Allow all user-defined types to be renamed via procmacros. (#2661)

Fixes #2632, fixes #2212.

Author: mhammond

CHANGELOG.md

@@ -13,6 +13,7 @@
 
 ### What's new?
 
+- All user-defined types can now be renamed with the proc-macro `name = "NewName"` attribute (like already supported for methods and constructors) ([#2661](https://github.com/mozilla/uniffi-rs/pull/2661))
 - Objects can export the `Ord` trait, allowing such objects to be ordered ([#2583](https://github.com/mozilla/uniffi-rs/pull/2583)).
 - Objects can implement external traits ([#2430](https://github.com/mozilla/uniffi-rs/issues/2430))
 - Procmacros support `#[uniffi(default)]` on a field or `#[uniffi::export(default(arg_name))]` (ie,

Cargo.lock

@@ -57,6 +57,7 @@ members = [
   "fixtures/regressions/swift-dictionary-nesting",
   "fixtures/regressions/unary-result-alias",
   "fixtures/regressions/wrong-lower-check",
+  "fixtures/rename",
   "fixtures/trait-methods",
   "fixtures/uitests",
   "fixtures/uniffi-fixture-time",

Cargo.toml

@@ -83,3 +83,17 @@ public enum MyEnum : UInt8 {
     case bar = 4
 }
 ```
+
+## Renaming enums
+
+Enums can be renamed in foreign language bindings using the `name` parameter:
+
+```rust
+#[derive(uniffi::Enum)]
+#[uniffi(name = "RenamedEnum")]
+pub enum MyEnum {
+    // ...
+}
+```
+
+See [Renaming](./renaming.md) for more details on renaming functionality.

docs/manual/src/proc_macro/enumerations.md

@@ -93,3 +93,5 @@ impl Something {
     fn do_something(&self) { }
 }
 ```
+
+See [Renaming](./renaming.md) for more details on all renaming capabilites.

docs/manual/src/proc_macro/functions.md

@@ -52,6 +52,7 @@ For more details:
 * [Interfaces](./interfaces.md)
 * [Functions, constructors, methods](./functions.md)
 * [Errors](./errors.md)
+* [Renaming](./renaming.md)
 
 ## The `uniffi::Object` derive to extend interfaces defined in UDL
 

docs/manual/src/proc_macro/index.md

@@ -123,3 +123,8 @@ but also be able to be used when a `MyTrait` is required.
 
 Not all bindings support this.
 
+## Renaming objects
+
+Objects can be renamed in foreign language bindings using the `name` parameter on the export attribute;
+See [Renaming](./renaming.md) for details.
+

docs/manual/src/proc_macro/interfaces.md

@@ -36,3 +36,17 @@ pub struct OptionalRecord {
 ```
 
 Most types can have [default values](../types/defaults.md)
+
+## Renaming records
+
+Records can be renamed in foreign language bindings using the `name` parameter:
+
+```rust
+#[derive(uniffi::Record)]
+#[uniffi(name = "RenamedRecord")]
+pub struct MyRecord {
+    // ...
+}
+```
+
+See [Renaming](./renaming.md) for more details on all renaming capabilites.

docs/manual/src/proc_macro/records.md

@@ -0,0 +1,84 @@
+# Renaming
+
+UniFFI allows you to rename all callables and user-defined types in the foreign bindings using the `name` attribute.
+
+## Examples
+
+### Functions:
+
+```rust
+#[uniffi::export(name = "renamed_function")]
+fn function(record: Record) -> Enum {
+    Enum::Record(record)
+}
+```
+
+### Records and Enums
+
+```rust
+#[derive(uniffi::Record)]
+#[uniffi(name = "RenamedRecord")]
+pub struct Record {
+    item: i32,
+}
+
+#[derive(uniffi::Enum)]
+#[uniffi(name = "RenamedEnum")]
+pub enum Enum {
+    VariantA,
+    Record(Record),
+}
+```
+
+### Objects, Traits, and methods
+
+If you are renaming both the object and a callable, you must specify the new name in both the `derive` and the `uniffi::export` macros.
+
+Traits cannot yet be renamed, but trait methods can be renamed as usual.
+
+```rust
+#[derive(uniffi::Object)]
+#[uniffi(name = "RenamedObject")]
+pub struct Object {
+    value: i32,
+}
+
+#[uniffi::export(name = "RenamedObject")]
+impl Object {
+    #[uniffi::constructor(name = "renamed_constructor")]
+    pub fn new(value: i32) -> Self {
+        Object { value }
+    }
+
+    #[uniffi::method(name = "renamed_method")]
+    pub fn method(&self) -> i32 {
+        self.value
+    }
+}
+```
+
+### In the bindings
+
+```python
+# Python
+record = RenamedRecord(item=42)
+result = renamed_function(record)
+obj = RenamedObject.renamed_constructor(123)
+value = obj.renamed_method()
+```
+
+```kotlin
+// Kotlin
+val record = RenamedRecord(item = 42)
+val result = renamedFunction(record)
+val obj = RenamedObject.renamedConstructor(123)
+val value = obj.renamedMethod()
+```
+
+```swift
+// Swift
+let record = RenamedRecord(item: 42)
+let result = renamedFunction(record: record)
+let obj = RenamedObject.renamedConstructor(value: 123)
+let value = obj.renamedMethod()
+```

docs/manual/src/proc_macro/renaming.md

@@ -0,0 +1,22 @@
+[package]
+name = "uniffi-fixture-rename"
+edition = "2021"
+version = "0.22.0"
+license = "MPL-2.0"
+publish = false
+
+[lib]
+crate-type = ["lib", "cdylib"]
+
+[dependencies]
+uniffi = { workspace = true }
+thiserror = "2"
+
+[build-dependencies]
+uniffi = { workspace = true, features = ["build"] }
+
+[dev-dependencies]
+uniffi = { workspace = true, features = ["bindgen-tests"] }
+
+[features]
+ffi-trace = ["uniffi/ffi-trace"]