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-rw-r--r--third_party/rust/enumset_derive/src/lib.rs949
1 files changed, 949 insertions, 0 deletions
diff --git a/third_party/rust/enumset_derive/src/lib.rs b/third_party/rust/enumset_derive/src/lib.rs
new file mode 100644
index 0000000000..7508d7546d
--- /dev/null
+++ b/third_party/rust/enumset_derive/src/lib.rs
@@ -0,0 +1,949 @@
+#![recursion_limit = "256"]
+
+extern crate proc_macro;
+
+use darling::util::SpannedValue;
+use darling::*;
+use proc_macro::TokenStream;
+use proc_macro2::{Literal, Span, TokenStream as SynTokenStream};
+use quote::*;
+use std::{collections::HashSet, fmt::Display};
+use syn::spanned::Spanned;
+use syn::{Error, Result, *};
+
+/// Helper function for emitting compile errors.
+fn error<T>(span: Span, message: impl Display) -> Result<T> {
+ Err(Error::new(span, message))
+}
+
+/// Decodes the custom attributes for our custom derive.
+#[derive(FromDeriveInput, Default)]
+#[darling(attributes(enumset), default)]
+struct EnumsetAttrs {
+ no_ops: bool,
+ no_super_impls: bool,
+ #[darling(default)]
+ repr: SpannedValue<Option<String>>,
+ #[darling(default)]
+ serialize_repr: SpannedValue<Option<String>>,
+ serialize_deny_unknown: bool,
+ #[darling(default)]
+ crate_name: Option<String>,
+
+ // legacy options
+ serialize_as_list: SpannedValue<bool>, // replaced with serialize_repr
+ serialize_as_map: SpannedValue<bool>, // replaced with serialize_repr
+}
+
+/// The internal representation of an enumset.
+#[derive(Copy, Clone)]
+enum InternalRepr {
+ /// internal repr: `u8`
+ U8,
+ /// internal repr: `u16`
+ U16,
+ /// internal repr: `u32`
+ U32,
+ /// internal repr: `u64`
+ U64,
+ /// internal repr: `u128`
+ U128,
+ /// internal repr: `[u64; size]`
+ Array(usize),
+}
+impl InternalRepr {
+ /// Determines the number of variants supported by this repr.
+ fn supported_variants(&self) -> usize {
+ match self {
+ InternalRepr::U8 => 8,
+ InternalRepr::U16 => 16,
+ InternalRepr::U32 => 32,
+ InternalRepr::U64 => 64,
+ InternalRepr::U128 => 128,
+ InternalRepr::Array(size) => size * 64,
+ }
+ }
+}
+
+/// The serde representation of the enumset.
+#[derive(Copy, Clone)]
+enum SerdeRepr {
+ /// serde type: `u8`
+ U8,
+ /// serde type: `u16`
+ U16,
+ /// serde type: `u32`
+ U32,
+ /// serde type: `u64`
+ U64,
+ /// serde type: `u128`
+ U128,
+ /// serde type: list of `T`
+ List,
+ /// serde type: map of `T` to `bool`
+ Map,
+ /// serde type: list of `u64`
+ Array,
+}
+impl SerdeRepr {
+ /// Determines the number of variants supported by this repr.
+ fn supported_variants(&self) -> Option<usize> {
+ match self {
+ SerdeRepr::U8 => Some(8),
+ SerdeRepr::U16 => Some(16),
+ SerdeRepr::U32 => Some(32),
+ SerdeRepr::U64 => Some(64),
+ SerdeRepr::U128 => Some(128),
+ SerdeRepr::List => None,
+ SerdeRepr::Map => None,
+ SerdeRepr::Array => None,
+ }
+ }
+}
+
+/// An variant in the enum set type.
+struct EnumSetValue {
+ /// The name of the variant.
+ name: Ident,
+ /// The discriminant of the variant.
+ variant_repr: u32,
+}
+
+/// Stores information about the enum set type.
+#[allow(dead_code)]
+struct EnumSetInfo {
+ /// The name of the enum.
+ name: Ident,
+ /// The crate name to use.
+ crate_name: Option<Ident>,
+ /// The numeric type to represent the `EnumSet` as in memory.
+ explicit_internal_repr: Option<InternalRepr>,
+ /// Forces the internal numeric type of the `EnumSet` to be an array.
+ internal_repr_force_array: bool,
+ /// The numeric type to serialize the enum as.
+ explicit_serde_repr: Option<SerdeRepr>,
+ /// A list of variants in the enum.
+ variants: Vec<EnumSetValue>,
+
+ /// The highest encountered variant discriminant.
+ max_discrim: u32,
+ /// The span of the highest encountered variant.
+ max_discrim_span: Option<Span>,
+ /// The current variant discriminant. Used to track, e.g. `A=10,B,C`.
+ cur_discrim: u32,
+ /// A list of variant names that are already in use.
+ used_variant_names: HashSet<String>,
+ /// A list of variant discriminants that are already in use.
+ used_discriminants: HashSet<u32>,
+
+ /// Avoid generating operator overloads on the enum type.
+ no_ops: bool,
+ /// Avoid generating implementations for `Clone`, `Copy`, `Eq`, and `PartialEq`.
+ no_super_impls: bool,
+ /// Disallow unknown bits while deserializing the enum.
+ serialize_deny_unknown: bool,
+}
+impl EnumSetInfo {
+ fn new(input: &DeriveInput, attrs: &EnumsetAttrs) -> EnumSetInfo {
+ EnumSetInfo {
+ name: input.ident.clone(),
+ crate_name: attrs
+ .crate_name
+ .as_ref()
+ .map(|x| Ident::new(x, Span::call_site())),
+ explicit_internal_repr: None,
+ internal_repr_force_array: false,
+ explicit_serde_repr: None,
+ variants: Vec::new(),
+ max_discrim: 0,
+ max_discrim_span: None,
+ cur_discrim: 0,
+ used_variant_names: HashSet::new(),
+ used_discriminants: HashSet::new(),
+ no_ops: attrs.no_ops,
+ no_super_impls: attrs.no_super_impls,
+ serialize_deny_unknown: attrs.serialize_deny_unknown,
+ }
+ }
+
+ /// Explicits sets the serde representation of the enumset from a string.
+ fn push_serialize_repr(&mut self, span: Span, ty: &str) -> Result<()> {
+ match ty {
+ "u8" => self.explicit_serde_repr = Some(SerdeRepr::U8),
+ "u16" => self.explicit_serde_repr = Some(SerdeRepr::U16),
+ "u32" => self.explicit_serde_repr = Some(SerdeRepr::U32),
+ "u64" => self.explicit_serde_repr = Some(SerdeRepr::U64),
+ "u128" => self.explicit_serde_repr = Some(SerdeRepr::U128),
+ "list" => self.explicit_serde_repr = Some(SerdeRepr::List),
+ "map" => self.explicit_serde_repr = Some(SerdeRepr::Map),
+ "array" => self.explicit_serde_repr = Some(SerdeRepr::Array),
+ _ => error(span, format!("`{}` is not a valid serialized representation.", ty))?,
+ }
+ Ok(())
+ }
+
+ /// Explicitly sets the representation of the enumset from a string.
+ fn push_repr(&mut self, span: Span, ty: &str) -> Result<()> {
+ match ty {
+ "u8" => self.explicit_internal_repr = Some(InternalRepr::U8),
+ "u16" => self.explicit_internal_repr = Some(InternalRepr::U16),
+ "u32" => self.explicit_internal_repr = Some(InternalRepr::U32),
+ "u64" => self.explicit_internal_repr = Some(InternalRepr::U64),
+ "u128" => self.explicit_internal_repr = Some(InternalRepr::U128),
+ "array" => self.internal_repr_force_array = true,
+ _ => error(span, format!("`{}` is not a valid internal enumset representation.", ty))?,
+ }
+ Ok(())
+ }
+
+ /// Adds a variant to the enumset.
+ fn push_variant(&mut self, variant: &Variant) -> Result<()> {
+ if self.used_variant_names.contains(&variant.ident.to_string()) {
+ error(variant.span(), "Duplicated variant name.")
+ } else if let Fields::Unit = variant.fields {
+ // Parse the discriminant.
+ if let Some((_, expr)) = &variant.discriminant {
+ if let Expr::Lit(ExprLit { lit: Lit::Int(i), .. }) = expr {
+ match i.base10_parse() {
+ Ok(val) => self.cur_discrim = val,
+ Err(_) => error(expr.span(), "Enum discriminants must fit into `u32`.")?,
+ }
+ } else if let Expr::Unary(ExprUnary { op: UnOp::Neg(_), .. }) = expr {
+ error(expr.span(), "Enum discriminants must not be negative.")?;
+ } else {
+ error(variant.span(), "Enum discriminants must be literal expressions.")?;
+ }
+ }
+
+ // Validate the discriminant.
+ let discriminant = self.cur_discrim;
+ if discriminant >= 0xFFFFFFC0 {
+ error(variant.span(), "Maximum discriminant allowed is `0xFFFFFFBF`.")?;
+ }
+ if self.used_discriminants.contains(&discriminant) {
+ error(variant.span(), "Duplicated enum discriminant.")?;
+ }
+
+ // Add the variant to the info.
+ self.cur_discrim += 1;
+ if discriminant > self.max_discrim {
+ self.max_discrim = discriminant;
+ self.max_discrim_span = Some(variant.span());
+ }
+ self.variants
+ .push(EnumSetValue { name: variant.ident.clone(), variant_repr: discriminant });
+ self.used_variant_names.insert(variant.ident.to_string());
+ self.used_discriminants.insert(discriminant);
+
+ Ok(())
+ } else {
+ error(variant.span(), "`#[derive(EnumSetType)]` can only be used on fieldless enums.")
+ }
+ }
+
+ /// Returns the actual internal representation of the set.
+ fn internal_repr(&self) -> InternalRepr {
+ match self.explicit_internal_repr {
+ Some(x) => x,
+ None => match self.max_discrim {
+ x if x < 8 && !self.internal_repr_force_array => InternalRepr::U8,
+ x if x < 16 && !self.internal_repr_force_array => InternalRepr::U16,
+ x if x < 32 && !self.internal_repr_force_array => InternalRepr::U32,
+ x if x < 64 && !self.internal_repr_force_array => InternalRepr::U64,
+ x => InternalRepr::Array((x as usize + 64) / 64),
+ },
+ }
+ }
+
+ /// Returns the actual serde representation of the set.
+ fn serde_repr(&self) -> SerdeRepr {
+ match self.explicit_serde_repr {
+ Some(x) => x,
+ None => match self.max_discrim {
+ x if x < 8 => SerdeRepr::U8,
+ x if x < 16 => SerdeRepr::U16,
+ x if x < 32 => SerdeRepr::U32,
+ x if x < 64 => SerdeRepr::U64,
+ x if x < 128 => SerdeRepr::U128,
+ _ => SerdeRepr::Array,
+ },
+ }
+ }
+
+ /// Validate the enumset type.
+ fn validate(&self) -> Result<()> {
+ // Gets the span of the maximum value.
+ let largest_discriminant_span = match &self.max_discrim_span {
+ Some(x) => *x,
+ None => Span::call_site(),
+ };
+
+ // Check if all bits of the bitset can fit in the memory representation, if one was given.
+ if self.internal_repr().supported_variants() <= self.max_discrim as usize {
+ error(
+ largest_discriminant_span,
+ "`repr` is too small to contain the largest discriminant.",
+ )?;
+ }
+
+ // Check if all bits of the bitset can fit in the serialization representation.
+ if let Some(supported_variants) = self.serde_repr().supported_variants() {
+ if supported_variants <= self.max_discrim as usize {
+ error(
+ largest_discriminant_span,
+ "`serialize_repr` is too small to contain the largest discriminant.",
+ )?;
+ }
+ }
+
+ Ok(())
+ }
+
+ /// Returns a bitmask of all variants in the set.
+ fn variant_map(&self) -> Vec<u64> {
+ let mut vec = vec![0];
+ for variant in &self.variants {
+ let (idx, bit) = (variant.variant_repr as usize / 64, variant.variant_repr % 64);
+ while idx >= vec.len() {
+ vec.push(0);
+ }
+ vec[idx] |= 1u64 << bit;
+ }
+ vec
+ }
+}
+
+/// Generates the actual `EnumSetType` impl.
+fn enum_set_type_impl(info: EnumSetInfo, warnings: Vec<(Span, &'static str)>) -> SynTokenStream {
+ let name = &info.name;
+
+ let enumset = match &info.crate_name {
+ Some(crate_name) => quote!(::#crate_name),
+ None => {
+ #[cfg(feature = "proc-macro-crate")]
+ {
+ use proc_macro_crate::FoundCrate;
+
+ let crate_name = proc_macro_crate::crate_name("enumset");
+ match crate_name {
+ Ok(FoundCrate::Name(name)) => {
+ let ident = Ident::new(&name, Span::call_site());
+ quote!(::#ident)
+ }
+ _ => quote!(::enumset),
+ }
+ }
+
+ #[cfg(not(feature = "proc-macro-crate"))]
+ {
+ quote!(::enumset)
+ }
+ }
+ };
+ let typed_enumset = quote!(#enumset::EnumSet<#name>);
+ let core = quote!(#enumset::__internal::core_export);
+ let internal = quote!(#enumset::__internal);
+ #[cfg(feature = "serde")]
+ let serde = quote!(#enumset::__internal::serde);
+
+ let repr = match info.internal_repr() {
+ InternalRepr::U8 => quote! { u8 },
+ InternalRepr::U16 => quote! { u16 },
+ InternalRepr::U32 => quote! { u32 },
+ InternalRepr::U64 => quote! { u64 },
+ InternalRepr::U128 => quote! { u128 },
+ InternalRepr::Array(size) => quote! { #internal::ArrayRepr<{ #size }> },
+ };
+ let variant_map = info.variant_map();
+ let all_variants = match info.internal_repr() {
+ InternalRepr::U8 | InternalRepr::U16 | InternalRepr::U32 | InternalRepr::U64 => {
+ let lit = Literal::u64_unsuffixed(variant_map[0]);
+ quote! { #lit }
+ }
+ InternalRepr::U128 => {
+ let lit = Literal::u128_unsuffixed(
+ variant_map[0] as u128 | variant_map.get(1).map_or(0, |x| (*x as u128) << 64),
+ );
+ quote! { #lit }
+ }
+ InternalRepr::Array(size) => {
+ let mut new = Vec::new();
+ for i in 0..size {
+ new.push(Literal::u64_unsuffixed(*variant_map.get(i).unwrap_or(&0)));
+ }
+ quote! { #internal::ArrayRepr::<{ #size }>([#(#new,)*]) }
+ }
+ };
+
+ let ops = if info.no_ops {
+ quote! {}
+ } else {
+ quote! {
+ #[automatically_derived]
+ impl<O: Into<#typed_enumset>> #core::ops::Sub<O> for #name {
+ type Output = #typed_enumset;
+ fn sub(self, other: O) -> Self::Output {
+ #enumset::EnumSet::only(self) - other.into()
+ }
+ }
+ #[automatically_derived]
+ impl<O: Into<#typed_enumset>> #core::ops::BitAnd<O> for #name {
+ type Output = #typed_enumset;
+ fn bitand(self, other: O) -> Self::Output {
+ #enumset::EnumSet::only(self) & other.into()
+ }
+ }
+ #[automatically_derived]
+ impl<O: Into<#typed_enumset>> #core::ops::BitOr<O> for #name {
+ type Output = #typed_enumset;
+ fn bitor(self, other: O) -> Self::Output {
+ #enumset::EnumSet::only(self) | other.into()
+ }
+ }
+ #[automatically_derived]
+ impl<O: Into<#typed_enumset>> #core::ops::BitXor<O> for #name {
+ type Output = #typed_enumset;
+ fn bitxor(self, other: O) -> Self::Output {
+ #enumset::EnumSet::only(self) ^ other.into()
+ }
+ }
+ #[automatically_derived]
+ impl #core::ops::Not for #name {
+ type Output = #typed_enumset;
+ fn not(self) -> Self::Output {
+ !#enumset::EnumSet::only(self)
+ }
+ }
+ #[automatically_derived]
+ impl #core::cmp::PartialEq<#typed_enumset> for #name {
+ fn eq(&self, other: &#typed_enumset) -> bool {
+ #enumset::EnumSet::only(*self) == *other
+ }
+ }
+ }
+ };
+
+ #[cfg(feature = "serde")]
+ let serde_repr = info.serde_repr();
+
+ #[cfg(feature = "serde")]
+ let serde_ops = match serde_repr {
+ SerdeRepr::U8 | SerdeRepr::U16 | SerdeRepr::U32 | SerdeRepr::U64 | SerdeRepr::U128 => {
+ let (serialize_repr, from_fn, to_fn) = match serde_repr {
+ SerdeRepr::U8 => (quote! { u8 }, quote! { from_u8 }, quote! { to_u8 }),
+ SerdeRepr::U16 => (quote! { u16 }, quote! { from_u16 }, quote! { to_u16 }),
+ SerdeRepr::U32 => (quote! { u32 }, quote! { from_u32 }, quote! { to_u32 }),
+ SerdeRepr::U64 => (quote! { u64 }, quote! { from_u64 }, quote! { to_u64 }),
+ SerdeRepr::U128 => (quote! { u128 }, quote! { from_u128 }, quote! { to_u128 }),
+ _ => unreachable!(),
+ };
+ let check_unknown = if info.serialize_deny_unknown {
+ quote! {
+ if value & !#all_variants != 0 {
+ use #serde::de::Error;
+ return #core::prelude::v1::Err(
+ D::Error::custom("enumset contains unknown bits")
+ )
+ }
+ }
+ } else {
+ quote! {}
+ };
+ quote! {
+ fn serialize<S: #serde::Serializer>(
+ set: #enumset::EnumSet<#name>, ser: S,
+ ) -> #core::result::Result<S::Ok, S::Error> {
+ let value =
+ <#repr as #enumset::__internal::EnumSetTypeRepr>::#to_fn(&set.__priv_repr);
+ #serde::Serialize::serialize(&value, ser)
+ }
+ fn deserialize<'de, D: #serde::Deserializer<'de>>(
+ de: D,
+ ) -> #core::result::Result<#enumset::EnumSet<#name>, D::Error> {
+ let value = <#serialize_repr as #serde::Deserialize>::deserialize(de)?;
+ #check_unknown
+ let value = <#repr as #enumset::__internal::EnumSetTypeRepr>::#from_fn(value);
+ #core::prelude::v1::Ok(#enumset::EnumSet {
+ __priv_repr: value & #all_variants,
+ })
+ }
+ }
+ }
+ SerdeRepr::List => {
+ let expecting_str = format!("a list of {}", name);
+ quote! {
+ fn serialize<S: #serde::Serializer>(
+ set: #enumset::EnumSet<#name>, ser: S,
+ ) -> #core::result::Result<S::Ok, S::Error> {
+ use #serde::ser::SerializeSeq;
+ let mut seq = ser.serialize_seq(#core::prelude::v1::Some(set.len()))?;
+ for bit in set {
+ seq.serialize_element(&bit)?;
+ }
+ seq.end()
+ }
+ fn deserialize<'de, D: #serde::Deserializer<'de>>(
+ de: D,
+ ) -> #core::result::Result<#enumset::EnumSet<#name>, D::Error> {
+ struct Visitor;
+ impl <'de> #serde::de::Visitor<'de> for Visitor {
+ type Value = #enumset::EnumSet<#name>;
+ fn expecting(
+ &self, formatter: &mut #core::fmt::Formatter,
+ ) -> #core::fmt::Result {
+ write!(formatter, #expecting_str)
+ }
+ fn visit_seq<A>(
+ mut self, mut seq: A,
+ ) -> #core::result::Result<Self::Value, A::Error> where
+ A: #serde::de::SeqAccess<'de>
+ {
+ let mut accum = #enumset::EnumSet::<#name>::new();
+ while let #core::prelude::v1::Some(val) = seq.next_element::<#name>()? {
+ accum |= val;
+ }
+ #core::prelude::v1::Ok(accum)
+ }
+ }
+ de.deserialize_seq(Visitor)
+ }
+ }
+ }
+ SerdeRepr::Map => {
+ let expecting_str = format!("a map from {} to bool", name);
+ quote! {
+ fn serialize<S: #serde::Serializer>(
+ set: #enumset::EnumSet<#name>, ser: S,
+ ) -> #core::result::Result<S::Ok, S::Error> {
+ use #serde::ser::SerializeMap;
+ let mut map = ser.serialize_map(#core::prelude::v1::Some(set.len()))?;
+ for bit in set {
+ map.serialize_entry(&bit, &true)?;
+ }
+ map.end()
+ }
+ fn deserialize<'de, D: #serde::Deserializer<'de>>(
+ de: D,
+ ) -> #core::result::Result<#enumset::EnumSet<#name>, D::Error> {
+ struct Visitor;
+ impl <'de> #serde::de::Visitor<'de> for Visitor {
+ type Value = #enumset::EnumSet<#name>;
+ fn expecting(
+ &self, formatter: &mut #core::fmt::Formatter,
+ ) -> #core::fmt::Result {
+ write!(formatter, #expecting_str)
+ }
+ fn visit_map<A>(
+ mut self, mut map: A,
+ ) -> #core::result::Result<Self::Value, A::Error> where
+ A: #serde::de::MapAccess<'de>
+ {
+ let mut accum = #enumset::EnumSet::<#name>::new();
+ while let #core::prelude::v1::Some((val, is_present)) =
+ map.next_entry::<#name, bool>()?
+ {
+ if is_present {
+ accum |= val;
+ }
+ }
+ #core::prelude::v1::Ok(accum)
+ }
+ }
+ de.deserialize_map(Visitor)
+ }
+ }
+ }
+ SerdeRepr::Array => {
+ let preferred_size = quote! {
+ <<#name as #internal::EnumSetTypePrivate>::Repr as #internal::EnumSetTypeRepr>
+ ::PREFERRED_ARRAY_LEN
+ };
+ let (check_extra, convert_array) = if info.serialize_deny_unknown {
+ (
+ quote! {
+ if _val != 0 {
+ return #core::prelude::v1::Err(
+ D::Error::custom("enumset contains unknown bits")
+ )
+ }
+ },
+ quote! {
+ match #enumset::EnumSet::<#name>::try_from_array(accum) {
+ Some(x) => x,
+ None => #core::prelude::v1::Err(
+ D::Error::custom("enumset contains unknown bits")
+ ),
+ }
+ },
+ )
+ } else {
+ (quote! {}, quote! {
+ #core::prelude::v1::Ok(#enumset::EnumSet::<#name>::from_array(accum))
+ })
+ };
+ quote! {
+ fn serialize<S: #serde::Serializer>(
+ set: #enumset::EnumSet<#name>, ser: S,
+ ) -> #core::result::Result<S::Ok, S::Error> {
+ // read the enum as an array
+ let array = set.as_array::<{ #preferred_size }>();
+
+ // find the last non-zero value in the array
+ let mut end = array.len();
+ for i in (0..array.len()).rev() {
+ if array[i] != 0 {
+ break;
+ }
+ end = i + 1;
+ }
+
+ // serialize the array
+ #serde::Serialize::serialize(&array[..end], ser)
+ }
+ fn deserialize<'de, D: #serde::Deserializer<'de>>(
+ de: D,
+ ) -> #core::result::Result<#enumset::EnumSet<#name>, D::Error> {
+ struct Visitor;
+ impl <'de> #serde::de::Visitor<'de> for Visitor {
+ type Value = #enumset::EnumSet<#name>;
+ fn expecting(
+ &self, formatter: &mut #core::fmt::Formatter,
+ ) -> #core::fmt::Result {
+ write!(formatter, "a list of u64")
+ }
+ fn visit_seq<A>(
+ mut self, mut seq: A,
+ ) -> #core::result::Result<Self::Value, A::Error> where
+ A: #serde::de::SeqAccess<'de>
+ {
+ let mut accum = [0; #preferred_size];
+
+ let mut i = 0;
+ while let #core::prelude::v1::Some(val) = seq.next_element::<u64>()? {
+ accum[i] = val;
+ i += 1;
+
+ if i == accum.len() {
+ break;
+ }
+ }
+ while let #core::prelude::v1::Some(_val) = seq.next_element::<u64>()? {
+ #check_extra
+ }
+
+ #convert_array
+ }
+ }
+ de.deserialize_seq(Visitor)
+ }
+ }
+ }
+ };
+
+ #[cfg(not(feature = "serde"))]
+ let serde_ops = quote! {};
+
+ let is_uninhabited = info.variants.is_empty();
+ let is_zst = info.variants.len() == 1;
+ let into_impl = if is_uninhabited {
+ quote! {
+ fn enum_into_u32(self) -> u32 {
+ panic!(concat!(stringify!(#name), " is uninhabited."))
+ }
+ unsafe fn enum_from_u32(val: u32) -> Self {
+ panic!(concat!(stringify!(#name), " is uninhabited."))
+ }
+ }
+ } else if is_zst {
+ let variant = &info.variants[0].name;
+ quote! {
+ fn enum_into_u32(self) -> u32 {
+ self as u32
+ }
+ unsafe fn enum_from_u32(val: u32) -> Self {
+ #name::#variant
+ }
+ }
+ } else {
+ let variant_name: Vec<_> = info.variants.iter().map(|x| &x.name).collect();
+ let variant_value: Vec<_> = info.variants.iter().map(|x| x.variant_repr).collect();
+
+ let const_field: Vec<_> = ["IS_U8", "IS_U16", "IS_U32", "IS_U64", "IS_U128"]
+ .iter()
+ .map(|x| Ident::new(x, Span::call_site()))
+ .collect();
+ let int_type: Vec<_> = ["u8", "u16", "u32", "u64", "u128"]
+ .iter()
+ .map(|x| Ident::new(x, Span::call_site()))
+ .collect();
+
+ quote! {
+ fn enum_into_u32(self) -> u32 {
+ self as u32
+ }
+ unsafe fn enum_from_u32(val: u32) -> Self {
+ // We put these in const fields so the branches they guard aren't generated even
+ // on -O0
+ #(const #const_field: bool =
+ #core::mem::size_of::<#name>() == #core::mem::size_of::<#int_type>();)*
+ match val {
+ // Every valid variant value has an explicit branch. If they get optimized out,
+ // great. If the representation has changed somehow, and they don't, oh well,
+ // there's still no UB.
+ #(#variant_value => #name::#variant_name,)*
+ // Helps hint to the LLVM that this is a transmute. Note that this branch is
+ // still unreachable.
+ #(x if #const_field => {
+ let x = x as #int_type;
+ *(&x as *const _ as *const #name)
+ })*
+ // Default case. Sometimes causes LLVM to generate a table instead of a simple
+ // transmute, but, oh well.
+ _ => #core::hint::unreachable_unchecked(),
+ }
+ }
+ }
+ };
+
+ let eq_impl = if is_uninhabited {
+ quote!(panic!(concat!(stringify!(#name), " is uninhabited.")))
+ } else {
+ quote!((*self as u32) == (*other as u32))
+ };
+
+ let super_impls = if info.no_super_impls {
+ quote! {}
+ } else {
+ quote! {
+ #[automatically_derived]
+ impl #core::cmp::PartialEq for #name {
+ fn eq(&self, other: &Self) -> bool {
+ #eq_impl
+ }
+ }
+ #[automatically_derived]
+ impl #core::cmp::Eq for #name { }
+ #[automatically_derived]
+ #[allow(clippy::expl_impl_clone_on_copy)]
+ impl #core::clone::Clone for #name {
+ fn clone(&self) -> Self {
+ *self
+ }
+ }
+ #[automatically_derived]
+ impl #core::marker::Copy for #name { }
+ }
+ };
+
+ let impl_with_repr = if info.explicit_internal_repr.is_some() {
+ quote! {
+ #[automatically_derived]
+ unsafe impl #enumset::EnumSetTypeWithRepr for #name {
+ type Repr = #repr;
+ }
+ }
+ } else {
+ quote! {}
+ };
+
+ let inherent_impl_blocks = match info.internal_repr() {
+ InternalRepr::U8
+ | InternalRepr::U16
+ | InternalRepr::U32
+ | InternalRepr::U64
+ | InternalRepr::U128 => {
+ let self_as_repr_mask = if is_uninhabited {
+ quote! { 0 } // impossible anyway
+ } else {
+ quote! { 1 << self as #repr }
+ };
+
+ quote! {
+ #[automatically_derived]
+ #[doc(hidden)]
+ impl #name {
+ /// Creates a new enumset with only this variant.
+ #[deprecated(note = "This method is an internal implementation detail \
+ generated by the `enumset` crate's procedural macro. It \
+ should not be used directly.")]
+ #[doc(hidden)]
+ pub const fn __impl_enumset_internal__const_only(
+ self,
+ ) -> #enumset::EnumSet<#name> {
+ #enumset::EnumSet { __priv_repr: #self_as_repr_mask }
+ }
+
+ /// Creates a new enumset with this variant added.
+ #[deprecated(note = "This method is an internal implementation detail \
+ generated by the `enumset` crate's procedural macro. It \
+ should not be used directly.")]
+ #[doc(hidden)]
+ pub const fn __impl_enumset_internal__const_merge(
+ self, chain: #enumset::EnumSet<#name>,
+ ) -> #enumset::EnumSet<#name> {
+ #enumset::EnumSet { __priv_repr: chain.__priv_repr | #self_as_repr_mask }
+ }
+ }
+ }
+ }
+ InternalRepr::Array(size) => {
+ quote! {
+ #[automatically_derived]
+ #[doc(hidden)]
+ impl #name {
+ /// Creates a new enumset with only this variant.
+ #[deprecated(note = "This method is an internal implementation detail \
+ generated by the `enumset` crate's procedural macro. It \
+ should not be used directly.")]
+ #[doc(hidden)]
+ pub const fn __impl_enumset_internal__const_only(
+ self,
+ ) -> #enumset::EnumSet<#name> {
+ let mut set = #enumset::EnumSet::<#name> {
+ __priv_repr: #internal::ArrayRepr::<{ #size }>([0; #size]),
+ };
+ let bit = self as u32;
+ let (idx, bit) = (bit as usize / 64, bit % 64);
+ set.__priv_repr.0[idx] |= 1u64 << bit;
+ set
+ }
+
+ /// Creates a new enumset with this variant added.
+ #[deprecated(note = "This method is an internal implementation detail \
+ generated by the `enumset` crate's procedural macro. It \
+ should not be used directly.")]
+ #[doc(hidden)]
+ pub const fn __impl_enumset_internal__const_merge(
+ self, mut chain: #enumset::EnumSet<#name>,
+ ) -> #enumset::EnumSet<#name> {
+ let bit = self as u32;
+ let (idx, bit) = (bit as usize / 64, bit % 64);
+ chain.__priv_repr.0[idx] |= 1u64 << bit;
+ chain
+ }
+ }
+ }
+ }
+ };
+
+ let mut generated_warnings = SynTokenStream::new();
+ for (span, warning) in warnings {
+ generated_warnings.extend(quote_spanned! {
+ span => {
+ #[deprecated(note = #warning)]
+ #[allow(non_upper_case_globals)]
+ const _w: () = ();
+ let _ = _w;
+ }
+ });
+ }
+
+ let bit_width = info.max_discrim + 1;
+ let variant_count = info.variants.len() as u32;
+ quote! {
+ #[automatically_derived]
+ unsafe impl #internal::EnumSetTypePrivate for #name {
+ type Repr = #repr;
+ const ALL_BITS: Self::Repr = #all_variants;
+ const BIT_WIDTH: u32 = #bit_width;
+ const VARIANT_COUNT: u32 = #variant_count;
+ #into_impl
+ #serde_ops
+ }
+
+ #[automatically_derived]
+ unsafe impl #enumset::EnumSetType for #name { }
+
+ #impl_with_repr
+ #super_impls
+ #inherent_impl_blocks
+
+ #ops
+
+ const _: () = {
+ fn __enumset_derive__generated_warnings() {
+ #generated_warnings
+ }
+ };
+ }
+}
+
+#[proc_macro_derive(EnumSetType, attributes(enumset))]
+pub fn derive_enum_set_type(input: TokenStream) -> TokenStream {
+ let input: DeriveInput = parse_macro_input!(input);
+ let attrs: EnumsetAttrs = match EnumsetAttrs::from_derive_input(&input) {
+ Ok(attrs) => attrs,
+ Err(e) => return e.write_errors().into(),
+ };
+ match derive_enum_set_type_0(input, attrs) {
+ Ok(v) => v,
+ Err(e) => e.to_compile_error().into(),
+ }
+}
+fn derive_enum_set_type_0(input: DeriveInput, attrs: EnumsetAttrs) -> Result<TokenStream> {
+ if !input.generics.params.is_empty() {
+ error(
+ input.generics.span(),
+ "`#[derive(EnumSetType)]` cannot be used on enums with type parameters.",
+ )
+ } else if let Data::Enum(data) = &input.data {
+ let mut info = EnumSetInfo::new(&input, &attrs);
+ let mut warnings = Vec::new();
+
+ // Check enum repr
+ for attr in &input.attrs {
+ if attr.path().is_ident("repr") {
+ let meta: Ident = attr.parse_args()?;
+ match meta.to_string().as_str() {
+ "C" | "Rust" => {}
+ "u8" | "u16" | "u32" | "u64" | "u128" | "usize" => {}
+ "i8" | "i16" | "i32" | "i64" | "i128" | "isize" => {}
+ x => error(
+ attr.span(),
+ format!("`#[repr({})]` cannot be used on enumset variants.", x),
+ )?,
+ }
+ }
+ }
+
+ // Parse internal representations
+ if let Some(repr) = &*attrs.repr {
+ info.push_repr(attrs.repr.span(), repr)?;
+ }
+
+ // Parse serialization representations
+ if let Some(serialize_repr) = &*attrs.serialize_repr {
+ info.push_serialize_repr(attrs.serialize_repr.span(), serialize_repr)?;
+ }
+ if *attrs.serialize_as_map {
+ info.explicit_serde_repr = Some(SerdeRepr::Map);
+ warnings.push((
+ attrs.serialize_as_map.span(),
+ "#[enumset(serialize_as_map)] is deprecated. \
+ Use `#[enumset(serialize_repr = \"map\")]` instead.",
+ ));
+ }
+ if *attrs.serialize_as_list {
+ // in old versions, serialize_as_list will override serialize_as_map
+ info.explicit_serde_repr = Some(SerdeRepr::List);
+ warnings.push((
+ attrs.serialize_as_list.span(),
+ "#[enumset(serialize_as_list)] is deprecated. \
+ Use `#[enumset(serialize_repr = \"list\")]` instead.",
+ ));
+ }
+
+ // Parse enum variants
+ for variant in &data.variants {
+ info.push_variant(variant)?;
+ }
+
+ // Validate the enumset
+ info.validate()?;
+
+ // Generates the actual `EnumSetType` implementation
+ Ok(enum_set_type_impl(info, warnings).into())
+ } else {
+ error(input.span(), "`#[derive(EnumSetType)]` may only be used on enums")
+ }
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-20 11:36:02 +0000