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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
commit36d22d82aa202bb199967e9512281e9a53db42c9 (patch)
tree105e8c98ddea1c1e4784a60a5a6410fa416be2de /third_party/rust/serde_repr/src
parentInitial commit. (diff)
downloadfirefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz
firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip
Adding upstream version 115.7.0esr.upstream/115.7.0esr
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/rust/serde_repr/src')
-rw-r--r--third_party/rust/serde_repr/src/lib.rs140
-rw-r--r--third_party/rust/serde_repr/src/parse.rs114
2 files changed, 254 insertions, 0 deletions
diff --git a/third_party/rust/serde_repr/src/lib.rs b/third_party/rust/serde_repr/src/lib.rs
new file mode 100644
index 0000000000..2ad67df065
--- /dev/null
+++ b/third_party/rust/serde_repr/src/lib.rs
@@ -0,0 +1,140 @@
+//! [![github]](https://github.com/dtolnay/serde-repr)&ensp;[![crates-io]](https://crates.io/crates/serde_repr)&ensp;[![docs-rs]](https://docs.rs/serde_repr)
+//!
+//! [github]: https://img.shields.io/badge/github-8da0cb?style=for-the-badge&labelColor=555555&logo=github
+//! [crates-io]: https://img.shields.io/badge/crates.io-fc8d62?style=for-the-badge&labelColor=555555&logo=rust
+//! [docs-rs]: https://img.shields.io/badge/docs.rs-66c2a5?style=for-the-badge&labelColor=555555&logo=docs.rs
+//!
+//! <br>
+//!
+//! Derive `Serialize` and `Deserialize` that delegates to the underlying repr
+//! of a C-like enum.
+//!
+//! # Examples
+//!
+//! ```
+//! use serde_repr::{Serialize_repr, Deserialize_repr};
+//!
+//! #[derive(Serialize_repr, Deserialize_repr, PartialEq, Debug)]
+//! #[repr(u8)]
+//! enum SmallPrime {
+//! Two = 2,
+//! Three = 3,
+//! Five = 5,
+//! Seven = 7,
+//! }
+//!
+//! fn main() -> serde_json::Result<()> {
+//! let j = serde_json::to_string(&SmallPrime::Seven)?;
+//! assert_eq!(j, "7");
+//!
+//! let p: SmallPrime = serde_json::from_str("2")?;
+//! assert_eq!(p, SmallPrime::Two);
+//!
+//! Ok(())
+//! }
+//! ```
+
+#![allow(clippy::single_match_else)]
+
+extern crate proc_macro;
+
+mod parse;
+
+use proc_macro::TokenStream;
+use quote::quote;
+use syn::parse_macro_input;
+
+use crate::parse::Input;
+
+#[proc_macro_derive(Serialize_repr)]
+pub fn derive_serialize(input: TokenStream) -> TokenStream {
+ let input = parse_macro_input!(input as Input);
+ let ident = input.ident;
+ let repr = input.repr;
+
+ let match_variants = input.variants.iter().map(|variant| {
+ let variant = &variant.ident;
+ quote! {
+ #ident::#variant => #ident::#variant as #repr,
+ }
+ });
+
+ TokenStream::from(quote! {
+ impl serde::Serialize for #ident {
+ #[allow(clippy::use_self)]
+ fn serialize<S>(&self, serializer: S) -> core::result::Result<S::Ok, S::Error>
+ where
+ S: serde::Serializer
+ {
+ let value: #repr = match *self {
+ #(#match_variants)*
+ };
+ serde::Serialize::serialize(&value, serializer)
+ }
+ }
+ })
+}
+
+#[proc_macro_derive(Deserialize_repr, attributes(serde))]
+pub fn derive_deserialize(input: TokenStream) -> TokenStream {
+ let input = parse_macro_input!(input as Input);
+ let ident = input.ident;
+ let repr = input.repr;
+ let variants = input.variants.iter().map(|variant| &variant.ident);
+
+ let declare_discriminants = input.variants.iter().map(|variant| {
+ let variant = &variant.ident;
+ quote! {
+ const #variant: #repr = #ident::#variant as #repr;
+ }
+ });
+
+ let match_discriminants = input.variants.iter().map(|variant| {
+ let variant = &variant.ident;
+ quote! {
+ discriminant::#variant => core::result::Result::Ok(#ident::#variant),
+ }
+ });
+
+ let error_format = match input.variants.len() {
+ 1 => "invalid value: {}, expected {}".to_owned(),
+ 2 => "invalid value: {}, expected {} or {}".to_owned(),
+ n => "invalid value: {}, expected one of: {}".to_owned() + &", {}".repeat(n - 1),
+ };
+
+ let other_arm = match input.default_variant {
+ Some(variant) => {
+ let variant = &variant.ident;
+ quote! {
+ core::result::Result::Ok(#ident::#variant)
+ }
+ }
+ None => quote! {
+ core::result::Result::Err(serde::de::Error::custom(
+ format_args!(#error_format, other #(, discriminant::#variants)*)
+ ))
+ },
+ };
+
+ TokenStream::from(quote! {
+ impl<'de> serde::Deserialize<'de> for #ident {
+ #[allow(clippy::use_self)]
+ fn deserialize<D>(deserializer: D) -> core::result::Result<Self, D::Error>
+ where
+ D: serde::Deserializer<'de>,
+ {
+ struct discriminant;
+
+ #[allow(non_upper_case_globals)]
+ impl discriminant {
+ #(#declare_discriminants)*
+ }
+
+ match <#repr as serde::Deserialize>::deserialize(deserializer)? {
+ #(#match_discriminants)*
+ other => #other_arm,
+ }
+ }
+ }
+ })
+}
diff --git a/third_party/rust/serde_repr/src/parse.rs b/third_party/rust/serde_repr/src/parse.rs
new file mode 100644
index 0000000000..2c0ad1e7dc
--- /dev/null
+++ b/third_party/rust/serde_repr/src/parse.rs
@@ -0,0 +1,114 @@
+use proc_macro2::Span;
+use syn::parse::{Error, Parse, ParseStream, Parser, Result};
+use syn::{parenthesized, Data, DeriveInput, Fields, Ident, Meta, NestedMeta};
+
+pub struct Input {
+ pub ident: Ident,
+ pub repr: Ident,
+ pub variants: Vec<Variant>,
+ pub default_variant: Option<Variant>,
+}
+
+#[derive(Clone)]
+pub struct Variant {
+ pub ident: Ident,
+ pub attrs: VariantAttrs,
+}
+
+#[derive(Clone)]
+pub struct VariantAttrs {
+ pub is_default: bool,
+}
+
+fn parse_meta(attrs: &mut VariantAttrs, meta: &Meta) {
+ if let Meta::List(value) = meta {
+ for meta in &value.nested {
+ if let NestedMeta::Meta(Meta::Path(path)) = meta {
+ if path.is_ident("other") {
+ attrs.is_default = true;
+ }
+ }
+ }
+ }
+}
+
+fn parse_attrs(variant: &syn::Variant) -> Result<VariantAttrs> {
+ let mut attrs = VariantAttrs { is_default: false };
+ for attr in &variant.attrs {
+ if attr.path.is_ident("serde") {
+ parse_meta(&mut attrs, &attr.parse_meta()?);
+ }
+ }
+ Ok(attrs)
+}
+
+impl Parse for Input {
+ fn parse(input: ParseStream) -> Result<Self> {
+ let call_site = Span::call_site();
+ let derive_input = DeriveInput::parse(input)?;
+
+ let data = match derive_input.data {
+ Data::Enum(data) => data,
+ _ => {
+ return Err(Error::new(call_site, "input must be an enum"));
+ }
+ };
+
+ let variants = data
+ .variants
+ .into_iter()
+ .map(|variant| match variant.fields {
+ Fields::Unit => {
+ let attrs = parse_attrs(&variant)?;
+ Ok(Variant {
+ ident: variant.ident,
+ attrs,
+ })
+ }
+ Fields::Named(_) | Fields::Unnamed(_) => {
+ Err(Error::new(variant.ident.span(), "must be a unit variant"))
+ }
+ })
+ .collect::<Result<Vec<Variant>>>()?;
+
+ if variants.is_empty() {
+ return Err(Error::new(call_site, "there must be at least one variant"));
+ }
+
+ let generics = derive_input.generics;
+ if !generics.params.is_empty() || generics.where_clause.is_some() {
+ return Err(Error::new(call_site, "generic enum is not supported"));
+ }
+
+ let mut repr = None;
+ for attr in derive_input.attrs {
+ if attr.path.is_ident("repr") {
+ fn repr_arg(input: ParseStream) -> Result<Ident> {
+ let content;
+ parenthesized!(content in input);
+ content.parse()
+ }
+ let ty = repr_arg.parse2(attr.tokens)?;
+ repr = Some(ty);
+ break;
+ }
+ }
+ let repr = repr.ok_or_else(|| Error::new(call_site, "missing #[repr(...)] attribute"))?;
+
+ let mut default_variants = variants.iter().filter(|x| x.attrs.is_default);
+ let default_variant = default_variants.next().cloned();
+ if default_variants.next().is_some() {
+ return Err(Error::new(
+ call_site,
+ "only one variant can be #[serde(other)]",
+ ));
+ }
+
+ Ok(Input {
+ ident: derive_input.ident,
+ repr,
+ variants,
+ default_variant,
+ })
+ }
+}