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Diffstat (limited to 'third_party/rust/nix/src/macros.rs')
| -rw-r--r-- | third_party/rust/nix/src/macros.rs | 328 |
1 files changed, 328 insertions, 0 deletions
diff --git a/third_party/rust/nix/src/macros.rs b/third_party/rust/nix/src/macros.rs new file mode 100644 index 0000000000..99e0de8866 --- /dev/null +++ b/third_party/rust/nix/src/macros.rs @@ -0,0 +1,328 @@ +// 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(any(target_os = "linux", target_os = "android"))] +/// PROT_GROWSDOWN; +/// #[cfg(any(target_os = "linux", target_os = "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! { + $(#[$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(any(target_os = "linux", target_os = "android"))] +/// PROT_GROWSDOWN, +/// #[cfg(any(target_os = "linux", target_os = "android"))] +/// PROT_GROWSUP, +/// } +/// } +/// ``` +// Some targets don't use all rules. +#[allow(unknown_lints)] +#[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)] + 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)* + } + }; +} |