/// 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 serialize the enum as.
explicit_serde_repr: Option<Ident>,
+ /// Whether the underlying repr of the enum supports negative values.
has_signed_repr: bool,
+ /// Whether the underlying repr of the enum supports values higher than 2^32.
has_large_repr: bool,
+ /// A list of variants in the enum.
variants: Vec<EnumSetValue>,
+ /// The highest encountered variant discriminant.
max_discrim: u32,
+ /// 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>,
- used_discriminators: HashSet<u32>,
+ /// 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,
+ /// Serialize the enum as a list.
serialize_as_list: bool,
+ /// Disallow unknown bits while deserializing the enum.
serialize_deny_unknown: bool,
}
impl EnumSetInfo {
max_discrim: 0,
cur_discrim: 0,
used_variant_names: HashSet::new(),
- used_discriminators: HashSet::new(),
+ used_discriminants: HashSet::new(),
no_ops: attrs.no_ops,
serialize_as_list: attrs.serialize_as_list,
serialize_deny_unknown: attrs.serialize_deny_unknown
}
}
+ /// Sets an explicit repr for the enumset.
fn push_explicit_repr(&mut self, attr_span: Span, repr: &str) -> Result<()> {
+ // Check whether the repr is supported, and if so, set some flags for better error
+ // messages later on.
match repr {
"Rust" | "C" | "u8" | "u16" | "u32" => Ok(()),
"usize" | "u64" | "u128" => {
_ => error(attr_span, "Unsupported repr.")
}
}
+ /// 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 {
let discriminant_fail_message = format!(
"Enum set discriminants must be `u32`s.{}",
}
}
+ // Validate the discriminant.
let discriminant = self.cur_discrim;
if discriminant >= 128 {
let message = if self.variants.len() <= 127 {
};
error(variant.span(), message)?;
}
-
- if self.used_discriminators.contains(&discriminant) {
+ 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;
variant_repr: discriminant,
});
self.used_variant_names.insert(variant.ident.to_string());
- self.used_discriminators.insert(discriminant);
+ self.used_discriminants.insert(discriminant);
Ok(())
} else {
error(variant.span(), "`#[derive(EnumSetType)]` can only be used on fieldless enums.")
}
}
+ /// Validate the enumset type.
fn validate(&self) -> Result<()> {
+ // Check if all bits of the bitset can fit in the serialization representation.
if let Some(explicit_serde_repr) = &self.explicit_serde_repr {
let is_overflowed = match explicit_serde_repr.to_string().as_str() {
"u8" => self.max_discrim >= 8,
Ok(())
}
+ /// Computes the underlying type used to store the enumset.
fn enumset_repr(&self) -> SynTokenStream {
if self.max_discrim <= 7 {
quote! { u8 }
panic!("max_variant > 127?")
}
}
+ /// Computes the underlying type used to serialize the enumset.
#[cfg(feature = "serde")]
fn serde_repr(&self) -> SynTokenStream {
if let Some(serde_repr) = &self.explicit_serde_repr {
}
}
+ /// Returns a bitmask of all variants in the set.
fn all_variants(&self) -> u128 {
let mut accum = 0u128;
for variant in &self.variants {
}
}
+/// Generates the actual `EnumSetType` impl.
fn enum_set_type_impl(info: EnumSetInfo) -> SynTokenStream {
let name = &info.name;
let enumset = match &info.crate_name {
self as u32
}
unsafe fn enum_from_u32(val: u32) -> Self {
- // We put these in const fields so they aren't generated even on -O0
+ // 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 {
}
}
-fn derive_enum_set_type_impl(input: DeriveInput, attrs: EnumsetAttrs) -> Result<TokenStream> {
+/// A wrapper that parses the input enum.
+#[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(),
} else {
error(input.span(), "`#[derive(EnumSetType)]` may only be used on enums")
}
-}
-
-#[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_impl(input, attrs) {
- Ok(v) => v,
- Err(e) => e.to_compile_error().into(),
- }
}
\ No newline at end of file
projects / enumset.git / blobdiff