enforce no empty structs in parsing

alloy-rs · May 8, 2023 · 29fdc4e · 29fdc4e
1 parent 8ce0e4c
commit 29fdc4e
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Showing 3 changed files with 8 additions and 11 deletions.
diff --git a/abi/sol-type-parser/src/common/variable.rs b/abi/sol-type-parser/src/common/variable.rs
@@ -58,7 +58,9 @@ impl Parse for Parameters<Token![,]> {
 impl Parse for Parameters<Token![;]> {
     fn parse(input: ParseStream) -> Result<Self> {
         let this = input.parse_terminated(VariableDeclaration::parse_for_struct, Token![;])?;
-        if !this.is_empty() && !this.trailing_punct() {
+        if this.is_empty() {
+            Err(input.error("defining empty structs is disallowed"))
+        } else if !this.trailing_punct() {
             Err(input.error("expected trailing semicolon"))
         } else {
             Ok(Self(this))

diff --git a/abi/sol-type-parser/src/struct.rs b/abi/sol-type-parser/src/struct.rs
@@ -3,7 +3,7 @@ use crate::{
     r#type::Type,
 };
 use proc_macro2::TokenStream;
-use quote::{quote, quote_spanned};
+use quote::quote;
 use std::fmt;
 use syn::{
     braced,
@@ -75,7 +75,7 @@ impl Struct {
         };
 
         let encode_data_impl = match self.fields.len() {
-            0 => quote! { vec![] },
+            0 => unreachable!(),
             1 => {
                 let VariableDeclaration { ty, name, .. } = self.fields.first().unwrap();
                 quote!(<#ty as ::ethers_abi_enc::SolDataType>::eip712_data_word(&self.#name).0.to_vec())
@@ -136,11 +136,6 @@ impl Struct {
     }
 
     pub fn to_tokens(&self, tokens: &mut TokenStream, attrs: &[Attribute]) {
-        if self.fields.is_empty() {
-            tokens.extend(quote_spanned! {self.name.span()=>
-                compile_error!("defining empty structs is disallowed.");
-            });
-        }
         tokens.extend(self.expand_impl(attrs))
     }
 

diff --git a/abi/tests/ui/empty.stderr b/abi/tests/ui/empty.stderr
@@ -6,8 +6,8 @@ error: unexpected end of input, expected at least one of: `type`, `struct`, `fun
   |
   = note: this error originates in the macro `sol` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: defining empty structs is disallowed.
- --> tests/ui/empty.rs:6:12
+error: unexpected end of input, defining empty structs is disallowed
+ --> tests/ui/empty.rs:6:25
   |
 6 |     struct EmptyStruct {}
-  |            ^^^^^^^^^^^
+  |                         ^