Opt out from default derives and attributes (#925)

* No default derives

* Clippy

* Clippy

* Review

* Review

* Typo

cli/src/commands/codegen.rs

@@ -19,11 +19,19 @@ pub struct Opts {
     /// Additional derives
     #[clap(long = "derive")]
     derives: Vec<String>,
+    /// Additional attributes
+    #[clap(long = "attribute")]
+    attributes: Vec<String>,
     /// Additional derives for a given type.
     ///
     /// Example `--derive-for-type my_module::my_type=serde::Serialize`.
     #[clap(long = "derive-for-type", value_parser = derive_for_type_parser)]
     derives_for_type: Vec<(String, String)>,
+    /// Additional attributes for a given type.
+    ///
+    /// Example `--attributes-for-type my_module::my_type=#[allow(clippy::all)]`.
+    #[clap(long = "attributes-for-type", value_parser = attributes_for_type_parser)]
+    attributes_for_type: Vec<(String, String)>,
     /// Substitute a type for another.
     ///
     /// Example `--substitute-type sp_runtime::MultiAddress<A,B>=subxt::utils::Static<::sp_runtime::MultiAddress<A,B>>`
@@ -39,8 +47,15 @@ pub struct Opts {
     #[clap(long, action)]
     no_docs: bool,
     /// Whether to limit code generation to only runtime types.
+    ///
+    /// Defaults to `false` (all types are generated).
     #[clap(long)]
     runtime_types_only: bool,
+    /// Do not provide default trait derivations for the generated types.
+    ///
+    /// Defaults to `false` (default trait derivations are provided).
+    #[clap(long)]
+    no_default_derives: bool,
 }
 
 fn derive_for_type_parser(src: &str) -> Result<(String, String), String> {
@@ -51,6 +66,14 @@ fn derive_for_type_parser(src: &str) -> Result<(String, String), String> {
     Ok((ty.to_string(), derive.to_string()))
 }
 
+fn attributes_for_type_parser(src: &str) -> Result<(String, String), String> {
+    let (ty, attribute) = src
+        .split_once('=')
+        .ok_or_else(|| String::from("Invalid pattern for `attribute-type`. It should be `type=attribute`, like `my_type=serde::#[allow(clippy::all)]`"))?;
+
+    Ok((ty.to_string(), attribute.to_string()))
+}
+
 fn substitute_type_parser(src: &str) -> Result<(String, String), String> {
     let (from, to) = src
         .split_once('=')
@@ -65,41 +88,71 @@ pub async fn run(opts: Opts) -> color_eyre::Result<()> {
     codegen(
         &bytes,
         opts.derives,
+        opts.attributes,
         opts.derives_for_type,
+        opts.attributes_for_type,
         opts.substitute_types,
         opts.crate_path,
         opts.no_docs,
         opts.runtime_types_only,
+        opts.no_default_derives,
     )?;
     Ok(())
 }
 
+#[derive(Clone, Debug)]
+struct OuterAttribute(syn::Attribute);
+
+impl syn::parse::Parse for OuterAttribute {
+    fn parse(input: syn::parse::ParseStream) -> syn::Result<Self> {
+        Ok(Self(input.call(syn::Attribute::parse_outer)?[0].clone()))
+    }
+}
+
+#[allow(clippy::too_many_arguments)]
 fn codegen(
     metadata_bytes: &[u8],
     raw_derives: Vec<String>,
+    raw_attributes: Vec<String>,
     derives_for_type: Vec<(String, String)>,
+    attributes_for_type: Vec<(String, String)>,
     substitute_types: Vec<(String, String)>,
     crate_path: Option<String>,
     no_docs: bool,
     runtime_types_only: bool,
+    no_default_derives: bool,
 ) -> color_eyre::Result<()> {
     let item_mod = syn::parse_quote!(
         pub mod api {}
     );
 
-    let p = raw_derives
+    let universal_derives = raw_derives
         .iter()
         .map(|raw| syn::parse_str(raw))
         .collect::<Result<Vec<_>, _>>()?;
+    let universal_attributes = raw_attributes
+        .iter()
+        .map(|raw| syn::parse_str(raw))
+        .map(|attr: syn::Result<OuterAttribute>| attr.map(|attr| attr.0))
+        .collect::<Result<Vec<_>, _>>()?;
 
     let crate_path = crate_path.map(Into::into).unwrap_or_default();
-    let mut derives = DerivesRegistry::new(&crate_path);
-    derives.extend_for_all(p.into_iter());
+    let mut derives = if no_default_derives {
+        DerivesRegistry::new()
+    } else {
+        DerivesRegistry::with_default_derives(&crate_path)
+    };
+    derives.extend_for_all(universal_derives, universal_attributes);
 
     for (ty, derive) in derives_for_type {
         let ty = syn::parse_str(&ty)?;
         let derive = syn::parse_str(&derive)?;
-        derives.extend_for_type(ty, std::iter::once(derive), &crate_path);
+        derives.extend_for_type(ty, std::iter::once(derive), vec![]);
+    }
+    for (ty, attr) in attributes_for_type {
+        let ty = syn::parse_str(&ty)?;
+        let attribute: OuterAttribute = syn::parse_str(&attr)?;
+        derives.extend_for_type(ty, vec![], std::iter::once(attribute.0));
     }
 
     let mut type_substitutes = TypeSubstitutes::new(&crate_path);

codegen/src/lib.rs

@@ -32,7 +32,7 @@
 //!     pub mod api {}
 //! );
 //! // Default module derivatives.
-//! let mut derives = DerivesRegistry::new(&CratePath::default());
+//! let mut derives = DerivesRegistry::with_default_derives(&CratePath::default());
 //! // Default type substitutes.
 //! let substs = TypeSubstitutes::new(&CratePath::default());
 //! // Generate the Runtime API.

codegen/src/types/derives.rs

@@ -16,35 +16,55 @@ pub struct DerivesRegistry {
     specific_type_derives: HashMap<syn::TypePath, Derives>,
 }
 
+impl Default for DerivesRegistry {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl DerivesRegistry {
-    /// Creates a new `DerivesRegistry` with the supplied `crate_path`.
+    /// Creates a new `DerivesRegistry` with no default derives.
+    pub fn new() -> Self {
+        Self {
+            default_derives: Derives::new(),
+            specific_type_derives: Default::default(),
+        }
+    }
+
+    /// Creates a new `DerivesRegistry` with default derives.
     ///
     /// The `crate_path` denotes the `subxt` crate access path in the
     /// generated code.
-    pub fn new(crate_path: &CratePath) -> Self {
+    pub fn with_default_derives(crate_path: &CratePath) -> Self {
         Self {
-            default_derives: Derives::new(crate_path),
+            default_derives: Derives::with_defaults(crate_path),
             specific_type_derives: Default::default(),
         }
     }
 
     /// Insert derives to be applied to all generated types.
-    pub fn extend_for_all(&mut self, derives: impl IntoIterator<Item = syn::Path>) {
-        self.default_derives.derives.extend(derives)
+    pub fn extend_for_all(
+        &mut self,
+        derives: impl IntoIterator<Item = syn::Path>,
+        attributes: impl IntoIterator<Item = syn::Attribute>,
+    ) {
+        self.default_derives.derives.extend(derives);
+        self.default_derives.attributes.extend(attributes);
     }
 
     /// Insert derives to be applied to a specific generated type.
     pub fn extend_for_type(
         &mut self,
         ty: syn::TypePath,
         derives: impl IntoIterator<Item = syn::Path>,
-        crate_path: &CratePath,
+        attributes: impl IntoIterator<Item = syn::Attribute>,
     ) {
         let type_derives = self
             .specific_type_derives
             .entry(ty)
-            .or_insert_with(|| Derives::new(crate_path));
-        type_derives.derives.extend(derives)
+            .or_insert_with(Derives::new);
+        type_derives.derives.extend(derives);
+        type_derives.attributes.extend(attributes);
     }
 
     /// Returns the derives to be applied to all generated types.
@@ -73,6 +93,12 @@ pub struct Derives {
     attributes: HashSet<syn::Attribute>,
 }
 
+impl Default for Derives {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl FromIterator<syn::Path> for Derives {
     fn from_iter<T: IntoIterator<Item = Path>>(iter: T) -> Self {
         let derives = iter.into_iter().collect();
@@ -84,9 +110,17 @@ impl FromIterator<syn::Path> for Derives {
 }
 
 impl Derives {
+    /// Creates an empty instance of `Derives` (with no default derives).
+    pub fn new() -> Self {
+        Self {
+            derives: HashSet::new(),
+            attributes: HashSet::new(),
+        }
+    }
+
     /// Creates a new instance of `Derives` with the `crate_path` prepended
     /// to the set of default derives that reside in `subxt`.
-    pub fn new(crate_path: &CratePath) -> Self {
+    pub fn with_defaults(crate_path: &CratePath) -> Self {
         let mut derives = HashSet::new();
         let mut attributes = HashSet::new();
 
@@ -99,8 +133,6 @@ impl Derives {
         attributes.insert(syn::parse_quote!(#[decode_as_type(crate_path = #decode_crate_path)]));
 
         derives.insert(syn::parse_quote!(#crate_path::ext::codec::Encode));
-        attributes.insert(syn::parse_quote!(#[codec(crate = #crate_path::ext::codec)]));
-
         derives.insert(syn::parse_quote!(#crate_path::ext::codec::Decode));
         attributes.insert(syn::parse_quote!(#[codec(crate = #crate_path::ext::codec)]));