# Copyright 2018 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/config/clang/clang.gni")
import("//build/config/compiler.gni")
import("//build/config/sysroot.gni")
import("//build/fidl/toolchain.gni")

default_rust_sysroot =
    rebase_path("//prebuilt/third_party/rust/${host_platform}", root_build_dir)

default_rustc_prefix =
    rebase_path("//prebuilt/third_party/rust/${host_platform}/bin",
                root_build_dir)

declare_args() {
  # Sets a custom base directory for `rustc` and `cargo`.
  # This can be used to test custom Rust toolchains.
  rustc_prefix = default_rustc_prefix

  # Sets a custom base directory for where rust tooling
  # looks for the standard library
  rust_sysroot = default_rust_sysroot

  # Sets the default LTO type for rustc bulids.
  rust_lto = ""

  # DEPRECATED: Sets the panic type for Rust on fuchsia.
  # Valid values are "unwind" and "abort".
  # This arg will be removed soon, and we will always use "abort".
  rust_panic = "abort"

  # Sets the fuchsia toolchain target triple suffix (after arch)
  rust_toolchain_triple_suffix = "fuchsia"

  # Sets the maximum lint level.
  # "deny" will make all warnings into errors, "warn" preserves them as warnings, and "allow" will
  # ignore warnings.
  rust_cap_lints = "deny"

  # Overrides the optimization level for all Rust builds, regardless of
  # debug/release flags or the `force_opt` arg to the rustc_ templates.
  # Valid values are 0-3, o, and z.
  rust_override_opt = ""

  # Overrides the LTO setting for all Rust builds, regardless of
  # debug/release flags or the `with_lto` arg to the rustc_ templates.
  # Valid values are "none", "thin", and "fat".
  rust_override_lto = ""
}

assert(rust_panic == "unwind" || rust_panic == "abort",
       "rust_panic was neither 'unwind' nor 'panic'")

# Always use panic=unwind on host, or proc macros won't work.
if (!is_fuchsia) {
  rust_panic = "unwind"
}

std_deps = []
if (is_fuchsia) {
  std_deps += [
    # These libraries are required by libstd.
    "//zircon/public/lib/fdio",
  ]
}

assert(
    current_os == "mac" || current_os == "linux" || current_os == "fuchsia" ||
        (current_os == "unknown" && current_cpu == "wasm32"),
    "current_os was neither mac, linux, unknown, nor fuchsia")
assert(
    current_cpu == "x64" || current_cpu == "arm64" || current_cpu == "wasm32")
if (current_os == "mac") {
  _suffix = "apple-darwin"
} else if (current_os == "linux") {
  _suffix = "unknown-linux-gnu"
} else if (current_os == "fuchsia") {
  _suffix = rust_toolchain_triple_suffix
}
if (current_cpu == "x64") {
  rust_target = "x86_64-${_suffix}"
} else if (current_cpu == "arm64") {
  rust_target = "aarch64-${_suffix}"
} else if (current_cpu == "wasm32" && current_os == "unknown") {
  rust_target = "wasm32-unknown-unknown"
}