xref: /aosp_15_r20/external/pigweed/pw_toolchain/cc/BUILD.bazel (revision 61c4878ac05f98d0ceed94b57d316916de578985)

# 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("@bazel_skylib//rules:common_settings.bzl", "string_flag")
load(
    "@pw_toolchain//cc_toolchain:defs.bzl",
    "pw_cc_feature",
    "pw_cc_flag_set",
)

package(default_visibility = ["//visibility:public"])

# The common set of warnings for clang and arm_gcc.
pw_cc_flag_set(
    name = "common_warnings",
    actions = [
        "@pw_toolchain//actions:all_c_compiler_actions",
        "@pw_toolchain//actions:all_cpp_compiler_actions",
    ],
    flags = [
        "-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
    ],
)

# Enables colors in compiler diagnostics. This uses the GCC spelling of the
# flag, which Clang supports as an undocumented extension.
pw_cc_flag_set(
    name = "color_diagnostics",
    actions = [
        "@pw_toolchain//actions:all_asm_actions",
        "@pw_toolchain//actions:all_c_compiler_actions",
        "@pw_toolchain//actions:all_cpp_compiler_actions",
        "@pw_toolchain//actions:all_link_actions",
    ],
    flags = ["-fdiagnostics-color"],
)

# 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.
pw_cc_flag_set(
    name = "internal_strict_warnings_flags",
    actions = [
        "@pw_toolchain//actions:all_c_compiler_actions",
        "@pw_toolchain//actions:all_cpp_compiler_actions",
    ],
    flags = [
        "-Wswitch-enum",
        "-Wextra-semi",
        # TODO: b/361229275 - Add -Wshadow-all, but for Clang only, since GCC
        # does not support it.
        # "-Wshadow-all",
    ] + 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.
pw_cc_feature(
    name = "internal_strict_warnings",
    enabled = False,
    feature_name = "internal_strict_warnings",
    flag_sets = [":internal_strict_warnings_flags"],
    visibility = ["//:__subpackages__"],
)

string_flag(
    name = "cxx_standard",
    build_setting_default = "20",
    values = [
        "17",
        "20",
    ],
)

config_setting(
    name = "c++17_enabled",
    flag_values = {
        ":cxx_standard": "17",
    },
)

pw_cc_feature(
    name = "c++17_feature",
    enabled = select({
        ":c++17_enabled": True,
        "//conditions:default": False,
    }),
    feature_name = "c++17",
    flag_sets = ["@pw_toolchain//flag_sets:c++17"],
)

config_setting(
    name = "c++20_enabled",
    flag_values = {
        ":cxx_standard": "20",
    },
)

pw_cc_feature(
    name = "c++20_feature",
    enabled = select({
        ":c++20_enabled": True,
        "//conditions:default": False,
    }),
    feature_name = "c++20",
    flag_sets = ["@pw_toolchain//flag_sets:c++20"],
)