fix: Don't expand macros in the same expansion tree after overflow
This patch fixes 2 bugs:
- In `Expander::enter_expand_id()` (and in code paths it's called), we never check whether we've reached the recursion limit. Although it hasn't been reported as far as I'm aware, this may cause hangs or stack overflows if some malformed attribute macro is used on associated items.
- We keep expansion even when recursion limit is reached. Take the following for example:
```rust
macro_rules! foo { () => {{ foo!(); foo!(); }} }
fn main() { foo!(); }
```
We keep expanding the first `foo!()` in each expansion and would reach the limit at some point, *after which* we would try expanding the second `foo!()` in each expansion until it hits the limit again. This will (by default) lead to ~2^128 expansions.
This is essentially what's happening in #14074. Unlike rustc, we don't just stop expanding macros when we fail as long as it produces some tokens so that we can provide completions and other services in incomplete macro calls.
This patch provides a method that takes care of recursion depths (`Expander::within_limit()`) and stops macro expansions in the whole macro expansion tree once it detects recursion depth overflow. To be honest, I'm not really satisfied with this fix because it can still be used in unintended ways to bypass overflow checks, and I'm still seeking ways such that misuses are caught by the compiler by leveraging types or something.
Fixes#14074
Support multi-character punct tokens in MBE
Fixes#11497
In the context of MBE, consecutive puncts are parsed as multi-character punct tokens whenever possible. For example, `:::` is parsed as ``[Punct(`::`), Punct(`:`)]`` and shouldn't get matched to patterns like `: : :` or `: ::`.
We have implemented this behavior only for when we match puncts against `tt` fragments, but not when we match puncts literally. This PR extracts the multi-character punct handling procedure into a separate method and extends its support for literal matching.
For good measure, this PR adds support for `<-` token, which is still [considered as one token in rustc](e396186407/compiler/rustc_ast/src/token.rs (L249)) despite the placement syntax having been removed.
Use `rustc_safe_intrinsic` attribute to check for intrinsic safety
Instead of maintaining a list that is poorly kept in sync we can just use the attribute.
This will make new RA versions unusable with old toolchains that don't have the attribute yet. Should we keep maintaining the list as a fallback or just don't care?
This makes code more readale and concise,
moving all format arguments like `format!("{}", foo)`
into the more compact `format!("{foo}")` form.
The change was automatically created with, so there are far less change
of an accidental typo.
```
cargo clippy --fix -- -A clippy::all -W clippy::uninlined_format_args
```
Seems like these can be safely fixed. With one, I was particularly
surprised -- `Some(pats) => &**pats,` in body.rs?
```
cargo clippy --fix -- -A clippy::all -D clippy::explicit_auto_deref
```
I am not certain if this will improve performance,
but it seems having a .clone() without any need should be removed.
This was done with clippy, and manually reviewed:
```
cargo clippy --fix -- -A clippy::all -D clippy::redundant_clone
```
Compute data layout of types
cc #4091
Things that aren't working:
* Closures
* Generators (so no support for `Future` I think)
* Opaque types
* Type alias and associated types which may need normalization
Things that show wrong result:
* ~Enums with explicit discriminant~
* SIMD types
* ~`NonZero*` and similar standard library items which control layout with special attributes~
At the user level, I didn't put much work, since I wasn't confident about what is the best way to present this information. Currently it shows size and align for ADTs, and size, align, offset for struct fields, in the hover, similar to clangd. I used it some days and I feel I liked it, but we may consider it too noisy and move it to an assist or command.
Mega-sync from `rust-lang/rust`
This essentially implements `@oli-obk's` suggestion here https://github.com/rust-lang/rust-analyzer/pull/13459#issuecomment-1297285607, with `@eddyb's` help.
This PR is equivalent to 14 syncs (back and forth) between `rust-lang/rust` and `rust-lang/rust-analyzer`.
Working from this list (from bottom to top):
```
(x) a2a1d9954⬆️ rust-analyzer
(x) 79923c382⬆️ rust-analyzer
(x) c60b1f641⬆️ rust-analyzer
(x) 8807fc4cc⬆️ rust-analyzer
(x) a99a48e78⬆️ rust-analyzer
(x) 4f55ebbd4⬆️ rust-analyzer
(x) f5fde4df4⬆️ rust-analyzer
(x) 459bbb422⬆️ rust-analyzer
(x) 65e1dc4d9⬆️ rust-analyzer
(x) 3e358a682⬆️ rust-analyzer
(x) 31519bb39⬆️ rust-analyzer
(x) 8231fee46⬆️ rust-analyzer
(x) 22c8c9c40⬆️ rust-analyzer
(x) 9d2cb42a4⬆️ rust-analyzer
```
(This listed was assembled by doing a `git subtree push`, which made a branch, and looking at the new commits in that branch, picking only those that were `⬆️ rust-analyzer` commits)
We used the following commands to simulate merges in both directions:
```shell
TO_MERGE=22c8c9c40 # taken from the list above, bottom to top
git merge --no-edit --no-ff $TO_MERGE
git merge --no-edit --no-ff $(git -C ../rust log --pretty=format:'%cN | %s | %ad => %P' | rg -m1 -F "$(git show --no-patch --pretty=format:%ad $TO_MERGE)" | tee /dev/stderr | rg '.* => \S+ (\S+)$' --replace '$1')
```
We encountered no merge conflicts that Git wasn't able to solve by doing it this way.
Here's what the commit graph looks like (as shown in the Git Lens VSCode extension):
<img width="1345" alt="image" src="https://user-images.githubusercontent.com/7998310/203984523-7c1a690a-8224-416c-8015-ed6e49667066.png">
This PR closes#13459
## Does this unbreak `rust->ra` syncs?
Yes, here's how we tried:
In `rust-analyzer`:
* check out `subtree-fix` (this PR's branch)
* make a new branch off of it: `git checkout -b subtree-fix-merge-test`
* simulate this PR getting merged with `git merge master`
In `rust`:
* pull latest master
* make a new branch: `git checkout -b test-change`
* mess with rust-analyzer (I added a comment to `src/tools/rust-analyzer/Cargo.toml`)
* commit
* run `git subtree push -P src/tools/rust-analyzer ra-local final-sync` (this follows the [Clippy sync guide](https://doc.rust-lang.org/nightly/clippy/development/infrastructure/sync.html))
This created a `final-sync` branch in `rust-analyzer`.
In `rust-analyzer`:
* `git merge --no-ff final-sync` (this follows the [Clippy sync guide](https://doc.rust-lang.org/nightly/clippy/development/infrastructure/sync.html))
Now `git log` in `rust-analyzer` shows this:
```
commit 460128387e46ddfc2b95921b2d7f6e913a3d2b9f (HEAD -> subtree-fix-merge-test)
Merge: 0513fc02a 9ce6a734f
Author: Amos Wenger <amoswenger@gmail.com>
Date: Fri Nov 25 13:28:24 2022 +0100
Merge branch 'final-sync' into subtree-fix-merge-test
commit 0513fc02a08ea9de952983624bd0a00e98044b36
Merge: 38c98d1ff6918009fe
Author: Amos Wenger <amoswenger@gmail.com>
Date: Fri Nov 25 13:28:02 2022 +0100
Merge branch 'master' into subtree-fix-merge-test
commit 9ce6a734f37ef8e53689f1c6f427a9efafe846bd (final-sync)
Author: Amos Wenger <amoswenger@gmail.com>
Date: Fri Nov 25 13:26:26 2022 +0100
Mess with rust-analyzer just for fun
```
And `git diff 0513fc02a08ea9de952983624bd0a00e98044b36` shows this:
```patch
diff --git a/Cargo.toml b/Cargo.toml
index 286ef1e7d..c9e24cd19 100644
--- a/Cargo.toml
+++ b/Cargo.toml
`@@` -32,3 +32,5 `@@` debug = 0
# ungrammar = { path = "../ungrammar" }
# salsa = { path = "../salsa" }
+
+# lol, hi
```
## Does this unbreak `ra->rust` syncs?
Yes, here's how we tried.
From `rust`:
* `git checkout -b sync-from-ra`
* `git subtree pull -P src/tools/rust-analyzer ra-local subtree-fix-merge-test` (this is adapted from the [Clippy sync guide](https://doc.rust-lang.org/nightly/clippy/development/infrastructure/sync.html#performing-the-sync-from-clippy-to-rust-langrust), you would normally use `ra-upstream master` but we're simulating things here)
A commit editor pops up, there was no merge conflicts.
## How do we prevent this from happening again?
Like `@bjorn3` said in https://github.com/rust-lang/rust-analyzer/pull/13459#issuecomment-1293587848
> Whenever syncing from rust-analyzer -> rust you have to immediately sync the merge commit from rust -> rust-analyzer to prevent merge conflicts in the future.
But if we get it wrong again, at least now we have a not-so-painful way to fix it.
fix: check visibility of each path segment
Upon path resolution, we have not been checking if every def pointed to by each segment of the path is visible from the original module. This leads to incorrect import resolutions, in particular when one uses glob imports and names collide.
There is decent amount of changes in this PR because:
- some of our tests were not correct in terms of visibility
- I left several basic nameres tests as-is (with expect test updated) since I thought it would be nice to ensure we don't resolve defs that are not visible.
- `fix_visibility` assist relied on `Semantics::resolve_path()`, which uses the name resolution procedure I'm fixing and wouldn't be able to "see through" the items with strict visibility with this patch
The first commit is the gist of the fix itself.
Fixes#10991Fixes#11473Fixes#13252
Fix `tt::Punct`'s spacing calculation
Fixes#13499
We currently set a `tt::Punct`'s spacing to `Spacing::Joint` unless its next token is a trivia (i.e. whitespaces or comment). As I understand it, rustc only [sets `Spacing::Joint` if the next token is an operator](5b3e909075/compiler/rustc_parse/src/lexer/tokentrees.rs (L77-L78)) and we should follow it to guarantee the consistent behavior of proc macros.
