1631952 - Fail loudly when trying to `xpimplement` multiple interfaces with the same method name in Rust

Status: RESOLVED FIXED

(Core :: XPCOM, task)

Description

[Lina Butler [:lina]]

I declared two methods with the same name (but different callback parameter types) in two different interfaces. That won't work in Rust, since it doesn't have function overloading like C++—but the compiler error only pointed to the derive[xpcom] line, saying something like expected type *const nsICallbackType, found type *const nsIOtherCallbackType, making it hard to figure out what the actual issue was.

We can't really do anything about this except use binaryname in XPIDL to rename one or both of those methods to something that doesn't conflict. So let's suggest that in the error that we return.

Comment 1

[Lina Butler [:lina]]

Attachment: Bug 1631952 - Ensure that all XPCOM interface methods have unique names when implementing them in Rust. r?nika!

Comment 2

[Lina Butler [:lina]]

 2:06.29    = help: message: #[derive(xpcom)] failed: "The method `Finalize` is declared on both `mozIExtensionStorageArea` and `mozIBridgedSyncEngine`, but a Rust type cannot implement two methods with the same name. You can add the `[binaryname(RenamedFinalize)]` XPIDL attribute to one of the declarations to rename it."

Much better! 😊

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/9371029b5814
Ensure that all XPCOM interface methods have unique names when implementing them in Rust. r=nika

Comment 4

[Arthur Iakab [arthur_iakab]]

https://hg.mozilla.org/mozilla-central/rev/9371029b5814