Beginning of MIR
This pull request introduces the initial implementation of MIR lowering and interpreting in Rust Analyzer.
The implementation of MIR has potential to bring several benefits:
- Executing a unit test without compiling it: This is my main goal. It can be useful for quickly testing code changes and print-debugging unit tests without the need for a full compilation (ideally in almost zero time, similar to languages like python and js). There is a probability that it goes nowhere, it might become slower than rustc, or it might need some unreasonable amount of memory, or we may fail to support a common pattern/function that make it unusable for most of the codes.
- Constant evaluation: MIR allows for easier and more correct constant evaluation, on par with rustc. If r-a wants to fully support the type system, it needs full const eval, which means arbitrary code execution, which needs MIR or something similar.
- Supporting more diagnostics: MIR can be used to detect errors, most famously borrow checker and lifetime errors, but also mutability errors and uninitialized variables, which can be difficult/impossible to detect in HIR.
- Lowering closures: With MIR we can find out closure capture modes, which is useful in detecting if a closure implements the `FnMut` or `Fn` traits, and calculating its size and data layout.
But the current PR implements no diagnostics and doesn't support closures. About const eval, I removed the old const eval code and it now uses the mir interpreter. Everything that is supported in stable rustc is either implemented or is super easy to implement. About interpreting unit tests, I added an experimental config, disabled by default, that shows a `pass` or `fail` on hover of unit tests (ideally it should be a button similar to `Run test` button, but I didn't figured out how to add them). Currently, no real world test works, due to missing features including closures, heap allocation, `dyn Trait` and ... so at this point it is only useful for me selecting what to implement next.
The implementation of MIR is based on the design of rustc, the data structures are almost copy paste (so it should be easy to migrate it to a possible future stable-mir), but the lowering and interpreting code is from me.
add: clean api to get `raw_ptr` type
There doesn't seem to be an API to fetch the type of `raw_ptr`, which is helpful for a project I work on.
Notes:
- I am unsure about the function name, do let me know if I should use something else.
- Also unsure about where to add tests, for hir changes. Will fix it as needed.
fix:add a case in which remainig is None in resolveing types when resolving hir path.
fix#14030 The variable type is being determined incorrectly
This PR fixed a problem in which `go to definition` is jumping to the incorrect position because it was failing to resolve the type in case it defined in the module when resolving hir.
In addition, I added a test for this issue and refactored the related code.
This is my first PR and I am using a translation tool to write this text. Let me know if you have any problems.
Respect $CARGO_HOME when looking up toolchains.
Some people set `$CARGO_HOME` to a location other than `~/.cargo` (`$XDG_DATA_DIR/cargo`, in my case), and I'd be a little nicer if the rust-analyzer extension and server respect that value when looking up toolchains, instead of having us configure all of `$CARGO`, `$RUSTC` ... manually.
The new implementation still defaults to `~/.cargo` if `$CARGO_HOME` is unset, pretty much like cargo itself does (as documented in https://doc.rust-lang.org/cargo/guide/cargo-home.html), so the change is backwards compatible for most people except those who has configured `$CARGO_HOME` explicitly.
I considered using https://crates.io/crates/home as suggested by https://doc.rust-lang.org/cargo/guide/cargo-home.html, but decided to put int on hold because i) we need mirror impl in node, ii) I thought the consistency matters more and iii) the new implementation shouldn't be worse than the current one (i.e. switching to `home` improvement is rather orthogonal and could be done in another PR). If you have any directions on this, please let me know.
fix: Add check for extra path segments after a fully qualified one
`type A = <()>;` is parsed just fine by rust-analyzer, but then rejected by rustc:
```
error: expected `::`, found `;`
--> x.rs:7:14
|
7 | type A = <()>;
| ^ expected `::`
```
Fixed by adding a lookahead for the `::` token after fully-qualified path segments.
minor: import `Either` from `either`
This is a clean-up patch to replace `use itertools::Either` with `use either::Either` for the sake of consistency.
add openDocs command to context menu in VS Code extension
This adds the `openDocs` command to the VS Code context menu. I believe there are probably many user who are unaware of this command existing in the rust analyzer extension, and that this should enhance the discoverability of the command. Additionally, even if people are aware of this capability, it's helpful to have this in the context menu anyway; for example, one might forget the name of the command, or the keybinding they have assigned to it. I think that opening docs is a common enough action to warrant the extra line added to the context menu.
This makes a few other small changes as well. There are two minor style changes to increase style consistency. First, it changes the titles of the two commands that the rust analyzer extension will contribute to the context menu to title case. All standard VS Code commands that appear in the context menu are in title case. Second, it shortens the title of the `openDocs` command from `Open docs under cursor` to `Open Docs`. The implicit assumption in the standard VS Code context menu command titles is that the action applies to the symbol under the cursor: `Go to Definition`, `Find All References`, etc. Note that since these are changes to the command titles, rather than the command names themselves, these changes will not break any users' existing keybindings for these commands.
Second, this adds further restrictions to the `where` clauses of the two commands that the rust analyzer extension will contribute to the context menu, so that the two commands will appear in the context menu only when in a Rust project **and** within a Rust file. Say you have a Python or bash script inside your Rust project. Having these commands appear in the context menu when you right click a symbol in such a non-Rust file is extraneous and potentially confusing.
Conditionally add snippet marker.
Fixes#14161.
Heya, I just added the code with some tests, but not sure if it's *the way* to do it -- I didn't refactor existing methods for the `check` test method, but added another calling layer.
