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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
commit26a029d407be480d791972afb5975cf62c9360a6 (patch)
treef435a8308119effd964b339f76abb83a57c29483 /third_party/rust/libc/src/macros.rs
parentInitial commit. (diff)
downloadfirefox-26a029d407be480d791972afb5975cf62c9360a6.tar.xz
firefox-26a029d407be480d791972afb5975cf62c9360a6.zip
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/rust/libc/src/macros.rs')
-rw-r--r--third_party/rust/libc/src/macros.rs349
1 files changed, 349 insertions, 0 deletions
diff --git a/third_party/rust/libc/src/macros.rs b/third_party/rust/libc/src/macros.rs
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+/// 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)
+ };
+}