feat: Display the value of enum variant on hover
fixes#12955
This PR adds const eval support for enums, as well as showing their value on hover, just as consts currently have.
I developed these two things at the same time, but I've realized now that they are separate. However since the hover is just a 10 line change (not including tests), I figured I may as well put them in the same PR. Though if you want them split up into "enum const eval support" and "show enum variant value on hover", I think that's reasonable too.
Since this adds const eval support for enums this also allows consts that reference enums to have their values computed now too.
The const evaluation itself is quite rudimentary, it doesn't keep track of the actual type of the enum, but it turns out that Rust doesn't actually either, and `E::A as u8` is valid regardless of the `repr` on `E`.
It also doesn't really care about what expression the enum variant contains, it could for example be a string, despite that not being allowed, but I guess it's up to the `cargo check` diagnostics to inform of such issues anyway?
Ensure at least one trait bound in `TyKind::DynTy`
One would expect `TyKind::DynTy` to have at least one trait bound, but we may produce a dyn type with no trait bounds at all. This patch prevents it by returning `TyKind::Error` in such cases.
An "empty" dyn type would have caused panic during method resolution without #13257. Although already fixed, I think an invariant to never produce such types would help prevent similar problems in the future.
Add a new configuration settings to set env vars when running cargo, rustc, etc. commands: cargo.extraEnv and checkOnSave.extraEnv
It can be extremely useful to be able to set environment variables when rust-analyzer is running various cargo or rustc commands (such as `cargo check`, `cargo --print cfg` or `cargo metadata`): users may want to set custom `RUSTFLAGS`, change `PATH` to use a custom toolchain or set a different `CARGO_HOME`.
There is the existing `server.extraEnv` setting that allows env vars to be set when the rust-analyzer server is launched, but using this as the recommended mechanism to also configure cargo/rust has some drawbacks:
- It convolutes configuring the rust-analyzer server with configuring cargo/rustc (one may want to change the `PATH` for cargo/rustc without affecting the rust-analyzer server).
- The name `server.extraEnv` doesn't indicate that cargo/rustc will be affected but renaming it to `cargo.extraEnv` doesn't indicate that the rust-analyzer server would be affected.
- To make the setting useful, it needs to be dynamically reloaded without requiring that the entire extension is reloaded. It might be possible to do this, but it would require the client communicating to the server what the overwritten env vars were at first launch, which isn't easy to do.
This change adds two new configuration settings: `cargo.extraEnv` and `checkOnSave.extraEnv` that can be used to change the environment for the rust-analyzer server after launch (thus affecting any process that rust-analyzer invokes) and the `cargo check` command respectively. `cargo.extraEnv` supports dynamic changes by keeping track of the pre-change values of environment variables, thus it can undo changes made previously before applying the new configuration (and then requesting a workspace reload).
Fix add reference action on macros.
Before we were using the range of the corresponding expression node in the macro expanded file, which is obviously incorrect as we are setting the text in the original source.
For some reason, the test I added is failing and I haven't found a way to fix it. Does anyone know why `check_fix` wouldn't work with macros? Getting this error:
```text
thread 'handlers::type_mismatch::tests::test_add_reference_to_macro_call' panicked at 'no diagnostics', crates/ide-diagnostics/src/handlers/type_mismatch.rs:317:9
```
closes#13219
Use memmem when searching for usages in ide-db
We already have this dependency, so there is no reason not to use it as it is generally faster than std in our use case.
Refactor macro-by-example code
I had a look at the MBE code because of #7857. I found some easy readability wins, that might also _marginally_ improve perf.
Allow configuration of annotation location.
I've added the ability to configure where lens annotations render relevant to the item they describe. Previously, these would render directly above the line the item is declared on. Now, there is the ability to render these annotations above the entire item (including doc comments, and attributes).
The names of the config options are up for debate, I did what seemed best to me but if anyone has better ideas let me know.
This is my first contribution so if I've missed anything please let me know.
Here's a preview of what the new option looks like:
<img width="577" alt="Screen Shot 2022-09-11 at 10 39 51 PM" src="https://user-images.githubusercontent.com/33100798/189570298-b4fcbf9c-ee49-4b79-aae6-1037ae4f26af.png">
closes https://github.com/rust-lang/rust-analyzer/issues/13218
fixup: remove unnecessary `Option`
Fixup for #13223, two things:
- `normalize_projection_query()` (and consequently `HirDatabase::normalize_projection()`) never returns `None` (well, it used to when I first wrote it...), so just return `Ty` instead of `Option<Ty>`
- When chalk cannot normalize projection uniquely, `normalize_trait_assoc_type()` used to return `None` before #13223, but not anymore because of the first point. I restored the behavior so its callers work as before.
Restructure `find_path` into a separate functions for modules and non-module items
Follow up to https://github.com/rust-lang/rust-analyzer/pull/13212
Also renames `prefer_core` imports config to `prefer_no_std` and changes the behavior of no_std path searching by preferring `core` paths `over` alloc
This PR turned into a slight rewrite, so it unfortunately does a few more things that I initially planned to (including a bug fix for enum variant paths)
