Export of internal Abseil changes

--
3e6352709da9a529e608eabff862a12bfaecb587 by Gennadiy Rozental <rogeeff@google.com>:

Replace local copy of FastTypeId with one shared in absl/base/internal.

PiperOrigin-RevId: 304181357

--
c89ea428f732226f4dceb508cd6ba3955a1e49e1 by Andy Getzendanner <durandal@google.com>:

Typo fix: add a missing colon.

PiperOrigin-RevId: 304064210

--
de2ee7a96bdc7193ffcceb6a2fd6bf464955cbe7 by Samuel Benzaquen <sbenza@google.com>:

Reduce the overhead of the registration token by using an empty struct instead
of bool.

PiperOrigin-RevId: 304054311

--
222f05d24fb1df7e815946543a7dc78847c83f92 by Derek Mauro <dmauro@google.com>:

Turn off hashtablez in opensource builds.

Hashtablez is an unsupported, internal-only feature for collecting
information about hashtable usage and performance. By turning it off
in builds where it is unsupported, we get just a little more performance.

PiperOrigin-RevId: 304035460
GitOrigin-RevId: 3e6352709da9a529e608eabff862a12bfaecb587
Change-Id: I0bfe9b5df808a7e35c154b39e6c80e68b0da2b70

absl/container/BUILD.bazel

@@ -257,6 +257,7 @@ cc_test(
         ":unordered_map_lookup_test",
         ":unordered_map_members_test",
         ":unordered_map_modifiers_test",
+        "//absl/base:raw_logging_internal",
         "//absl/types:any",
         "@com_google_googletest//:gtest_main",
     ],
@@ -290,6 +291,7 @@ cc_test(
         ":unordered_set_lookup_test",
         ":unordered_set_members_test",
         ":unordered_set_modifiers_test",
+        "//absl/base:raw_logging_internal",
         "//absl/memory",
         "//absl/strings",
         "@com_google_googletest//:gtest_main",

absl/container/CMakeLists.txt

@@ -303,6 +303,7 @@ absl_cc_test(
     absl::unordered_map_members_test
     absl::unordered_map_modifiers_test
     absl::any
+    absl::raw_logging_internal
     gmock_main
 )
 
@@ -339,6 +340,7 @@ absl_cc_test(
     absl::unordered_set_members_test
     absl::unordered_set_modifiers_test
     absl::memory
+    absl::raw_logging_internal
     absl::strings
     gmock_main
 )

absl/container/flat_hash_map_test.cc

@@ -16,6 +16,7 @@
 
 #include <memory>
 
+#include "absl/base/internal/raw_logging.h"
 #include "absl/container/internal/hash_generator_testing.h"
 #include "absl/container/internal/unordered_map_constructor_test.h"
 #include "absl/container/internal/unordered_map_lookup_test.h"
@@ -34,6 +35,19 @@ using ::testing::IsEmpty;
 using ::testing::Pair;
 using ::testing::UnorderedElementsAre;
 
+// Check that absl::flat_hash_map works in a global constructor.
+struct BeforeMain {
+  BeforeMain() {
+    absl::flat_hash_map<int, int> x;
+    x.insert({1, 1});
+    ABSL_RAW_CHECK(x.find(0) == x.end(), "x should not contain 0");
+    auto it = x.find(1);
+    ABSL_RAW_CHECK(it != x.end(), "x should contain 1");
+    ABSL_RAW_CHECK(it->second, "1 should map to 1");
+  }
+};
+const BeforeMain before_main;
+
 template <class K, class V>
 using Map = flat_hash_map<K, V, StatefulTestingHash, StatefulTestingEqual,
                           Alloc<std::pair<const K, V>>>;

absl/container/flat_hash_set_test.cc

@@ -16,6 +16,7 @@
 
 #include <vector>
 
+#include "absl/base/internal/raw_logging.h"
 #include "absl/container/internal/hash_generator_testing.h"
 #include "absl/container/internal/unordered_set_constructor_test.h"
 #include "absl/container/internal/unordered_set_lookup_test.h"
@@ -36,6 +37,17 @@ using ::testing::Pointee;
 using ::testing::UnorderedElementsAre;
 using ::testing::UnorderedElementsAreArray;
 
+// Check that absl::flat_hash_set works in a global constructor.
+struct BeforeMain {
+  BeforeMain() {
+    absl::flat_hash_set<int> x;
+    x.insert(1);
+    ABSL_RAW_CHECK(!x.contains(0), "x should not contain 0");
+    ABSL_RAW_CHECK(x.contains(1), "x should contain 1");
+  }
+};
+const BeforeMain before_main;
+
 template <class T>
 using Set =
     absl::flat_hash_set<T, StatefulTestingHash, StatefulTestingEqual, Alloc<T>>;

absl/container/internal/hashtablez_sampler.h

@@ -184,11 +184,6 @@ class HashtablezInfoHandle {
 #error ABSL_INTERNAL_HASHTABLEZ_SAMPLE cannot be directly set
 #endif  // defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE)
 
-#if (ABSL_PER_THREAD_TLS == 1) && !defined(ABSL_BUILD_DLL) && \
-    !defined(ABSL_CONSUME_DLL)
-#define ABSL_INTERNAL_HASHTABLEZ_SAMPLE
-#endif
-
 #if defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE)
 extern ABSL_PER_THREAD_TLS_KEYWORD int64_t global_next_sample;
 #endif  // ABSL_PER_THREAD_TLS

absl/flags/flag.h

@@ -333,8 +333,9 @@ ABSL_NAMESPACE_END
       ABSL_FLAG_IMPL_FLAGNAME(#name), ABSL_FLAG_IMPL_FILENAME(),    \
       absl::flags_internal::HelpArg<AbslFlagHelpGenFor##name>(0),   \
       &AbslFlagsInitFlag##name};                                    \
-  extern bool FLAGS_no##name;                                       \
-  bool FLAGS_no##name = ABSL_FLAG_IMPL_REGISTRAR(Type, FLAGS_##name)
+  extern absl::flags_internal::FlagRegistrarEmpty FLAGS_no##name;   \
+  absl::flags_internal::FlagRegistrarEmpty FLAGS_no##name =         \
+      ABSL_FLAG_IMPL_REGISTRAR(Type, FLAGS_##name)
 #else
 // MSVC version uses aggregate initialization. We also do not try to
 // optimize away help wrapper.
@@ -345,8 +346,9 @@ ABSL_NAMESPACE_END
   ABSL_CONST_INIT absl::Flag<Type> FLAGS_##name{                      \
       ABSL_FLAG_IMPL_FLAGNAME(#name), ABSL_FLAG_IMPL_FILENAME(),      \
       &AbslFlagHelpGenFor##name::NonConst, &AbslFlagsInitFlag##name}; \
-  extern bool FLAGS_no##name;                                         \
-  bool FLAGS_no##name = ABSL_FLAG_IMPL_REGISTRAR(Type, FLAGS_##name)
+  extern absl::flags_internal::FlagRegistrarEmpty FLAGS_no##name;     \
+  absl::flags_internal::FlagRegistrarEmpty FLAGS_no##name =           \
+      ABSL_FLAG_IMPL_REGISTRAR(Type, FLAGS_##name)
 #endif
 
 // ABSL_RETIRED_FLAG

absl/flags/internal/flag.h

@@ -648,6 +648,7 @@ void* FlagOps(FlagOp op, const void* v1, void* v2, void* v3) {
 // This class facilitates Flag object registration and tail expression-based
 // flag definition, for example:
 // ABSL_FLAG(int, foo, 42, "Foo help").OnUpdate(NotifyFooWatcher);
+struct FlagRegistrarEmpty {};
 template <typename T, bool do_register>
 class FlagRegistrar {
  public:
@@ -660,9 +661,10 @@ class FlagRegistrar {
     return *this;
   }
 
-  // Make the registrar "die" gracefully as a bool on a line where registration
-  // happens. Registrar objects are intended to live only as temporary.
-  operator bool() const { return true; }  // NOLINT
+  // Make the registrar "die" gracefully as an empty struct on a line where
+  // registration happens. Registrar objects are intended to live only as
+  // temporary.
+  operator FlagRegistrarEmpty() const { return {}; }  // NOLINT
 
  private:
   Flag<T>* flag_;  // Flag being registered (not owned).

absl/strings/cord.h

@@ -385,7 +385,7 @@ class Cord {
   // Determines whether the given Cord is empty, returning `true` is so.
   bool empty() const;
 
-  // Cord:EstimatedMemoryUsage()
+  // Cord::EstimatedMemoryUsage()
   //
   // Returns the *approximate* number of bytes held in full or in part by this
   // Cord (which may not remain the same between invocations).  Note that Cords

absl/types/BUILD.bazel

@@ -35,6 +35,7 @@ cc_library(
         ":bad_any_cast",
         "//absl/base:config",
         "//absl/base:core_headers",
+        "//absl/base:fast_type_id",
         "//absl/meta:type_traits",
         "//absl/utility",
     ],

absl/types/CMakeLists.txt

@@ -24,6 +24,7 @@ absl_cc_library(
     absl::bad_any_cast
     absl::config
     absl::core_headers
+    absl::fast_type_id
     absl::type_traits
     absl::utility
   PUBLIC

absl/types/any.h

@@ -80,6 +80,7 @@ ABSL_NAMESPACE_END
 #include <typeinfo>
 #include <utility>
 
+#include "absl/base/internal/fast_type_id.h"
 #include "absl/base/macros.h"
 #include "absl/meta/type_traits.h"
 #include "absl/types/bad_any_cast.h"
@@ -95,26 +96,6 @@ ABSL_NAMESPACE_END
 namespace absl {
 ABSL_NAMESPACE_BEGIN
 
-namespace any_internal {
-
-template <typename Type>
-struct TypeTag {
-  constexpr static char dummy_var = 0;
-};
-
-template <typename Type>
-constexpr char TypeTag<Type>::dummy_var;
-
-// FastTypeId<Type>() evaluates at compile/link-time to a unique pointer for the
-// passed in type. These are meant to be good match for keys into maps or
-// straight up comparisons.
-template<typename Type>
-constexpr inline const void* FastTypeId() {
-  return &TypeTag<Type>::dummy_var;
-}
-
-}  // namespace any_internal
-
 class any;
 
 // swap()
@@ -423,11 +404,11 @@ class any {
     using NormalizedType =
         typename std::remove_cv<typename std::remove_reference<T>::type>::type;
 
-    return any_internal::FastTypeId<NormalizedType>();
+    return base_internal::FastTypeId<NormalizedType>();
   }
 
   const void* GetObjTypeId() const {
-    return obj_ ? obj_->ObjTypeId() : any_internal::FastTypeId<void>();
+    return obj_ ? obj_->ObjTypeId() : base_internal::FastTypeId<void>();
   }
 
   // `absl::any` nonmember functions //