Revert https://codereview.chromium.org/1291903002 (protobuf roll).

third_party/protobuf/src/google/protobuf/stubs/hash.h

Index: third_party/protobuf/src/google/protobuf/stubs/hash.h
diff --git a/third_party/protobuf/src/google/protobuf/stubs/hash.h b/third_party/protobuf/src/google/protobuf/stubs/hash.h
index 3ff72535a317e4304600f12de643fea954ec68fa..82d5052ecaff918f911c9924a77a46af78603d59 100644
--- a/third_party/protobuf/src/google/protobuf/stubs/hash.h
+++ b/third_party/protobuf/src/google/protobuf/stubs/hash.h
@@ -37,117 +37,12 @@
 
 #include <string.h>
 #include <google/protobuf/stubs/common.h>
-
-#define GOOGLE_PROTOBUF_HAVE_HASH_MAP 1
-#define GOOGLE_PROTOBUF_HAVE_HASH_SET 1
-
-// Use C++11 unordered_{map|set} if available.
-#if ((__cplusplus >= 201103L) &&                            \
-     ((defined(__GLIBCXX__) && (__GLIBCXX__ > 20090421)) || \
-      (defined(_LIBCPP_VERSION) && (_LIBCPP_STD_VER >= 11))))
-# define GOOGLE_PROTOBUF_HAS_CXX11_HASH
-
-// For XCode >= 4.6:  the compiler is clang with libc++.
-// For earlier XCode version: the compiler is gcc-4.2.1 with libstdc++.
-// libc++ provides <unordered_map> and friends even in non C++11 mode,
-// and it does not provide the tr1 library. Therefore the following macro
-// checks against this special case.
-// Note that we should not test the __APPLE_CC__ version number or the
-// __clang__ macro, since the new compiler can still use -stdlib=libstdc++, in
-// which case <unordered_map> is not compilable without -std=c++11
-#elif defined(__APPLE_CC__)
-# if __GNUC__ >= 4
-#  define GOOGLE_PROTOBUF_HAS_TR1
-# else
-// Not tested for gcc < 4... These setting can compile under 4.2.1 though.
-#  define GOOGLE_PROTOBUF_HASH_NAMESPACE __gnu_cxx
-#  include <ext/hash_map>
-#  define GOOGLE_PROTOBUF_HASH_MAP_CLASS hash_map
-#  include <ext/hash_set>
-#  define GOOGLE_PROTOBUF_HASH_SET_CLASS hash_set
-# endif
-
-// Version checks for gcc.
-#elif defined(__GNUC__)
-// For GCC 4.x+, use tr1::unordered_map/set; otherwise, follow the
-// instructions from:
-// https://gcc.gnu.org/onlinedocs/libstdc++/manual/backwards.html
-# if __GNUC__ >= 4
-#  define GOOGLE_PROTOBUF_HAS_TR1
-# elif __GNUC__ >= 3
-#  include <backward/hash_map>
-#  define GOOGLE_PROTOBUF_HASH_MAP_CLASS hash_map
-#  include <backward/hash_set>
-#  define GOOGLE_PROTOBUF_HASH_SET_CLASS hash_set
-#  if __GNUC__ == 3 && __GNUC_MINOR__ == 0
-#   define GOOGLE_PROTOBUF_HASH_NAMESPACE std       // GCC 3.0
-#  else
-#   define GOOGLE_PROTOBUF_HASH_NAMESPACE __gnu_cxx // GCC 3.1 and later
-#  endif
-# else
-#  define GOOGLE_PROTOBUF_HASH_NAMESPACE
-#  include <hash_map>
-#  define GOOGLE_PROTOBUF_HASH_MAP_CLASS hash_map
-#  include <hash_set>
-#  define GOOGLE_PROTOBUF_HASH_SET_CLASS hash_set
-# endif
-
-// Version checks for MSC.
-// Apparently Microsoft decided to move hash_map *back* to the std namespace in
-// MSVC 2010:
-// http://blogs.msdn.com/vcblog/archive/2009/05/25/stl-breaking-changes-in-visual-studio-2010-beta-1.aspx
-// And.. they are moved back to stdext in MSVC 2013 (haven't checked 2012). That
-// said, use unordered_map for MSVC 2010 and beyond is our safest bet.
-#elif defined(_MSC_VER)
-# if _MSC_VER >= 1600  // Since Visual Studio 2010
-#  define GOOGLE_PROTOBUF_HAS_CXX11_HASH
-#  define GOOGLE_PROTOBUF_HASH_COMPARE std::hash_compare
-# elif _MSC_VER >= 1500  // Since Visual Studio 2008
-#  define GOOGLE_PROTOBUF_HAS_TR1
-#  define GOOGLE_PROTOBUF_HASH_COMPARE stdext::hash_compare
-# elif _MSC_VER >= 1310
-#  define GOOGLE_PROTOBUF_HASH_NAMESPACE stdext
-#  include <hash_map>
-#  define GOOGLE_PROTOBUF_HASH_MAP_CLASS hash_map
-#  include <hash_set>
-#  define GOOGLE_PROTOBUF_HASH_SET_CLASS hash_set
-#  define GOOGLE_PROTOBUF_HASH_COMPARE stdext::hash_compare
-# else
-#  define GOOGLE_PROTOBUF_HASH_NAMESPACE std
-#  include <hash_map>
-#  define GOOGLE_PROTOBUF_HASH_MAP_CLASS hash_map
-#  include <hash_set>
-#  define GOOGLE_PROTOBUF_HASH_SET_CLASS hash_set
-#  define GOOGLE_PROTOBUF_HASH_COMPARE stdext::hash_compare
-# endif
-
-// **ADD NEW COMPILERS SUPPORT HERE.**
-// For other compilers, undefine the macro and fallback to use std::map, in
-// google/protobuf/stubs/hash.h
-#else
-# undef GOOGLE_PROTOBUF_HAVE_HASH_MAP
-# undef GOOGLE_PROTOBUF_HAVE_HASH_SET
-#endif
-
-#if defined(GOOGLE_PROTOBUF_HAS_CXX11_HASH)
-# define GOOGLE_PROTOBUF_HASH_NAMESPACE std
-# include <unordered_map>
-# define GOOGLE_PROTOBUF_HASH_MAP_CLASS unordered_map
-# include <unordered_set>
-# define GOOGLE_PROTOBUF_HASH_SET_CLASS unordered_set
-#elif defined(GOOGLE_PROTOBUF_HAS_TR1)
-# define GOOGLE_PROTOBUF_HASH_NAMESPACE std::tr1
-# include <tr1/unordered_map>
-# define GOOGLE_PROTOBUF_HASH_MAP_CLASS unordered_map
-# include <tr1/unordered_set>
-# define GOOGLE_PROTOBUF_HASH_SET_CLASS unordered_set
-#endif
-
-#undef GOOGLE_PROTOBUF_HAS_CXX11_HASH
-#undef GOOGLE_PROTOBUF_HAS_TR1
+#include <google/protobuf/stubs/pbconfig.h>
 
 #if defined(GOOGLE_PROTOBUF_HAVE_HASH_MAP) && \
     defined(GOOGLE_PROTOBUF_HAVE_HASH_SET)
+#include GOOGLE_PROTOBUF_HASH_MAP_H
+#include GOOGLE_PROTOBUF_HASH_SET_H
 #else
 #define GOOGLE_PROTOBUF_MISSING_HASH
 #include <map>
@@ -158,7 +53,6 @@ namespace google {
 namespace protobuf {
 
 #ifdef GOOGLE_PROTOBUF_MISSING_HASH
-#undef GOOGLE_PROTOBUF_MISSING_HASH
 
 // This system doesn't have hash_map or hash_set.  Emulate them using map and
 // set.
@@ -197,13 +91,10 @@ template <typename Key, typename Data,
           typename HashFcn = hash<Key>,
           typename EqualKey = std::equal_to<Key>,
           typename Alloc = std::allocator< std::pair<const Key, Data> > >
-class hash_map : public std::map<Key, Data, HashFcn, Alloc> {
-  typedef std::map<Key, Data, HashFcn, Alloc> BaseClass;
-
+class hash_map : public std::map<Key, Data, HashFcn, EqualKey, Alloc> {
  public:
-  hash_map(int a = 0, const HashFcn& b = HashFcn(),
-           const EqualKey& c = EqualKey(),
-           const Alloc& d = Alloc()) : BaseClass(b, d) {}
+  hash_map(int = 0, const HashFcn& = HashFcn(), const EqualKey& = EqualKey(),
+           const Alloc& = Alloc()) {}
 };
 
 template <typename Key,
@@ -217,7 +108,7 @@ class hash_set : public std::set<Key, HashFcn> {
 #elif defined(_MSC_VER) && !defined(_STLPORT_VERSION)
 
 template <typename Key>
-struct hash : public GOOGLE_PROTOBUF_HASH_COMPARE<Key> {
+struct hash : public GOOGLE_PROTOBUF_HASH_NAMESPACE::hash_compare<Key> {
 };
 
 // MSVC's hash_compare<const char*> hashes based on the string contents but
@@ -231,7 +122,8 @@ class CstringLess {
 
 template <>
 struct hash<const char*>
-    : public GOOGLE_PROTOBUF_HASH_COMPARE<const char*, CstringLess> {};
+    : public GOOGLE_PROTOBUF_HASH_NAMESPACE::hash_compare<
+        const char*, CstringLess> {};
 
 template <typename Key, typename Data,
           typename HashFcn = hash<Key>,
@@ -240,13 +132,9 @@ template <typename Key, typename Data,
 class hash_map
     : public GOOGLE_PROTOBUF_HASH_NAMESPACE::GOOGLE_PROTOBUF_HASH_MAP_CLASS<
           Key, Data, HashFcn, EqualKey, Alloc> {
-  typedef GOOGLE_PROTOBUF_HASH_NAMESPACE::GOOGLE_PROTOBUF_HASH_MAP_CLASS<
-      Key, Data, HashFcn, EqualKey, Alloc> BaseClass;
-
  public:
-  hash_map(int a = 0, const HashFcn& b = HashFcn(),
-           const EqualKey& c = EqualKey(),
-           const Alloc& d = Alloc()) : BaseClass(a, b, c, d) {}
+  hash_map(int = 0, const HashFcn& = HashFcn(), const EqualKey& = EqualKey(),
+           const Alloc& = Alloc()) {}
 };
 
 template <typename Key, typename HashFcn = hash<Key>,
@@ -284,13 +172,6 @@ struct hash<const char*> {
   }
 };
 
-template<>
-struct hash<bool> {
-  size_t operator()(bool x) const {
-    return static_cast<size_t>(x);
-  }
-};
-
 template <typename Key, typename Data,
           typename HashFcn = hash<Key>,
           typename EqualKey = std::equal_to<Key>,
@@ -298,13 +179,9 @@ template <typename Key, typename Data,
 class hash_map
     : public GOOGLE_PROTOBUF_HASH_NAMESPACE::GOOGLE_PROTOBUF_HASH_MAP_CLASS<
           Key, Data, HashFcn, EqualKey, Alloc> {
-  typedef GOOGLE_PROTOBUF_HASH_NAMESPACE::GOOGLE_PROTOBUF_HASH_MAP_CLASS<
-      Key, Data, HashFcn, EqualKey, Alloc> BaseClass;
-
  public:
-  hash_map(int a = 0, const HashFcn& b = HashFcn(),
-           const EqualKey& c = EqualKey(),
-           const Alloc& d = Alloc()) : BaseClass(a, b, c, d) {}
+  hash_map(int = 0, const HashFcn& = HashFcn(), const EqualKey& = EqualKey(),
+           const Alloc& = Alloc()) {}
 };
 
 template <typename Key, typename HashFcn = hash<Key>,
@@ -316,6 +193,7 @@ class hash_set
   hash_set(int = 0) {}
 };
 
+#undef GOOGLE_PROTOBUF_MISSING_HASH
 #endif  // !GOOGLE_PROTOBUF_MISSING_HASH
 
 template <>
@@ -326,7 +204,7 @@ struct hash<string> {
 
   static const size_t bucket_size = 4;
   static const size_t min_buckets = 8;
-  inline bool operator()(const string& a, const string& b) const {
+  inline size_t operator()(const string& a, const string& b) const {
     return a < b;
   }
 };
@@ -344,7 +222,7 @@ struct hash<pair<First, Second> > {
 
   static const size_t bucket_size = 4;
   static const size_t min_buckets = 8;
-  inline bool operator()(const pair<First, Second>& a,
+  inline size_t operator()(const pair<First, Second>& a,
                            const pair<First, Second>& b) const {
     return a < b;
   }