| /// A macro for defining #[cfg] if-else statements. |
| /// |
| /// This is similar to the `if/elif` C preprocessor macro by allowing definition |
| /// of a cascade of `#[cfg]` cases, emitting the implementation which matches |
| /// first. |
| /// |
| /// This allows you to conveniently provide a long list #[cfg]'d blocks of code |
| /// without having to rewrite each clause multiple times. |
| #[allow(unused_macros)] |
| macro_rules! cfg_if { |
| // match if/else chains with a final `else` |
| ($( |
| if #[cfg($($meta:meta),*)] { $($it:item)* } |
| ) else * else { |
| $($it2:item)* |
| }) => { |
| cfg_if! { |
| @__items |
| () ; |
| $( ( ($($meta),*) ($($it)*) ), )* |
| ( () ($($it2)*) ), |
| } |
| }; |
| |
| // match if/else chains lacking a final `else` |
| ( |
| if #[cfg($($i_met:meta),*)] { $($i_it:item)* } |
| $( |
| else if #[cfg($($e_met:meta),*)] { $($e_it:item)* } |
| )* |
| ) => { |
| cfg_if! { |
| @__items |
| () ; |
| ( ($($i_met),*) ($($i_it)*) ), |
| $( ( ($($e_met),*) ($($e_it)*) ), )* |
| ( () () ), |
| } |
| }; |
| |
| // Internal and recursive macro to emit all the items |
| // |
| // Collects all the negated `cfg`s in a list at the beginning and after the |
| // semicolon is all the remaining items |
| (@__items ($($not:meta,)*) ; ) => {}; |
| (@__items ($($not:meta,)*) ; ( ($($m:meta),*) ($($it:item)*) ), |
| $($rest:tt)*) => { |
| // Emit all items within one block, applying an appropriate #[cfg]. The |
| // #[cfg] will require all `$m` matchers specified and must also negate |
| // all previous matchers. |
| cfg_if! { @__apply cfg(all($($m,)* not(any($($not),*)))), $($it)* } |
| |
| // Recurse to emit all other items in `$rest`, and when we do so add all |
| // our `$m` matchers to the list of `$not` matchers as future emissions |
| // will have to negate everything we just matched as well. |
| cfg_if! { @__items ($($not,)* $($m,)*) ; $($rest)* } |
| }; |
| |
| // Internal macro to Apply a cfg attribute to a list of items |
| (@__apply $m:meta, $($it:item)*) => { |
| $(#[$m] $it)* |
| }; |
| } |
| |
| #[allow(unused_macros)] |
| macro_rules! s { |
| ($($(#[$attr:meta])* pub $t:ident $i:ident { $($field:tt)* })*) => ($( |
| s!(it: $(#[$attr])* pub $t $i { $($field)* }); |
| )*); |
| (it: $(#[$attr:meta])* pub union $i:ident { $($field:tt)* }) => ( |
| compile_error!("unions cannot derive extra traits, use s_no_extra_traits instead"); |
| ); |
| (it: $(#[$attr:meta])* pub struct $i:ident { $($field:tt)* }) => ( |
| __item! { |
| #[repr(C)] |
| #[cfg_attr(feature = "extra_traits", derive(Debug, Eq, Hash, PartialEq))] |
| #[allow(deprecated)] |
| $(#[$attr])* |
| pub struct $i { $($field)* } |
| } |
| #[allow(deprecated)] |
| impl ::Copy for $i {} |
| #[allow(deprecated)] |
| impl ::Clone for $i { |
| fn clone(&self) -> $i { *self } |
| } |
| ); |
| } |
| |
| #[allow(unused_macros)] |
| macro_rules! s_no_extra_traits { |
| ($($(#[$attr:meta])* pub $t:ident $i:ident { $($field:tt)* })*) => ($( |
| s_no_extra_traits!(it: $(#[$attr])* pub $t $i { $($field)* }); |
| )*); |
| (it: $(#[$attr:meta])* pub union $i:ident { $($field:tt)* }) => ( |
| cfg_if! { |
| if #[cfg(libc_union)] { |
| __item! { |
| #[repr(C)] |
| $(#[$attr])* |
| pub union $i { $($field)* } |
| } |
| |
| impl ::Copy for $i {} |
| impl ::Clone for $i { |
| fn clone(&self) -> $i { *self } |
| } |
| } |
| } |
| ); |
| (it: $(#[$attr:meta])* pub struct $i:ident { $($field:tt)* }) => ( |
| __item! { |
| #[repr(C)] |
| $(#[$attr])* |
| pub struct $i { $($field)* } |
| } |
| #[allow(deprecated)] |
| impl ::Copy for $i {} |
| #[allow(deprecated)] |
| impl ::Clone for $i { |
| fn clone(&self) -> $i { *self } |
| } |
| ); |
| } |
| |
| #[allow(unused_macros)] |
| macro_rules! e { |
| ($($(#[$attr:meta])* pub enum $i:ident { $($field:tt)* })*) => ($( |
| __item! { |
| #[cfg_attr(feature = "extra_traits", derive(Debug, Eq, Hash, PartialEq))] |
| $(#[$attr])* |
| pub enum $i { $($field)* } |
| } |
| impl ::Copy for $i {} |
| impl ::Clone for $i { |
| fn clone(&self) -> $i { *self } |
| } |
| )*); |
| } |
| |
| #[allow(unused_macros)] |
| macro_rules! s_paren { |
| ($($(#[$attr:meta])* pub struct $i:ident ( $($field:tt)* ); )* ) => ($( |
| __item! { |
| #[cfg_attr(feature = "extra_traits", derive(Debug, Eq, Hash, PartialEq))] |
| $(#[$attr])* |
| pub struct $i ( $($field)* ); |
| } |
| impl ::Copy for $i {} |
| impl ::Clone for $i { |
| fn clone(&self) -> $i { *self } |
| } |
| )*); |
| } |
| |
| // This is a pretty horrible hack to allow us to conditionally mark |
| // some functions as 'const', without requiring users of this macro |
| // to care about the "const-extern-fn" feature. |
| // |
| // When 'const-extern-fn' is enabled, we emit the captured 'const' keyword |
| // in the expanded function. |
| // |
| // When 'const-extern-fn' is disabled, we always emit a plain 'pub unsafe extern fn'. |
| // Note that the expression matched by the macro is exactly the same - this allows |
| // users of this macro to work whether or not 'const-extern-fn' is enabled |
| // |
| // Unfortunately, we need to duplicate most of this macro between the 'cfg_if' blocks. |
| // This is because 'const unsafe extern fn' won't even parse on older compilers, |
| // so we need to avoid emitting it at all of 'const-extern-fn'. |
| // |
| // Specifically, moving the 'cfg_if' into the macro body will *not* work. |
| // Doing so would cause the '#[cfg(feature = "const-extern-fn")]' to be emitted |
| // into user code. The 'cfg' gate will not stop Rust from trying to parse the |
| // 'pub const unsafe extern fn', so users would get a compiler error even when |
| // the 'const-extern-fn' feature is disabled |
| // |
| // Note that users of this macro need to place 'const' in a weird position |
| // (after the closing ')' for the arguments, but before the return type). |
| // This was the only way I could satisfy the following two requirements: |
| // 1. Avoid ambiguity errors from 'macro_rules!' (which happen when writing '$foo:ident fn' |
| // 2. Allow users of this macro to mix 'pub fn foo' and 'pub const fn bar' within the same |
| // 'f!' block |
| cfg_if! { |
| if #[cfg(libc_const_extern_fn)] { |
| #[allow(unused_macros)] |
| macro_rules! f { |
| ($($(#[$attr:meta])* pub $({$constness:ident})* fn $i:ident( |
| $($arg:ident: $argty:ty),* |
| ) -> $ret:ty { |
| $($body:stmt);* |
| })*) => ($( |
| #[inline] |
| $(#[$attr])* |
| pub $($constness)* unsafe extern fn $i($($arg: $argty),* |
| ) -> $ret { |
| $($body);* |
| } |
| )*) |
| } |
| |
| #[allow(unused_macros)] |
| macro_rules! safe_f { |
| ($($(#[$attr:meta])* pub $({$constness:ident})* fn $i:ident( |
| $($arg:ident: $argty:ty),* |
| ) -> $ret:ty { |
| $($body:stmt);* |
| })*) => ($( |
| #[inline] |
| $(#[$attr])* |
| pub $($constness)* extern fn $i($($arg: $argty),* |
| ) -> $ret { |
| $($body);* |
| } |
| )*) |
| } |
| |
| #[allow(unused_macros)] |
| macro_rules! const_fn { |
| ($($(#[$attr:meta])* $({$constness:ident})* fn $i:ident( |
| $($arg:ident: $argty:ty),* |
| ) -> $ret:ty { |
| $($body:stmt);* |
| })*) => ($( |
| #[inline] |
| $(#[$attr])* |
| $($constness)* fn $i($($arg: $argty),* |
| ) -> $ret { |
| $($body);* |
| } |
| )*) |
| } |
| |
| } else { |
| #[allow(unused_macros)] |
| macro_rules! f { |
| ($($(#[$attr:meta])* pub $({$constness:ident})* fn $i:ident( |
| $($arg:ident: $argty:ty),* |
| ) -> $ret:ty { |
| $($body:stmt);* |
| })*) => ($( |
| #[inline] |
| $(#[$attr])* |
| pub unsafe extern fn $i($($arg: $argty),* |
| ) -> $ret { |
| $($body);* |
| } |
| )*) |
| } |
| |
| #[allow(unused_macros)] |
| macro_rules! safe_f { |
| ($($(#[$attr:meta])* pub $({$constness:ident})* fn $i:ident( |
| $($arg:ident: $argty:ty),* |
| ) -> $ret:ty { |
| $($body:stmt);* |
| })*) => ($( |
| #[inline] |
| $(#[$attr])* |
| pub extern fn $i($($arg: $argty),* |
| ) -> $ret { |
| $($body);* |
| } |
| )*) |
| } |
| |
| #[allow(unused_macros)] |
| macro_rules! const_fn { |
| ($($(#[$attr:meta])* $({$constness:ident})* fn $i:ident( |
| $($arg:ident: $argty:ty),* |
| ) -> $ret:ty { |
| $($body:stmt);* |
| })*) => ($( |
| #[inline] |
| $(#[$attr])* |
| fn $i($($arg: $argty),* |
| ) -> $ret { |
| $($body);* |
| } |
| )*) |
| } |
| } |
| } |
| |
| #[allow(unused_macros)] |
| macro_rules! __item { |
| ($i:item) => { |
| $i |
| }; |
| } |
| |
| #[allow(unused_macros)] |
| macro_rules! align_const { |
| ($($(#[$attr:meta])* |
| pub const $name:ident : $t1:ty |
| = $t2:ident { $($field:tt)* };)*) => ($( |
| #[cfg(libc_align)] |
| $(#[$attr])* |
| pub const $name : $t1 = $t2 { |
| $($field)* |
| }; |
| #[cfg(not(libc_align))] |
| $(#[$attr])* |
| pub const $name : $t1 = $t2 { |
| $($field)* |
| __align: [], |
| }; |
| )*) |
| } |
| |
| // This macro is used to deprecate items that should be accessed via the mach crate |
| #[allow(unused_macros)] |
| macro_rules! deprecated_mach { |
| (pub const $id:ident: $ty:ty = $expr:expr;) => { |
| #[deprecated( |
| since = "0.2.55", |
| note = "Use the `mach` crate instead", |
| )] |
| #[allow(deprecated)] |
| pub const $id: $ty = $expr; |
| }; |
| ($(pub const $id:ident: $ty:ty = $expr:expr;)*) => { |
| $( |
| deprecated_mach!( |
| pub const $id: $ty = $expr; |
| ); |
| )* |
| }; |
| (pub type $id:ident = $ty:ty;) => { |
| #[deprecated( |
| since = "0.2.55", |
| note = "Use the `mach` crate instead", |
| )] |
| #[allow(deprecated)] |
| pub type $id = $ty; |
| }; |
| ($(pub type $id:ident = $ty:ty;)*) => { |
| $( |
| deprecated_mach!( |
| pub type $id = $ty; |
| ); |
| )* |
| } |
| } |
