It's just not useful. It also makes it hard to have tests that probe
internal state, since the interning number is very sensitive.
Dumping the number in the case of gensym is not ideal but will do for
now.
It's inefficient, and the substitution there doesn't account for the
extra regions used by NLL inference, so it's a bad thing to encourage.
As it happens all callers already know if they have a closure or not,
from what I can tell.
ui tests are the future, especially since the
recent improvement where we have gained
checking and requiring of //~ERROR comments.
The tidy feature-gate test check is intended
to be 50% an actual insurance that there is
a check, and 50% to be a teacher that such
checks are required.
With this commit applied, newbies might
interpret stuff wrongly and create tests
that don't fail but succeed instead.
This is not what feature gate tests are
for though. Therefore, in a later step,
when only ui tests are allowed to be feature
gate tests, we will add checking to ensure
that a file marked as gate test is actually
required to be a compilation failure.
Right now implementing such a check is a
bit annoying as one needs to only do it
when the compile-fail test is in the
ui test suite :/.
compiletest: account for `ui` reference files when deciding to skip
The stamp files for compiletest were ignoring `.stderr` and `.stdout` files. This was driving me crazy.
r? @alexcrichton
Stabilize abi_sysv64
Closes#36167, stabilizing the use of the "sysv64" ABI on x64 platforms where it is not the default ABI.
FCP on this is complete in the tracking issue.
rustc_mir: promote references of statics from other statics.
Fixes#46522 by also allowing `STATIC_REF` in MIR const-qualification, not just AST rvalue promotion.
Display `\t` in diagnostics code as four spaces
Follow up to #44386 using the unicode variable width machinery from #45711 to replace tabs in the source code when displaying a diagnostic error with four spaces (instead of only one), while properly accounting for this when calculating underlines.
Partly addresses #44618.
MIR borrowck: implement union-and-array-compatible semantics
Fixes#44831.
Fixes#44834.
Fixes#45537.
Fixes#45696 (by implementing DerefPure semantics, which is what we want going forward).
r? @nikomatsakis
Give compile_error macro examples
I cannot get Rust to build at all with it complaining about GCC not being a valid C compiler or something, so letting TravisCI be my tester...
Fixes#46171
Mention the name of ? in Result's docs
Fixes#42725
or at least, this is the best we can really do. #35946 is tracking
better errors already, so that should cover the other part of it.
coherence: fix is_knowable logic
A trait-ref that passes the orphan-check rules can still be implemented in a crate downstream from our crate (for example, `LocalType for LocalTrait<_>` might be matched by a `LocalType for LocalTrait<TypeFromDownstreamCrate>`), and this should be known by the `is_knowable` logic.
Trait selection had a hackfix for this, but it's an hacky fix that does not handle all cases. This patch removes it.
fixes#43355.
r? @nikomatsakis
Needs a crater run
rustc_mir: don't move temporaries that are still used later.
This should unbreak using the MIR borrow-checker on `libcore` (assuming #46268 is merged).
Remove librustdoc dependency on log
This change should have been included in PR #46386.
Since librustdoc doesn't explicitly depend on internal crates
(such as librustc_driver) through its Cargo.toml, it ends up using the
sysroot to resolve them. By removing the dependency on 'log',
we ensure that the syroot is used to resolve `log` as well. This ensures
that only one version of log is in use, so that `env_logger::init()`
enables all uses of `log!` macros.
This change should have been included in PR #46386.
Since librustdoc doesn't explicitly depend on internal crates
(such as librustc_driver) through its Cargo.toml, it ends up using the
sysroot to resolve them. By removing the dependency on 'log',
we ensure that the syroot is used to resolve `log` as well. This ensures
that only one version of log is in use, so that `env_logger::init()`
enables all uses of `log!` macros.
incr.comp.: Incorporate the stable commandline arg hash and SVHs of upstream crates into the SVH.
So far the SVH detected changes in the HIR, which is already very sensitive, but in order for `eval_always` queries to also be sensitive to changes in upstream crates, the SVH also needs to capture changes there.
This PR fixes [rust-icci/crossbeam](https://travis-ci.org/rust-icci/crossbeam/builds/308936448), but I have not yet been able to come up with a minimal regression test.
r? @nikomatsakis
NLL: improve inference with flow results, represent regions with bitsets, and more
This PR begins with a number of edits to the NLL code and then includes a large number of smaller refactorings (these refactorings ought not to change behavior). There are a lot of commits here, but each is individually simple. The goal is to land everything up to but not including the changes to how we handle closures, which are conceptually more complex.
The NLL specific changes are as follows (in order of appearance):
**Modify the region inferencer's approach to free regions.** Previously, for each free region (lifetime parameter) `'a`, it would compute the set of other free regions that `'a` outlives (e.g., if we have `where 'a: 'b`, then this set would be `{'a, 'b}`). Then it would mark those free regions as "constants" and report an error if inference tried to extend `'a` to include any other region (e.g., `'c`) that is not in that outlives set. In this way, the value of `'a` would never grow beyond the maximum that could type check. The new approach is to allow `'a` to grow larger. Then, after the fact, we check over the value of `'a` and see what other free regions it is required to outlive, and we check that those outlives relationships are justified by the where clauses in scope etc.
**Modify constraint generation to consider maybe-init.** When we have a "drop-live" variable `x` (i.e., a variable that will be dropped but will not be otherwise used), we now consider whether `x` is "maybe initialized" at that point. If not, then we know the drop is a no-op, and we can allow its regions to be dead. Due to limitations in the fragment code, this currently only works at the level of entire variables.
**Change representation of regions to use a `BitMatrix`.** We used to use a `BTreeSet`, which was rather silly. We now use a MxN matrix of bits, where `M` is the number of variables and `N` is the number of possible elements in each set (size of the CFG + number of free regions).
The remaining commits (starting from
extract the `implied_bounds` code into a helper function ") are all "no-op" refactorings, I believe.
~~One concern I have is with the commit "with -Zverbose, print all details of closure substs"; this commit seems to include some "internal" stuff in the mir-dump files, such as internal interner numbers, that I fear may vary by platform. Annoying. I guess we will see.~~ (I removed this commit.)
As for reviewer, @arielb1 has been reviewing the PRs, and they are certainly welcome to review this one too. But I figured it'd maybe be good to have more people taking a look and being familiar with this code, so I'll "nominate" @pnkfelix .
r? @pnkfelix
Fix invalid docs path for compiler plugins
The path to the docs `src/doc/guide-plugin.md` moved to
`src/doc/unstable-book/src/language-features/plugin.md`.
This patch updates it in the comment of WARNING message of the test
code.
This has been bugging me. All the regions appear free in the source;
the real difference is that some of them are universally quantified
(those in the function signature) and some are existentially
quantified (those for which we are inferring values).
We now visit just the stuff in the CFG, and we add liveness
constraints for all the random types, regions etc that appear within
rvalues and statements.
In particular, if we see a variable is DROP-LIVE, but it is not
MAYBE-INIT, then we can ignore the drop. This leavess attempt to use
more complex refinements of the idea (e.g., for subpaths or subfields)
to future work.
Rather than declaring some region variables to be constant, and
reporting errors when they would have to change, we instead populate
each free region X with a minimal set of points (the CFG plus end(X)),
and then we let inference do its thing. This may add other `end(Y)`
points into X; we can then check after the fact that indeed `X: Y`
holds.
This requires a bit of "blame" detection to find where the bad
constraint came from: we are currently using a pretty dumb
algorithm. Good place for later expansion.
Add a specialization of read_exact for Cursor.
The read_exact implementation for &[u8] is optimized and usually allows LLVM to reduce a read_exact call for small numbers of bytes to a bounds check and a register load instead of a generic memcpy. On a workload I have that decompresses, deserializes (via bincode), and processes some data, this leads to a 40% speedup by essentially eliminating the deserialization overhead entirely.
The read_exact implementation for &[u8] is optimized and usually allows LLVM to reduce a read_exact call for small numbers of bytes to a bounds check and a register load instead of a generic memcpy. On a workload I have that decompresses, deserializes (via bincode), and processes some data, this leads to a 40% speedup by essentially eliminating the deserialization overhead entirely.
Consistent parameter name for numeric ‘checked’ operations.
Some checked operations use `rhs` as a parameter name, and some use
`other`. For the sake of consistency, unify everything under the `rhs`
name.
Fixes https://github.com/rust-lang/rust/issues/46308.
Fix invalid link to lint_plugin_test.rs
The path to `lint_plugin_test.rs` was moved to `src/test/ui-fulldeps/`
from `src/test/run-pass-fulldeps/` in 38ef85696d
This patch updates it in the docs.
Fix CopyPropagation regression (2)
Remaining part of MIR copyprop regression by (I think) #45380, which I missed in #45753.
```rust
fn foo(mut x: i32) -> i32 {
let y = x;
x = 123; // `x` is assigned only once in MIR, but cannot be propagated to `y`
y
}
```
So any assignment to an argument cannot be propagated.
