build/config/rust/BUILD.gn

# Copyright 2021 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import("//build/rust/config.gni")

declare_args() {
  # Controls whether the rust compiler uses v0 symbol mangling scheme
  # (see https://github.com/rust-lang/rfcs/blob/HEAD/text/2603-rust-symbol-name-mangling-v0.md).
  # The v0 symbol mangling scheme requires upstream LLVM support when demangling,
  # so it is not on by default.
  # TODO(fxbug.dev/57302): Enable v0 mangling by default.
  rust_v0_symbol_mangling = false

  # Enable incremental rust compilation. Takes a path to the directory to use
  # as the cache.
  rust_incremental = ""
}

# Defines a Rust cfg flag with the value of the rust_panic build arg.
# Useful for changing behavior of code based on panic behavior.
config("panic_cfg") {
  rustflags = [ "--cfg=rust_panic=\"${rust_panic}\"" ]
}

# Turns on the rust compilation analysis generator. This will produce a
# directory $OUT/save-analysis-temp, which will dump all the source analysis
# that the compiler collected while analyzing the source.  This config is
# included conditionally, see //build/config/BUILDCONFIG.gn for details.
config("analysis") {
  rustflags = [ "-Zsave-analysis" ]
}

config("edition_2018") {
  rustflags = [ "--edition=2018" ]
}

config("edition_2015") {
  rustflags = [ "--edition=2015" ]
}

config("opt_level_z") {
  rustflags = [ "-Copt-level=z" ]
}

config("no_features") {
  rustflags = [ "-Zallow-features=" ]
}

config("incremental") {
  if (rust_incremental != "") {
    rustflags = [ "-Cincremental=" + rust_incremental ]
  }
}

config("netstack3_only_specialization_feature") {
  rustflags = [
    "-Zallow-features=min_specialization,specialization",
    "-Aincomplete-features",
  ]
}

config("2018_idioms") {
  rustflags = [ "-Wrust-2018-idioms" ]
}

config("target") {
  rustflags = [
    "--target",
    rust_target,
    "--cap-lints=$rust_cap_lints",
  ]
}

config("panic_abort") {
  rustflags = [
    "-Cpanic=abort",
    "-Cforce-unwind-tables=yes",
    "-Zpanic_abort_tests",
  ]
}

config("v0_symbol_mangling") {
  if (rust_v0_symbol_mangling) {
    rustflags = [ "-Zsymbol-mangling-version=v0" ]
  }
}

config("allow_unknown_lints") {
  rustflags = [ "-Aunknown-lints" ]
}

# TODO(fxbug.dev/67118) remove this allowance
config("allow_redundant_semicolons") {
  rustflags = [ "-Aredundant-semicolons" ]
}

# TODO(fxbug.dev/68148) remove this allowance
config("allow_unused_extern_crates") {
  rustflags = [ "-Aunused-extern-crates" ]
}

# TODO(fxbug.dev/69442) remove this allowance
config("allow_legacy_derive_helpers") {
  rustflags = [ "-Alegacy-derive-helpers" ]
}

config("deny_unused_results") {
  rustflags = [ "-Dunused_results" ]
}

config("allow_unused_results") {
  rustflags = [ "-Aunused_results" ]

  # This visibility list allows for targets to opt out of allowing unused results.
  #
  # There is currently no platform mandate to adopt the unused_results lint and it's opt-in for
  # developers that want to use it. See https://fxbug.dev/73468 for more context.
  #
  # To adopt the lint, add the following to your rust target:
  #   configs -= ["//build/config/rust:allow_unused_results"]
  # The visibility list below can be used to enforce the list on certain areas of the tree while
  # we evaluate wider adoption.
  #
  # To update this list run:
  # $ scripts/gn/gen_visibility_globs.py \
  #    --all=//build/config/rust:deny_unused_results \
  #    --allow=//build/config/rust:allow_unused_results
  #
  # TODO(https://fxbug.dev/73468): remove all references to src/connectivity/network and friends.
  visibility = [
    "//build/*",
    "//examples/*",
    "//garnet/*",
    "//sdk/*",
    "//src/bringup/*",
    "//src/camera/*",
    "//src/cobalt/*",
    "//src/connectivity/bluetooth/*",
    "//src/connectivity/ethernet/*",
    "//src/connectivity/lib/*",
    "//src/connectivity/location/*",
    "//src/connectivity/lowpan/*",
    "//src/connectivity/management/*",
    "//src/connectivity/network/http-client/*",
    "//src/connectivity/network/lib/*",
    "//src/connectivity/network/netstack/*",
    "//src/connectivity/network/netstack3/*",
    "//src/connectivity/network/testing/netemul/*",
    "//src/connectivity/network/tests/connect/*",
    "//src/connectivity/network/tests/dhcp_interop/*",
    "//src/connectivity/network/tools/*",
    "//src/connectivity/openthread/*",
    "//src/connectivity/overnet/*",
    "//src/connectivity/ppp/*",
    "//src/connectivity/telephony/*",
    "//src/connectivity/weave/*",
    "//src/connectivity/wlan/*",
    "//src/developer/*",
    "//src/devices/*",
    "//src/diagnostics/*",
    "//src/experiences/*",
    "//src/factory/*",
    "//src/fonts/*",
    "//src/graphics/*",
    "//src/hwinfo/*",
    "//src/identity/*",
    "//src/intl/*",
    "//src/lib/*",
    "//src/media/*",
    "//src/modular/*",
    "//src/power/*",
    "//src/proc/*",
    "//src/recovery/*",
    "//src/security/*",
    "//src/session/*",
    "//src/storage/*",
    "//src/sys/*",
    "//src/testing/*",
    "//src/tests/*",
    "//src/ui/*",
    "//src/virtualization/*",
    "//third_party/*",
    "//tools/*",
    "//vendor/*",
    "//zircon/*",
  ]
}