| 1 | use std::env; |
| 2 | use std::ffi::OsString; |
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| 3 | use std::path::PathBuf; |
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| 4 | use std::process::Command; |
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| 5 | |
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| 6 | use super::error::Error; |
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| 7 | use super::version::Version; |
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| 8 | |
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| 9 | #[derive (Clone, Debug)] |
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| 10 | pub struct Rustc { |
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| 11 | rustc: PathBuf, |
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| 12 | rustc_wrapper: Option<PathBuf>, |
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| 13 | rustc_workspace_wrapper: Option<PathBuf>, |
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| 14 | } |
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| 15 | |
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| 16 | impl Rustc { |
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| 17 | pub fn new() -> Self { |
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| 18 | Rustc { |
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| 19 | rustc: env::var_os("RUSTC" ) |
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| 20 | .unwrap_or_else(|| "rustc" .into()) |
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| 21 | .into(), |
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| 22 | rustc_wrapper: get_rustc_wrapper(false), |
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| 23 | rustc_workspace_wrapper: get_rustc_wrapper(true), |
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| 24 | } |
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| 25 | } |
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| 26 | |
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| 27 | /// Build the command with possible wrappers. |
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| 28 | pub fn command(&self) -> Command { |
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| 29 | let mut rustc = self |
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| 30 | .rustc_wrapper |
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| 31 | .iter() |
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| 32 | .chain(self.rustc_workspace_wrapper.iter()) |
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| 33 | .chain(Some(&self.rustc)); |
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| 34 | let mut command = Command::new(rustc.next().unwrap()); |
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| 35 | for arg in rustc { |
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| 36 | command.arg(arg); |
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| 37 | } |
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| 38 | command |
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| 39 | } |
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| 40 | |
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| 41 | /// Try to get the `rustc` version. |
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| 42 | pub fn version(&self) -> Result<Version, Error> { |
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| 43 | // Some wrappers like clippy-driver don't pass through version commands, |
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| 44 | // so we try to fall back to combinations without each wrapper. |
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| 45 | macro_rules! try_version { |
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| 46 | ($command:expr) => { |
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| 47 | if let Ok(value) = Version::from_command($command) { |
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| 48 | return Ok(value); |
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| 49 | } |
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| 50 | }; |
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| 51 | } |
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| 52 | |
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| 53 | let rustc = &self.rustc; |
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| 54 | if let Some(ref rw) = self.rustc_wrapper { |
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| 55 | if let Some(ref rww) = self.rustc_workspace_wrapper { |
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| 56 | try_version!(Command::new(rw).args(&[rww, rustc])); |
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| 57 | } |
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| 58 | try_version!(Command::new(rw).arg(rustc)); |
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| 59 | } |
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| 60 | if let Some(ref rww) = self.rustc_workspace_wrapper { |
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| 61 | try_version!(Command::new(rww).arg(rustc)); |
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| 62 | } |
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| 63 | Version::from_command(&mut Command::new(rustc)) |
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| 64 | } |
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| 65 | } |
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| 66 | |
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| 67 | fn get_rustc_wrapper(workspace: bool) -> Option<PathBuf> { |
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| 68 | // We didn't really know whether the workspace wrapper is applicable until Cargo started |
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| 69 | // deliberately setting or unsetting it in rust-lang/cargo#9601. We'll use the encoded |
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| 70 | // rustflags as a proxy for that change for now, but we could instead check version 1.55. |
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| 71 | if workspace && env::var_os(key:"CARGO_ENCODED_RUSTFLAGS" ).is_none() { |
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| 72 | return None; |
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| 73 | } |
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| 74 | |
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| 75 | let name: &'static str = if workspace { |
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| 76 | "RUSTC_WORKSPACE_WRAPPER" |
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| 77 | } else { |
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| 78 | "RUSTC_WRAPPER" |
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| 79 | }; |
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| 80 | |
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| 81 | if let Some(wrapper: OsString) = env::var_os(key:name) { |
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| 82 | // NB: `OsStr` didn't get `len` or `is_empty` until 1.9. |
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| 83 | if wrapper != OsString::new() { |
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| 84 | return Some(wrapper.into()); |
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| 85 | } |
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| 86 | } |
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| 87 | |
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| 88 | None |
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| 89 | } |
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| 90 | |
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