pw_polyfill: Move std::endian polyfill to pw::endian

- Provide the endian enum as pw::endian. Alias it to std::endian in the <bit> polyfill header. - Remove automatic polyfilling for Bazel. The current setup doesn't seem to support having the <bit> polyfill depend on pw_bytes/bit.h. Since automatic polyfills are being removed anyway, it is simpler to remove them from Bazel now. Bug: b/235237667 Change-Id: I20fa9c7bfca2b6858ee2a121ef755a953ce78ef0 Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/97570 Commit-Queue: Wyatt Hepler <[email protected]> Reviewed-by: Ted Pudlik <[email protected]>
google · Jun 9, 2022 · ed6629a · ed6629a
1 parent e267413
commit ed6629a
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Showing 14 changed files with 104 additions and 140 deletions.
diff --git a/.bazelrc b/.bazelrc
@@ -40,9 +40,6 @@ build:asan-libfuzzer \
     --@rules_fuzzing//fuzzing:cc_engine_instrumentation=libfuzzer
 build:asan-libfuzzer --@rules_fuzzing//fuzzing:cc_engine_sanitizer=asan
 
-# Configures toolchain with polyfill headers.
-build --@rules_cc_toolchain_config//:user_defined=//pw_polyfill:toolchain_polyfill_overrides
-
 # Specifies desired output mode for running tests.
 # Valid values are
 #   'summary' to output only test status summary

diff --git a/WORKSPACE b/WORKSPACE
@@ -232,15 +232,6 @@ git_repository(
     remote = "https://github.com/bazelembedded/bazel-embedded.git",
 )
 
-# Instantiate Pigweed configuration for embedded toolchain,
-# this must be called before bazel_embedded_deps.
-load(
-    "//pw_build:pigweed_toolchain_upstream.bzl",
-    "toolchain_upstream_deps",
-)
-
-toolchain_upstream_deps()
-
 # Configure bazel_embedded toolchains and platforms.
 load(
     "@bazel_embedded//:bazel_embedded_deps.bzl",

diff --git a/pw_build/pigweed_toolchain_upstream.bzl b/pw_build/pigweed_toolchain_upstream.bzl
diff --git a/pw_bytes/BUILD.bazel b/pw_bytes/BUILD.bazel
@@ -45,6 +45,12 @@ pw_cc_library(
     ],
 )
 
+pw_cc_library(
+    name = "bit",
+    hdrs = ["public/pw_bytes/bit.h"],
+    includes = ["public"],
+)
+
 pw_cc_test(
     name = "array_test",
     srcs = ["array_test.cc"],

diff --git a/pw_bytes/BUILD.gn b/pw_bytes/BUILD.gn
@@ -19,13 +19,13 @@ import("$dir_pw_build/target_types.gni")
 import("$dir_pw_docgen/docs.gni")
 import("$dir_pw_unit_test/test.gni")
 
-config("default_config") {
+config("public_include_path") {
   include_dirs = [ "public" ]
   visibility = [ ":*" ]
 }
 
 pw_source_set("pw_bytes") {
-  public_configs = [ ":default_config" ]
+  public_configs = [ ":public_include_path" ]
   public = [
     "public/pw_bytes/array.h",
     "public/pw_bytes/byte_builder.h",
@@ -41,6 +41,12 @@ pw_source_set("pw_bytes") {
   ]
 }
 
+pw_source_set("bit") {
+  public_configs = [ ":public_include_path" ]
+  public = [ "public/pw_bytes/bit.h" ]
+  remove_public_deps = [ "*" ]
+}
+
 pw_test_group("tests") {
   tests = [
     ":array_test",

diff --git a/pw_bytes/CMakeLists.txt b/pw_bytes/CMakeLists.txt
@@ -37,6 +37,13 @@ if(Zephyr_FOUND AND CONFIG_PIGWEED_BYTES)
   zephyr_link_libraries(pw_bytes)
 endif()
 
+pw_add_module_library(pw_bytes.bit
+  HEADERS
+    public/pw_bytes/bit.h
+  PUBLIC_INCLUDES
+    public
+)
+
 pw_add_test(pw_bytes.array_test
   SOURCES
     array_test.cc

diff --git a/pw_bytes/docs.rst b/pw_bytes/docs.rst
@@ -1,30 +1,33 @@
 .. _module-pw_bytes:
 
----------
+=========
 pw_bytes
----------
+=========
 pw_bytes is a collection of utilities for manipulating binary data.
 
+-------------
 Compatibility
-=============
+-------------
 C++17
 
+------------
 Dependencies
-============
+------------
 * ``pw_preprocessor``
 * ``pw_status``
 * ``pw_span``
 
+--------
 Features
-========
+--------
 
 pw_bytes/array.h
-----------------
+================
 Functions for working with byte arrays, primarily for building fixed-size byte
 arrays at compile time.
 
 pw_bytes/byte_builder.h
------------------------
+=======================
 .. cpp:class:: ByteBuilder
 
   ``ByteBuilder`` is a class that facilitates building or reading arrays of
@@ -36,15 +39,22 @@ pw_bytes/byte_builder.h
   ``ByteBuilder`` with an internally allocated buffer.
 
 Size report: using ByteBuffer
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+-----------------------------
 .. include:: byte_builder_size_report
 
+pw_bytes/bit.h
+================
+Implementation of features provided by C++20's ``<bit>`` header. Supported
+features:
+
+* ``pw::endian`` -- Implementation of the ``std::endian`` enum.
+
 pw_bytes/endian.h
------------------
+=================
 Functions for converting the endianness of integral values.
 
 pw_bytes/units.h
-----------------
+================
 Constants, functions and user-defined literals for specifying a number of bytes
 in powers of two, as defined by IEC 60027-2 A.2 and ISO/IEC 80000:13-2008.
 
@@ -78,7 +88,8 @@ also similar functions:
 
   constexpr size_t kBufferSizeBytes = pw::bytes::MiB(1) + pw::bytes::KiB(42);
 
+------
 Zephyr
-======
+------
 To enable ``pw_bytes`` for Zephyr add ``CONFIG_PIGWEED_BYTES=y`` to the
 project's configuration.
diff --git a/pw_bytes/public/pw_bytes/bit.h b/pw_bytes/public/pw_bytes/bit.h
@@ -0,0 +1,44 @@
+// Copyright 2022 The Pigweed 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.
+
+// Features from the <bit> header introduced in C++20.
+#pragma once
+
+#if __has_include(<bit>)
+#include <bit>
+#endif  // __has_include(<bit>)
+
+namespace pw {
+
+#ifdef __cpp_lib_endian
+
+using std::endian;
+
+#elif defined(__GNUC__)
+
+enum class endian {
+  little = __ORDER_LITTLE_ENDIAN__,
+  big = __ORDER_BIG_ENDIAN__,
+  native = __BYTE_ORDER__,
+};
+
+#else
+
+static_assert(false,
+              "The pw::endian enum is not defined for this compiler. Add a "
+              "definition to pw_bytes/bit.h.");
+
+#endif  // __cpp_lib_endian
+
+}  // namespace pw
diff --git a/pw_polyfill/BUILD.bazel b/pw_polyfill/BUILD.bazel
@@ -17,26 +17,11 @@ load(
     "pw_cc_library",
     "pw_cc_test",
 )
-load("@rules_cc_toolchain//cc_toolchain:cc_toolchain_import.bzl", "cc_toolchain_import")
 
 package(default_visibility = ["//visibility:public"])
 
 licenses(["notice"])
 
-cc_toolchain_import(
-    name = "toolchain_polyfill_overrides",
-    hdrs = [
-        "bit_public_overrides/bit",
-        "standard_library_public/pw_polyfill/standard_library/bit.h",
-        "standard_library_public/pw_polyfill/standard_library/namespace.h",
-    ],
-    includes = [
-        "bit_public_overrides",
-        "public",
-        "standard_library_public",
-    ],
-)
-
 pw_cc_library(
     name = "pw_polyfill",
     hdrs = [
@@ -46,16 +31,6 @@ pw_cc_library(
     includes = ["public"],
 )
 
-# TODO(b/235237667): Deprecate this once all users have been migrated to targeted
-# polyfill deps.
-pw_cc_library(
-    name = "overrides",
-    deps = [
-        ":bit",
-        ":span",
-    ],
-)
-
 # Provides <bit>'s std::endian.
 pw_cc_library(
     name = "bit",
@@ -64,10 +39,13 @@ pw_cc_library(
         "standard_library_public/pw_polyfill/standard_library/bit.h",
     ],
     includes = [
-        "public_overrides",
+        "bit_public_overrides",
         "standard_library_public",
     ],
-    deps = [":standard_library"],
+    deps = [
+        ":standard_library",
+        "//pw_bytes:bit",
+    ],
 )
 
 # Provides <cstddef>'s std::byte.
@@ -117,6 +95,7 @@ pw_cc_test(
     name = "test",
     srcs = ["test.cc"],
     deps = [
+        ":bit",
         ":cstddef",
         ":iterator",
         ":pw_polyfill",

diff --git a/pw_polyfill/BUILD.gn b/pw_polyfill/BUILD.gn
@@ -67,7 +67,10 @@ pw_source_set("bit") {
     ":standard_library_public",
     ":bit_overrides_config",
   ]
-  public_deps = [ ":standard_library" ]
+  public_deps = [
+    ":standard_library",
+    "$dir_pw_bytes:bit",
+  ]
   remove_public_deps = [ "*" ]
   inputs = [ "bit_public_overrides/bit" ]
   public = [ "standard_library_public/pw_polyfill/standard_library/bit.h" ]

diff --git a/pw_polyfill/CMakeLists.txt b/pw_polyfill/CMakeLists.txt
@@ -45,6 +45,7 @@ pw_add_module_library(pw_polyfill.bit
     bit_public_overrides
     standard_library_public
   PUBLIC_DEPS
+    pw_bytes.bit
     pw_polyfill.standard_library
 )
 

diff --git a/pw_polyfill/standard_library_public/pw_polyfill/standard_library/bit.h b/pw_polyfill/standard_library_public/pw_polyfill/standard_library/bit.h
@@ -13,19 +13,16 @@
 // the License.
 #pragma once
 
+#include "pw_bytes/bit.h"
 #include "pw_polyfill/standard_library/namespace.h"
 
-_PW_POLYFILL_BEGIN_NAMESPACE_STD
-
 #ifndef __cpp_lib_endian
 #define __cpp_lib_endian 201907L
 
-enum class endian {
-  little = __ORDER_LITTLE_ENDIAN__,
-  big = __ORDER_BIG_ENDIAN__,
-  native = __BYTE_ORDER__,
-};
+_PW_POLYFILL_BEGIN_NAMESPACE_STD
 
-#endif  // __cpp_lib_endian
+using pw::endian;
 
 _PW_POLYFILL_END_NAMESPACE_STD
+
+#endif  // __cpp_lib_endian