| Age | Commit message (Collapse) | Author | Lines |
|---|
|
rustc_mir: Hide initial block state when defining transfer functions
This PR addresses [this FIXME](https://github.com/rust-lang/rust/blob/2887008e0ce0824be4e0e9562c22ea397b165c97/src/librustc_mir/dataflow/mod.rs#L594-L596).
This makes `sets.on_entry` inaccessible in `{before_,}{statement,terminator}_effect`. This field was meant to allow implementors of `BitDenotation` to access the initial state for each block (optionally with the effect of all previous statements applied via `accumulates_intrablock_state`) while defining transfer functions. However, the ability to set the initial value for the entry set of each basic block (except for START_BLOCK) no longer exists. As a result, this functionality is mostly useless, and when it *was* used it was used erroneously (see #62007).
Since `on_entry` is now useless, we can also remove `BlockSets`, which held the `gen`, `kill`, and `on_entry` bitvectors and replace it with a `GenKill` struct. Variables of this type are called `trans` since they represent a transfer function. `GenKill`s are stored contiguously in `AllSets`, which reduces the number of bounds checks and may improve cache performance: one is almost never accessed without the other.
Replacing `BlockSets` with `GenKill` allows us to define some new helper functions which streamline dataflow iteration and the dataflow-at-location APIs. Notably, `state_for_location` used a subtle side-effect of the `kill`/`kill_all` setters to apply the transfer function, and could be incorrect if a transfer function depended on effects of previous statements in the block on `gen_set`.
Additionally, this PR merges `BitSetOperator` and `InitialFlow` into one trait. Since the value of `InitialFlow` defines the semantics of the `join` operation, there's no reason to have seperate traits for each. We can add a default impl of `join` which branches based on `BOTTOM_VALUE`. This should get optimized away.
|
|
Since the value of `InitialFlow` defines the semantics of the `join`
operation, there's no reason to have seperate traits for each. We can
add a default impl of `join` which branches based on `BOTTOM_VALUE`.
This should get optimized away.
|
|
This commit makes `sets.on_entry` inaccessible in
`{before_,}{statement,terminator}_effect`. This field was meant to allow
implementors of `BitDenotation` to access the initial state for each
block (optionally with the effect of all previous statements applied via
`accumulates_intrablock_state`) while defining transfer functions.
However, the ability to set the initial value for the entry set of each
basic block (except for START_BLOCK) no longer exists. As a result, this
functionality is mostly useless, and when it *was* used it was used
erroneously (see #62007).
Since `on_entry` is now useless, we can also remove `BlockSets`, which
held the `gen`, `kill`, and `on_entry` bitvectors and replace it with a
`GenKill` struct. Variables of this type are called `trans` since they
represent a transfer function. `GenKill`s are stored contiguously in
`AllSets`, which reduces the number of bounds checks and may improve
cache performance: one is almost never accessed without the other.
Replacing `BlockSets` with `GenKill` allows us to define some new helper
functions which streamline dataflow iteration and the
dataflow-at-location APIs. Notably, `state_for_location` used a subtle
side-effect of the `kill`/`kill_all` setters to apply the transfer
function, and could be incorrect if a transfer function depended on
effects of previous statements in the block on `gen_set`.
|
|
|
|
Resolves #62007.
Due to a bug, the previous version of this check did not actually kill
any conflicting borrows unless the borrowed place had no projections.
Specifically, `entry_set` will always be empty when `statement_effect`
is called. It does not contain the set of borrows which are live at this
point in the program.
|
|
Remove unnecessary lift calls
Note that some of these might be useful for sanity checking that there's no infer types or regions.
r? @eddyb
|
|
|
|
|
|
|
|
Optimize matches
Attempt to fix or improve #60571
This is breaking some diagnostics because the MIR for match arms isn't in source order any more.
cc @centril
|
|
|
|
|
|
|
|
We never have more than one imaginary target, so we have no reason for
a `Vec`
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Emit StorageDead along unwind paths for generators
Completion of the work done in #60840. That PR made a change to implicitly consider a local `StorageDead` after Drop, but that was incorrect for DropAndReplace (see also #61060 which tried to fix this in a different way).
This finally enables the optimization implemented in #60187.
r? @eddyb
cc @Zoxc @cramertj @RalfJung
|
|
This reverts commit dd2eabc49d415dd30cea0953df5d7659d4d9440f.
|
|
Make MIR drop terminators borrow the dropped location
r? @eddyb
cc @tmandry
|
|
Rename Place::local to Place::local_or_deref_local
r? @oli-obk
|
|
The commit should have changed comments as well.
At the time of writting, it passes the tidy and check tool.
Revisions asked by eddyb :
- Renamed of all the occurences of {visit/super}_mir
- Renamed test structures `CachedMir` to `Cached`
Fixing the missing import on `AggregateKind`
|
|
|
|
|
|
|
|
Rollup of 6 pull requests
Successful merges:
- #61092 (Make sanitize_place iterate instead of recurse)
- #61093 (Make borrow_of_local_data iterate instead of recurse)
- #61094 (Make find_local iterate instead of recurse)
- #61099 (Make ignore_borrow iterate instead of recurse)
- #61103 (Make find iterate instead of recurse)
- #61104 (Make eval_place_to_op iterate instead of recurse)
Failed merges:
r? @ghost
|
|
Make find iterate instead of recurse
r? @oli-obk
|
|
|
|
Once upon a time (commit 9bd35c07c26) there were two kinds of
projection: one for places, and one for constants. It therefore made
sense to share the `Projection` struct for both. Although the different
use-cases used different concrete types, sharing was made possible by
type-parameterisation of `Projection`.
Since then, however, the usage of projections in constants has
disappeared, meaning that (forgetting lifetimes for a moment) the
parameterised type is only every instantiated under one guise. So it may
as well be a concrete type.
|
|
|
|
Add match arm scopes and other scope fixes
* Add drop and lint scopes for match arms.
* Lint attributes are now respected on match arms.
* Make sure we emit a StorageDead if we diverge when initializing a temporary.
* Adjust MIR pretty printing of scopes for locals.
* Don't generate duplicate lint scopes for `let statements`.
* Add some previously missing fake borrows for matches.
closes #46525
cc @rust-lang/compiler
|
|
|
|
|
|
|
|
|
|
Cleanup the MIR visitor
* Remove useless `BasicBlock` parameters on methods with `Location`s.
* Prefer `visit_terminator_kind` to `visit_terminator`.
* Remove `Region` from PlaceContexts. `visit_rvalue` should be used when the region is important.
* Remove unused visitor methods.
|
|
|
|
|
|
Use normal newtype_index macro for MIR dataflows
* Makes the definition of these structs contain `struct IndexName`
* Avoids having an offset by removing high values, rather than 0
* Implements some traits for us.
|
|
|
|
Shrink `mir::Statement`.
The `InlineAsm` variant is extremely rare, and `mir::Statement` often
contributes significantly to peak memory usage.
|
|
The `InlineAsm` variant is extremely rare, and `mir::Statement` often
contributes significantly to peak memory usage.
|
|
|
|
|
|
|
