rust/compiler/rustc_mir_dataflow/src/framework/results.rs, branch 1.90.0

Separate `Analysis` and `Results`.

2025-04-24T01:36:07+00:00

`Results` contains and `Analysis` and an `EntryStates`. The unfortunate thing about this is that the analysis needs to be mutable everywhere (`&mut Analysis`) which forces the `Results` to be mutable everywhere, even though `EntryStates` is immutable everywhere. To fix this, this commit renames `Results` as `AnalysisAndResults`, renames `EntryStates` as `Results`, and separates the analysis and results as much as possible. (`AnalysisAndResults` doesn't get much use, it's mostly there to facilitate method chaining of `iterate_to_fixpoint`.) `Results` is immutable everywhere, which: - is a bit clearer on how the data is used, - avoids an unnecessary clone of entry states in `locals_live_across_suspend_points`, and - moves the results outside the `RefCell` in Formatter. The commit also reformulates `ResultsHandle` as the generic `CowMut`, which is simpler than `ResultsHandle` because it doesn't need the `'tcx` lifetime and the trait bounds. It also which sits nicely alongside the new use of `Cow` in `ResultsCursor`.

Remove unnecessary lifetime on `ResultsVisitor`.

2025-04-22T00:08:05+00:00

Rollup merge of #133938 - nnethercote:rustc_mir_dataflow-renamings, r=oli-obk

2024-12-13T16:25:29+00:00

`rustc_mir_dataflow` cleanups, including some renamings Some opinionated commits in this collection, let's see how we go. r? `@cjgillot`

Rename `EntrySets` as `EntryStates`.

2024-12-10T01:04:45+00:00

"Set" doesn't make much sense here, we refer to domain values as "state" everywhere else. (This name confused me for a while.)

Move `write_graphviz_results` from `results.rs` to `graphviz.rs`.

2024-12-09T09:49:36+00:00

It's more graphviz-y than it is results-y. This lets us reduce visibility of several types in `graphviz.rs`.

Simplify `ResultsHandle`.

2024-12-02T05:19:17+00:00

The `Borrowed` variant is no longer used. This commit removes it, along with the `as_results_cursor` method that produces it, and renames `as_results_cursor_mut` as `as_results_cursor`.

Fix crash with `-Zdump-mir-dataflow`

2024-12-02T05:17:55+00:00

As of #133155 `Formatter:new` uses `as_results_cursor` to create a non-mutable results reference, and then later that is accessed via `deref_mut` which results in a runtime abort. Changing to `as_results_cursor_mut` fixes it. Fixes #133641.

Make it possible for `ResultsCursor` to borrow a `Results`.

2024-11-26T00:23:40+00:00

`ResultsCursor` currently owns its `Results`. But sometimes the `Results` is needed again afterwards. So there is `ResultsCursor::into_results` for extracting the `Results`, which leads to some awkwardness. This commit adds `ResultsHandle`, a `Cow`-like type that can either borrow or own a a `Results`. `ResultsCursor` now uses it. This is good because some `ResultsCursor`s really want to own their `Results`, while others just want to borrow it. We end with with a few more lines of code, but get some nice cleanups. - `ResultsCursor::into_results` and `Formatter::into_results` are removed. - `write_graphviz_results` now just borrows a `Results`, instead of the awkward "take ownership of a `Results` and then return it unchanged" pattern. This reinstates the cursor flexibility that was lost in #118230 -- which removed the old `ResultsRefCursor` and `ResultsCloneCursor` types -- but in a much simpler way. Hooray!

Add some useful comments.

2024-11-26T00:23:36+00:00

Describing some things that took me a long time to understand.

Remove `ResultsVisitable`.

2024-11-04T23:18:03+00:00

Now that `Results` is the only impl of `ResultsVisitable`, the trait can be removed. This simplifies things by removining unnecessary layers of indirection and abstraction. - `ResultsVisitor` is simpler. - Its type parameter changes from `R` (an analysis result) to the simpler `A` (an analysis). - It no longer needs the `Domain` associated type, because it can use `A::Domain`. - Occurrences of `R` become `Results<'tcx, A>`, because there is now only one kind of analysis results. - `save_as_intervals` also changes type parameter from `R` to `A`. - The `results.reconstruct_*` method calls are replaced with `results.analysis.apply_*` method calls, which are equivalent. - `Direction::visit_results_in_block` is simpler, with a single generic param (`A`) instead of two (`D` and `R`/`F`, with a bound connecting them). Likewise for `visit_results`. - The `ResultsVisitor` impls for `MirBorrowCtxt` and `StorageConflictVisitor` are now specific about the type of the analysis results they work with. They both used to have a type param `R` but they weren't genuinely generic. In both cases there was only a single results type that made sense to instantiate them with.