Previously if someone wrote an enum containing:
- `A` (untagged)
- `B` (tagged)
- `C` (tagged)
- `D` (untagged)
- `E` (tagged)
- `F` (untagged)
serde_derive would produce errors referring to B and E only, saying
you're supposed to put untagged variants at the end. The choice of B and
E for this error doesn't make a lot of sense because in order to resolve
the issue, the user must either:
- move A and D down
or:
- move B, C, and E up.
This commit changes the error to appear on A and D instead.
error: consider adding a `;` to the last statement for consistent formatting
--> serde_derive/src/internals/ast.rs:161:13
|
161 | seen_untagged = variant.attrs.untagged()
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: add a `;` here: `seen_untagged = variant.attrs.untagged();`
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#semicolon_if_nothing_returned
= note: `-D clippy::semicolon-if-nothing-returned` implied by `-D clippy::pedantic`
error: consider adding a `;` to the last statement for consistent formatting
--> serde_derive/src/internals/ast.rs:159:17
|
159 | ... cx.error_spanned_by(&variant.ident, "all variants with the #[serde(untagged)] attribute must be placed at the end of the enum")
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: add a `;` here: `cx.error_spanned_by(&variant.ident, "all variants with the #[serde(untagged)] attribute must be placed at the end of the enum");`
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#semicolon_if_nothing_returned
Without this, if it fails, the only information printed is useless:
Preparing a sysroot for Miri (target: x86_64-unknown-linux-gnu)...
fatal error: failed to build sysroot; run `cargo miri setup` to see the error details
warning: this loop could be written as a `for` loop
--> serde/src/private/de.rs:2905:9
|
2905 | while let Some(item) = self.iter.next() {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `for item in self.iter.by_ref()`
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#while_let_on_iterator
= note: `#[warn(clippy::while_let_on_iterator)]` on by default
Fixes these being treated as "tests" by `cargo test` in serde_derive:
running 3 tests
test src/internals/check.rs - internals::check::check_remote_generic (line 23) ... FAILED
test src/internals/check.rs - internals::check::check_remote_generic (line 29) ... FAILED
test src/lib.rs - (line 3) ... ok
failures:
---- src/internals/check.rs - internals::check::check_remote_generic (line 23) stdout ----
error: unknown start of token: \u{2026}
--> src/internals/check.rs:25:20
|
4 | struct Generic<T> {…}
| ^
error: cannot find attribute `serde` in this scope
--> src/internals/check.rs:24:3
|
3 | #[serde(remote = "Generic")]
| ^^^^^
|
= note: `serde` is in scope, but it is a crate, not an attribute
error[E0392]: parameter `T` is never used
--> src/internals/check.rs:25:16
|
4 | struct Generic<T> {…}
| ^ unused parameter
|
= help: consider removing `T`, referring to it in a field, or using a marker such as `PhantomData`
= help: if you intended `T` to be a const parameter, use `const T: usize` instead
---- src/internals/check.rs - internals::check::check_remote_generic (line 29) stdout ----
error: unknown start of token: \u{2026}
--> src/internals/check.rs:31:21
|
4 | struct ConcreteDef {…}
| ^
error: cannot find attribute `serde` in this scope
--> src/internals/check.rs:30:3
|
3 | #[serde(remote = "Generic<T>")]
| ^^^^^
|
= note: `serde` is in scope, but it is a crate, not an attribute
This works just fine if we make syn parse "where " as a syn::WhereClause.
The serde(bound = "") attribute is definitely not common enough that it
would warrant a micro-optimization.
Without serde(bound = ""), serde_derive infers a bound of `T: Serialize`
for the generated Serialize impl and `T: Deserialize<'de> + Default` for
the Deserialize impl. `X` implements none of these so the generated code
would fail to compile.
error[E0277]: the trait bound `X: Serialize` is not satisfied
--> test_suite/tests/test_gen.rs:268:14
|
268 | assert::<PhantomDataWrapper<X>>();
| ^^^^^^^^^^^^^^^^^^^^^ the trait `Serialize` is not implemented for `X`
|
= help: the following other types implement trait `Serialize`:
&'a T
&'a mut T
()
(T0, T1)
(T0, T1, T2)
(T0, T1, T2, T3)
(T0, T1, T2, T3, T4)
(T0, T1, T2, T3, T4, T5)
and 248 others
note: required for `PhantomDataWrapper<X>` to implement `Serialize`
--> test_suite/tests/test_gen.rs:262:14
|
262 | #[derive(Serialize, Deserialize)]
| ^^^^^^^^^ unsatisfied trait bound introduced in this `derive` macro
263 | //#[serde(bound = "")]
264 | struct PhantomDataWrapper<T> {
| ^^^^^^^^^^^^^^^^^^^^^
note: required by a bound in `assert`
--> test_suite/tests/test_gen.rs:767:14
|
767 | fn assert<T: Serialize + DeserializeOwned>() {}
| ^^^^^^^^^ required by this bound in `assert`
= note: this error originates in the derive macro `Serialize` (in Nightly builds, run with -Z macro-backtrace for more info)
error[E0277]: the trait bound `X: Deserialize<'_>` is not satisfied
--> test_suite/tests/test_gen.rs:268:14
|
268 | assert::<PhantomDataWrapper<X>>();
| ^^^^^^^^^^^^^^^^^^^^^ the trait `Deserialize<'_>` is not implemented for `X`
|
= help: the following other types implement trait `Deserialize<'de>`:
<&'a Path as Deserialize<'de>>
<&'a [u8] as Deserialize<'de>>
<&'a str as Deserialize<'de>>
<() as Deserialize<'de>>
<(T0, T1) as Deserialize<'de>>
<(T0, T1, T2) as Deserialize<'de>>
<(T0, T1, T2, T3) as Deserialize<'de>>
<(T0, T1, T2, T3, T4) as Deserialize<'de>>
and 331 others
note: required for `PhantomDataWrapper<X>` to implement `for<'de> Deserialize<'de>`
--> test_suite/tests/test_gen.rs:262:25
|
262 | #[derive(Serialize, Deserialize)]
| ^^^^^^^^^^^ unsatisfied trait bound introduced in this `derive` macro
263 | //#[serde(bound = "")]
264 | struct PhantomDataWrapper<T> {
| ^^^^^^^^^^^^^^^^^^^^^
= note: required for `PhantomDataWrapper<X>` to implement `DeserializeOwned`
note: required by a bound in `assert`
--> test_suite/tests/test_gen.rs:767:26
|
767 | fn assert<T: Serialize + DeserializeOwned>() {}
| ^^^^^^^^^^^^^^^^ required by this bound in `assert`
= note: this error originates in the derive macro `Deserialize` (in Nightly builds, run with -Z macro-backtrace for more info)
error[E0277]: the trait bound `X: Default` is not satisfied
--> test_suite/tests/test_gen.rs:268:14
|
268 | assert::<PhantomDataWrapper<X>>();
| ^^^^^^^^^^^^^^^^^^^^^ the trait `Default` is not implemented for `X`
|
note: required for `PhantomDataWrapper<X>` to implement `for<'de> Deserialize<'de>`
--> test_suite/tests/test_gen.rs:262:25
|
262 | #[derive(Serialize, Deserialize)]
| ^^^^^^^^^^^ unsatisfied trait bound introduced in this `derive` macro
263 | //#[serde(bound = "")]
264 | struct PhantomDataWrapper<T> {
| ^^^^^^^^^^^^^^^^^^^^^
= note: required for `PhantomDataWrapper<X>` to implement `DeserializeOwned`
note: required by a bound in `assert`
--> test_suite/tests/test_gen.rs:767:26
|
767 | fn assert<T: Serialize + DeserializeOwned>() {}
| ^^^^^^^^^^^^^^^^ required by this bound in `assert`
= note: this error originates in the derive macro `Deserialize` (in Nightly builds, run with -Z macro-backtrace for more info)
help: consider annotating `X` with `#[derive(Default)]`
|
779 | #[derive(Default)]
|
David Tolnay