error[E0106]: missing lifetime specifier
--> /checkout/obj/build/x86_64-unknown-linux-gnu/test/error-index.md:11424:23
|
9 | fn demo(s: &mut S) -> &mut String { let p = &mut *(*s).data; p }
| ^ expected lifetime parameter
|
= help: this function's return type contains a borrowed value, but the signature does not say which one of `s`'s 2 lifetimes it is borrowed from
Use `HybridBitSet` in `SparseBitMatrix`.
This fixes most of the remaining NLL memory regression.
r? @pnkfelix, because you reviewed #54286.
cc @nikomatsakis, because NLL
cc @Mark-Simulacrum, because this removes `array_vec.rs`
cc @lqd, because this massively improves `unic-ucd-name`, and probably other public crates
By introducing a new map that tracks the errors reported and the
`Place`s that spawned those errors against the move out that the error
was referring to, we are able to silence duplicate errors by emitting
only the error which corresponds to the most specific `Place` (that which
other `Place`s which reported errors are prefixes of).
This generally is an improvement, however there is a case -
`liveness-move-in-while` - where the output regresses.
This requires adding a few extra methods to `HybridBitSet`. (These are
tested in a new unit test.)
This commit reduces the `max-rss` for `nll-check` builds of `html5ever`
by 46%, `ucd` by 45%, `clap-rs` by 23%, `inflate` by 14%. And the
results for the `unic-ucd-name` crate are even more impressive: a 21%
reduction in instructions, a 60% reduction in wall-time, a 96%
reduction in `max-rss`, and a 97% reduction in faults!
Fixes#52028.
Merge `bitvec.rs` and `indexed_set.rs`
Because it's not good to have two separate implementations. Also, I will combine the best parts of each to improve NLL memory usage on some benchmarks significantly.
In particular:
1. Extend `WriteKind::StorageDeadOrDrop` with state to track whether
we are running a destructor or just freeing backing storage. (As
part of this, when we drop a Box<..<Box<T>..> where `T` does not
need drop, we now signal that the drop of `T` is a kind of storage
dead rather than a drop.)
2. When reporting that a value does not live long enough, check if
we're doing an "interesting" drop, i.e. we aren't just trivally
freeing the borrowed state, but rather a user-defined dtor will
run and potentially require exclusive aces to the borrowed state.
3. Added a new diagnosic to describe the scenario here.
`BitwiseOperator` is an unnecessarily low-level thing. This commit
replaces it with `BitSetOperator`, which works on `BitSet`s instead of
words. Within `bit_set.rs`, the commit eliminates `Intersect`, `Union`,
and `Subtract` by instead passing a function to `bitwise()`.
Currently we have two files implementing bitsets (and 2D bit matrices).
This commit combines them into one, taking the best features from each.
This involves renaming a lot of things. The high level changes are as
follows.
- bitvec.rs --> bit_set.rs
- indexed_set.rs --> (removed)
- BitArray + IdxSet --> BitSet (merged, see below)
- BitVector --> GrowableBitSet
- {,Sparse,Hybrid}IdxSet --> {,Sparse,Hybrid}BitSet
- BitMatrix --> BitMatrix
- SparseBitMatrix --> SparseBitMatrix
The changes within the bitset types themselves are as follows.
```
OLD OLD NEW
BitArray<C> IdxSet<T> BitSet<T>
-------- ------ ------
grow - grow
new - (remove)
new_empty new_empty new_empty
new_filled new_filled new_filled
- to_hybrid to_hybrid
clear clear clear
set_up_to set_up_to set_up_to
clear_above - clear_above
count - count
contains(T) contains(&T) contains(T)
contains_all - superset
is_empty - is_empty
insert(T) add(&T) insert(T)
insert_all - insert_all()
remove(T) remove(&T) remove(T)
words words words
words_mut words_mut words_mut
- overwrite overwrite
merge union union
- subtract subtract
- intersect intersect
iter iter iter
```
In general, when choosing names I went with:
- names that are more obvious (e.g. `BitSet` over `IdxSet`).
- names that are more like the Rust libraries (e.g. `T` over `C`,
`insert` over `add`);
- names that are more set-like (e.g. `union` over `merge`, `superset`
over `contains_all`, `domain_size` over `num_bits`).
Also, using `T` for index arguments seems more sensible than `&T` --
even though the latter is standard in Rust collection types -- because
indices are always copyable. It also results in fewer `&` and `*`
sigils in practice.
Note it requires MIR-borrowck to be enabled to actually do anything.
Note also that it implicitly turns off our AST-based check for
mutation in guards.
Make rustc::middle::region::Scope's fields public
This PR makes the following changes to `rustc::middle::region::Scope`:
- [x] Makes `region::Scope`'s fields public
- [x] Removes the `impl Scope` block with constructors (as per [this comment](https://github.com/rust-lang/rust/pull/54032#discussion_r216618208))
- [x] Updates call sites throughout the compiler
Closes#54122.
miri engine: keep around some information for dead allocations
We use it to test if a dangling ptr is aligned and non-NULL. This makes some code pass that should pass (writing a ZST to a properly aligned dangling pointer), and makes some code fail that should fail (writing a ZST to a pointer obtained via pointer arithmetic from a real location, but ouf-of-bounds -- that pointer could be NULL, so we cannot allow writing to it).
CTFE does not allow these operations; tests are added to miri with https://github.com/solson/miri/pull/453.
De-overlap the lifetimes of `flow_inits` and `flow_{un,ever_}inits`.
This reduces `max-rss` for an `nll-check` build by 27% for `keccak`, and
by 8% for `inflate`.
r? @nikomatsakis
use structured suggestion for "missing mut" label
Fixes#54133 for both NLL and non-NLL.
r? @estebank
I'm not super happy with the existing wording here, since it's now a suggestion. I wonder if the message would work better as something like "help: make binding mutable: `mut foo`"?
Also, are the `HELP` and `SUGGESTION` comments necessary?
[NLL] Suggest let binding
Closes#49821
Also adds an alternative to `explain_why_borrow_contains_point` that allows changing error messages based on the reason that will be given. This will also be useful for #51026, #51169 and maybe further changes to does not live long enough messages.
miri loop detector hashing
* fix enum hashing to also consider discriminant
* do not hash extra machine state
* standalone miri is not interested in loop detection, so let it opt-out
In the future I think we want to move the hashing logic out of the miri engine, this is CTFE-only.
r? @oli-obk
This requires the following changes.
- It moves parts of bitslice.rs into bitvec.rs: `bitwise()`,
`BitwiseOperator`, `bits_to_string()`.
- It changes `IdxSet` to just be a wrapper around `BitArray`.
- It changes `BitArray` and `BitVec` to use `usize` words instead of
`u128` words. (`BitSlice` and `IdxSet` already use `usize`.) Local
profiling showed `usize` was better.
- It moves some operations from `IdxSet` into `BitArray`:
`new_filled()`, `clear()`, `set_up_to()`, `trim_to()` (renamed
`clear_above()`), `words()` and `words_mut()`, `encode()` and
`decode(). The `IdxSet` operations now just call the `BitArray`
operations.
- It replaces `BitArray`'s iterator implementation with `IdxSet`'s,
because the latter is more concise. It also removes the buggy
`size_hint` function from `BitArray`'s iterator, which counted the
number of *words* rather than the number of *bits*. `IdxSet`'s
iterator is now just a thin wrapper around `BitArray`'s iterator.
- It moves some unit tests from `indexed_set.rs` to `bitvec.rs`.
First step towards `u128` instead of `Const` in `PatternKind::Range`
This PR accomplishes two things:
* It adds `ty::Ty` to `PatternKind::Range`. The extra type information will make it easier to remove it from the `hi` and `lo` members.
* It exchanges `Const` for `u128` in `Constructor::ConstantRange`.
For some weird reason this fixes `intrinsic-move-val`. It also affects
various test heuristics. I removed one test (`reborrow_basic`) that
didn't seem to really be testing anything in particular anymore,
compared to all the other tests we've got.
Optimize miri checking of integer array/slices
This pull request implements the optimization described in #53845 (the `E-easy` part of that issue, not the refactoring). Instead of checking every element of an integral array, we can check the whole memory range at once.
r? @RalfJung
use `NonZeroU32` in `newtype_index!`macro, change syntax
Various improvements to the `newtype_index!` macro:
- Use `NonZeroU32` so that `Option<T>` is cheap
- More ergonomic helper method, no need to import `Idx` trait all the time
- Improve syntax to use `struct` keyword so that ripgrep works to find type def'n
Fixes https://github.com/rust-lang/rust/issues/50337
I'm curious to see if this passes tests =)
Rewrite `precompute_borrows_out_of_scope` for fewer hash table lookups.
It now does one hash table lookup per basic block, instead of one per
statement. This is worthwhile because this function is hot for NLL
builds of `ucd`.
I haven't measured the effect of this yet because I'm having trouble doing optimized builds of rustc that are suitable for profiling (#53916). I will do an online perf run instead.
r? @nikomatsakis
[NLL] Remove base_place
This function was supposed to make `Box` less special. But
* I think that the consensus is that MIR borrowck is going to fully special case `Box`
* It wasn't implemented correctly, it's looking at the type of the wrong `Place`, resulting in weird behaviour:
```rust
#![feature(nll)]
type A = Box<i32>; // If this is changed to another type then this will compile.
pub fn foo(x: Box<(String, A)>) {
let a = x.0; // This will compile if these lines are swapped
let b = x.1;
}
```
r? @nikomatsakis
This allows it to print out the "late-bound regions" from the closure
context more easily. Besides, all the state that is being printed it
is private to the `UniversalRegions`.
[nll] teach SCC about `'static`
r? @nikomatsakis
I think this is right? I am seeing better performance on the `html5ever` benchmark but I'd like a perf run to quantify the exact speedup. There's a few ui tests failing due to changes in the error messages. The main issue seems to be that returns aren't being detected correctly?
`mir_check_cast_unsize.rs` before:
```
error: unsatisfied lifetime constraints
--> mir_check_cast_unsize.rs:17:46
|
17 | fn bar<'a>(x: &'a u32) -> &'static dyn Debug {
| ________--____________________________________^
| | |
| | lifetime `'a` defined here
18 | | //~^ ERROR unsatisfied lifetime constraints
19 | | x
20 | | //~^ WARNING not reporting region error due to nll
21 | | }
| |_^ return requires that `'a` must outlive `'static`
```
`mir_check_cast_unsize.rs` after:
```
error: unsatisfied lifetime constraints
--> mir_check_cast_unsize.rs:19:5
|
17 | fn bar<'a>(x: &'a u32) -> &'static dyn Debug {
| -- lifetime `'a` defined here
18 | //~^ ERROR unsatisfied lifetime constraints
19 | x
| ^ cast requires that `'a` must outlive `'static`
```
Rollup of 17 pull requests
Successful merges:
- #53299 (Updated core/macros.rs to note it works in a no_std environment.)
- #53376 (Cross reference io::copy and fs::copy in docs.)
- #53455 (Individual docs for {from,to}_*_bytes)
- #53550 (librustc_lint: In recursion warning, change 'recurring' to 'recursing')
- #53860 (Migrate (some) of run-pass/ to ui)
- #53874 (Implement Unpin for Box, Rc, and Arc)
- #53895 (tidy: Cleanups and clippy warning fixes)
- #53946 (Clarify `ManuallyDrop` docs)
- #53948 (Minimized clippy test from when NLL disabled two-phase borrows)
- #53959 (Add .git extension to submodule paths missing it)
- #53966 (A few cleanups and minor improvements to mir/dataflow)
- #53967 (propagate build.python into cmake)
- #53979 (Remove `#[repr(transparent)]` from atomics)
- #53991 (Add unchecked_shl/shr check for intrinsics to fix miri's test suit)
- #53992 (migrate run-pass/borrowck to ui/run-pass)
- #53994 (migrate run-pass/*/ to ui/run-pass)
- #54023 (update clippy submodule)
A few cleanups and minor improvements to mir/dataflow
- simplify `dot::GraphWalk::edges` and optimize its vector's allocation
- turn a `kill` loop into `kill_all`
- remove the `prepost` parameter from `dataflow_path` (it doesn't seem to do anything)
- a couple of other minor improvements
Don't reduce E0161 to a warning in NLL migrate mode
This error has been on stable for a while, and allowing such code cause the compile to later ICE (since we can't codegen it). Errors `box UNSIZED EXPR` with unsized locals because it's not compatible with the current evaluation order (create the box before evaluating the expressions).
cc #53469 (fixes the ICE in this case)
cc @qnighy
Fix issue #52475: Make loop detector only consider reachable memory
As [suggested](https://github.com/rust-lang/rust/pull/51702#discussion_r197585664) by @oli-obk `alloc_id`s should be ignored by traversing all `Allocation`s in interpreter memory at a given moment in time, beginning by `ByRef` locals in the stack.
- [x] Generalize the implementation of `Hash` for `EvalSnapshot` to traverse `Allocation`s
- [x] Generalize the implementation of `PartialEq` for `EvalSnapshot` to traverse `Allocation`s
- [x] Commit regression tests
Fixes#52626
Fixes https://github.com/rust-lang/rust/issues/52849
fix `is_non_exhaustive` confusion between structs and enums
Structs and enums can both be non-exhaustive, with a very different
meaning. This PR splits `is_non_exhaustive` to 2 separate functions - 1
for structs, and another for enums, and fixes the places that got the
usage confused.
Fixes#53549.
r? @eddyb
It now does one hash table lookup per basic block, instead of one per
statement. This is worthwhile because this function is hot for NLL
builds of `ucd`.
Enable ThinLTO with incremental compilation.
This is an updated version of #52309. This PR allows `rustc` to use (local) ThinLTO and incremental compilation at the same time. In theory this should allow for getting compile-time improvements for small changes while keeping the runtime performance of the generated code roughly the same as when compiling non-incrementally.
The difference to #52309 is that this version also caches the pre-LTO version of LLVM bitcode. This allows for another layer of caching:
1. if the module itself has changed, we have to re-codegen and re-optimize.
2. if the module itself has not changed, but a module it imported from during ThinLTO has, we don't need to re-codegen and don't need to re-run the first optimization phase. Only the second (i.e. ThinLTO-) optimization phase is re-run.
3. if neither the module itself nor any of its imports have changed then we can re-use the final, post-ThinLTO version of the module. (We might have to load its pre-ThinLTO version though so it's available for other modules to import from)
Various small diagnostic and code clean up
- Point at def span on incorrect `panic` or `oom` function
- Use structured suggestion instead of note for `+=` that can be performed on a dereference of the left binding
- Small code formatting cleanup
refactor match guard
This is the first step to implement RFC 2294: if-let-guard. Tracking issue: https://github.com/rust-lang/rust/issues/51114
The second step should be introducing another variant `IfLet` in the Guard enum. I separated them into 2 PRs for the convenience of reviewers.
r? @petrochenkov
Implement the `min_const_fn` feature gate
cc @RalfJung @eddyb
r? @Centril
implements the feature gate for #53555
I added a hack so the `const_fn` feature gate also enables the `min_const_fn` feature gate. This ensures that nightly users of `const_fn` don't have to touch their code at all.
The `min_const_fn` checks are run first, and if they succeeded, the `const_fn` checks are run additionally to ensure we didn't miss anything.
