Bump the Rust version to 1.84.0, but MSR remains the same. (#2422)

In line with our Rust version policy, this matches a current mozilla-central.

fixtures/callbacks/src/lib.rs

@@ -103,6 +103,7 @@ impl Default for RustGetters {
 #[allow(clippy::wrong_self_convention)]
 trait StoredForeignStringifier: Send + Sync + std::fmt::Debug {
     fn from_simple_type(&self, value: i32) -> String;
+    #[allow(dead_code)]
     fn from_complex_type(&self, values: Option<Vec<Option<f64>>>) -> String;
 }
 

fixtures/keywords/kotlin/src/lib.rs

@@ -2,6 +2,8 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+#![allow(dead_code)]
+
 use std::{collections::HashMap, sync::Arc};
 
 pub fn r#if(_object: u8) {}

fixtures/uitests/src/lib.rs

@@ -2,7 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-/// This crate only exists for its tests.
+//! This crate only exists for its tests.
 
 #[cfg(test)]
 mod test {

fixtures/uitests/tests/ui/fieldless_errors_used_in_callbacks_cant_have_fields.stderr

@@ -1,7 +1,11 @@
 error[E0533]: expected value, found struct variant `Self::DivisionByZero`
- --> $OUT_DIR[uniffi_uitests]/errors.uniffi.rs
-  |
-  | #[::uniffi::udl_derive(Error)]
-  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not a value
-  |
-  = note: this error originates in the attribute macro `::uniffi::udl_derive` (in Nightly builds, run with -Z macro-backtrace for more info)
+  --> $OUT_DIR[uniffi_uitests]/errors.uniffi.rs
+   |
+   | #[::uniffi::udl_derive(Error)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not a value
+   |
+   = note: this error originates in the attribute macro `::uniffi::udl_derive` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: you might have meant to create a new value of the struct
+   |
+29 | #[::uniffi::udl_derive(Error)] { numerator: /* value */ }
+   |                                ++++++++++++++++++++++++++

fixtures/uitests/tests/ui/interface_not_sync_and_send.stderr

@@ -4,7 +4,7 @@ error[E0277]: `Cell<u32>` cannot be shared between threads safely
   | struct r#Counter { }
   |        ^^^^^^^^^ `Cell<u32>` cannot be shared between threads safely
   |
-  = help: within `Counter`, the trait `Sync` is not implemented for `Cell<u32>`, which is required by `Counter: Sync`
+  = help: within `Counter`, the trait `Sync` is not implemented for `Cell<u32>`
   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` or `std::sync::atomic::AtomicU32` instead
 note: required because it appears within the type `Counter`
  --> tests/ui/interface_not_sync_and_send.rs:9:12
@@ -24,7 +24,7 @@ error[E0277]: `Cell<u32>` cannot be shared between threads safely
   | struct r#Counter { }
   |        ^^^^^^^^^ `Cell<u32>` cannot be shared between threads safely
   |
-  = help: within `Counter`, the trait `Sync` is not implemented for `Cell<u32>`, which is required by `Counter: Sync`
+  = help: within `Counter`, the trait `Sync` is not implemented for `Cell<u32>`
   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` or `std::sync::atomic::AtomicU32` instead
 note: required because it appears within the type `Counter`
  --> tests/ui/interface_not_sync_and_send.rs:9:12
@@ -43,7 +43,7 @@ error[E0277]: `Cell<u32>` cannot be shared between threads safely
 27 | pub struct ProcMacroCounter {
    |            ^^^^^^^^^^^^^^^^ `Cell<u32>` cannot be shared between threads safely
    |
-   = help: within `ProcMacroCounter`, the trait `Sync` is not implemented for `Cell<u32>`, which is required by `ProcMacroCounter: Sync`
+   = help: within `ProcMacroCounter`, the trait `Sync` is not implemented for `Cell<u32>`
    = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` or `std::sync::atomic::AtomicU32` instead
 note: required because it appears within the type `ProcMacroCounter`
   --> tests/ui/interface_not_sync_and_send.rs:27:12
@@ -63,7 +63,7 @@ error[E0277]: `Cell<u32>` cannot be shared between threads safely
 27 | pub struct ProcMacroCounter {
    |            ^^^^^^^^^^^^^^^^ `Cell<u32>` cannot be shared between threads safely
    |
-   = help: within `ProcMacroCounter`, the trait `Sync` is not implemented for `Cell<u32>`, which is required by `ProcMacroCounter: Sync`
+   = help: within `ProcMacroCounter`, the trait `Sync` is not implemented for `Cell<u32>`
    = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` or `std::sync::atomic::AtomicU32` instead
 note: required because it appears within the type `ProcMacroCounter`
   --> tests/ui/interface_not_sync_and_send.rs:27:12
@@ -75,3 +75,47 @@ note: required by a bound in `FfiConverterArc`
    |
    | pub unsafe trait FfiConverterArc<UT>: Send + Sync {
    |                                              ^^^^ required by this bound in `FfiConverterArc`
+
+error[E0277]: `Cell<u32>` cannot be shared between threads safely
+ --> $OUT_DIR[uniffi_uitests]/counter.uniffi.rs
+  |
+  | #[::uniffi::udl_derive(Object)]
+  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `Cell<u32>` cannot be shared between threads safely
+  |
+  = help: within `Counter`, the trait `Sync` is not implemented for `Cell<u32>`
+  = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` or `std::sync::atomic::AtomicU32` instead
+note: required because it appears within the type `Counter`
+ --> tests/ui/interface_not_sync_and_send.rs:9:12
+  |
+9 | pub struct Counter {
+  |            ^^^^^^^
+note: required by a bound in `uniffi::FfiConverterArc::FfiType`
+ --> $WORKSPACE/uniffi_core/src/ffi_converter_traits.rs
+  |
+  | pub unsafe trait FfiConverterArc<UT>: Send + Sync {
+  |                                              ^^^^ required by this bound in `FfiConverterArc::FfiType`
+  |     type FfiType: FfiDefault;
+  |          ------- required by a bound in this associated type
+  = note: this error originates in the attribute macro `::uniffi::udl_derive` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: `Cell<u32>` cannot be shared between threads safely
+  --> tests/ui/interface_not_sync_and_send.rs:26:10
+   |
+26 | #[derive(uniffi::Object)]
+   |          ^^^^^^^^^^^^^^ `Cell<u32>` cannot be shared between threads safely
+   |
+   = help: within `ProcMacroCounter`, the trait `Sync` is not implemented for `Cell<u32>`
+   = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` or `std::sync::atomic::AtomicU32` instead
+note: required because it appears within the type `ProcMacroCounter`
+  --> tests/ui/interface_not_sync_and_send.rs:27:12
+   |
+27 | pub struct ProcMacroCounter {
+   |            ^^^^^^^^^^^^^^^^
+note: required by a bound in `uniffi::FfiConverterArc::FfiType`
+  --> $WORKSPACE/uniffi_core/src/ffi_converter_traits.rs
+   |
+   | pub unsafe trait FfiConverterArc<UT>: Send + Sync {
+   |                                              ^^^^ required by this bound in `FfiConverterArc::FfiType`
+   |     type FfiType: FfiDefault;
+   |          ------- required by a bound in this associated type
+   = note: this error originates in the derive macro `uniffi::Object` (in Nightly builds, run with -Z macro-backtrace for more info)

fixtures/uitests/tests/ui/interface_trait_not_sync_and_send.stderr

@@ -109,3 +109,67 @@ note: required by a bound in `FfiConverterArc`
    | pub unsafe trait FfiConverterArc<UT>: Send + Sync {
    |                                       ^^^^ required by this bound in `FfiConverterArc`
    = note: this error originates in the attribute macro `uniffi::export` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: `(dyn Trait + 'static)` cannot be sent between threads safely
+ --> $OUT_DIR[uniffi_uitests]/trait.uniffi.rs
+  |
+  | #[::uniffi::export_for_udl]
+  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ `(dyn Trait + 'static)` cannot be sent between threads safely
+  |
+  = help: the trait `Send` is not implemented for `(dyn Trait + 'static)`
+note: required by a bound in `uniffi::FfiConverterArc::FfiType`
+ --> $WORKSPACE/uniffi_core/src/ffi_converter_traits.rs
+  |
+  | pub unsafe trait FfiConverterArc<UT>: Send + Sync {
+  |                                       ^^^^ required by this bound in `FfiConverterArc::FfiType`
+  |     type FfiType: FfiDefault;
+  |          ------- required by a bound in this associated type
+  = note: this error originates in the attribute macro `::uniffi::export_for_udl` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: `(dyn Trait + 'static)` cannot be shared between threads safely
+ --> $OUT_DIR[uniffi_uitests]/trait.uniffi.rs
+  |
+  | #[::uniffi::export_for_udl]
+  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ `(dyn Trait + 'static)` cannot be shared between threads safely
+  |
+  = help: the trait `Sync` is not implemented for `(dyn Trait + 'static)`
+note: required by a bound in `uniffi::FfiConverterArc::FfiType`
+ --> $WORKSPACE/uniffi_core/src/ffi_converter_traits.rs
+  |
+  | pub unsafe trait FfiConverterArc<UT>: Send + Sync {
+  |                                              ^^^^ required by this bound in `FfiConverterArc::FfiType`
+  |     type FfiType: FfiDefault;
+  |          ------- required by a bound in this associated type
+  = note: this error originates in the attribute macro `::uniffi::export_for_udl` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: `(dyn ProcMacroTrait + 'static)` cannot be sent between threads safely
+  --> tests/ui/interface_trait_not_sync_and_send.rs:11:1
+   |
+11 | #[uniffi::export]
+   | ^^^^^^^^^^^^^^^^^ `(dyn ProcMacroTrait + 'static)` cannot be sent between threads safely
+   |
+   = help: the trait `Send` is not implemented for `(dyn ProcMacroTrait + 'static)`
+note: required by a bound in `uniffi::FfiConverterArc::FfiType`
+  --> $WORKSPACE/uniffi_core/src/ffi_converter_traits.rs
+   |
+   | pub unsafe trait FfiConverterArc<UT>: Send + Sync {
+   |                                       ^^^^ required by this bound in `FfiConverterArc::FfiType`
+   |     type FfiType: FfiDefault;
+   |          ------- required by a bound in this associated type
+   = note: this error originates in the attribute macro `uniffi::export` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: `(dyn ProcMacroTrait + 'static)` cannot be shared between threads safely
+  --> tests/ui/interface_trait_not_sync_and_send.rs:11:1
+   |
+11 | #[uniffi::export]
+   | ^^^^^^^^^^^^^^^^^ `(dyn ProcMacroTrait + 'static)` cannot be shared between threads safely
+   |
+   = help: the trait `Sync` is not implemented for `(dyn ProcMacroTrait + 'static)`
+note: required by a bound in `uniffi::FfiConverterArc::FfiType`
+  --> $WORKSPACE/uniffi_core/src/ffi_converter_traits.rs
+   |
+   | pub unsafe trait FfiConverterArc<UT>: Send + Sync {
+   |                                              ^^^^ required by this bound in `FfiConverterArc::FfiType`
+   |     type FfiType: FfiDefault;
+   |          ------- required by a bound in this associated type
+   = note: this error originates in the attribute macro `uniffi::export` (in Nightly builds, run with -Z macro-backtrace for more info)

fixtures/uitests/tests/ui/invalid_types_in_signatures.stderr

@@ -5,33 +5,86 @@ error[E0277]: the trait bound `Result<(), ErrorType>: Lift<UniFfiTag>` is not sa
    | ^^^^^^^^^^^^^^^^^ the trait `Lift<UniFfiTag>` is not implemented for `Result<(), ErrorType>`
    |
    = help: the following other types implement trait `Lift<UT>`:
-             bool
-             i8
-             i16
-             i32
-             i64
-             u8
-             u16
-             u32
+             Arc<T>
+             Duration
+             ErrorType
+             HashMap<K, V>
+             Option<T>
+             String
+             SystemTime
+             Vec<T>
            and $N others
    = note: this error originates in the attribute macro `uniffi::export` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0277]: the trait bound `Result<(), ErrorType>: Lower<UniFfiTag>` is not satisfied
   --> tests/ui/invalid_types_in_signatures.rs:20:1
    |
 20 | #[uniffi::export]
-   | ^^^^^^^^^^^^^^^^^ the trait `Lower<UniFfiTag>` is not implemented for `Result<(), ErrorType>`, which is required by `Option<Result<(), ErrorType>>: LowerReturn<UniFfiTag>`
+   | ^^^^^^^^^^^^^^^^^ the trait `Lower<UniFfiTag>` is not implemented for `Result<(), ErrorType>`
    |
    = help: the following other types implement trait `Lower<UT>`:
-             bool
-             i8
-             i16
-             i32
-             i64
-             u8
-             u16
-             u32
+             Arc<T>
+             Duration
+             ErrorType
+             HashMap<K, V>
+             Option<T>
+             String
+             SystemTime
+             Vec<T>
            and $N others
    = note: required for `Option<Result<(), ErrorType>>` to implement `Lower<UniFfiTag>`
    = note: required for `Option<Result<(), ErrorType>>` to implement `LowerReturn<UniFfiTag>`
    = note: this error originates in the attribute macro `uniffi::export` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `Result<(), ErrorType>: Lift<UniFfiTag>` is not satisfied
+  --> tests/ui/invalid_types_in_signatures.rs:18:25
+   |
+18 | pub fn input_result(_r: Result<(), ErrorType>) { }
+   |                         ^^^^^^^^^^^^^^^^^^^^^ the trait `Lift<UniFfiTag>` is not implemented for `Result<(), ErrorType>`
+   |
+   = help: the following other types implement trait `Lift<UT>`:
+             Arc<T>
+             Duration
+             ErrorType
+             HashMap<K, V>
+             Option<T>
+             String
+             SystemTime
+             Vec<T>
+           and $N others
+
+error[E0277]: the trait bound `Result<(), ErrorType>: Lift<UniFfiTag>` is not satisfied
+  --> tests/ui/invalid_types_in_signatures.rs:18:21
+   |
+18 | pub fn input_result(_r: Result<(), ErrorType>) { }
+   |                     ^^ the trait `Lift<UniFfiTag>` is not implemented for `Result<(), ErrorType>`
+   |
+   = help: the following other types implement trait `Lift<UT>`:
+             Arc<T>
+             Duration
+             ErrorType
+             HashMap<K, V>
+             Option<T>
+             String
+             SystemTime
+             Vec<T>
+           and $N others
+
+error[E0277]: the trait bound `Result<(), ErrorType>: Lower<UniFfiTag>` is not satisfied
+  --> tests/ui/invalid_types_in_signatures.rs:20:1
+   |
+20 | #[uniffi::export]
+   | ^^^^^^^^^^^^^^^^^ the trait `Lower<UniFfiTag>` is not implemented for `Result<(), ErrorType>`
+   |
+   = help: the following other types implement trait `Lower<UT>`:
+             Arc<T>
+             Duration
+             ErrorType
+             HashMap<K, V>
+             Option<T>
+             String
+             SystemTime
+             Vec<T>
+           and $N others
+   = note: required for `Option<Result<(), ErrorType>>` to implement `Lower<UniFfiTag>`
+   = note: this error originates in the attribute macro `uniffi::export` (in Nightly builds, run with -Z macro-backtrace for more info)