[OPENMP] Fix for http://llvm.org/PR25221: Infinite loop while parsing OpenMP directive

Clang skipped annot_pragma_openmp token, while it should be considered as a stop token while skipping tokens.

llvm-svn: 250684

clang/lib/Parse/Parser.cpp

@@ -282,6 +282,7 @@ bool Parser::SkipUntil(ArrayRef<tok::TokenKind> Toks, SkipUntilFlags Flags) {
       // Ran out of tokens.
       return false;
 
+    case tok::annot_pragma_openmp:
     case tok::annot_pragma_openmp_end:
       // Stop before an OpenMP pragma boundary.
     case tok::annot_module_begin:

clang/test/OpenMP/openmp_check.cpp

@@ -0,0 +1,15 @@
+// RUN: %clang_cc1 -verify -fopenmp -ferror-limit 100 %s
+int nested(int a) {
+#pragma omp parallel
+  ++a;
+
+  auto F = [&]() { // expected-error {{expected expression}} expected-error {{expected ';' at end of declaration}} expected-warning {{'auto' type specifier is a C++11 extension}}
+#pragma omp parallel
+    {
+#pragma omp target
+      ++a;
+    }
+  };
+  F(); // expected-error {{C++ requires a type specifier for all declarations}}
+  return a; // expected-error {{expected unqualified-id}}
+}// expected-error {{extraneous closing brace ('}')}}