Adding upstream version 86.0.1.upstream/86.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

2 files changed, 249 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..b80fa9988f
--- /dev/null
+++ b/third_party/rust/serde_repr/src/lib.rs
@@ -0,0 +1,135 @@
+//! 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(())
+//! }
+//! ```
+
+#![recursion_limit = "128"]
+
+extern crate proc_macro;
+
+mod parse;
+
+use proc_macro::TokenStream;
+use quote::quote;
+use syn::parse_macro_input;
+
+use crate::parse::Input;
+
+use std::iter;
+
+#[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 {
+            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! {
+            #[allow(non_upper_case_globals)]
+            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()
+                + &iter::repeat(", {}").take(n - 1).collect::<String>()
+        }
+    };
+
+    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 {
+            fn deserialize<D>(deserializer: D) -> core::result::Result<Self, D::Error>
+            where
+                D: serde::Deserializer<'de>,
+            {
+                struct discriminant;
+
+                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,
+        })
+    }
+}