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Diffstat (limited to 'vendor/libc/src/macros.rs')
| -rw-r--r-- | vendor/libc/src/macros.rs | 349 |
1 files changed, 349 insertions, 0 deletions
diff --git a/vendor/libc/src/macros.rs b/vendor/libc/src/macros.rs new file mode 100644 index 0000000..beb8002 --- /dev/null +++ b/vendor/libc/src/macros.rs @@ -0,0 +1,349 @@ +/// 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. +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] $it)* + }; +} + +macro_rules! s { + ($($(#[$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) -> $i { *self } + } + ); +} + +macro_rules! s_no_extra_traits { + ($($(#[$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) -> $i { *self } + } + ); +} + +macro_rules! missing { + ($($(#[$attr:meta])* pub enum $i:ident {})*) => ($( + $(#[$attr])* #[allow(missing_copy_implementations)] pub enum $i { } + )*); +} + +macro_rules! e { + ($($(#[$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) -> $i { *self } + } + )*); +} + +macro_rules! s_paren { + ($($(#[$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)] { + 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);* + } + )*) + } + + 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);* + } + )*) + } + + 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 { + 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);* + } + )*) + } + + 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);* + } + )*) + } + + 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);* + } + )*) + } + } +} + +macro_rules! __item { + ($i:item) => { + $i + }; +} + +macro_rules! align_const { + ($($(#[$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 mach2 crate +macro_rules! deprecated_mach { + (pub const $id:ident: $ty:ty = $expr:expr;) => { + #[deprecated( + since = "0.2.55", + note = "Use the `mach2` 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 `mach2` crate instead", + )] + #[allow(deprecated)] + pub type $id = $ty; + }; + ($(pub type $id:ident = $ty:ty;)*) => { + $( + deprecated_mach!( + pub type $id = $ty; + ); + )* + } +} + +#[cfg(not(libc_ptr_addr_of))] +macro_rules! ptr_addr_of { + ($place:expr) => { + &$place + }; +} + +#[cfg(libc_ptr_addr_of)] +macro_rules! ptr_addr_of { + ($place:expr) => { + ::core::ptr::addr_of!($place) + }; +} |