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|
#[macro_export]
#[allow_internal_unstable(stdsimd)]
macro_rules! detect_feature {
($feature:tt, $feature_lit:tt) => {
$crate::detect_feature!($feature, $feature_lit : $feature_lit)
};
($feature:tt, $feature_lit:tt : $($target_feature_lit:tt),*) => {
$(cfg!(target_feature = $target_feature_lit) ||)*
$crate::detect::__is_feature_detected::$feature()
};
}
#[allow(unused)]
macro_rules! features {
(
@TARGET: $target:ident;
@CFG: $cfg:meta;
@MACRO_NAME: $macro_name:ident;
@MACRO_ATTRS: $(#[$macro_attrs:meta])*
$(@BIND_FEATURE_NAME: $bind_feature:tt; $feature_impl:tt; )*
$(@NO_RUNTIME_DETECTION: $nort_feature:tt; )*
$(@FEATURE: #[$stability_attr:meta] $feature:ident: $feature_lit:tt;
$(implied by target_features: [$($target_feature_lit:tt),*];)?
$(#[$feature_comment:meta])*)*
) => {
#[macro_export]
$(#[$macro_attrs])*
#[allow_internal_unstable(stdsimd_internal, stdsimd)]
#[cfg($cfg)]
#[doc(cfg($cfg))]
macro_rules! $macro_name {
$(
($feature_lit) => {
$crate::detect_feature!($feature, $feature_lit $(: $($target_feature_lit),*)?)
};
)*
$(
($bind_feature) => { $crate::$macro_name!($feature_impl) };
)*
$(
($nort_feature) => {
compile_error!(
concat!(
stringify!($nort_feature),
" feature cannot be detected at run-time"
)
)
};
)*
($t:tt,) => {
$crate::$macro_name!($t);
};
($t:tt) => {
compile_error!(
concat!(
concat!("unknown ", stringify!($target)),
concat!(" target feature: ", $t)
)
)
};
}
$(#[$macro_attrs])*
#[macro_export]
#[cfg(not($cfg))]
#[doc(cfg($cfg))]
macro_rules! $macro_name {
$(
($feature_lit) => {
compile_error!(
concat!(
r#"This macro cannot be used on the current target.
You can prevent it from being used in other architectures by
guarding it behind a cfg("#,
stringify!($cfg),
")."
)
)
};
)*
$(
($bind_feature) => { $crate::$macro_name!($feature_impl) };
)*
$(
($nort_feature) => {
compile_error!(
concat!(
stringify!($nort_feature),
" feature cannot be detected at run-time"
)
)
};
)*
($t:tt,) => {
$crate::$macro_name!($t);
};
($t:tt) => {
compile_error!(
concat!(
concat!("unknown ", stringify!($target)),
concat!(" target feature: ", $t)
)
)
};
}
/// Each variant denotes a position in a bitset for a particular feature.
///
/// PLEASE: do not use this, it is an implementation detail subject
/// to change.
#[doc(hidden)]
#[allow(non_camel_case_types)]
#[derive(Copy, Clone)]
#[repr(u8)]
#[unstable(feature = "stdsimd_internal", issue = "none")]
#[cfg($cfg)]
pub(crate) enum Feature {
$(
$(#[$feature_comment])*
$feature,
)*
// Do not add variants after last:
_last
}
#[cfg($cfg)]
impl Feature {
pub(crate) fn to_str(self) -> &'static str {
match self {
$(Feature::$feature => $feature_lit,)*
Feature::_last => unreachable!(),
}
}
#[cfg(feature = "std_detect_env_override")]
pub(crate) fn from_str(s: &str) -> Result<Feature, ()> {
match s {
$($feature_lit => Ok(Feature::$feature),)*
_ => Err(())
}
}
}
/// Each function performs run-time feature detection for a single
/// feature. This allow us to use stability attributes on a per feature
/// basis.
///
/// PLEASE: do not use this, it is an implementation detail subject
/// to change.
#[doc(hidden)]
#[cfg($cfg)]
pub mod __is_feature_detected {
$(
/// PLEASE: do not use this, it is an implementation detail
/// subject to change.
#[inline]
#[doc(hidden)]
#[$stability_attr]
pub fn $feature() -> bool {
$crate::detect::check_for($crate::detect::Feature::$feature)
}
)*
}
};
}
|
