+
+struct _mystruct {
+  int (*printf)(const char *format, ...) __attribute__((__format__(printf, 1, 2))); // no-error
+  int (*printf2)(double format, ...) __attribute__((__format__(printf, 1, 2))); // expected-error {{format argument not a string type}}
+};