Scope generated fn code mod by contract type name (#1556)

### What
Change the name of the generated code module that contains the generated
functions for calling the contract, so that the name includes the
contract type's name.

  ### Why
Prevents naming conflicts between functions with the same name across
different contract implementations. This is particularly helpful in
tests and examples where a developer may legitimately define two
contracts, that are intended to be used independently, but exist in the
same namespace. Today those contracts will see a compile error if the
contracts share the same name, which is much more of a common problem
now that constructors exist and have a common name.

This problem was reported by @ozgunozerk.

### Trying it out

Edit your Cargo.toml to include the patch:

```toml
[patch.crates-io.soroban-sdk]
git = "https://github.com/stellar/rs-soroban-sdk"
branch = "allow-coexisting-contractimpls-with-same-names"
```

Author: leighmcculloch

soroban-sdk-macros/src/derive_fn.rs

@@ -1,4 +1,6 @@
-use crate::{attribute::pass_through_attr_to_gen_code, map_type::map_type};
+use crate::{
+    attribute::pass_through_attr_to_gen_code, map_type::map_type, syn_ext::ty_to_safe_ident_str,
+};
 use itertools::MultiUnzip;
 use proc_macro2::TokenStream as TokenStream2;
 use quote::{format_ident, quote};
@@ -13,6 +15,7 @@ use syn::{
 #[allow(clippy::too_many_arguments)]
 pub fn derive_pub_fn(
     crate_path: &Path,
+    impl_ty: &Type,
     call: &TokenStream2,
     ident: &Ident,
     attrs: &[Attribute],
@@ -97,8 +100,9 @@ pub fn derive_pub_fn(
         .multiunzip();
 
     // Generated code parameters.
+    let impl_ty_safe_str = ty_to_safe_ident_str(impl_ty);
     let wrap_export_name = &format!("{}", ident);
-    let hidden_mod_ident = format_ident!("__{}", ident);
+    let hidden_mod_ident = format_ident!("__{}__{}", impl_ty_safe_str, ident);
     let deprecated_note = format!(
         "use `{}::new(&env, &contract_id).{}` instead",
         client_ident, &ident
@@ -154,6 +158,7 @@ pub fn derive_pub_fn(
     Ok(quote! {
         #[doc(hidden)]
         #(#attrs)*
+        #[allow(non_snake_case)]
         pub mod #hidden_mod_ident {
             use super::*;
 
@@ -198,15 +203,15 @@ pub fn derive_contract_function_registration_ctor<'a>(
         return quote!();
     }
 
+    let ty_str = ty_to_safe_ident_str(ty);
     let (idents, wrap_idents): (Vec<_>, Vec<_>) = methods
         .map(|m| {
             let ident = format!("{}", m.sig.ident);
-            let wrap_ident = format_ident!("__{}", m.sig.ident);
+            let wrap_ident = format_ident!("__{}__{}", ty_str, ident);
             (ident, wrap_ident)
         })
         .multiunzip();
 
-    let ty_str = quote!(#ty).to_string().replace(' ', "").replace(':', "_");
     let trait_str = quote!(#trait_ident).to_string();
     let methods_hash = format!("{:x}", Sha256::digest(idents.join(",").as_bytes()));
     let ctor_ident = format_ident!("__{ty_str}_{trait_str}_{methods_hash}_ctor");

soroban-sdk-macros/src/derive_spec_fn.rs

@@ -12,6 +12,7 @@ use syn::{
 };
 
 use crate::attribute::pass_through_attr_to_gen_code;
+use crate::syn_ext::ty_to_safe_ident_str;
 use crate::{doc::docs_from_attrs, map_type::map_type, DEFAULT_XDR_RW_LIMITS};
 
 #[allow(clippy::too_many_arguments)]
@@ -173,14 +174,21 @@ pub fn derive_fn_spec(
         .filter(|attr| pass_through_attr_to_gen_code(attr))
         .collect::<Vec<_>>();
 
+    let ty_str = ty_to_safe_ident_str(ty);
+    let hidden_mod_ident = format_ident!("__{}__{}__spec", ty_str, ident);
     let exported = if export {
         Some(quote! {
             #[doc(hidden)]
-            #[allow(non_snake_case)]
-            #[allow(non_upper_case_globals)]
             #(#attrs)*
-            #[cfg_attr(target_family = "wasm", link_section = "contractspecv0")]
-            pub static #spec_ident: [u8; #spec_xdr_len] = #ty::#spec_fn_ident();
+            #[allow(non_snake_case)]
+            pub mod #hidden_mod_ident {
+                #[doc(hidden)]
+                #[allow(non_snake_case)]
+                #[allow(non_upper_case_globals)]
+                #(#attrs)*
+                #[cfg_attr(target_family = "wasm", link_section = "contractspecv0")]
+                pub static #spec_ident: [u8; #spec_xdr_len] = super::#ty::#spec_fn_ident();
+            }
         })
     } else {
         None

soroban-sdk-macros/src/lib.rs

@@ -247,6 +247,7 @@ pub fn contractimpl(metadata: TokenStream, input: TokenStream) -> TokenStream {
             let call = quote! { <super::#ty>::#ident };
             derive_pub_fn(
                 crate_path,
+                &ty,
                 &call,
                 ident,
                 &m.attrs,

soroban-sdk-macros/src/syn_ext.rs

@@ -268,3 +268,7 @@ fn flatten_associated_items_in_impl_fns(imp: &mut ItemImpl) {
         }
     }
 }
+
+pub fn ty_to_safe_ident_str(ty: &Type) -> String {
+    quote!(#ty).to_string().replace(' ', "").replace(':', "_")
+}

soroban-sdk/src/tests/contract_add_i32.rs

@@ -28,7 +28,7 @@ fn test_functional() {
 
 #[test]
 fn test_spec() {
-    let entries = ScSpecEntry::from_xdr(__SPEC_XDR_FN_ADD, Limits::none()).unwrap();
+    let entries = ScSpecEntry::from_xdr(Contract::spec_xdr_add(), Limits::none()).unwrap();
     let expect = ScSpecEntry::FunctionV0(ScSpecFunctionV0 {
         doc: "".try_into().unwrap(),
         name: "add".try_into().unwrap(),

soroban-sdk/src/tests/contract_docs.rs

@@ -25,7 +25,7 @@ mod fn_ {
 
     #[test]
     fn test_spec() {
-        let entry = ScSpecEntry::from_xdr(__SPEC_XDR_FN_ADD, Limits::none()).unwrap();
+        let entry = ScSpecEntry::from_xdr(Contract::spec_xdr_add(), Limits::none()).unwrap();
         let expect = ScSpecEntry::FunctionV0(ScSpecFunctionV0 {
             doc: "Add adds\nthings together.".try_into().unwrap(),
             name: "add".try_into().unwrap(),

soroban-sdk/src/tests/contract_duration.rs

@@ -21,7 +21,8 @@ fn test_functional() {
 
 #[test]
 fn test_spec() {
-    let entries = xdr::ScSpecEntry::from_xdr(__SPEC_XDR_FN_EXEC, xdr::Limits::none()).unwrap();
+    let entries =
+        xdr::ScSpecEntry::from_xdr(Contract::spec_xdr_exec(), xdr::Limits::none()).unwrap();
     let expect = xdr::ScSpecEntry::FunctionV0(xdr::ScSpecFunctionV0 {
         doc: "".try_into().unwrap(),
         name: "exec".try_into().unwrap(),

soroban-sdk/src/tests/contract_fn.rs

@@ -19,6 +19,16 @@ impl Contract {
     }
 }
 
+#[contract]
+pub struct Contract2;
+
+#[contractimpl]
+impl Contract2 {
+    pub fn add(_e: &Env, a: i32, b: i32) -> i32 {
+        a + b
+    }
+}
+
 #[test]
 fn test_functional() {
     let e = Env::default();
@@ -32,7 +42,7 @@ fn test_functional() {
 
 #[test]
 fn test_spec() {
-    let entries = ScSpecEntry::from_xdr(__SPEC_XDR_FN_ADD, Limits::none()).unwrap();
+    let entries = ScSpecEntry::from_xdr(Contract::spec_xdr_add(), Limits::none()).unwrap();
     let expect = ScSpecEntry::FunctionV0(ScSpecFunctionV0 {
         doc: "".try_into().unwrap(),
         name: "add".try_into().unwrap(),
@@ -57,7 +67,8 @@ fn test_spec() {
 
 #[test]
 fn test_spec_with_unused_arg() {
-    let entries = ScSpecEntry::from_xdr(__SPEC_XDR_FN_ADD_WITH_UNUSED_ARG, Limits::none()).unwrap();
+    let entries =
+        ScSpecEntry::from_xdr(Contract::spec_xdr_add_with_unused_arg(), Limits::none()).unwrap();
     let expect = ScSpecEntry::FunctionV0(ScSpecFunctionV0 {
         doc: "".try_into().unwrap(),
         name: "add_with_unused_arg".try_into().unwrap(),

soroban-sdk/src/tests/contract_timepoint.rs

@@ -21,7 +21,8 @@ fn test_functional() {
 
 #[test]
 fn test_spec() {
-    let entries = xdr::ScSpecEntry::from_xdr(__SPEC_XDR_FN_EXEC, xdr::Limits::none()).unwrap();
+    let entries =
+        xdr::ScSpecEntry::from_xdr(Contract::spec_xdr_exec(), xdr::Limits::none()).unwrap();
     let expect = xdr::ScSpecEntry::FunctionV0(xdr::ScSpecFunctionV0 {
         doc: "".try_into().unwrap(),
         name: "exec".try_into().unwrap(),

soroban-sdk/src/tests/contract_udt_struct.rs

@@ -127,7 +127,7 @@ fn test_error_on_partial_decode() {
 
 #[test]
 fn test_spec() {
-    let entries = ScSpecEntry::from_xdr(__SPEC_XDR_FN_ADD, Limits::none()).unwrap();
+    let entries = ScSpecEntry::from_xdr(Contract::spec_xdr_add(), Limits::none()).unwrap();
     let expect = ScSpecEntry::FunctionV0(ScSpecFunctionV0 {
         doc: "".try_into().unwrap(),
         name: "add".try_into().unwrap(),
@@ -170,7 +170,7 @@ fn test_spec() {
 #[test]
 fn test_spec_with_long_names() {
     let entries =
-        ScSpecEntry::from_xdr(__SPEC_XDR_FN_ADD_UDT_WITH_LONG_NAME, Limits::none()).unwrap();
+        ScSpecEntry::from_xdr(Contract::spec_xdr_add_udt_with_long_name(), Limits::none()).unwrap();
     let expect = ScSpecEntry::FunctionV0(ScSpecFunctionV0 {
         doc: "".try_into().unwrap(),
         name: "add_udt_with_long_name".try_into().unwrap(),