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// Thanks to Tokio for this macro
macro_rules! feature {
(
#![$meta:meta]
$($item:item)*
) => {
$(
#[cfg($meta)]
#[cfg_attr(docsrs, doc(cfg($meta)))]
$item
)*
}
}
/// The `libc_bitflags!` macro helps with a common use case of defining a public bitflags type
/// with values from the libc crate. It is used the same way as the `bitflags!` macro, except
/// that only the name of the flag value has to be given.
///
/// The `libc` crate must be in scope with the name `libc`.
///
/// # Example
/// ```ignore
/// libc_bitflags!{
/// pub struct ProtFlags: libc::c_int {
/// PROT_NONE;
/// PROT_READ;
/// /// PROT_WRITE enables write protect
/// PROT_WRITE;
/// PROT_EXEC;
/// #[cfg(linux_android)]
/// PROT_GROWSDOWN;
/// #[cfg(linux_android)]
/// PROT_GROWSUP;
/// }
/// }
/// ```
///
/// Example with casting, due to a mistake in libc. In this example, the
/// various flags have different types, so we cast the broken ones to the right
/// type.
///
/// ```ignore
/// libc_bitflags!{
/// pub struct SaFlags: libc::c_ulong {
/// SA_NOCLDSTOP as libc::c_ulong;
/// SA_NOCLDWAIT;
/// SA_NODEFER as libc::c_ulong;
/// SA_ONSTACK;
/// SA_RESETHAND as libc::c_ulong;
/// SA_RESTART as libc::c_ulong;
/// SA_SIGINFO;
/// }
/// }
/// ```
macro_rules! libc_bitflags {
(
$(#[$outer:meta])*
pub struct $BitFlags:ident: $T:ty {
$(
$(#[$inner:ident $($args:tt)*])*
$Flag:ident $(as $cast:ty)*;
)+
}
) => {
::bitflags::bitflags! {
#[derive(Copy, Clone, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
#[repr(transparent)]
$(#[$outer])*
pub struct $BitFlags: $T {
$(
$(#[$inner $($args)*])*
const $Flag = libc::$Flag $(as $cast)*;
)+
}
}
};
}
/// The `libc_enum!` macro helps with a common use case of defining an enum exclusively using
/// values from the `libc` crate. This macro supports both `pub` and private `enum`s.
///
/// The `libc` crate must be in scope with the name `libc`.
///
/// # Example
/// ```ignore
/// libc_enum!{
/// pub enum ProtFlags {
/// PROT_NONE,
/// PROT_READ,
/// PROT_WRITE,
/// PROT_EXEC,
/// #[cfg(linux_android)]
/// PROT_GROWSDOWN,
/// #[cfg(linux_android)]
/// PROT_GROWSUP,
/// }
/// }
/// ```
// Some targets don't use all rules.
#[allow(unused_macro_rules)]
macro_rules! libc_enum {
// Exit rule.
(@make_enum
name: $BitFlags:ident,
{
$v:vis
attrs: [$($attrs:tt)*],
entries: [$($entries:tt)*],
}
) => {
$($attrs)*
#[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
$v enum $BitFlags {
$($entries)*
}
};
// Exit rule including TryFrom
(@make_enum
name: $BitFlags:ident,
{
$v:vis
attrs: [$($attrs:tt)*],
entries: [$($entries:tt)*],
from_type: $repr:path,
try_froms: [$($try_froms:tt)*]
}
) => {
$($attrs)*
#[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
$v enum $BitFlags {
$($entries)*
}
impl ::std::convert::TryFrom<$repr> for $BitFlags {
type Error = $crate::Error;
#[allow(unused_doc_comments)]
#[allow(deprecated)]
#[allow(unused_attributes)]
fn try_from(x: $repr) -> $crate::Result<Self> {
match x {
$($try_froms)*
_ => Err($crate::Error::EINVAL)
}
}
}
};
// Done accumulating.
(@accumulate_entries
name: $BitFlags:ident,
{
$v:vis
attrs: $attrs:tt,
},
$entries:tt,
$try_froms:tt;
) => {
libc_enum! {
@make_enum
name: $BitFlags,
{
$v
attrs: $attrs,
entries: $entries,
}
}
};
// Done accumulating and want TryFrom
(@accumulate_entries
name: $BitFlags:ident,
{
$v:vis
attrs: $attrs:tt,
from_type: $repr:path,
},
$entries:tt,
$try_froms:tt;
) => {
libc_enum! {
@make_enum
name: $BitFlags,
{
$v
attrs: $attrs,
entries: $entries,
from_type: $repr,
try_froms: $try_froms
}
}
};
// Munch an attr.
(@accumulate_entries
name: $BitFlags:ident,
$prefix:tt,
[$($entries:tt)*],
[$($try_froms:tt)*];
#[$attr:meta] $($tail:tt)*
) => {
libc_enum! {
@accumulate_entries
name: $BitFlags,
$prefix,
[
$($entries)*
#[$attr]
],
[
$($try_froms)*
#[$attr]
];
$($tail)*
}
};
// Munch last ident if not followed by a comma.
(@accumulate_entries
name: $BitFlags:ident,
$prefix:tt,
[$($entries:tt)*],
[$($try_froms:tt)*];
$entry:ident
) => {
libc_enum! {
@accumulate_entries
name: $BitFlags,
$prefix,
[
$($entries)*
$entry = libc::$entry,
],
[
$($try_froms)*
libc::$entry => Ok($BitFlags::$entry),
];
}
};
// Munch an ident; covers terminating comma case.
(@accumulate_entries
name: $BitFlags:ident,
$prefix:tt,
[$($entries:tt)*],
[$($try_froms:tt)*];
$entry:ident,
$($tail:tt)*
) => {
libc_enum! {
@accumulate_entries
name: $BitFlags,
$prefix,
[
$($entries)*
$entry = libc::$entry,
],
[
$($try_froms)*
libc::$entry => Ok($BitFlags::$entry),
];
$($tail)*
}
};
// Munch an ident and cast it to the given type; covers terminating comma.
(@accumulate_entries
name: $BitFlags:ident,
$prefix:tt,
[$($entries:tt)*],
[$($try_froms:tt)*];
$entry:ident as $ty:ty,
$($tail:tt)*
) => {
libc_enum! {
@accumulate_entries
name: $BitFlags,
$prefix,
[
$($entries)*
$entry = libc::$entry as $ty,
],
[
$($try_froms)*
libc::$entry as $ty => Ok($BitFlags::$entry),
];
$($tail)*
}
};
// Entry rule.
(
$(#[$attr:meta])*
$v:vis enum $BitFlags:ident {
$($vals:tt)*
}
) => {
libc_enum! {
@accumulate_entries
name: $BitFlags,
{
$v
attrs: [$(#[$attr])*],
},
[],
[];
$($vals)*
}
};
// Entry rule including TryFrom
(
$(#[$attr:meta])*
$v:vis enum $BitFlags:ident {
$($vals:tt)*
}
impl TryFrom<$repr:path>
) => {
libc_enum! {
@accumulate_entries
name: $BitFlags,
{
$v
attrs: [$(#[$attr])*],
from_type: $repr,
},
[],
[];
$($vals)*
}
};
}