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| 1 | +// This Source Code Form is subject to the terms of the Mozilla Public |
| 2 | +// License, v. 2.0. If a copy of the MPL was not distributed with this |
| 3 | +// file, You can obtain one at https://mozilla.org/MPL/2.0/. |
| 4 | + |
| 5 | +//! External xtasks. (extasks?) |
| 6 | +
|
| 7 | +use std::ffi::OsString; |
| 8 | +use std::os::unix::process::CommandExt; |
| 9 | +use std::process::Command; |
| 10 | + |
| 11 | +use anyhow::{Context, Result}; |
| 12 | +use clap::Parser; |
| 13 | + |
| 14 | +/// Argument parser for external xtasks. |
| 15 | +/// |
| 16 | +/// In general we want all developer tasks to be discoverable simply by running |
| 17 | +/// `cargo xtask`, but some development tools end up with a particularly |
| 18 | +/// large dependency tree. It's not ideal to have to pay the cost of building |
| 19 | +/// our release engineering tooling if all the user wants to do is check for |
| 20 | +/// workspace dependency issues. |
| 21 | +/// |
| 22 | +/// `External` provides a pattern for creating xtasks that live in other crates. |
| 23 | +/// An external xtask is defined on `crate::Cmds` as a tuple variant containing |
| 24 | +/// `External`, which captures all arguments and options (even `--help`) as |
| 25 | +/// a `Vec<OsString>`. The main function then calls `External::exec` with the |
| 26 | +/// appropriate bin target name and any additional Cargo arguments. |
| 27 | +#[derive(Debug, Parser)] |
| 28 | +#[clap( |
| 29 | + disable_help_flag(true), |
| 30 | + disable_help_subcommand(true), |
| 31 | + disable_version_flag(true) |
| 32 | +)] |
| 33 | +pub struct External { |
| 34 | + #[clap(trailing_var_arg(true), allow_hyphen_values(true))] |
| 35 | + args: Vec<OsString>, |
| 36 | + |
| 37 | + // This stores an in-progress Command builder. `cargo_args` appends args |
| 38 | + // to it, and `exec` consumes it. Clap does not treat this as a command |
| 39 | + // (`skip`), but fills in this field by calling `new_command`. |
| 40 | + #[clap(skip = new_command())] |
| 41 | + command: Command, |
| 42 | +} |
| 43 | + |
| 44 | +impl External { |
| 45 | + pub fn exec_bin( |
| 46 | + self, |
| 47 | + package: impl AsRef<str>, |
| 48 | + bin_target: impl AsRef<str>, |
| 49 | + ) -> Result<()> { |
| 50 | + self.exec_common(&[ |
| 51 | + "--package", |
| 52 | + package.as_ref(), |
| 53 | + "--bin", |
| 54 | + bin_target.as_ref(), |
| 55 | + ]) |
| 56 | + } |
| 57 | + |
| 58 | + fn exec_common(mut self, args: &[&str]) -> Result<()> { |
| 59 | + let error = self.command.args(args).arg("--").args(self.args).exec(); |
| 60 | + Err(error).context("failed to exec `cargo run`") |
| 61 | + } |
| 62 | +} |
| 63 | + |
| 64 | +fn new_command() -> Command { |
| 65 | + let mut command = cargo_command(CargoLocation::FromEnv); |
| 66 | + command.arg("run"); |
| 67 | + command |
| 68 | +} |
| 69 | + |
| 70 | +/// Creates and prepares a `std::process::Command` for the `cargo` executable. |
| 71 | +pub fn cargo_command(location: CargoLocation) -> Command { |
| 72 | + let mut command = location.resolve(); |
| 73 | + |
| 74 | + for (key, _) in std::env::vars_os() { |
| 75 | + let Some(key) = key.to_str() else { continue }; |
| 76 | + if SANITIZED_ENV_VARS.matches(key) { |
| 77 | + command.env_remove(key); |
| 78 | + } |
| 79 | + } |
| 80 | + |
| 81 | + command |
| 82 | +} |
| 83 | + |
| 84 | +/// How to determine the location of the `cargo` executable. |
| 85 | +#[derive(Clone, Copy, Debug)] |
| 86 | +pub enum CargoLocation { |
| 87 | + /// Use the `CARGO` environment variable, and fall back to `"cargo"` if it |
| 88 | + /// is not set. |
| 89 | + FromEnv, |
| 90 | +} |
| 91 | + |
| 92 | +impl CargoLocation { |
| 93 | + fn resolve(self) -> Command { |
| 94 | + match self { |
| 95 | + CargoLocation::FromEnv => { |
| 96 | + let cargo = std::env::var_os("CARGO") |
| 97 | + .unwrap_or_else(|| OsString::from("cargo")); |
| 98 | + Command::new(&cargo) |
| 99 | + } |
| 100 | + } |
| 101 | + } |
| 102 | +} |
| 103 | + |
| 104 | +#[derive(Debug)] |
| 105 | +struct SanitizedEnvVars { |
| 106 | + // At the moment we only ban some prefixes, but we may also want to ban env |
| 107 | + // vars by exact name in the future. |
| 108 | + prefixes: &'static [&'static str], |
| 109 | +} |
| 110 | + |
| 111 | +impl SanitizedEnvVars { |
| 112 | + const fn new() -> Self { |
| 113 | + // Remove many of the environment variables set in |
| 114 | + // https://doc.rust-lang.org/cargo/reference/environment-variables.html#environment-variables-cargo-sets-for-build-scripts. |
| 115 | + // This is done to avoid recompilation with crates like ring between |
| 116 | + // `cargo clippy` and `cargo xtask clippy`. (This is really a bug in |
| 117 | + // both ring's build script and in Cargo.) |
| 118 | + // |
| 119 | + // The current list is informed by looking at ring's build script, so |
| 120 | + // it's not guaranteed to be exhaustive and it may need to grow over |
| 121 | + // time. |
| 122 | + let prefixes = &["CARGO_PKG_", "CARGO_MANIFEST_", "CARGO_CFG_"]; |
| 123 | + Self { prefixes } |
| 124 | + } |
| 125 | + |
| 126 | + fn matches(&self, key: &str) -> bool { |
| 127 | + self.prefixes.iter().any(|prefix| key.starts_with(prefix)) |
| 128 | + } |
| 129 | +} |
| 130 | + |
| 131 | +static SANITIZED_ENV_VARS: SanitizedEnvVars = SanitizedEnvVars::new(); |
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