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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:02:58 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:02:58 +0000
commit698f8c2f01ea549d77d7dc3338a12e04c11057b9 (patch)
tree173a775858bd501c378080a10dca74132f05bc50 /vendor/serde_derive/src/internals/ast.rs
parentInitial commit. (diff)
downloadrustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.tar.xz
rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.zip
Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'vendor/serde_derive/src/internals/ast.rs')
-rw-r--r--vendor/serde_derive/src/internals/ast.rs202
1 files changed, 202 insertions, 0 deletions
diff --git a/vendor/serde_derive/src/internals/ast.rs b/vendor/serde_derive/src/internals/ast.rs
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+//! A Serde ast, parsed from the Syn ast and ready to generate Rust code.
+
+use internals::attr;
+use internals::check;
+use internals::{Ctxt, Derive};
+use syn;
+use syn::punctuated::Punctuated;
+
+/// A source data structure annotated with `#[derive(Serialize)]` and/or `#[derive(Deserialize)]`,
+/// parsed into an internal representation.
+pub struct Container<'a> {
+ /// The struct or enum name (without generics).
+ pub ident: syn::Ident,
+ /// Attributes on the structure, parsed for Serde.
+ pub attrs: attr::Container,
+ /// The contents of the struct or enum.
+ pub data: Data<'a>,
+ /// Any generics on the struct or enum.
+ pub generics: &'a syn::Generics,
+ /// Original input.
+ pub original: &'a syn::DeriveInput,
+}
+
+/// The fields of a struct or enum.
+///
+/// Analogous to `syn::Data`.
+pub enum Data<'a> {
+ Enum(Vec<Variant<'a>>),
+ Struct(Style, Vec<Field<'a>>),
+}
+
+/// A variant of an enum.
+pub struct Variant<'a> {
+ pub ident: syn::Ident,
+ pub attrs: attr::Variant,
+ pub style: Style,
+ pub fields: Vec<Field<'a>>,
+ pub original: &'a syn::Variant,
+}
+
+/// A field of a struct.
+pub struct Field<'a> {
+ pub member: syn::Member,
+ pub attrs: attr::Field,
+ pub ty: &'a syn::Type,
+ pub original: &'a syn::Field,
+}
+
+#[derive(Copy, Clone)]
+pub enum Style {
+ /// Named fields.
+ Struct,
+ /// Many unnamed fields.
+ Tuple,
+ /// One unnamed field.
+ Newtype,
+ /// No fields.
+ Unit,
+}
+
+impl<'a> Container<'a> {
+ /// Convert the raw Syn ast into a parsed container object, collecting errors in `cx`.
+ pub fn from_ast(
+ cx: &Ctxt,
+ item: &'a syn::DeriveInput,
+ derive: Derive,
+ ) -> Option<Container<'a>> {
+ let mut attrs = attr::Container::from_ast(cx, item);
+
+ let mut data = match &item.data {
+ syn::Data::Enum(data) => Data::Enum(enum_from_ast(cx, &data.variants, attrs.default())),
+ syn::Data::Struct(data) => {
+ let (style, fields) = struct_from_ast(cx, &data.fields, None, attrs.default());
+ Data::Struct(style, fields)
+ }
+ syn::Data::Union(_) => {
+ cx.error_spanned_by(item, "Serde does not support derive for unions");
+ return None;
+ }
+ };
+
+ let mut has_flatten = false;
+ match &mut data {
+ Data::Enum(variants) => {
+ for variant in variants {
+ variant.attrs.rename_by_rules(attrs.rename_all_rules());
+ for field in &mut variant.fields {
+ if field.attrs.flatten() {
+ has_flatten = true;
+ }
+ field
+ .attrs
+ .rename_by_rules(variant.attrs.rename_all_rules());
+ }
+ }
+ }
+ Data::Struct(_, fields) => {
+ for field in fields {
+ if field.attrs.flatten() {
+ has_flatten = true;
+ }
+ field.attrs.rename_by_rules(attrs.rename_all_rules());
+ }
+ }
+ }
+
+ if has_flatten {
+ attrs.mark_has_flatten();
+ }
+
+ let mut item = Container {
+ ident: item.ident.clone(),
+ attrs,
+ data,
+ generics: &item.generics,
+ original: item,
+ };
+ check::check(cx, &mut item, derive);
+ Some(item)
+ }
+}
+
+impl<'a> Data<'a> {
+ pub fn all_fields(&'a self) -> Box<Iterator<Item = &'a Field<'a>> + 'a> {
+ match self {
+ Data::Enum(variants) => {
+ Box::new(variants.iter().flat_map(|variant| variant.fields.iter()))
+ }
+ Data::Struct(_, fields) => Box::new(fields.iter()),
+ }
+ }
+
+ pub fn has_getter(&self) -> bool {
+ self.all_fields().any(|f| f.attrs.getter().is_some())
+ }
+}
+
+fn enum_from_ast<'a>(
+ cx: &Ctxt,
+ variants: &'a Punctuated<syn::Variant, Token![,]>,
+ container_default: &attr::Default,
+) -> Vec<Variant<'a>> {
+ variants
+ .iter()
+ .map(|variant| {
+ let attrs = attr::Variant::from_ast(cx, variant);
+ let (style, fields) =
+ struct_from_ast(cx, &variant.fields, Some(&attrs), container_default);
+ Variant {
+ ident: variant.ident.clone(),
+ attrs,
+ style,
+ fields,
+ original: variant,
+ }
+ })
+ .collect()
+}
+
+fn struct_from_ast<'a>(
+ cx: &Ctxt,
+ fields: &'a syn::Fields,
+ attrs: Option<&attr::Variant>,
+ container_default: &attr::Default,
+) -> (Style, Vec<Field<'a>>) {
+ match fields {
+ syn::Fields::Named(fields) => (
+ Style::Struct,
+ fields_from_ast(cx, &fields.named, attrs, container_default),
+ ),
+ syn::Fields::Unnamed(fields) if fields.unnamed.len() == 1 => (
+ Style::Newtype,
+ fields_from_ast(cx, &fields.unnamed, attrs, container_default),
+ ),
+ syn::Fields::Unnamed(fields) => (
+ Style::Tuple,
+ fields_from_ast(cx, &fields.unnamed, attrs, container_default),
+ ),
+ syn::Fields::Unit => (Style::Unit, Vec::new()),
+ }
+}
+
+fn fields_from_ast<'a>(
+ cx: &Ctxt,
+ fields: &'a Punctuated<syn::Field, Token![,]>,
+ attrs: Option<&attr::Variant>,
+ container_default: &attr::Default,
+) -> Vec<Field<'a>> {
+ fields
+ .iter()
+ .enumerate()
+ .map(|(i, field)| Field {
+ member: match &field.ident {
+ Some(ident) => syn::Member::Named(ident.clone()),
+ None => syn::Member::Unnamed(i.into()),
+ },
+ attrs: attr::Field::from_ast(cx, i, field, attrs, container_default),
+ ty: &field.ty,
+ original: field,
+ })
+ .collect()
+}