Abseil LTS 2020092320200923

What's New:
* `absl::StatusOr<T>` has been released. See our [blog
  post](https://abseil.io/blog/2020-091021-status) for more
  information.
* Abseil Flags reflection interfaces have been released.
* Abseil Flags memory usage has been significantly optimized.
* Abseil now supports a "hardened" build mode. This build mode enables
  runtime checks that guard against programming errors that may lead
  to security vulnerabilities.

Notable Fixes:
* Sanitizer dynamic annotations like `AnnotateRWLockCreate` that are
  also defined by the compiler sanitizer implementation are no longer
  also defined by Abseil.
* Sanitizer macros are now prefixed with `ABSL_` to avoid naming collisions.
* Sanitizer usage is now automatically detected and no longer requires
  macros like `ADDRESS_SANITIZER` to be defined on the command line.

Breaking Changes:
* Abseil no longer contains a `dynamic_annotations` library. Users
  using a supported build system (Bazel or CMake) are unaffected by
  this, but users manually specifying link libraries may get an error
  about a missing linker input.

Baseline: 7680a5f8efe32de4753baadbd63e74e59d95bac1
Cherry picks: None

1 files changed, 29 insertions, 0 deletions

diff --git a/absl/container/flat_hash_map_test.cc b/absl/container/flat_hash_map_test.cc
index 728b693a..89ec60c9 100644
--- a/absl/container/flat_hash_map_test.cc
+++ b/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>>>;
@@ -253,6 +267,21 @@ TEST(FlatHashMap, EraseIf) {
   }
 }
 
+// This test requires std::launder for mutable key access in node handles.
+#if defined(__cpp_lib_launder) && __cpp_lib_launder >= 201606
+TEST(FlatHashMap, NodeHandleMutableKeyAccess) {
+  flat_hash_map<std::string, std::string> map;
+
+  map["key1"] = "mapped";
+
+  auto nh = map.extract(map.begin());
+  nh.key().resize(3);
+  map.insert(std::move(nh));
+
+  EXPECT_THAT(map, testing::ElementsAre(Pair("key", "mapped")));
+}
+#endif
+
 }  // namespace
 }  // namespace container_internal
 ABSL_NAMESPACE_END