Expand polonius MIR dump
This PR starts expanding the polonius MIR:
- switches to an HTML file, to show graphs in the same document as the MIR dump, share them more easily since it's a single file that can be hosted as a gist, and also to allow for interactivity in the near future.
- adds the regular NLL MIR + polonius constraints
- embeds a mermaid version of the CFG, similar to the graphviz one, but that needs a smaller js than `dot`'s emscripten js from graphvizonline
[Here's an example](https://gistpreview.github.io/?0c18f2a59b5e24ac0f96447aa34ffe00) of how it looks.
---
In future PRs: mermaid graphs of the NLL region graph, of the NLL SCCs, of the polonius localized outlives constraints, and the interactive polonius MIR dump.
r? ```@matthewjasper```
Use short ty string for move errors
```
error[E0382]: use of moved value: `x`
--> bay.rs:14:14
|
12 | fn foo(x: D) {
| - move occurs because `x` has type `(((..., ..., ..., ...), ..., ..., ...), ..., ..., ...)`, which does not implement the `Copy` trait
13 | let _a = x;
| - value moved here
14 | let _b = x; //~ ERROR use of moved value
| ^ value used here after move
|
= note: the full type name has been written to 'bay.long-type-14349227078439097973.txt'
= note: consider using `--verbose` to print the full type name to the console
help: consider cloning the value if the performance cost is acceptable
|
13 | let _a = x.clone();
| ++++++++
```
Address 4th case in #135919.
```
error[E0382]: use of moved value: `x`
--> bay.rs:14:14
|
12 | fn foo(x: D) {
| - move occurs because `x` has type `(((..., ..., ..., ...), ..., ..., ...), ..., ..., ...)`, which does not implement the `Copy` trait
13 | let _a = x;
| - value moved here
14 | let _b = x; //~ ERROR use of moved value
| ^ value used here after move
|
= note: the full type name has been written to 'bay.long-type-14349227078439097973.txt'
= note: consider using `--verbose` to print the full type name to the console
help: consider cloning the value if the performance cost is acceptable
|
13 | let _a = x.clone();
| ++++++++
```
Rollup of 7 pull requests
Successful merges:
- #133700 (const-eval: detect more pointers as definitely not-null)
- #135290 (Encode constraints that hold at all points as logical edges in location-sensitive polonius)
- #135478 (Run clippy for rustc_codegen_gcc on CI)
- #135583 (Move `std::pipe::*` into `std::io`)
- #135612 (Include x scripts in tarballs)
- #135624 (ci: mirror buildkit image to ghcr)
- #135661 (Stabilize `float_next_up_down`)
r? `@ghost`
`@rustbot` modify labels: rollup
Instead of materializing `Locations::All` constraints as physical edges
at all the points in the CFG, we record them as logical edges and only
materialize them during traversal as successors for a given node.
This fixes the slowness/hang in the `saturating-float-casts.rs` test.
Location-sensitive polonius prototype: endgame
This PR sets up the naive location-sensitive analysis end-to-end, and replaces the location-insensitive analysis. It's roughly all the in-progress work I wanted to land for the prototype, modulo cleanups I still want to do after the holidays, or the polonius debugger, and so on.
Here, we traverse the localized constraint graph, have to deal with kills and time-traveling (👌), and record that as loan liveness for the existing scope and active loans computations.
Then the near future looks like this, especially if the 2025h1 project goal is accepted:
- gradually bringing it up to completion
- analyzing and fixing the few remaining test failures
- going over the *numerous* fixmes in this prototype (one of which is similar to a hang on one test's millions and millions of constraints)
- trying to see how to lower the impact of the lack of NLL liveness optimization on diagnostics, and their categorization of local variables and temporaries (the vast majority of blessed expectations differences), as well as the couple ICEs trying to find an NLL constraint to blame for errors.
- dealing with the theoretical weakness around kills, conflating reachability for the two TCS, etc that is described ad nauseam in the code.
- switching the compare mode to the in-tree implementation, and blessing the diagnostics
- apart from the hang, it's not catastrophically slower on our test suite, so then we can try to enable it on CI
- checking crater, maybe trying to make it faster :3, etc.
I've tried to gradually introduce this PR's work over 4 commits, because it's kind of subtle/annoying, and Niko/I are not completely convinced yet. That one comment explaining the situation is maybe 30% of the PR 😓. Who knew that spacetime reachability and time-traveling could be mind bending.
I kinda found this late and the impact on this part of the computation was a bit unexpected to us. A bit more care/thought will be needed here. I've described my plan in the comments though. In any case, I believe we have the current implementation is a conservative approximation that shouldn't result in unsoundness but false positives at worst. So it feels fine for now.
r? ``@jackh726``
---
Fixes#127628 -- which was a assertion triggered for a difference in loan computation between NLLs and the location-insensitive analysis. That doesn't exist anymore so I've removed this crash test.
Make sure to scrape region constraints from deeply normalizing type outlives assumptions in borrowck
Otherwise we're just randomly registering these region relations into the infcx which isn't good
r? lcnr
Rollup of 6 pull requests
Successful merges:
- #129259 (Add inherent versions of MaybeUninit methods for slices)
- #135374 (Suggest typo fix when trait path expression is typo'ed)
- #135377 (Make MIR cleanup for functions with impossible predicates into a real MIR pass)
- #135378 (Remove a bunch of diagnostic stashing that doesn't do anything)
- #135397 (compiletest: add erroneous variant to `string_enum`s conversions error)
- #135398 (add more crash tests)
r? `@ghost`
`@rustbot` modify labels: rollup
Remove a bunch of diagnostic stashing that doesn't do anything
#121669 removed a bunch of conditional diagnostic stashing/canceling, but left around the `steal` calls which just emitted the error eagerly instead of canceling the diagnostic. I think that these no-op `steal` calls don't do much and are confusing to encounter, so let's remove them.
The net effect is:
1. We emit more duplicated errors, since stashing has the side effect of duplicating diagnostics. This is not a big deal, since outside of `-Zdeduplicate-diagnostics=no`, the errors are already being deduplicated by the compiler.
2. It changes the order of diagnostics, since we're no longer stashing and then later stealing the errors. I don't think this matters much for the changes that the UI test suite manifests, and it makes these errors less order dependent.
Cleanup `suggest_binding_for_closure_capture_self` diag in borrowck
Mostly grammar fix/improvement, but also a small cleanup to use iterators instead of for loops for collecting into a vector.
this addresses review comments while:
- keeping the symmetry between the NLL and Polonius out of scope
precomputers
- keeping the unstable `calculate_borrows_out_of_scope_at_location`
function to avoid churn for consumers
we're in in the endgame now
set up the location-sensitive analysis end to end:
- stop recording inflowing loans and loan liveness in liveness
- replace location-insensitive liveness data with live loans computed by
reachability
- remove equivalence between polonius scopes and NLL scopes, and only
run one scope computation
in NLLs some locals are marked live at all points if one of their
regions escapes the function but that doesn't work in a flow-sensitive
setting like polonius
A couple simple borrowck cleanups
This PR has a couple simple renamings:
- it's been a long time since the mapping from `Location`s to `PointIndex`es was extracted from `RegionElements` into the `DenseLocationMap`, but only the types were renamed at the time. borrowck still refers to this map as `elements`. That's confusing, especially since sometimes we also use the mapping via `LivenessValues`, and makes more sense as `location_map` instead.
- to clarify `LocationTable` is not as general as it sounds, and is only for datalog polonius. In this branch I didn't rename the handful of `location_table` fields and params to `polonius_table`, but can do that to differentiate it even more from `location_map`. I did try it locally and it looks worthwhile, so if you'd prefer I can also push it here. (Or we could even switch these datalog types and fields to even more explicit names)
- to clarify the incomprehensible `AllFacts`, it is renamed to `PoloniusFacts`. These can be referred to as `facts` within the legacy polonius module, but as `polonius_facts` outside of it to make it clear that they're not about NLLs (nor are they about in-tree polonius but that'll be magically fixed when they're removed in the future)
r? `@matthewjasper`
