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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
commit26a029d407be480d791972afb5975cf62c9360a6 (patch)
treef435a8308119effd964b339f76abb83a57c29483 /third_party/rust/prost-derive/src/field/oneof.rs
parentInitial commit. (diff)
downloadfirefox-26a029d407be480d791972afb5975cf62c9360a6.tar.xz
firefox-26a029d407be480d791972afb5975cf62c9360a6.zip
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/rust/prost-derive/src/field/oneof.rs')
-rw-r--r--third_party/rust/prost-derive/src/field/oneof.rs92
1 files changed, 92 insertions, 0 deletions
diff --git a/third_party/rust/prost-derive/src/field/oneof.rs b/third_party/rust/prost-derive/src/field/oneof.rs
new file mode 100644
index 0000000000..78c77eeb13
--- /dev/null
+++ b/third_party/rust/prost-derive/src/field/oneof.rs
@@ -0,0 +1,92 @@
+use anyhow::{bail, Error};
+use proc_macro2::TokenStream;
+use quote::quote;
+use syn::{parse_str, Expr, ExprLit, Ident, Lit, Meta, MetaNameValue, Path};
+
+use crate::field::{set_option, tags_attr};
+
+#[derive(Clone)]
+pub struct Field {
+ pub ty: Path,
+ pub tags: Vec<u32>,
+}
+
+impl Field {
+ pub fn new(attrs: &[Meta]) -> Result<Option<Field>, Error> {
+ let mut ty = None;
+ let mut tags = None;
+ let mut unknown_attrs = Vec::new();
+
+ for attr in attrs {
+ if attr.path().is_ident("oneof") {
+ let t = match *attr {
+ Meta::NameValue(MetaNameValue {
+ value:
+ Expr::Lit(ExprLit {
+ lit: Lit::Str(ref lit),
+ ..
+ }),
+ ..
+ }) => parse_str::<Path>(&lit.value())?,
+ Meta::List(ref list) => list.parse_args::<Ident>()?.into(),
+ _ => bail!("invalid oneof attribute: {:?}", attr),
+ };
+ set_option(&mut ty, t, "duplicate oneof attribute")?;
+ } else if let Some(t) = tags_attr(attr)? {
+ set_option(&mut tags, t, "duplicate tags attributes")?;
+ } else {
+ unknown_attrs.push(attr);
+ }
+ }
+
+ let ty = match ty {
+ Some(ty) => ty,
+ None => return Ok(None),
+ };
+
+ match unknown_attrs.len() {
+ 0 => (),
+ 1 => bail!(
+ "unknown attribute for message field: {:?}",
+ unknown_attrs[0]
+ ),
+ _ => bail!("unknown attributes for message field: {:?}", unknown_attrs),
+ }
+
+ let tags = match tags {
+ Some(tags) => tags,
+ None => bail!("oneof field is missing a tags attribute"),
+ };
+
+ Ok(Some(Field { ty, tags }))
+ }
+
+ /// Returns a statement which encodes the oneof field.
+ pub fn encode(&self, ident: TokenStream) -> TokenStream {
+ quote! {
+ if let Some(ref oneof) = #ident {
+ oneof.encode(buf)
+ }
+ }
+ }
+
+ /// Returns an expression which evaluates to the result of decoding the oneof field.
+ pub fn merge(&self, ident: TokenStream) -> TokenStream {
+ let ty = &self.ty;
+ quote! {
+ #ty::merge(#ident, tag, wire_type, buf, ctx)
+ }
+ }
+
+ /// Returns an expression which evaluates to the encoded length of the oneof field.
+ pub fn encoded_len(&self, ident: TokenStream) -> TokenStream {
+ let ty = &self.ty;
+ quote! {
+ #ident.as_ref().map_or(0, #ty::encoded_len)
+ }
+ }
+
+ pub fn clear(&self, ident: TokenStream) -> TokenStream {
+ quote!(#ident = ::core::option::Option::None)
+ }
+}