Export of internal Abseil changes

--
f73e17cb24f7878933fc100bd9bfc39fce190b64 by Derek Mauro <dmauro@google.com>:

Internal change

PiperOrigin-RevId: 394306402

--
3d3eeffa4e37f63aa50fec1b90858043b40fe377 by Abseil Team <absl-team@google.com>:

Release a few more absl::Cord unit tests that were accidentally omitted from the OSS release before.

PiperOrigin-RevId: 394016464

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8a77a8eb93d021aadd8fdf43e219bf35328001ad by CJ Johnson <johnsoncj@google.com>:

Fix typo in identifier

PiperOrigin-RevId: 394000560

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d87206c7c8e045b03d74b91e47ef3db0eb47a17b by Derek Mauro <dmauro@google.com>:

Fix typo: RandenHwAes

PiperOrigin-RevId: 393879427

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980a3402eea77b0c77fb20dd124203002ff791ba by Derek Mauro <dmauro@google.com>:

Adds macros `ABSL_LTS_RELEASE_VERSION` and `ABSL_LTS_RELEASE_PATCH_LEVEL`
to allow projects to detect if an LTS version is being used.

Fixes #1006

PiperOrigin-RevId: 393807178

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aecc7ed34de718c64733dab76621eacb5af9af5f by CJ Johnson <johnsoncj@google.com>:

Change `alloc` to `allocator` to match the fact that other identifiers are full words

PiperOrigin-RevId: 393794869

--
ad754bbcf7b78f5d51ed5f39193ac3159429b2b4 by Derek Mauro <dmauro@google.com>:

Remove self-include of cord_rep_btree.h

PiperOrigin-RevId: 393792085

--
f8e937a0d8fe26400560754f3596e3c21bb6d0d7 by Abseil Team <absl-team@google.com>:

Fix trivial typo in comment.

PiperOrigin-RevId: 393770527

--
7a58ca5d708038d222c6a2b6ff5076b4ceffd370 by Tomas Dzetkulic <dzetkulic@google.com>:

Update Cord::AppendArray resize policy.

PiperOrigin-RevId: 393362184

--
316050d171190d9d6312cadf88b1cc2db2d1caa7 by Abseil Team <absl-team@google.com>:

Add a new top level profiling/ directory to the Abseil library

PiperOrigin-RevId: 393358109

--
0dbb8e10f7fa4a7ac74e12b178e936a67b266c51 by CJ Johnson <johnsoncj@google.com>:

Switch to the more common enable_if pattern of ` = 0` in InlinedVector

PiperOrigin-RevId: 393301549

--
136d3068ce33b50ac820e8bd01395a7164d5181f by Abseil Team <absl-team@google.com>:

Clean up typedefs in internal/inlined_vector.h

PiperOrigin-RevId: 393181754
GitOrigin-RevId: f73e17cb24f7878933fc100bd9bfc39fce190b64
Change-Id: I0c4cd4d71d97bd1bf651701b6302ea3d9ac59b66

CMake/install_test_project/CMakeLists.txt

@@ -22,4 +22,4 @@ add_executable(simple simple.cc)
 
 find_package(absl REQUIRED)
 
-target_link_libraries(simple absl::strings)
+target_link_libraries(simple absl::strings absl::config)

CMake/install_test_project/simple.cc

@@ -14,8 +14,17 @@
 // limitations under the License.
 
 #include <iostream>
+#include "absl/base/config.h"
 #include "absl/strings/substitute.h"
 
+#if !defined(ABSL_LTS_RELEASE_VERSION) || ABSL_LTS_RELEASE_VERSION != 99998877
+#error ABSL_LTS_RELEASE_VERSION is not set correctly.
+#endif
+
+#if !defined(ABSL_LTS_RELEASE_PATCH_LEVEL) || ABSL_LTS_RELEASE_PATCH_LEVEL != 0
+#error ABSL_LTS_RELEASE_PATCH_LEVEL is not set correctly.
+#endif
+
 int main(int argc, char** argv) {
   for (int i = 0; i < argc; ++i) {
     std::cout << absl::Substitute("Arg $0: $1\n", i, argv[i]);

README.md

@@ -92,6 +92,9 @@ Abseil contains the following C++ library components:
   available within C++14 and C++17 versions of the C++ `<type_traits>` library.
 * [`numeric`](absl/numeric/)
   <br /> The `numeric` library contains C++11-compatible 128-bit integers.
+* [`profiling`](absl/profiling/)
+  <br /> The `profiling` library contains utility code for profiling C++
+  entities.  It is currently a private dependency of other Abseil libraries.
 * [`status`](absl/status/)
   <br /> The `status` contains abstractions for error handling, specifically
   `absl::Status` and `absl::StatusOr<T>`.

absl/CMakeLists.txt

@@ -25,6 +25,7 @@ add_subdirectory(hash)
 add_subdirectory(memory)
 add_subdirectory(meta)
 add_subdirectory(numeric)
+add_subdirectory(profiling)
 add_subdirectory(random)
 add_subdirectory(status)
 add_subdirectory(strings)

absl/base/config.h

@@ -66,6 +66,35 @@
 #include "absl/base/options.h"
 #include "absl/base/policy_checks.h"
 
+// Abseil long-term support (LTS) releases will define
+// `ABSL_LTS_RELEASE_VERSION` to the integer representing the date string of the
+// LTS release version, and will define `ABSL_LTS_RELEASE_PATCH_LEVEL` to the
+// integer representing the patch-level for that release.
+//
+// For example, for LTS release version "20300401.2", this would give us
+// ABSL_LTS_RELEASE_VERSION == 20300401 && ABSL_LTS_RELEASE_PATCH_LEVEL == 2
+//
+// These symbols will not be defined in non-LTS code.
+//
+// Abseil recommends that clients live-at-head. Therefore, if you are using
+// these symbols to assert a minimum version requirement, we recommend you do it
+// as
+//
+// #if defined(ABSL_LTS_RELEASE_VERSION) && ABSL_LTS_RELEASE_VERSION < 20300401
+// #error Project foo requires Abseil LTS version >= 20300401
+// #endif
+//
+// The `defined(ABSL_LTS_RELEASE_VERSION)` part of the check excludes
+// live-at-head clients from the minimum version assertion.
+//
+// See https://abseil.io/about/releases for more information on Abseil release
+// management.
+//
+// LTS releases can be obtained from
+// https://github.com/abseil/abseil-cpp/releases.
+#undef ABSL_LTS_RELEASE_VERSION
+#undef ABSL_LTS_RELEASE_PATCH_LEVEL
+
 // Helper macro to convert a CPP variable to a string literal.
 #define ABSL_INTERNAL_DO_TOKEN_STR(x) #x
 #define ABSL_INTERNAL_TOKEN_STR(x) ABSL_INTERNAL_DO_TOKEN_STR(x)

absl/profiling/BUILD.bazel

+# Copyright 2021 The Abseil Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+package(default_visibility = ["//visibility:private"])
+
+licenses(["notice"])

absl/profiling/CMakeLists.txt

+# Copyright 2021 The Abseil Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+

absl/random/internal/randen_hwaes.cc

@@ -31,7 +31,7 @@
 // a hardware accelerated implementation of randen, or whether it
 // will contain stubs that exit the process.
 #if ABSL_HAVE_ACCELERATED_AES
-// The following plaforms have implemented RandenHwAws.
+// The following plaforms have implemented RandenHwAes.
 #if defined(ABSL_ARCH_X86_64) || defined(ABSL_ARCH_X86_32) || \
     defined(ABSL_ARCH_PPC) || defined(ABSL_ARCH_ARM) ||       \
     defined(ABSL_ARCH_AARCH64)

absl/strings/cord.cc

@@ -689,13 +689,10 @@ void Cord::InlineRep::AppendArray(absl::string_view src,
       return;
     }
 
-    // Note: we don't concern ourselves if src aliases data stored in the
-    // inlined data of 'this',  as we update the InlineData only at the end.
-    // We are going from an inline size to beyond inline size. Make the new size
-    // either double the inlined size, or the added size + 10%.
-    const size_t size1 = inline_length * 2 + src.size();
-    const size_t size2 = inline_length + src.size() / 10;
-    rep = CordRepFlat::New(std::max<size_t>(size1, size2));
+    // Allocate flat to be a perfect fit on first append exceeding inlined size.
+    // Subsequent growth will use amortized growth until we reach maximum flat
+    // size.
+    rep = CordRepFlat::New(inline_length + src.size());
     appended = std::min(src.size(), rep->flat()->Capacity() - inline_length);
     memcpy(rep->flat()->Data(), data_.as_chars(), inline_length);
     memcpy(rep->flat()->Data() + inline_length, src.data(), appended);

absl/strings/cord_test.cc

@@ -1385,6 +1385,59 @@ TEST_P(CordTest, DiabolicalGrowth) {
                cord.EstimatedMemoryUsage());
 }
 
+// The following tests check support for >4GB cords in 64-bit binaries, and
+// 2GB-4GB cords in 32-bit binaries.  This function returns the large cord size
+// that's appropriate for the binary.
+
+// Construct a huge cord with the specified valid prefix.
+static absl::Cord MakeHuge(absl::string_view prefix) {
+  absl::Cord cord;
+  if (sizeof(size_t) > 4) {
+    // In 64-bit binaries, test 64-bit Cord support.
+    const size_t size =
+        static_cast<size_t>(std::numeric_limits<uint32_t>::max()) + 314;
+    cord.Append(absl::MakeCordFromExternal(
+        absl::string_view(prefix.data(), size),
+        [](absl::string_view s) { DoNothing(s, nullptr); }));
+  } else {
+    // Cords are limited to 32-bit lengths in 32-bit binaries.  The following
+    // tests check for use of "signed int" to represent Cord length/offset.
+    // However absl::string_view does not allow lengths >= (1u<<31), so we need
+    // to append in two parts;
+    const size_t s1 = (1u << 31) - 1;
+    // For shorter cord, `Append` copies the data rather than allocating a new
+    // node. The threshold is currently set to 511, so `s2` needs to be bigger
+    // to not trigger the copy.
+    const size_t s2 = 600;
+    cord.Append(absl::MakeCordFromExternal(
+        absl::string_view(prefix.data(), s1),
+        [](absl::string_view s) { DoNothing(s, nullptr); }));
+    cord.Append(absl::MakeCordFromExternal(
+        absl::string_view("", s2),
+        [](absl::string_view s) { DoNothing(s, nullptr); }));
+  }
+  return cord;
+}
+
+TEST_P(CordTest, HugeCord) {
+  absl::Cord cord = MakeHuge("huge cord");
+  EXPECT_LE(cord.size(), cord.EstimatedMemoryUsage());
+  EXPECT_GE(cord.size() + 100, cord.EstimatedMemoryUsage());
+}
+
+// Tests that Append() works ok when handed a self reference
+TEST_P(CordTest, AppendSelf) {
+  // We run the test until data is ~16K
+  // This guarantees it covers small, medium and large data.
+  std::string control_data = "Abc";
+  absl::Cord data(control_data);
+  while (control_data.length() < 0x4000) {
+    data.Append(data);
+    control_data.append(control_data);
+    ASSERT_EQ(control_data, data);
+  }
+}
+
 TEST_P(CordTest, MakeFragmentedCordFromInitializerList) {
   absl::Cord fragmented =
       absl::MakeFragmentedCord({"A ", "fragmented ", "Cord"});

absl/strings/internal/cord_rep_btree.h

@@ -23,7 +23,6 @@
 #include "absl/base/internal/raw_logging.h"
 #include "absl/base/optimization.h"
 #include "absl/strings/internal/cord_internal.h"
-#include "absl/strings/internal/cord_rep_btree.h"
 #include "absl/strings/internal/cord_rep_flat.h"
 #include "absl/strings/string_view.h"
 #include "absl/types/span.h"

absl/strings/internal/str_format/bind.h

@@ -100,7 +100,7 @@ class FormatSpecTemplate
   // We use the 'unavailable' attribute to give a better compiler error than
   // just 'method is deleted'.
   // To avoid checking the format twice, we just check that the format is
-  // constexpr. If is it valid, then the overload below will kick in.
+  // constexpr. If it is valid, then the overload below will kick in.
   // We add the template here to make this overload have lower priority.
   template <typename = void>
   FormatSpecTemplate(const char* s)  // NOLINT

create_lts.py

@@ -96,6 +96,13 @@ def main(argv):
 
   # Replacement directives go here.
   ReplaceStringsInFile(
+      'absl/base/config.h', {
+          '#undef ABSL_LTS_RELEASE_VERSION':
+              '#define ABSL_LTS_RELEASE_VERSION {}'.format(datestamp),
+          '#undef ABSL_LTS_RELEASE_PATCH_LEVEL':
+              '#define ABSL_LTS_RELEASE_PATCH_LEVEL 0'
+      })
+  ReplaceStringsInFile(
       'absl/base/options.h', {
           '#define ABSL_OPTION_USE_INLINE_NAMESPACE 0':
               '#define ABSL_OPTION_USE_INLINE_NAMESPACE 1',