Source code
Revision control
Copy as Markdown
Other Tools
//! Contains code for selecting features
#![deny(unused_extern_crates)]
#![deny(clippy::missing_docs_in_private_items)]
#![allow(deprecated)]
use std::cmp::Ordering;
use std::io;
use std::str::FromStr;
/// This macro defines the [`RustTarget`] and [`RustFeatures`] types.
macro_rules! define_rust_targets {
(
Nightly => {$($nightly_feature:ident $(: #$issue:literal)?),* $(,)?} $(,)?
$(
$(#[$attrs:meta])*
$variant:ident($minor:literal) => {$($feature:ident $(: #$pull:literal)?),* $(,)?},
)*
$(,)?
) => {
/// Represents the version of the Rust language to target.
///
/// To support a beta release, use the corresponding stable release.
///
/// This enum will have more variants added as necessary.
#[allow(non_camel_case_types)]
#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
pub enum RustTarget {
/// Rust Nightly
$(#[doc = concat!(
"- [`", stringify!($nightly_feature), "`]",
)])*
Nightly,
$(
#[doc = concat!("Rust 1.", stringify!($minor))]
$(#[doc = concat!(
"- [`", stringify!($feature), "`]",
)])*
$(#[$attrs])*
$variant,
)*
}
impl RustTarget {
fn minor(self) -> Option<u64> {
match self {
$( Self::$variant => Some($minor),)*
Self::Nightly => None
}
}
const fn stable_releases() -> [(Self, u64); [$($minor,)*].len()] {
[$((Self::$variant, $minor),)*]
}
}
#[cfg(feature = "__cli")]
/// Strings of allowed `RustTarget` values
pub const RUST_TARGET_STRINGS: &[&str] = &[$(concat!("1.", stringify!($minor)),)*];
#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
pub(crate) struct RustFeatures {
$($(pub(crate) $feature: bool,)*)*
$(pub(crate) $nightly_feature: bool,)*
}
impl From<RustTarget> for RustFeatures {
fn from(target: RustTarget) -> Self {
if target == RustTarget::Nightly {
return Self {
$($($feature: true,)*)*
$($nightly_feature: true,)*
};
}
let mut features = Self {
$($($feature: false,)*)*
$($nightly_feature: false,)*
};
$(if target >= RustTarget::$variant {
$(features.$feature = true;)*
})*
features
}
}
};
}
// NOTE: When adding or removing features here, make sure to add the stabilization PR
// number for the feature if it has been stabilized or the tracking issue number if the feature is
// not stable.
define_rust_targets! {
Nightly => {
vectorcall_abi,
},
Stable_1_73(73) => { thiscall_abi: #42202 },
Stable_1_71(71) => { c_unwind_abi: #106075 },
Stable_1_68(68) => { abi_efiapi: #105795 },
Stable_1_64(64) => { core_ffi_c: #94503 },
Stable_1_59(59) => { const_cstr: #54745 },
Stable_1_47(47) => { larger_arrays: #74060 },
Stable_1_40(40) => { non_exhaustive: #44109 },
Stable_1_36(36) => { maybe_uninit: #60445 },
Stable_1_33(33) => { repr_packed_n: #57049 },
#[deprecated]
Stable_1_30(30) => {
core_ffi_c_void: #53910,
min_const_fn: #54835,
},
#[deprecated]
Stable_1_28(28) => { repr_transparent: #51562 },
#[deprecated]
Stable_1_27(27) => { must_use_function: #48925 },
#[deprecated]
Stable_1_26(26) => { i128_and_u128: #49101 },
#[deprecated]
Stable_1_25(25) => { repr_align: #47006 },
#[deprecated]
Stable_1_21(21) => { builtin_clone_impls: #43690 },
#[deprecated]
Stable_1_20(20) => { associated_const: #42809 },
#[deprecated]
Stable_1_19(19) => { untagged_union: #42068 },
#[deprecated]
Stable_1_17(17) => { static_lifetime_elision: #39265 },
#[deprecated]
Stable_1_0(0) => {},
}
/// Latest stable release of Rust
pub const LATEST_STABLE_RUST: RustTarget = {
// FIXME: replace all this code by
// ```
// RustTarget::stable_releases()
// .into_iter()
// .max_by_key(|(_, m)| m)
// .map(|(t, _)| t)
// .unwrap_or(RustTarget::Nightly)
// ```
// once those operations can be used in constants.
let targets = RustTarget::stable_releases();
let mut i = 0;
let mut latest_target = None;
let mut latest_minor = 0;
while i < targets.len() {
let (target, minor) = targets[i];
if latest_minor < minor {
latest_minor = minor;
latest_target = Some(target);
}
i += 1;
}
match latest_target {
Some(target) => target,
None => unreachable!(),
}
};
impl Default for RustTarget {
fn default() -> Self {
LATEST_STABLE_RUST
}
}
impl PartialOrd for RustTarget {
fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
Some(self.cmp(other))
}
}
impl Ord for RustTarget {
fn cmp(&self, other: &Self) -> Ordering {
match (self.minor(), other.minor()) {
(Some(a), Some(b)) => a.cmp(&b),
(Some(_), None) => Ordering::Less,
(None, Some(_)) => Ordering::Greater,
(None, None) => Ordering::Equal,
}
}
}
impl FromStr for RustTarget {
type Err = io::Error;
fn from_str(s: &str) -> Result<Self, Self::Err> {
if s == "nightly" {
return Ok(Self::Nightly);
}
if let Some(("1", str_minor)) = s.split_once('.') {
if let Ok(minor) = str_minor.parse::<u64>() {
for (target, target_minor) in Self::stable_releases() {
if minor == target_minor {
return Ok(target);
}
}
}
}
Err(io::Error::new(
io::ErrorKind::InvalidInput,
"Got an invalid Rust target. Accepted values are of the form \"1.71\" or \"nightly\"."
))
}
}
impl std::fmt::Display for RustTarget {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
match self.minor() {
Some(minor) => write!(f, "1.{}", minor),
None => "nightly".fmt(f),
}
}
}
impl Default for RustFeatures {
fn default() -> Self {
RustTarget::default().into()
}
}
#[cfg(test)]
mod test {
#![allow(unused_imports)]
use super::*;
#[test]
fn target_features() {
let f_1_0 = RustFeatures::from(RustTarget::Stable_1_0);
assert!(
!f_1_0.static_lifetime_elision &&
!f_1_0.core_ffi_c_void &&
!f_1_0.untagged_union &&
!f_1_0.associated_const &&
!f_1_0.builtin_clone_impls &&
!f_1_0.repr_align &&
!f_1_0.thiscall_abi &&
!f_1_0.vectorcall_abi
);
let f_1_21 = RustFeatures::from(RustTarget::Stable_1_21);
assert!(
f_1_21.static_lifetime_elision &&
!f_1_21.core_ffi_c_void &&
f_1_21.untagged_union &&
f_1_21.associated_const &&
f_1_21.builtin_clone_impls &&
!f_1_21.repr_align &&
!f_1_21.thiscall_abi &&
!f_1_21.vectorcall_abi
);
let features = RustFeatures::from(RustTarget::Stable_1_71);
assert!(
features.c_unwind_abi &&
features.abi_efiapi &&
!features.thiscall_abi
);
let f_nightly = RustFeatures::from(RustTarget::Nightly);
assert!(
f_nightly.static_lifetime_elision &&
f_nightly.core_ffi_c_void &&
f_nightly.untagged_union &&
f_nightly.associated_const &&
f_nightly.builtin_clone_impls &&
f_nightly.maybe_uninit &&
f_nightly.repr_align &&
f_nightly.thiscall_abi &&
f_nightly.vectorcall_abi
);
}
fn test_target(target_str: &str, target: RustTarget) {
let target_string = target.to_string();
assert_eq!(target_str, target_string);
assert_eq!(target, RustTarget::from_str(target_str).unwrap());
}
#[test]
fn str_to_target() {
test_target("1.0", RustTarget::Stable_1_0);
test_target("1.17", RustTarget::Stable_1_17);
test_target("1.19", RustTarget::Stable_1_19);
test_target("1.21", RustTarget::Stable_1_21);
test_target("1.25", RustTarget::Stable_1_25);
test_target("1.71", RustTarget::Stable_1_71);
test_target("nightly", RustTarget::Nightly);
}
}