settings.rs

// Copyright 2018 Google Inc.
//
// 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.

use std::collections::HashMap;

pub type CrateSettingsPerVersion = HashMap<String, CrateSettings>;

/**
 * A "deserializable struct" for the whole Cargo.toml
 *
 * Contains only `raze` settings, (we drop everything else in the toml on the floor).
 */
#[derive(Debug, Clone, Deserialize)]
pub struct CargoToml {
  pub raze: RazeSettings,
}

/** The configuration settings for `cargo-raze`, included in Cargo.toml. */
#[derive(Debug, Clone, Deserialize)]
pub struct RazeSettings {
  /**
   * The path to the Cargo.toml working directory.
   */
  pub workspace_path: String,

  /**
   * The platform target to generate BUILD rules for.
   *
   * This comes in the form of a "triple", such as "x86_64-unknown-linux-gnu"
   */
  #[serde(default = "default_raze_settings_field_target")]
  pub target: String,

  /** Any crate-specific configuration. See CrateSetings for details. */
  #[serde(default)]
  pub crates: HashMap<String, CrateSettingsPerVersion>,

  /**
   * Prefix for generated Bazel workspaces (from workspace_rules)
   *
   * This is only useful with remote genmode. It prefixes the names of the workspaces for
   * dependencies (@PREFIX_crateName_crateVersion) as well as the name of the repository function
   * generated in crates.bzl (PREFIX_fetch_remote_crates()).
   *
   * TODO(acmcarther): Does this have a non-bazel analogue?
   */
  #[serde(default = "default_raze_settings_field_gen_workspace_prefix")]
  pub gen_workspace_prefix: String,

  /** How to generate the dependencies. See GenMode for details. */
  #[serde(default = "default_raze_settings_field_genmode")]
  pub genmode: GenMode,

  /**
    * Suffix for generated build files, uses whole value for Vendored mode
    * Default: BUILD
    */
  #[serde(default = "default_raze_settings_field_output_buildfile_suffix")]
  pub output_buildfile_suffix: String,
}

/** Override settings for individual crates (as part of RazeSettings). */
#[derive(Debug, Clone, Deserialize, Serialize)]
pub struct CrateSettings {
  /**
   * Dependencies to be added to a crate.
   *
   * Importantly, the format of dependency references depends on the genmode.
   * Remote: @{gen_workspace_prefix}__{dep_name}__{dep_version_sanitized}/:{dep_name}
   * Vendored: //{workspace_path}/vendor/{dep_name}-{dep_version}:{dep_name}
   *
   * In addition, the added deps must be accessible from a remote workspace under Remote GenMode.
   * Usually, this means they _also_ need to be remote, but a "local" build path prefixed with
   * "@", in the form "@//something_local" may work.
   */
  #[serde(default)]
  pub additional_deps: Vec<String>,

  /**
   * Dependencies to be removed from a crate, in the form "{dep-name}-{dep-version}"
   *
   * This is applied during Cargo analysis, so it uses Cargo-style labeling
   */
  #[serde(default)]
  pub skipped_deps: Vec<String>,

  /**
   * Library targets that should be aliased in the root BUILD file.
   *
   * This is useful to facilitate using binary utility crates, such as bindgen, as part of genrules.
   */
  #[serde(default)]
  pub extra_aliased_targets: Vec<String>,

  /** Flags to be added to the crate compilation process, in the form "--flag". */
  #[serde(default)]
  pub additional_flags: Vec<String>,

  /**
   * Whether or not to generate the build script that goes with this crate.
   *
   * Many build scripts will not function, as they will still be built hermetically. However, build
   * scripts that merely generate files into OUT_DIR may be fully functional.
   */
  #[serde(default = "default_crate_settings_field_gen_buildrs")]
  pub gen_buildrs: bool,

  /**
   * The verbatim `data` clause to be included for the generated build targets.
   *
   * N.B. Build scripts are always provided all crate files for their `data` attr.
   */
  #[serde(default = "default_crate_settings_field_data_attr")]
  pub data_attr: Option<String>,

  /**
   * Additional environment variables to add when running the build script.
   * 
   * Values should looks like "KEY=VALUE".
   */
  #[serde(default)]
  pub buildrs_additional_environment_variables: Vec<String>
}

/**
 * Describes how dependencies should be managed in tree. Options are {Remote, Vendored}.
 *
 * Remote:
 * This mode assumes that files are not locally vendored, and generates a workspace-level
 * function that can bring them in.
 *
 * Vendored:
 * This mode assumes that files are vendored (into vendor/), and generates BUILD files
 * accordingly
 */
#[derive(Debug, Clone, Deserialize, PartialEq, Eq)]
pub enum GenMode {
  Vendored,
  Remote,
}

impl Default for CrateSettings {
  fn default() -> CrateSettings {
    CrateSettings {
      additional_deps: Vec::new(),
      skipped_deps: Vec::new(),
      extra_aliased_targets: Vec::new(),
      additional_flags: Vec::new(),
      gen_buildrs: default_crate_settings_field_gen_buildrs(),
      data_attr: default_crate_settings_field_data_attr(),
      buildrs_additional_environment_variables: Vec::new(),
    }
  }
}

#[cfg(test)]
pub mod testing {
  use super::*;

  pub fn dummy_raze_settings() -> RazeSettings {
    RazeSettings {
      workspace_path: "//cargo".to_owned(),
      target: "x86_64-unknown-linux-gnu".to_owned(),
      crates: HashMap::new(),
      gen_workspace_prefix: "raze_test".to_owned(),
      genmode: GenMode::Remote,
      output_buildfile_suffix: "BUILD".to_owned(),
    }
  }
}

fn default_raze_settings_field_target() -> String {
  "x86_64-unknown-linux-gnu".to_owned()
}

fn default_raze_settings_field_gen_workspace_prefix() -> String {
  "raze".to_owned()
}

fn default_raze_settings_field_genmode() -> GenMode {
  GenMode::Vendored
}

fn default_raze_settings_field_output_buildfile_suffix() -> String {
  "BUILD".to_owned()
}

fn default_crate_settings_field_gen_buildrs() -> bool {
  false
}

fn default_crate_settings_field_data_attr() -> Option<String> {
  None
}