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-rw-r--r--third_party/rust/syn/src/macros.rs177
1 files changed, 177 insertions, 0 deletions
diff --git a/third_party/rust/syn/src/macros.rs b/third_party/rust/syn/src/macros.rs
new file mode 100644
index 0000000000..da10a1a550
--- /dev/null
+++ b/third_party/rust/syn/src/macros.rs
@@ -0,0 +1,177 @@
+#[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)::+) )*,
+ )*
+ }
+
+ $($remaining:tt)*
+ ) => {
+ check_keyword_matches!(pub $pub);
+ check_keyword_matches!(enum $enum);
+
+ $($(
+ ast_enum_from_struct!($name::$variant, $($member)::+);
+ )*)*
+
+ #[cfg(feature = "printing")]
+ generate_to_tokens! {
+ $($remaining)*
+ ()
+ 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")]
+#[cfg_attr(
+ not(any(feature = "full", feature = "derive")),
+ allow(unknown_lints, unused_macro_rules)
+)]
+macro_rules! generate_to_tokens {
+ (do_not_generate_to_tokens $($foo:tt)*) => ();
+
+ (
+ ($($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) => {};
+}