build/toolchain/pw_fuzzer/BUILD.gn

# Copyright (c) 2024 Project CHIP 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
#
# http://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.

import("//build_overrides/build.gni")
import("//build_overrides/pigweed.gni")

import("$dir_pigweed/targets/host/target_toolchains.gni")
import("${build_root}/toolchain/gcc_toolchain.gni")

# creating a secondary toolchain to be used with pw_fuzzer FuzzTests
# This toolchain is downstreamed from pigweed's pw_target_toolchain_host.clang_fuzz
# it allows us to specifically use googletest for fuzzing (instead of the lighter version of googletest used for unit testing)

gcc_toolchain("chip_pw_fuzztest") {
  forward_variables_from(pw_target_toolchain_host.clang_fuzz, "*", [ "name" ])

  toolchain_args = {
    # This is needed to have the defaults passed from pw_target_toolchain_host.clang_fuzz to the current scope
    forward_variables_from(defaults, "*")

    pw_unit_test_MAIN = "$dir_pw_fuzzer:fuzztest_main"
    pw_unit_test_BACKEND = "$dir_pw_fuzzer:gtest"

    # The next three lines are needed by the gcc_toolchain template
    current_os = host_os
    current_cpu = host_cpu
    is_clang = true

    # the upstream pigweed host_clang toolchain defines a default sysroot, which results in build errors
    # since it does not include SSL lib and is supposed to be minimal by design.
    # by removing this default config, we will use the system's libs. Otherwise we can define our own sysroot.
    # discussion on: https://discord.com/channels/691686718377558037/1275092695764959232
    remove_default_configs = [ "$dir_pw_toolchain/host_clang:linux_sysroot" ]

    # when is_debug = true, we pass -O0 to cflags and ldflags, while upstream pw_fuzzer toolchain defines "optimize_speed" config that passes -O2.
    # This condition was added to prevent mixing the flags
    if (is_debug) {
      remove_default_configs += [ "$dir_pw_build:optimize_speed" ]
    }

    # removing pigweed downstreamed configs related to warnings
    # These are triggering an error related to -Wcast-qual in third_party/nlio
    remove_default_configs += [
      "$dir_pw_build:strict_warnings",
      "$dir_pw_build:extra_strict_warnings",
    ]

    # the third_party abseil-cpp triggers warnings related to [-Wformat-nonliteral]
    treat_warnings_as_errors = false

    dir_pw_third_party_abseil_cpp = "//third_party/abseil-cpp/src"
    dir_pw_third_party_fuzztest = "//third_party/fuzztest"
    dir_pw_third_party_googletest = "//third_party/googletest"

    # TODO: Seems that re2 support within FuzzTest was deprecated, keeping it defined is triggering warning
    # Remove if re2 is indeed not needed
    # dir_pw_third_party_re2 = "//third_party/re2/src"
  }
}