diff options
Diffstat (limited to 'vendor/syn/src/macros.rs')
-rw-r--r-- | vendor/syn/src/macros.rs | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/vendor/syn/src/macros.rs b/vendor/syn/src/macros.rs new file mode 100644 index 0000000..06ceb54 --- /dev/null +++ b/vendor/syn/src/macros.rs @@ -0,0 +1,185 @@ +#[cfg_attr( + not(any(feature = "full", feature = "derive")), + allow(unknown_lints, unused_macro_rules) +)] +macro_rules! ast_struct { + ( + [$($attrs_pub:tt)*] + struct $name:ident #full $($rest:tt)* + ) => { + #[cfg(feature = "full")] + $($attrs_pub)* struct $name $($rest)* + + #[cfg(not(feature = "full"))] + $($attrs_pub)* struct $name { + _noconstruct: ::std::marker::PhantomData<::proc_macro2::Span>, + } + + #[cfg(all(not(feature = "full"), feature = "printing"))] + impl ::quote::ToTokens for $name { + fn to_tokens(&self, _: &mut ::proc_macro2::TokenStream) { + unreachable!() + } + } + }; + + ( + [$($attrs_pub:tt)*] + struct $name:ident $($rest:tt)* + ) => { + $($attrs_pub)* struct $name $($rest)* + }; + + ($($t:tt)*) => { + strip_attrs_pub!(ast_struct!($($t)*)); + }; +} + +macro_rules! ast_enum { + // Drop the `#no_visit` attribute, if present. + ( + [$($attrs_pub:tt)*] + enum $name:ident #no_visit $($rest:tt)* + ) => ( + ast_enum!([$($attrs_pub)*] enum $name $($rest)*); + ); + + ( + [$($attrs_pub:tt)*] + enum $name:ident $($rest:tt)* + ) => ( + $($attrs_pub)* enum $name $($rest)* + ); + + ($($t:tt)*) => { + strip_attrs_pub!(ast_enum!($($t)*)); + }; +} + +macro_rules! ast_enum_of_structs { + ( + $(#[$enum_attr:meta])* + $pub:ident $enum:ident $name:ident $body:tt + $($remaining:tt)* + ) => { + ast_enum!($(#[$enum_attr])* $pub $enum $name $body); + ast_enum_of_structs_impl!($pub $enum $name $body $($remaining)*); + }; +} + +macro_rules! ast_enum_of_structs_impl { + ( + $pub:ident $enum:ident $name:ident { + $( + $(#[cfg $cfg_attr:tt])* + $(#[doc $($doc_attr:tt)*])* + $variant:ident $( ($($member:ident)::+) )*, + )* + } + ) => { + check_keyword_matches!(pub $pub); + check_keyword_matches!(enum $enum); + + $($( + ast_enum_from_struct!($name::$variant, $($member)::+); + )*)* + + #[cfg(feature = "printing")] + generate_to_tokens! { + () + tokens + $name { + $( + $(#[cfg $cfg_attr])* + $(#[doc $($doc_attr)*])* + $variant $($($member)::+)*, + )* + } + } + }; +} + +macro_rules! ast_enum_from_struct { + // No From<TokenStream> for verbatim variants. + ($name:ident::Verbatim, $member:ident) => {}; + + ($name:ident::$variant:ident, $member:ident) => { + impl From<$member> for $name { + fn from(e: $member) -> $name { + $name::$variant(e) + } + } + }; +} + +#[cfg(feature = "printing")] +macro_rules! generate_to_tokens { + ( + ($($arms:tt)*) $tokens:ident $name:ident { + $(#[cfg $cfg_attr:tt])* + $(#[doc $($doc_attr:tt)*])* + $variant:ident, + $($next:tt)* + } + ) => { + generate_to_tokens!( + ($($arms)* $(#[cfg $cfg_attr])* $name::$variant => {}) + $tokens $name { $($next)* } + ); + }; + + ( + ($($arms:tt)*) $tokens:ident $name:ident { + $(#[cfg $cfg_attr:tt])* + $(#[doc $($doc_attr:tt)*])* + $variant:ident $member:ident, + $($next:tt)* + } + ) => { + generate_to_tokens!( + ($($arms)* $(#[cfg $cfg_attr])* $name::$variant(_e) => _e.to_tokens($tokens),) + $tokens $name { $($next)* } + ); + }; + + (($($arms:tt)*) $tokens:ident $name:ident {}) => { + #[cfg_attr(doc_cfg, doc(cfg(feature = "printing")))] + impl ::quote::ToTokens for $name { + fn to_tokens(&self, $tokens: &mut ::proc_macro2::TokenStream) { + match self { + $($arms)* + } + } + } + }; +} + +macro_rules! strip_attrs_pub { + ($mac:ident!($(#[$m:meta])* $pub:ident $($t:tt)*)) => { + check_keyword_matches!(pub $pub); + + $mac!([$(#[$m])* $pub] $($t)*); + }; +} + +macro_rules! check_keyword_matches { + (enum enum) => {}; + (pub pub) => {}; +} + +// Rustdoc bug: does not respect the doc(hidden) on some items. +#[cfg(all(doc, feature = "parsing"))] +macro_rules! pub_if_not_doc { + ($(#[$m:meta])* pub $($item:tt)*) => { + $(#[$m])* + pub(crate) $($item)* + }; +} + +#[cfg(all(not(doc), feature = "parsing"))] +macro_rules! pub_if_not_doc { + ($(#[$m:meta])* pub $($item:tt)*) => { + $(#[$m])* + pub $($item)* + }; +} |