pw_toolchain: Migrate host clang to rules_cc toolchains

Migrates Pigweed to use the toolchain rules upstreamed to rules_cc.

Bug: b/346388161
Change-Id: I692153827f1f2fc871828bc8f594dcf82378f5f5
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/207550
Pigweed-Auto-Submit: Armando Montanez <amontanez@google.com>
Docs-Not-Needed: Armando Montanez <amontanez@google.com>
Commit-Queue: Armando Montanez <amontanez@google.com>
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
Presubmit-Verified: CQ Bot Account <pigweed-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Ted Pudlik <tpudlik@google.com>

.bazelrc

@@ -26,6 +26,11 @@ import %workspace%/pw_build/pigweed.bazelrc
 common --per_file_copt=external/.*@-w
 common --host_per_file_copt=external/.*@-w
 
+# TODO: https://pwbug.dev/324107025 - Temporary workaround until Sapphire
+# migration is done or warnings are fixed.
+common --per_file_copt=pw_bluetooth_sapphire/.*@-Wno-unused-parameter
+common --host_per_file_copt=pw_bluetooth_sapphire/.*@-Wno-unused-parameter
+
 # Picotool needs to build with exceptions and RTTI enabled.
 common --per_file_copt=external.*picotool.*@-fexceptions,-frtti
 common --host_per_file_copt=external.*picotool.*@-fexceptions,-frtti

MODULE.bazel

@@ -106,9 +106,12 @@ local_path_override(
     path = "pw_toolchain_bazel",
 )
 
-xcode = use_repo_rule("@pw_toolchain//features/macos/private:xcode_command_line_tools.bzl", "pw_xcode_repository")
+xcode_sdk_repository = use_repo_rule("//pw_toolchain:xcode.bzl", "xcode_sdk_repository")
 
-xcode(name = "pw_xcode_command_line_tools")
+xcode_sdk_repository(
+    name = "macos_sysroot",
+    build_file = "//pw_toolchain/host_clang:macos_sysroot.BUILD",
+)
 
 cipd_client_repository = use_repo_rule("//pw_env_setup/bazel/cipd_setup:cipd_rules.bzl", "_cipd_client_repository")
 
@@ -119,7 +122,7 @@ cipd_repository = use_repo_rule("//pw_env_setup/bazel/cipd_setup:cipd_rules.bzl"
 # Fetch llvm toolchain.
 cipd_repository(
     name = "llvm_toolchain",
-    build_file = "@pw_toolchain//build_external:llvm_clang_legacy.BUILD",
+    build_file = "//pw_toolchain/build_external:llvm_clang.BUILD",
     path = "fuchsia/third_party/clang/${os}-${arch}",
     tag = "git_revision:c58bc24fcf678c55b0bf522be89eff070507a005",
 )
@@ -134,6 +137,7 @@ cipd_repository(
 # Fetch linux sysroot for host builds.
 cipd_repository(
     name = "linux_sysroot",
+    build_file = "//pw_toolchain/host_clang:linux_sysroot.BUILD",
     path = "fuchsia/third_party/sysroot/bionic",
     tag = "git_revision:702eb9654703a7cec1cadf93a7e3aa269d053943",
 )

pw_build/constraint/cortex-m/BUILD.bazel

@@ -0,0 +1,15 @@
+# Copyright 2024 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.
+
+package(default_visibility = ["//visibility:public"])

pw_build/constraint/cortex-m/lists.bzl

@@ -0,0 +1,26 @@
+# Copyright 2024 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.
+"""A programatic list of all known Cortex-M CPUs."""
+
+ALL_CORTEX_M_CPUS = (
+    "@platforms//cpu:armv6-m",
+    "@platforms//cpu:armv7-m",
+    "@platforms//cpu:armv7e-m",
+    # TODO: https://github.com/bazelbuild/platforms/issues/100 - Kept for legacy
+    # reasons.
+    "@platforms//cpu:armv7e-mf",
+    # TODO: https://github.com/bazelbuild/platforms/issues/104 - Kept for legacy
+    # reasons.
+    "@platforms//cpu:armv8-m",
+)

pw_toolchain/action/BUILD.bazel

@@ -0,0 +1,24 @@
+# Copyright 2024 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.
+
+load("@rules_cc//cc/toolchains:actions.bzl", "cc_action_type")
+
+package(default_visibility = ["//visibility:public"])
+
+# TODO: https://pwbug.dev/367352331 - Rename and upstream this to Bazel
+# (rules_cc, bazeltools).
+cc_action_type(
+    name = "objdump",
+    action_name = "objdump_embed_data",
+)

pw_toolchain/args/BUILD.bazel

@@ -0,0 +1,252 @@
+# Copyright 2024 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.
+
+load("@rules_cc//cc/toolchains:args.bzl", "cc_args")
+load("@rules_cc//cc/toolchains:feature.bzl", "cc_feature")
+
+package(default_visibility = ["//visibility:public"])
+
+# The common set of warnings for clang and arm_gcc.
+cc_args(
+    name = "common_warnings",
+    actions = [
+        "@rules_cc//cc/toolchains/actions:c_compile_actions",
+        "@rules_cc//cc/toolchains/actions:cpp_compile_actions",
+    ],
+    args = [
+        "-Wall",
+        "-Wextra",
+        "-Wimplicit-fallthrough",
+        "-Wcast-qual",
+        "-Wpointer-arith",
+        "-Wshadow",
+        "-Wredundant-decls",
+        # TODO: b/259746255 - Enable implicit conversion warnings once fixed.
+        # "-Wconversion",
+        # Make all warnings errors, except for the exemptions below.
+        "-Werror",
+        "-Wno-error=cpp",  # preprocessor #warning statement
+        "-Wno-error=deprecated-declarations",  # [[deprecated]] attribute
+    ],
+)
+
+# This config contains warnings that are enabled for upstream Pigweed.
+# This config MUST NOT be used downstream to allow for warnings to be
+# added in the future without breaking downstream.
+cc_args(
+    name = "internal_strict_warnings_flags",
+    actions = [
+        "@rules_cc//cc/toolchains/actions:c_compile_actions",
+        "@rules_cc//cc/toolchains/actions:cpp_compile_actions",
+    ],
+    args = [
+        "-Wswitch-enum",
+        "-Wextra-semi",
+    ] + select({
+        "@platforms//os:windows": [],
+        # TODO: b/243069432 - Enable pedantic warnings on Windows once passing.
+        "//conditions:default": [":pedantic_warnings"],
+    }),
+    visibility = ["//:__subpackages__"],
+)
+
+# Add `--features=internal_strict_warnings` to your Bazel invocation to enable.
+cc_feature(
+    name = "internal_strict_warnings",
+    args = [":internal_strict_warnings_flags"],
+    feature_name = "internal_strict_warnings",
+    visibility = ["//:__subpackages__"],
+)
+
+# Allow uses of the register keyword, which may appear in C headers.
+cc_args(
+    name = "wno_register",
+    actions = ["@rules_cc//cc/toolchains/actions:cpp_compile_actions"],
+    args = ["-Wno-register"],
+)
+
+# Issue a warning when a class appears to be polymorphic, yet it declares a
+# non-virtual destructor
+cc_args(
+    name = "wnon_virtual_dtor",
+    actions = ["@rules_cc//cc/toolchains/actions:cpp_compile_actions"],
+    args = ["-Wnon-virtual-dtor"],
+)
+
+# Prevent relative paths from being converted to absolute paths.
+cc_args(
+    name = "no_canonical_prefixes",
+    actions = [
+        "@rules_cc//cc/toolchains/actions:c_compile_actions",
+        "@rules_cc//cc/toolchains/actions:cpp_compile_actions",
+    ],
+    args = ["-no-canonical-prefixes"],
+)
+
+# Enables colors in compiler diagnostics. This uses the GCC spelling of the
+# flag, which Clang supports as an undocumented extension.
+cc_args(
+    name = "color_diagnostics",
+    actions = [
+        "@rules_cc//cc/toolchains/actions:assembly_actions",
+        "@rules_cc//cc/toolchains/actions:c_compile_actions",
+        "@rules_cc//cc/toolchains/actions:cpp_compile_actions",
+        "@rules_cc//cc/toolchains/actions:link_actions",
+    ],
+    args = ["-fdiagnostics-color"],
+)
+
+cc_args(
+    name = "debugging",
+    actions = [
+        "@rules_cc//cc/toolchains/actions:c_compile_actions",
+        "@rules_cc//cc/toolchains/actions:cpp_compile_actions",
+    ],
+    args = ["-g"],
+)
+
+# Compile without runtime type information (RTTI). This produces smaller binaries.
+cc_args(
+    name = "no_rtti",
+    actions = ["@rules_cc//cc/toolchains/actions:cpp_compile_actions"],
+    args = ["-fno-rtti"],
+)
+
+# Optimization level option
+cc_args(
+    name = "o2",
+    actions = [
+        "@rules_cc//cc/toolchains/actions:c_compile_actions",
+        "@rules_cc//cc/toolchains/actions:cpp_compile_actions",
+        "@rules_cc//cc/toolchains/actions:link_actions",
+    ],
+    args = ["-O2"],
+)
+
+# Optimization aggressively for size rather than speed option
+cc_args(
+    name = "oz",
+    actions = [
+        "@rules_cc//cc/toolchains/actions:c_compile_actions",
+        "@rules_cc//cc/toolchains/actions:cpp_compile_actions",
+        "@rules_cc//cc/toolchains/actions:link_actions",
+    ],
+    args = ["-Oz"],
+)
+
+# Standard compiler flags to reduce output binary size.
+cc_args(
+    name = "reduced_size",
+    actions = [
+        "@rules_cc//cc/toolchains/actions:c_compile_actions",
+        "@rules_cc//cc/toolchains/actions:cpp_compile_actions",
+        "@rules_cc//cc/toolchains/actions:link_actions",
+    ],
+    args = [
+        "-fno-common",
+        "-fno-exceptions",
+        "-ffunction-sections",
+        "-fdata-sections",
+    ],
+)
+
+cc_feature(
+    name = "c++17_feature",
+    args = [":c++17"],
+    feature_name = "c++17",
+)
+
+# Compile for the C++17 standard.
+cc_args(
+    name = "c++17",
+    actions = [
+        "@rules_cc//cc/toolchains/actions:cpp_compile_actions",
+        "@rules_cc//cc/toolchains/actions:link_actions",
+    ],
+    args = ["-std=c++17"],
+)
+
+cc_feature(
+    name = "c++20_feature",
+    args = [":c++20"],
+    feature_name = "c++20",
+)
+
+# Compile for the C++20 standard.
+cc_args(
+    name = "c++20",
+    actions = [
+        "@rules_cc//cc/toolchains/actions:cpp_compile_actions",
+        "@rules_cc//cc/toolchains/actions:link_actions",
+    ],
+    args = ["-std=c++20"],
+)
+
+cc_args(
+    name = "asan",
+    actions = [
+        "@rules_cc//cc/toolchains/actions:c_compile_actions",
+        "@rules_cc//cc/toolchains/actions:cpp_compile_actions",
+        "@rules_cc//cc/toolchains/actions:link_actions",
+    ],
+    args = [
+        "-fsanitize=address",
+        "-DADDRESS_SANITIZER",
+    ],
+)
+
+# TODO: https://pwbug.dev/346388161 - Push this to upstream rules_cc.
+cc_args(
+    name = "ubsan",
+    actions = [
+        "@rules_cc//cc/toolchains/actions:c_compile_actions",
+        "@rules_cc//cc/toolchains/actions:cpp_compile_actions",
+        "@rules_cc//cc/toolchains/actions:link_actions",
+    ],
+    args = [
+        "-fsanitize=undefined",
+        "-DUNDEFINED_SANITIZER",
+    ],
+)
+
+# TODO: https://pwbug.dev/346388161 - Push this to upstream rules_cc.
+cc_args(
+    name = "tsan",
+    actions = [
+        "@rules_cc//cc/toolchains/actions:c_compile_actions",
+        "@rules_cc//cc/toolchains/actions:cpp_compile_actions",
+        "@rules_cc//cc/toolchains/actions:link_actions",
+    ],
+    args = [
+        "-fsanitize=thread",
+        "-DTHREAD_SANITIZER",
+    ],
+)
+
+cc_args(
+    name = "fuzztest",
+    actions = [
+        "@rules_cc//cc/toolchains/actions:c_compile_actions",
+        "@rules_cc//cc/toolchains/actions:cpp_compile_actions",
+        "@rules_cc//cc/toolchains/actions:link_actions",
+    ],
+    args = [
+        "-DFUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION",
+        "-UNDEBUG",
+        "-D_LIBCPP_ENABLE_ASSERTIONS=1",
+    ] + select({
+        "@platforms//cpu:x86_64": ["-mcrc32"],
+        "//conditions:default": [],
+    }),
+)

pw_toolchain/build_external/BUILD.bazel

@@ -0,0 +1,17 @@
+# Copyright 2024 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.
+
+package(default_visibility = ["//visibility:public"])
+
+licenses(["notice"])