Feat/xml encoding rules (#416)

* feat(xer): pass identifier to encode functions

* test(xer): add round trip tests

* refactor(types): remove constructed asntype bound

* fix(macros): generate choice implementation for encode_with_identifier

* test(xer): add round trip tests

* chore: bump compiler version

* fix(xer): fix typo in codec impl

Co-authored-by: XAMPPRocky <[email protected]>

* refactor: create `Identifier` newtype with consts

* style: fmt and clippy

* test(xer): un-flake SET OF tests

* style: implement clippy suggestions

---------

Co-authored-by: XAMPPRocky <[email protected]>

Author: 6d7a

Cargo.lock

@@ -91,12 +91,13 @@ once_cell = { version = "1.20.2", default-features = false, features = [
     "race",
     "alloc",
 ] }
-rasn-compiler = { version = "0.5.3", optional = true }
+rasn-compiler = { version = "0.7", optional = true }
 rasn-derive = { version = "0.24", path = "macros" }
 snafu = { version = "0.8.5", default-features = false, features = [
     "rust_1_81",
 ] }
 serde_json = { version = "1", default-features = false, features = ["alloc"] }
+xml-no-std = "0.8.19"
 
 [dev-dependencies]
 criterion = { version = "0.5.1", default-features = false, features = [

Cargo.toml

@@ -8,8 +8,11 @@
 Welcome to `rasn` (pronounced "raisin"), a safe `#[no_std]` ASN.1 codec framework.
 That enables you to safely create, share, and handle ASN.1 data types from and to different encoding rules. If you are unfamiliar with ASN.1 and encoding formats like BER/DER, I would recommend reading [*"A Warm Welcome to ASN.1 and DER"*][lenc] by Let's Encrypt as a quick introduction before continuing. In short it is an "Interface Description Language" (and data model) with a set of encoding formats (called rules) for that model. It was originally designed in the late 1980s and is used throughout the industry especially in telecommunications and cryptography.
 
+The [`rasn` compiler][compiler] can be used to generate `rasn` bindings for ASN.1 modules.
+
 [ghs]: https://github.com/sponsors/XAMPPRocky
 [lenc]: https://letsencrypt.org/docs/a-warm-welcome-to-asn1-and-der/
+[compiler]: https://github.com/librasn/compiler
 
 ## Features
 
@@ -37,6 +40,7 @@ The encoder and decoder have been written in 100% safe Rust and fuzzed with [Ame
 - JSON Encoding Rules (JER)
 - Octet Encoding Rules (OER)
 - Canonical Octet Encoding Rules (COER)
+- XML Encoding Rules (XER)
 
 [bun]: https://aflplus.plus
 
@@ -98,7 +102,10 @@ Next is the `Decode` and `Encode` traits. These are mirrors of each other and bo
 ```rust
 # use rasn::{AsnType, types::{Constructed, fields::{Field, Fields}}};
 # struct Person { name: Utf8String, age: Integer }
-# impl AsnType for Person { const TAG: Tag = Tag::SEQUENCE; }
+# impl AsnType for Person {
+#    const TAG: Tag = Tag::SEQUENCE;
+#    const IDENTIFIER: Identifier = Identifier(Some("Person"));
+# }
 # impl Constructed<2, 0> for Person {
 #     const FIELDS: Fields<2> = Fields::from_static([
 #          Field::new_required(0, Utf8String::TAG, Utf8String::TAG_TREE, "age"),
@@ -119,13 +126,13 @@ impl Decode for Person {
 }
 
 impl Encode for Person {
-    fn encode_with_tag_and_constraints<'encoder, E: Encoder<'encoder>>(&self, encoder: &mut E, tag: Tag, constraints: Constraints) -> Result<(), E::Error> {
+    fn encode_with_tag_and_constraints<'encoder, E: Encoder<'encoder>>(&self, encoder: &mut E, tag: Tag, constraints: Constraints, identifier: Identifier) -> Result<(), E::Error> {
         // Accepts a closure that encodes the contents of the sequence.
         encoder.encode_sequence::<2, 0, Self, _>(tag, |encoder| {
             self.age.encode(encoder)?;
             self.name.encode(encoder)?;
             Ok(())
-        })?;
+        }, identifier)?;
 
         Ok(())
     }

README.md

@@ -7,7 +7,7 @@
 // Wrap with black_box to prevent the compiler from optimizing out the code
 
 use criterion::{black_box, criterion_group, criterion_main, Criterion};
-use rasn::{ber, oer, uper};
+use rasn::{ber, oer, uper, xer};
 
 #[allow(non_camel_case_types, non_snake_case, non_upper_case_globals, unused)]
 pub mod world3d {
@@ -154,10 +154,12 @@ macro_rules! rasn_dec_fn {
 rasn_enc_fn!(uper_rasn_enc, uper);
 rasn_enc_fn!(oer_rasn_enc, oer);
 rasn_enc_fn!(ber_rasn_enc, ber);
+rasn_enc_fn!(xer_rasn_enc, xer);
 
 rasn_dec_fn!(uper_rasn_dec, uper);
 rasn_dec_fn!(oer_rasn_dec, oer);
 rasn_dec_fn!(ber_rasn_dec, ber);
+rasn_dec_fn!(xer_rasn_dec, xer);
 
 criterion_group!(
     benches,
@@ -166,6 +168,8 @@ criterion_group!(
     oer_rasn_enc,
     oer_rasn_dec,
     ber_rasn_enc,
-    ber_rasn_dec
+    ber_rasn_dec,
+    xer_rasn_enc,
+    xer_rasn_dec
 );
 criterion_main!(benches);

benches/integer.rs

@@ -8,6 +8,7 @@ pub fn derive_struct_impl(
     container: syn::DataStruct,
     config: &Config,
 ) -> syn::Result<proc_macro2::TokenStream> {
+    let name_literal = name.to_string();
     let crate_root = &config.crate_root;
     let tag = config.tag_for_struct(&container.fields);
     let field_configs = container
@@ -90,8 +91,8 @@ pub fn derive_struct_impl(
     let constraints_def = config.constraints.const_static_def(crate_root);
 
     let alt_identifier = config.identifier.as_ref().map_or(
-        quote!(),
-        |id| quote!(const IDENTIFIER: Option<&'static str> = Some(#id);),
+        quote!(const IDENTIFIER: #crate_root::types::Identifier = #crate_root::types::Identifier(Some(#name_literal));),
+        |id| quote!(const IDENTIFIER: #crate_root::types::Identifier = #crate_root::types::Identifier(Some(#id));),
     );
 
     Ok(quote! {

macros/macros_impl/src/asn_type.rs

@@ -1,4 +1,5 @@
 use crate::{ext::TypeExt, tag::Tag};
+use proc_macro2::Span;
 use quote::ToTokens;
 use std::ops::Deref;
 use syn::spanned::Spanned;
@@ -810,10 +811,20 @@ impl<'a> FieldConfig<'a> {
             .as_ref()
             .map(|name| quote!(#name))
             .unwrap_or_else(|| quote!(#i));
-        let mut ty = self.field.ty.clone();
         let crate_root = &self.container_config.crate_root;
+        let identifier = self
+            .identifier
+            .clone()
+            .or(self
+                .field
+                .ident
+                .as_ref()
+                .map(|i| LitStr::new(&i.to_string(), Span::call_site())))
+            .map(|i| quote!(#crate_root::types::Identifier(Some(#i))))
+            .unwrap_or(quote!(#crate_root::types::Identifier::EMPTY));
+        let mut ty = self.field.ty.clone();
         ty.strip_lifetimes();
-        let default_fn = self.default_fn();
+        let default_fn = self.default_fn().map(|d| quote!(#d,));
         let has_generics = !type_params.is_empty() && {
             if let Type::Path(ref ty) = ty {
                 ty.path.segments.iter().any(|seg| {
@@ -847,18 +858,19 @@ impl<'a> FieldConfig<'a> {
         let encode = if self.tag.is_some() || self.container_config.automatic_tags {
             if self.tag.as_ref().is_some_and(|tag| tag.is_explicit()) {
                 // Note: encoder must be aware if the field is optional and present, so we should not do the presence check on this level
-                quote!(encoder.encode_explicit_prefix(#tag, &self.#field)?;)
+                quote!(encoder.encode_explicit_prefix(#tag, &self.#field, #identifier)?;)
             } else if self.extension_addition {
                 quote!(
                     #constraint_def
                     encoder.encode_extension_addition(
                         #tag,
                         #constraint_name,
-                        &#this #field
+                        &#this #field,
+                        #identifier,
                     )?;
                 )
             } else if self.extension_addition_group {
-                quote!(encoder.encode_extension_addition_group(#this #field.as_ref())?;)
+                quote!(encoder.encode_extension_addition_group(#this #field.as_ref(), #identifier)?;)
             } else {
                 match (self.constraints.has_constraints(), self.default.is_some()) {
                     (true, true) => {
@@ -869,6 +881,7 @@ impl<'a> FieldConfig<'a> {
                                 #constraint_name,
                                 &#this #field,
                                 #default_fn
+                                #identifier,
                             )?;
                         )
                     }
@@ -880,13 +893,16 @@ impl<'a> FieldConfig<'a> {
                                 #tag,
                                 #constraint_name,
                                 #default_fn
+                                #identifier,
                             )?;
                         )
                     }
                     (false, true) => {
-                        quote!(encoder.encode_default_with_tag(#tag, &#this #field, #default_fn)?;)
+                        quote!(encoder.encode_default_with_tag(#tag, &#this #field, #default_fn #identifier)?;)
+                    }
+                    (false, false) => {
+                        quote!(#this #field.encode_with_tag_and_identifier(encoder, #tag, #identifier)?;)
                     }
-                    (false, false) => quote!(#this #field.encode_with_tag(encoder, #tag)?;),
                 }
             }
         } else if self.extension_addition {
@@ -895,11 +911,12 @@ impl<'a> FieldConfig<'a> {
                 encoder.encode_extension_addition(
                     #tag,
                     #constraint_name,
-                    &#this #field
+                    &#this #field,
+                    #identifier,
                 )?;
             )
         } else if self.extension_addition_group {
-            quote!(encoder.encode_extension_addition_group(#this #field.as_ref())?;)
+            quote!(encoder.encode_extension_addition_group(#this #field.as_ref(), #identifier)?;)
         } else {
             match (self.constraints.has_constraints(), self.default.is_some()) {
                 (true, true) => {
@@ -909,19 +926,23 @@ impl<'a> FieldConfig<'a> {
                             #constraint_name,
                             &#this #field,
                             #default_fn
+                            #identifier,
                         )?;
                     )
                 }
                 (true, false) => {
                     quote!(
                         #constraint_def
-                        #this #field.encode_with_constraints(
+                        #this #field.encode_with_constraints_and_identifier(
                             encoder,
                             #constraint_name,
+                            #identifier,
                         )?;
                     )
                 }
-                (false, true) => quote!(encoder.encode_default(&#this #field, #default_fn)?;),
+                (false, true) => {
+                    quote!(encoder.encode_default(&#this #field, #default_fn #identifier)?;)
+                }
                 (false, false) => quote!(#this #field.encode(encoder)?;),
             }
         };

macros/macros_impl/src/config.rs

@@ -1,3 +1,4 @@
+use quote::ToTokens;
 use syn::Fields;
 
 use crate::config::*;
@@ -11,6 +12,7 @@ pub fn derive_struct_impl(
 ) -> syn::Result<proc_macro2::TokenStream> {
     let mut list = vec![];
     let crate_root = &config.crate_root;
+    let crate_root_literal = crate_root.to_token_stream().to_string();
     let (impl_generics, ty_generics, where_clause) = generics.split_for_impl();
 
     let field_configs = container
@@ -100,7 +102,7 @@ pub fn derive_struct_impl(
                     name.clone(),
                     quote! {
                         #[derive(#crate_root::AsnType, #crate_root::Decode, #crate_root::Encode)]
-                        #[rasn(delegate)]
+                        #[rasn(delegate, crate_root = #crate_root_literal)]
                         #tag_attr
                         #constraints
                         pub struct #name(#ty);
@@ -113,7 +115,7 @@ pub fn derive_struct_impl(
 
         let choice_def = quote! {
             #[derive(#crate_root::AsnType, #crate_root::Decode, #crate_root::Encode)]
-            #[rasn(choice)]
+            #[rasn(choice, crate_root = #crate_root_literal)]
             enum #choice_name {
                 #(#field_type_names(#field_type_names)),*
             }
@@ -144,15 +146,15 @@ pub fn derive_struct_impl(
                 let set_field_impl = if config.extension_addition || config.extension_addition_group {
                     quote! {
                         if #ident.is_some() {
-                            return Err(rasn::de::Error::duplicate_field(stringify!(#ident), codec))
+                            return Err(#crate_root::de::Error::duplicate_field(stringify!(#ident), codec))
                         } else {
                             #ident = value.0;
                         }
                     }
                 } else {
                     quote! {
                         if #ident.replace(value.0).is_some() {
-                            return Err(rasn::de::Error::duplicate_field(stringify!(#ident), codec))
+                            return Err(#crate_root::de::Error::duplicate_field(stringify!(#ident), codec))
                         }
                     }
                 };