| commit | 1065514ef332d036f3437e950e78d35ce6b7c740 | [log] [tgz] |
|---|---|---|
| author | Abseil Team <absl-team@google.com> | Mon Dec 13 14:47:02 2021 -0800 |
| committer | rogeeff <rogeeff@google.com> | Mon Dec 13 17:57:09 2021 -0500 |
| tree | e77e2b82db0160e569b62f0f68d70d1a69f97d9e | |
| parent | fb7dd24b18e82893e5922be5d1c8ae0f3fe3c9fa [diff] |
Export of internal Abseil changes -- 07240ca7822d007cdcc79f2c40bd58b2c2010348 by Abseil Team <absl-team@google.com>: Correct the comment from "AlphaNum" to "Arg". PiperOrigin-RevId: 416139192 -- adcba4a6b3763626e1db7b1e8c108b3114903557 by Martijn Vels <mvels@google.com>: Fix NewExternalRep() to require data being non-empty, and remove nullptr return. PiperOrigin-RevId: 416135865 -- c0d14cd918fb16f15d1d84de9284b5c5ecc1f8f2 by Abseil Team <absl-team@google.com>: Fix doc comment for absl::ascii_isprint(). The comment was incorrectly saying that it includes all whitespace. It doesn't; the only whitespace char it includes is ' '. PiperOrigin-RevId: 416112524 -- d83327800159c07002b6865e21232a12463e02dd by Abseil Team <absl-team@google.com>: Internal change PiperOrigin-RevId: 416099978 -- baf11e9ca42ca9140cdbf8075f971db8d65b1195 by Ilya Tokar <tokarip@google.com>: Prevent compiler from optimizing Group_Match* benchmarks away. Currently we benchmark single store of precomputed value. Not all affected benchmarks show performance changes: BM_Group_Match 0.53ns ± 1% 0.53ns ± 0% -0.42% (p=0.038 n=10+10) BM_Group_MatchEmpty 0.26ns ± 1% 0.26ns ± 1% ~ (p=1.000 n=10+10) BM_Group_MatchEmptyOrDeleted 0.26ns ± 1% 0.26ns ± 1% ~ (p=0.121 n=10+10) BM_Group_CountLeadingEmptyOrDeleted 0.26ns ± 1% 0.45ns ± 0% +70.05% (p=0.000 n=10+8) BM_Group_MatchFirstEmptyOrDeleted 0.26ns ± 0% 0.44ns ± 1% +65.91% (p=0.000 n=8+9) But inspecting the generated code shows the difference, e. g. BM_Group_MatchFirstEmptyOrDeleted Before: add $0xffffffffffffffff,%rbx jne 30 After: pcmpeqd %xmm0,%xmm0 pcmpgtb -0x30(%rbp),%xmm0 pmovmskb %xmm0,%eax add: 0x23$0xffffffffffffffff,%rbx jne 40 PiperOrigin-RevId: 416083515 -- 122fbff893dc4571b3e75e4b241eb4495b925610 by Abseil Team <absl-team@google.com>: Put namespace guard in ABSL_DECLARE_FLAG to make declaring a flag in a namespace a compiler error instead of a linker error. PiperOrigin-RevId: 416036072 -- 020fd8a20f5fa319e948846e003391fcb9e03868 by Ilya Tokar <tokarip@google.com>: Make Cord::InlineRep::set_data unconditionally zero out memory. Currently there is a single case where we don't zero out memory as an optimization. Unconditional zeroing doesn't show any changes in benchmarks, except for the unrelated improvement: BM_CordPartialCopyToCord/1M/1 12.6ns ± 4% 12.6ns ± 4% ~ (p=0.857 n=16+19) BM_CordPartialCopyToCord/1M/128 44.9ns ± 7% 45.0ns ± 3% ~ (p=0.468 n=18+17) BM_CordPartialCopyToCord/1M/1k 64.5ns ± 4% 61.4ns ± 4% -4.82% (p=0.000 n=19+17) BM_CordPartialCopyToCord/1M/8k 139ns ± 3% 128ns ±15% -7.76% (p=0.009 n=17+20) BM_CordPartialCopyToCord/1M/16k 193ns ± 6% 168ns ± 6% -13.17% (p=0.000 n=17+17) BM_CordPartialCopyToCord/4M/16k 199ns ± 4% 177ns ± 4% -11.36% (p=0.000 n=17+18) BM_CordPartialCopyToCord/4M/32k 275ns ± 3% 250ns ± 4% -9.00% (p=0.000 n=18+18) BM_CordPartialCopyToCord/4M/64k 291ns ± 4% 266ns ± 5% -8.53% (p=0.000 n=18+16) BM_CordPartialCopyToCord/4M/128k 322ns ± 5% 291ns ± 4% -9.43% (p=0.000 n=20+18) BM_CordPartialCopyToCord/8M/32k 281ns ± 5% 251ns ± 4% -10.38% (p=0.000 n=20+16) BM_CordPartialCopyToCord/8M/64k 293ns ± 6% 267ns ± 4% -8.87% (p=0.000 n=16+19) BM_CordPartialCopyToCord/8M/128k 334ns ± 3% 305ns ± 2% -8.56% (p=0.000 n=17+16) This is clearly an alignmnet effect since number of the executed instructions is the same: M_CordPartialCopyToCord/1M/1 155 ± 0% 155 ± 0% ~ (all samples are equal) BM_CordPartialCopyToCord/1M/128 446 ± 0% 446 ± 0% ~ (p=0.332 n=36+39) BM_CordPartialCopyToCord/1M/1k 473 ± 0% 473 ± 0% ~ (p=0.969 n=40+40) BM_CordPartialCopyToCord/1M/8k 808 ± 0% 808 ± 0% ~ (p=0.127 n=40+39) BM_CordPartialCopyToCord/1M/16k 957 ± 0% 957 ± 0% ~ (p=0.532 n=40+40) BM_CordPartialCopyToCord/4M/16k 952 ± 0% 952 ± 0% ~ (p=0.686 n=39+39) BM_CordPartialCopyToCord/4M/32k 1.12k ± 0% 1.12k ± 0% ~ (p=0.690 n=40+40) BM_CordPartialCopyToCord/4M/64k 1.23k ± 0% 1.23k ± 0% ~ (p=0.182 n=40+39) BM_CordPartialCopyToCord/4M/128k 1.44k ± 0% 1.44k ± 0% ~ (p=0.711 n=40+40) BM_CordPartialCopyToCord/8M/32k 1.12k ± 0% 1.12k ± 0% ~ (p=0.697 n=40+40) BM_CordPartialCopyToCord/8M/64k 1.23k ± 0% 1.23k ± 0% +0.00% (p=0.049 n=40+40) BM_CordPartialCopyToCord/8M/128k 1.44k ± 0% 1.44k ± 0% ~ (p=0.507 n=40+40) This makes code simpler and doesn't regress performance. PiperOrigin-RevId: 415560574 -- 37305b2690b31682088749e4d62f40d7095bdc54 by Derek Mauro <dmauro@google.com>: Internal change PiperOrigin-RevId: 415558737 -- 86aaed569b9e743c1eb813a5f48def978a793db3 by Martijn Vels <mvels@google.com>: Internal change PiperOrigin-RevId: 415515201 -- 6cdb8786cdcb4fa0b8a4b72fc98940877d1fdeff by Abseil Team <absl-team@google.com>: Update SubmitMutexProfileData to accept wait_cycles instead of wait_timestamp PiperOrigin-RevId: 415360871 -- 9f979d307aa16ad09f214e04876cbe84395c0901 by Abseil Team <absl-team@google.com>: absl::flat_hash_set compiles with -Wconversion -Wsign-compare PiperOrigin-RevId: 415357498 -- 9eceb14174708f15e61259d449b214a8a4c7f9e7 by Abseil Team <absl-team@google.com>: Fix AddressIsReadable for the corner case of (aligned) addr == NULL. PiperOrigin-RevId: 415307792 -- 1a39ffe55898375e2d7f88c17c99db5a1b95b313 by Martijn Vels <mvels@google.com>: Internal change PiperOrigin-RevId: 415162872 -- 64378549b110d5f5762185a5906c520fba70f0e7 by Abseil Team <absl-team@google.com>: Fix a typo in the comments PiperOrigin-RevId: 415088461 -- 41aae8322e913b82710153c22b97c611fdb6e1fb by Abseil Team <absl-team@google.com>: Switch from `connect` to `rt_sigreturn` -- the latter is much less problematic for system call sandboxes. PiperOrigin-RevId: 415073965 -- 870c5e3388b6a35611bff538626fe7a1c8c87171 by Abseil Team <absl-team@google.com>: Add ABSL_HAVE_HWADDRESS_SANITIZER and ABSL_HAVE_LEAK_SANITIZER PiperOrigin-RevId: 414871189 -- f213ed60a66b58da7ac40555adfb1d529ff0a4db by Derek Mauro <dmauro@google.com>: Remove reference to __SANITIZE_MEMORY__, which does not exist It appears to have been copied by pattern matching from the ASAN/TSAN code blocks. https://github.com/gcc-mirror/gcc/blob/f47662204de27f7685699eeef89aa173ccf32d85/gcc/cppbuiltin.c#L79-L126 PiperOrigin-RevId: 414806587 -- b152891e73ab515f397ceb53f66c8ee2f33863ea by Abseil Team <absl-team@google.com>: Rollback previous commit: SYS_open is not defined in certain environments. PiperOrigin-RevId: 414521820 -- 5a1cbb282331023902e1374dd0d920c4effbe47f by Abseil Team <absl-team@google.com>: Use syscall(SYS_open, ...) instead of open() to avoid possible symbol interposition. Also add some warning notes. PiperOrigin-RevId: 414508186 -- 1824d6593612710aafdc599a89b0adced7d787f6 by Abseil Team <absl-team@google.com>: Correct aarch64 macro check The macro is __aarch64__, not __arch64__. PiperOrigin-RevId: 414446225 -- a1536a57b64dfd53945d33a01cfc08b18c99c97b by Abseil Team <absl-team@google.com>: Fix backwards comment in the last commit. PiperOrigin-RevId: 414281214 -- 11ac021ba779513667a31cf2563ddafc57d6d913 by Abseil Team <absl-team@google.com>: AddressIsReadable() didn't work correctly on ARM when the given pointer was misaligned at the end of the page. Fix that by aligning the pointer on an 8-byte boundary before checking it. PiperOrigin-RevId: 414203863 GitOrigin-RevId: 07240ca7822d007cdcc79f2c40bd58b2c2010348 Change-Id: If5f129194d59f5c9e5d84efd8cd9e17a70e072ab
The repository contains the Abseil C++ library code. Abseil is an open-source collection of C++ code (compliant to C++11) designed to augment the C++ standard library.
Abseil is an open-source collection of C++ library code designed to augment the C++ standard library. The Abseil library code is collected from Google's own C++ code base, has been extensively tested and used in production, and is the same code we depend on in our daily coding lives.
In some cases, Abseil provides pieces missing from the C++ standard; in others, Abseil provides alternatives to the standard for special needs we've found through usage in the Google code base. We denote those cases clearly within the library code we provide you.
Abseil is not meant to be a competitor to the standard library; we've just found that many of these utilities serve a purpose within our code base, and we now want to provide those resources to the C++ community as a whole.
If you want to just get started, make sure you at least run through the Abseil Quickstart. The Quickstart contains information about setting up your development environment, downloading the Abseil code, running tests, and getting a simple binary working.
Bazel and CMake are the official build systems for Abseil.
See the quickstart for more information on building Abseil using the Bazel build system.
If you require CMake support, please check the CMake build instructions and CMake Quickstart.
Abseil is officially supported on many platforms. See the Abseil platform support guide for details on supported operating systems, compilers, CPUs, etc.
Abseil contains the following C++ library components:
base Abseil Fundamentals base library contains initialization code and other code which all other Abseil code depends on. Code within base may not depend on any other code (other than the C++ standard library).algorithm algorithm library contains additions to the C++ <algorithm> library and container-based versions of such algorithms.cleanup cleanup library contains the control-flow-construct-like type absl::Cleanup which is used for executing a callback on scope exit.container container library contains additional STL-style containers, including Abseil's unordered “Swiss table” containers.debugging debugging library contains code useful for enabling leak checks, and stacktrace and symbolization utilities.hash hash library contains the hashing framework and default hash functor implementations for hashable types in Abseil.memory memory library contains C++11-compatible versions of std::make_unique() and related memory management facilities.meta meta library contains C++11-compatible versions of type checks available within C++14 and C++17 versions of the C++ <type_traits> library.numeric numeric library contains C++11-compatible 128-bit integers.profiling profiling library contains utility code for profiling C++ entities. It is currently a private dependency of other Abseil libraries.status status contains abstractions for error handling, specifically absl::Status and absl::StatusOr<T>.strings strings library contains a variety of strings routines and utilities, including a C++11-compatible version of the C++17 std::string_view type.synchronization synchronization library contains concurrency primitives (Abseil's absl::Mutex class, an alternative to std::mutex) and a variety of synchronization abstractions.time time library contains abstractions for computing with absolute points in time, durations of time, and formatting and parsing time within time zones.types types library contains non-container utility types, like a C++11-compatible version of the C++17 std::optional type.utility utility library contains utility and helper code.Abseil recommends users “live-at-head” (update to the latest commit from the master branch as often as possible). However, we realize this philosophy doesn't work for every project, so we also provide Long Term Support Releases to which we backport fixes for severe bugs. See our release management document for more details.
The Abseil C++ library is licensed under the terms of the Apache license. See LICENSE for more information.
For more information about Abseil: