feat(abigen): use AbiType when parsing Function abi signature fails at compile time (#647)

* refactor: improved from token impl

* feat: add AbiType support

* feat: no need for expect

* feat: add missing abiarraytype impl

* test: add struct derive test

* chore: rustfmt

* chore: update changelog

* chore: rustfmt

CHANGELOG.md

@@ -92,6 +92,8 @@
 
 ### Unreleased
 
+- Add AbiType implementation during EthAbiType expansion
+  [#647](https://github.com/gakonst/ethers-rs/pull/647)
 - fix Etherscan conditional HTTP support
   [#632](https://github.com/gakonst/ethers-rs/pull/632)
 - use `CARGO_MANIFEST_DIR` as root for relative paths in abigen

ethers-contract/ethers-contract-derive/src/abi_ty.rs

@@ -1,5 +1,6 @@
 //! Helper functions for deriving `EthAbiType`
 
+use crate::utils;
 use ethers_core::macros::ethers_core_crate;
 use proc_macro2::{Ident, Literal, TokenStream};
 use quote::{quote, quote_spanned};
@@ -38,7 +39,7 @@ pub fn derive_tokenizeable_impl(input: &DeriveInput) -> proc_macro2::TokenStream
 
                 let assignments = fields.named.iter().map(|f| {
                     let name = f.ident.as_ref().expect("Named fields have names");
-                    quote_spanned! { f.span() => #name: #core_crate::abi::Tokenizable::from_token(iter.next().expect("tokens size is sufficient qed").into_token())? }
+                    quote_spanned! { f.span() => #name: #core_crate::abi::Tokenizable::from_token(iter.next().unwrap())? }
                 });
                 let init_struct_impl = quote! { Self { #(#assignments,)* } };
 
@@ -58,7 +59,7 @@ pub fn derive_tokenizeable_impl(input: &DeriveInput) -> proc_macro2::TokenStream
                 let tokenize_predicates = quote! { #(#tokenize_predicates,)* };
 
                 let assignments = fields.unnamed.iter().map(|f| {
-                    quote_spanned! { f.span() => #core_crate::abi::Tokenizable::from_token(iter.next().expect("tokens size is sufficient qed").into_token())? }
+                    quote_spanned! { f.span() => #core_crate::abi::Tokenizable::from_token(iter.next().unwrap())? }
                 });
                 let init_struct_impl = quote! { Self(#(#assignments,)* ) };
 
@@ -131,7 +132,20 @@ pub fn derive_tokenizeable_impl(input: &DeriveInput) -> proc_macro2::TokenStream
         }
     };
 
+    let params = match utils::derive_param_type_with_abi_type(input, "EthAbiType") {
+        Ok(params) => params,
+        Err(err) => return err.to_compile_error(),
+    };
     quote! {
+
+        impl<#generic_params> #core_crate::abi::AbiType for #name<#generic_args>  {
+            fn param_type() -> #core_crate::abi::ParamType {
+                #params
+            }
+        }
+
+       impl<#generic_params> #core_crate::abi::AbiArrayType for #name<#generic_args> {}
+
          impl<#generic_params> #core_crate::abi::Tokenizable for #name<#generic_args>
          where
              #generic_predicates

ethers-contract/ethers-contract-derive/src/call.rs

@@ -13,11 +13,6 @@ use crate::{abi_ty, utils};
 
 /// Generates the `ethcall` trait support
 pub(crate) fn derive_eth_call_impl(input: DeriveInput) -> TokenStream {
-    // the ethers crates to use
-    let core_crate = ethers_core_crate();
-    let contract_crate = ethers_contract_crate();
-
-    let name = &input.ident;
     let attributes = match parse_call_attributes(&input) {
         Ok(attributes) => attributes,
         Err(errors) => return errors,
@@ -56,27 +51,58 @@ pub(crate) fn derive_eth_call_impl(input: DeriveInput) -> TokenStream {
                     state_mutability: Default::default(),
                 }
             } else {
-                return Error::new(span, format!("Unable to determine ABI: {}", src))
+                // try to determine the abi by using its fields at runtime
+                return match derive_trait_impls_with_abi_type(&input, &function_call_name) {
+                    Ok(derived) => derived,
+                    Err(err) => {
+                        Error::new(span, format!("Unable to determine ABI for `{}` : {}", src, err))
                             .to_compile_error()
                     }
                 }
+            }
+        }
     } else {
-        // // try to determine the abi from the fields
+        // try to determine the abi by using its fields at runtime
-        match derive_abi_function_from_fields(&input) {
+        return match derive_trait_impls_with_abi_type(&input, &function_call_name) {
-            Ok(event) => event,
+            Ok(derived) => derived,
-            Err(err) => return err.to_compile_error(),
+            Err(err) => err.to_compile_error(),
         }
     };
-
     function.name = function_call_name.clone();
-
     let abi = function.abi_signature();
     let selector = utils::selector(function.selector());
+    let decode_impl = derive_decode_impl_from_function(&function);
 
-    let decode_impl = derive_decode_impl(&function);
+    derive_trait_impls(
+        &input,
+        &function_call_name,
+        quote! {#abi.into()},
+        Some(selector),
+        decode_impl,
+    )
+}
+
+/// Generates the EthCall implementation
+pub fn derive_trait_impls(
+    input: &DeriveInput,
+    function_call_name: &str,
+    abi_signature: TokenStream,
+    selector: Option<TokenStream>,
+    decode_impl: TokenStream,
+) -> TokenStream {
+    // the ethers crates to use
+    let core_crate = ethers_core_crate();
+    let contract_crate = ethers_contract_crate();
+    let struct_name = &input.ident;
+
+    let selector = selector.unwrap_or_else(|| {
+        quote! {
+             #core_crate::utils::id(Self::abi_signature())
+        }
+    });
 
     let ethcall_impl = quote! {
-        impl #contract_crate::EthCall for #name {
+        impl #contract_crate::EthCall for #struct_name {
 
             fn function_name() -> ::std::borrow::Cow<'static, str> {
                 #function_call_name.into()
@@ -87,17 +113,17 @@ pub(crate) fn derive_eth_call_impl(input: DeriveInput) -> TokenStream {
             }
 
             fn abi_signature() -> ::std::borrow::Cow<'static, str> {
-                #abi.into()
+                #abi_signature
             }
         }
 
-        impl  #core_crate::abi::AbiDecode for #name {
+        impl  #core_crate::abi::AbiDecode for #struct_name {
             fn decode(bytes: impl AsRef<[u8]>) -> Result<Self, #core_crate::abi::AbiError> {
                 #decode_impl
             }
         }
 
-        impl #core_crate::abi::AbiEncode for #name {
+        impl #core_crate::abi::AbiEncode for #struct_name {
             fn encode(self) -> ::std::vec::Vec<u8> {
                 let tokens =  #core_crate::abi::Tokenize::into_tokens(self);
                 let selector = <Self as #contract_crate::EthCall>::selector();
@@ -111,7 +137,7 @@ pub(crate) fn derive_eth_call_impl(input: DeriveInput) -> TokenStream {
         }
 
     };
-    let tokenize_impl = abi_ty::derive_tokenizeable_impl(&input);
+    let tokenize_impl = abi_ty::derive_tokenizeable_impl(input);
 
     quote! {
         #tokenize_impl
@@ -119,12 +145,23 @@ pub(crate) fn derive_eth_call_impl(input: DeriveInput) -> TokenStream {
     }
 }
 
-fn derive_decode_impl(function: &Function) -> TokenStream {
+/// Generates the decode implementation based on the function's input types
+fn derive_decode_impl_from_function(function: &Function) -> TokenStream {
+    let datatypes = function.inputs.iter().map(|input| utils::param_type_quote(&input.kind));
+    let datatypes_array = quote! {[#( #datatypes ),*]};
+    derive_decode_impl(datatypes_array)
+}
+
+/// Generates the decode implementation based on the function's runtime `AbiType` impl
+fn derive_decode_impl_with_abi_type(input: &DeriveInput) -> Result<TokenStream, Error> {
+    let datatypes_array = utils::derive_abi_parameters_array(input, "EthCall")?;
+    Ok(derive_decode_impl(datatypes_array))
+}
+
+fn derive_decode_impl(datatypes_array: TokenStream) -> TokenStream {
     let core_crate = ethers_core_crate();
     let contract_crate = ethers_contract_crate();
-    let data_types = function.inputs.iter().map(|input| utils::param_type_quote(&input.kind));
+    let data_types_init = quote! {let data_types = #datatypes_array;};
-
-    let data_types_init = quote! {let data_types = [#( #data_types ),*];};
 
     quote! {
         let bytes = bytes.as_ref();
@@ -137,20 +174,18 @@ fn derive_decode_impl(function: &Function) -> TokenStream {
     }
 }
 
-/// Determine the function's ABI by parsing the AST
+/// Use the `AbiType` trait to determine the correct `ParamType` and signature at runtime
-fn derive_abi_function_from_fields(input: &DeriveInput) -> Result<Function, Error> {
+fn derive_trait_impls_with_abi_type(
-    #[allow(deprecated)]
+    input: &DeriveInput,
-    let function = Function {
+    function_call_name: &str,
-        name: "".to_string(),
+) -> Result<TokenStream, Error> {
-        inputs: utils::derive_abi_inputs_from_fields(input, "EthCall")?
+    let abi_signature =
-            .into_iter()
+        utils::derive_abi_signature_with_abi_type(input, function_call_name, "EthCall")?;
-            .map(|(name, kind)| Param { name, kind, internal_type: None })
+    let abi_signature = quote! {
-            .collect(),
+         ::std::borrow::Cow::Owned(#abi_signature)
-        outputs: vec![],
-        constant: false,
-        state_mutability: Default::default(),
     };
-    Ok(function)
+    let decode_impl = derive_decode_impl_with_abi_type(input)?;
+    Ok(derive_trait_impls(input, function_call_name, abi_signature, None, decode_impl))
 }
 
 /// All the attributes the `EthCall` macro supports

ethers-contract/ethers-contract-derive/src/utils.rs

@@ -1,6 +1,6 @@
 use ethers_core::{abi::ParamType, macros::ethers_core_crate, types::Selector};
 use proc_macro2::Literal;
-use quote::quote;
+use quote::{quote, quote_spanned};
 use syn::{
     parse::Error, spanned::Spanned as _, Data, DeriveInput, Expr, Fields, GenericArgument, Lit,
     PathArguments, Type,
@@ -187,3 +187,88 @@ pub fn derive_abi_inputs_from_fields(
         })
         .collect()
 }
+
+/// Use `AbiType::param_type` fo each field to construct the input types own param type
+pub fn derive_param_type_with_abi_type(
+    input: &DeriveInput,
+    trait_name: &str,
+) -> Result<proc_macro2::TokenStream, Error> {
+    let core_crate = ethers_core_crate();
+    let params = derive_abi_parameters_array(input, trait_name)?;
+    Ok(quote! {
+        #core_crate::abi::ParamType::Tuple(::std::vec!#params)
+    })
+}
+
+/// Use `AbiType::param_type` fo each field to construct the whole signature `<name>(<params,>*)` as
+/// `String`
+pub fn derive_abi_signature_with_abi_type(
+    input: &DeriveInput,
+    function_name: &str,
+    trait_name: &str,
+) -> Result<proc_macro2::TokenStream, Error> {
+    let params = derive_abi_parameters_array(input, trait_name)?;
+    Ok(quote! {
+        {
+            let params: String = #params
+                                 .iter()
+                                 .map(|p| p.to_string())
+                                 .collect::<::std::vec::Vec<_>>()
+                                 .join(",");
+            let function_name = #function_name;
+            format!("{}({})", function_name, params)
+        }
+    })
+}
+
+/// Use `AbiType::param_type` fo each field to construct the signature's parameters as runtime array
+/// `[param1, param2,...]`
+pub fn derive_abi_parameters_array(
+    input: &DeriveInput,
+    trait_name: &str,
+) -> Result<proc_macro2::TokenStream, Error> {
+    let core_crate = ethers_core_crate();
+
+    let param_types: Vec<_> = match input.data {
+        Data::Struct(ref data) => match data.fields {
+            Fields::Named(ref fields) => fields
+                .named
+                .iter()
+                .map(|f| {
+                    let ty = &f.ty;
+                    quote_spanned! { f.span() => <#ty as #core_crate::abi::AbiType>::param_type() }
+                })
+                .collect(),
+            Fields::Unnamed(ref fields) => fields
+                .unnamed
+                .iter()
+                .map(|f| {
+                    let ty = &f.ty;
+                    quote_spanned! { f.span() => <#ty as #core_crate::abi::AbiType>::param_type() }
+                })
+                .collect(),
+            Fields::Unit => {
+                return Err(Error::new(
+                    input.span(),
+                    format!("{} cannot be derived for empty structs and unit", trait_name),
+                ))
+            }
+        },
+        Data::Enum(_) => {
+            return Err(Error::new(
+                input.span(),
+                format!("{} cannot be derived for enums", trait_name),
+            ))
+        }
+        Data::Union(_) => {
+            return Err(Error::new(
+                input.span(),
+                format!("{} cannot be derived for unions", trait_name),
+            ))
+        }
+    };
+
+    Ok(quote! {
+        [#( #param_types ),*]
+    })
+}

ethers-contract/tests/abigen.rs

@@ -1,6 +1,6 @@
 #![cfg(feature = "abigen")]
 //! Test cases to validate the `abigen!` macro
-use ethers_contract::{abigen, EthEvent};
+use ethers_contract::{abigen, EthCall, EthEvent};
 use ethers_core::{
     abi::{AbiDecode, AbiEncode, Address, Tokenizable},
     types::{transaction::eip2718::TypedTransaction, Eip1559TransactionRequest, U256},
@@ -375,3 +375,30 @@ fn can_handle_duplicates_with_same_name() {
 fn can_abigen_console_sol() {
     abigen!(Console, "ethers-contract/tests/solidity-contracts/console.json",);
 }
+
+#[test]
+fn can_generate_nested_types() {
+    abigen!(
+        Test,
+        r#"[
+        struct Outer {Inner inner; uint256[] arr;}
+        struct Inner {uint256 inner;}
+        function myfun(Outer calldata a)
+    ]"#,
+    );
+
+    assert_eq!(MyfunCall::abi_signature(), "myfun(((uint256),uint256[]))");
+
+    let (client, _mock) = Provider::mocked();
+    let contract = Test::new(Address::default(), Arc::new(client));
+
+    let inner = Inner { inner: 100u64.into() };
+    let a = Outer { inner, arr: vec![101u64.into()] };
+    let _ = contract.myfun(a.clone());
+
+    let call = MyfunCall { a: a.clone() };
+    let encoded_call = contract.encode("myfun", (a,)).unwrap();
+    assert_eq!(encoded_call, call.clone().encode().into());
+    let decoded_call = MyfunCall::decode(encoded_call.as_ref()).unwrap();
+    assert_eq!(call, decoded_call);
+}

ethers-core/src/abi/mod.rs

@@ -22,7 +22,7 @@ pub use error::{AbiError, ParseError};
 mod human_readable;
 pub use human_readable::{parse as parse_abi, parse_str as parse_abi_str, AbiParser};
 
-use crate::types::{H256, H512, U128, U256, U64};
+use crate::types::{H256, H512, I256, U128, U256, U64};
 
 /// Extension trait for `ethabi::Function`.
 pub trait FunctionExt {
@@ -98,6 +98,8 @@ impl<T: AbiArrayType, const N: usize> AbiType for [T; N] {
     }
 }
 
+impl<T: AbiArrayType, const N: usize> AbiArrayType for [T; N] {}
+
 impl<const N: usize> AbiType for [u8; N] {
     fn param_type() -> ParamType {
         ParamType::FixedBytes(N)
@@ -138,7 +140,8 @@ impl_abi_type!(
     i16 => Int(16),
     i32 => Int(32),
     i64 => Int(64),
-    i128 => Int(128)
+    i128 => Int(128),
+    I256 => Int(256)
 );
 
 macro_rules! impl_abi_type_tuple {