//===-- Support/hash_set - "Portable" wrapper around hash_set ---*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// vim:ft=cpp
//
// This file provides a wrapper around the mysterious <hash_set> header file
// that seems to move around between GCC releases into and out of namespaces at
//
//===----------------------------------------------------------------------===//
-#ifndef SUPPORT_HASHSET_H
-#define SUPPORT_HASHSET_H
+#ifndef SUPPORT_HASH_SET
+#define SUPPORT_HASH_SET
// Compiler Support Matrix
//
// 3.0.4 std ext/hash_set
// 3.1 __gnu_cxx ext/hash_set
//
-#if __GNUC__==3
-#include <ext/hash_set>
-#ifndef HASH_NAMESPACE
-#if __GNUC_MINOR__ == 0
-#define HASH_NAMESPACE std
-#else
-#define HASH_NAMESPACE __gnu_cxx
-#endif
-#endif
+#include "Config/config.h"
-#else
+// GCC versions 3.1 and later put hash_set in <ext/hash_set> and in
+// the __gnu_cxx namespace.
+#if defined(HAVE_GNU_EXT_HASH_SET)
+# include <ext/hash_set>
+# ifndef HASH_NAMESPACE
+# define HASH_NAMESPACE __gnu_cxx
+# endif
-#include <hash_set>
-#ifndef HASH_NAMESPACE
-#define HASH_NAMESPACE std
-#endif
+// GCC 3.0.x puts hash_set in <ext/hash_set> and in the std namespace.
+#elif defined(HAVE_STD_EXT_HASH_SET)
+# include <ext/hash_set>
+# ifndef HASH_NAMESPACE
+# define HASH_NAMESPACE std
+# endif
+
+// Older compilers such as GCC before version 3.0 do not keep
+// extensions in the `ext' directory, and ignore the `std' namespace.
+#elif defined(HAVE_GLOBAL_HASH_SET)
+# include <hash_set>
+# ifndef HASH_NAMESPACE
+# define HASH_NAMESPACE std
+# endif
+
+// Give a warning if we couldn't find it, instead of (or in addition to)
+// randomly doing something dumb.
+#else
+# warning "Autoconfiguration failed to find the hash_set header file."
#endif
using HASH_NAMESPACE::hash_set;
using HASH_NAMESPACE::hash;
-#endif
+// Include vector because ext/hash_set includes stl_vector.h and leaves
+// out specializations like stl_bvector.h, causing link conflicts.
+#include <vector>
+
+#include <Support/HashExtras.h>
+#endif