Replace const eval limit by a lint and add an exponential backoff warning
The lint triggers at the first power of 2 that comes after 1 million function calls or traversed back-edges (takes less than a second on usual programs). After the first emission, an unsilenceable warning is repeated at every following power of 2 terminators, causing it to get reported less and less the longer the evaluation runs.
cc `@rust-lang/wg-const-eval`
fixes#93481closes#67217
Only rewrite valtree-constants to patterns and keep other constants opaque
Now that we can reliably fall back to comparing constants with `PartialEq::eq` to the match scrutinee, we can
1. eagerly try to convert constants to valtrees
2. then deeply convert the valtree to a pattern
3. if the to-valtree conversion failed, create an "opaque constant" pattern.
This PR specifically avoids any behavioral changes or major cleanups. What we can now do as follow ups is
* move the two remaining call sites to `destructure_mir_constant` off that query
* make valtree to pattern conversion infallible
* this needs to be done after careful analysis of the effects. There may be user visible changes from that.
based on https://github.com/rust-lang/rust/pull/111768
change `BorrowKind::Unique` to be a mutating `PlaceContext`
fixes#112056
I believe that `BorrowKind::Unique` is a footgun in general, so I added a FIXME and opened https://github.com/rust-lang/rust/issues/112072. This is a bit too involved for this PR though.
Ensure Fluent messages are in alphabetical order
Fixes#111847
This adds a tidy check to ensure Fluent messages are in alphabetical order, as well as sorting all existing messages. I think the error could be worded better, would appreciate suggestions.
<details>
<summary>Script used to sort files</summary>
```py
import sys
import re
fn = sys.argv[1]
with open(fn, 'r') as f:
data = f.read().split("\n")
chunks = []
cur = ""
for line in data:
if re.match(r"^([a-zA-Z0-9_]+)\s*=\s*", line):
chunks.append(cur)
cur = ""
cur += line + "\n"
chunks.append(cur)
chunks.sort()
with open(fn, 'w') as f:
f.write(''.join(chunks).strip("\n\n") + "\n")
```
</details>
Pretty-print inherent projections correctly
Previously, we were trying to pretty-print inherent projections with `Printer::print_def_path` which is incorrect since
it expects the substitutions to be of a certain format (parents substs followed by own substs) which doesn't hold for
inherent projections (self type subst followed by own substs).
Now we print inherent projections manually.
Fixes#111390.
Fixes#111397.
Lacking tests! Is there a test suite / compiletest flags for the pretty-printer? In most if not all cases,
inherent projections are normalized away before they get the chance to appear in diagnostics.
If I were to create regression tests for linked issues, they would need to be `mir-opt` tests to exercise
`-Zdump-mir=all` (right?) which doesn't feel quite adequate to me.
`@rustbot` label F-inherent_associated_types
Suppress "erroneous constant used" for constants tainted by errors
When constant evaluation fails because its MIR is tainted by errors,
suppress note indicating that erroneous constant was used, since those
errors have to be fixed regardless of the constant being used or not.
Fixes#110891.
Move expansion of query macros in rustc_middle to rustc_middle::query
This moves the expansion of `define_callbacks!` and `define_feedable!` from `rustc_middle::ty::query` to `rustc_middle::query`.
This means that types used in queries are both imported and used in `rustc_middle::query` instead of being split between these modules. It also decouples `rustc_middle::ty::query` further from `rustc_middle` which is helpful since we want to move `rustc_middle::ty::query` to the query system crates.
When constant evaluation fails because its MIR is tainted by errors,
suppress note indicating that erroneous constant was used, since those
errors have to be fixed regardless of the constant being used or not.
Change the immediate_dominator return type to Option, and use None to
indicate that node has no immediate dominator.
Also fix the issue where the start node would be returned as its own
immediate dominator.
Currently a `{D,Subd}iagnosticMessage` can be created from any type that
impls `Into<String>`. That includes `&str`, `String`, and `Cow<'static,
str>`, which are reasonable. It also includes `&String`, which is pretty
weird, and results in many places making unnecessary allocations for
patterns like this:
```
self.fatal(&format!(...))
```
This creates a string with `format!`, takes a reference, passes the
reference to `fatal`, which does an `into()`, which clones the
reference, doing a second allocation. Two allocations for a single
string, bleh.
This commit changes the `From` impls so that you can only create a
`{D,Subd}iagnosticMessage` from `&str`, `String`, or `Cow<'static,
str>`. This requires changing all the places that currently create one
from a `&String`. Most of these are of the `&format!(...)` form
described above; each one removes an unnecessary static `&`, plus an
allocation when executed. There are also a few places where the existing
use of `&String` was more reasonable; these now just use `clone()` at
the call site.
As well as making the code nicer and more efficient, this is a step
towards possibly using `Cow<'static, str>` in
`{D,Subd}iagnosticMessage::{Str,Eager}`. That would require changing
the `From<&'a str>` impls to `From<&'static str>`, which is doable, but
I'm not yet sure if it's worthwhile.
Don't validate constants in const propagation
Validation is neither necessary nor desirable.
The constant validation is already omitted at mir-opt-level >= 3, so there there are not changes in MIR test output (the propagation of invalid constants is covered by an existing test in tests/mir-opt/const_prop/invalid_constant.rs).
Tweak await span to not contain dot
Fixes a discrepancy between method calls and await expressions where the latter are desugared to have a span that *contains* the dot (i.e. `.await`) but method call identifiers don't contain the dot. This leads to weird suggestions suggestions in borrowck -- see linked issue.
Fixes#110761
This mostly touches a bunch of tests to tighten their `await` span.
More core::fmt::rt cleanup.
- Removes the `V1` suffix from the `Argument` and `Flag` types.
- Moves more of the format_args lang items into the `core::fmt::rt` module. (The only remaining lang item in `core::fmt` is `Arguments` itself, which is a public type.)
Part of https://github.com/rust-lang/rust/issues/99012
Follow-up to https://github.com/rust-lang/rust/pull/110616
They're semantically the same, so this means the backends don't need to handle the intrinsic and means fewer MIR basic blocks in pointer arithmetic code.
