Compute liveness constraints in location-sensitive polonius
This continues the location-sensitive prototype. In this episode, we build the liveness constraints.
Reminder of the approach we're taking: we need variance data to create liveness edges in the forward/backward/both directions (respectively in the cases of covariance, contravariance, invariance) in the localized constraint graph.
This PR:
- introduces the holder for that, and for the liveness data in the correct shape: the transpose of what we're using today, "live regions per points".
- records use/drop live region variance during tracing
- records regular live region variance at the end of liveness
- records the correctly shaped live region per point matrix
- uses all of the above to compute the liveness constraints
(There's still technically one tiny part of the liveness owl left to do, but I'll leave it for a future PR: we also need to disable the NLL optimization that avoids computing liveness for locals whose types contain a region outliving a free region -- the existing constraints make it effectively live at all points; this doesn't work under polonius)
r? `@jackh726` cc `@matthewjasper`
Rollup of 4 pull requests
Successful merges:
- #134870 (Fix sentence fragment in `pin` module docs)
- #134884 (Fix typos)
- #134892 (Added codegen test for elidings bounds check when indexes are manually checked)
- #134894 (Document how to run the split Docker pipelines)
r? `@ghost`
`@rustbot` modify labels: rollup
Improve default target options for x86_64-unknown-linux-none
Without a standard library, we cannot unwind, so it should be panic=abort by default.
Additionally, it does not have std because while it is Linux, it cannot use libc, which std uses today for Linux.
Using PIE by default may be surprising to users, as shown in #134763, so I've documented it explicitly. I'm not sure if we want to count that as fixing the issue or not.
cc `@morr0ne,` as you added the target (and are the maintainer), and `@Noratrieb,` who reviewed that PR (:D).
- add a FIXME when looking for the region variance of unexpected regions
- drive-by: fix a doc comment link
- drive-by: simplify the variance match using exported variants instead
This context struct will hold data to help creating localized
constraints:
- the live regions, with the shape matching a CFG walk, indexed per
point
- the variance of these live regions, represented as the direction we'll
add the appropriate
We also add this structure to the mir typeck to record liveness data,
and make it responsible for localized constraint creation.
Avoid ICE in borrowck
Provide a fallback in `best_blame_constraint` when `find_constraint_paths_between_regions` doesn't have a result. This code is due a rework to avoid the letf-over `unwrap()`, but avoids the ICE caused by the repro.
Fix#133252.
Implement `default_overrides_default_fields` lint
Detect when a manual `Default` implementation isn't using the existing default field values and suggest using `..` instead:
```
error: `Default` impl doesn't use the declared default field values
--> $DIR/manual-default-impl-could-be-derived.rs:14:1
|
LL | / impl Default for A {
LL | | fn default() -> Self {
LL | | A {
LL | | y: 0,
| | - this field has a default value
... |
LL | | }
| |_^
|
= help: use the default values in the `impl` with `Struct { mandatory_field, .. }` to avoid them diverging over time
note: the lint level is defined here
--> $DIR/manual-default-impl-could-be-derived.rs:5:9
|
LL | #![deny(default_overrides_default_fields)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
```
r? `@compiler-errors`
This is a simpler version of #134441, detecting the simpler case when a field with a default should have not been specified in the manual `Default::default()`, instead using `..` for it. It doesn't provide any suggestions, nor the checks for "equivalences" nor whether the value used in the imp being used would be suitable as a default field value.
Skip parenthesis around tuple struct field calls
The pretty-printer previously did not distinguish between named vs unnamed fields when printing a function call containing a struct field. It would print the call as `(self.fun)()` for a named field which is correct, and `(self.0)()` for an unnamed field which is redundant.
This PR changes function calls of tuple struct fields to print without parens.
**Before:**
```rust
struct Tuple(fn());
fn main() {
let tuple = Tuple(|| {});
(tuple.0)();
}
```
**After:**
```rust
struct Tuple(fn());
fn main() {
let tuple = Tuple(|| {});
tuple.0();
}
```
Skip parenthesis if `.` makes statement boundary unambiguous
There is a rule in the parser that statements and match-arms never end in front of a `.` or `?` token (except when the `.` is really `..` or `..=` or `...`). So some of the leading subexpressions that need parentheses inserted when followed by some other operator like `-` or `+`, do not need parentheses when followed by `.` or `?`.
Example:
```rust
fn main() {
loop {}.to_string() + "";
match () {
_ => loop {}.to_string() + "",
};
}
```
`-Zunpretty=expanded` before:
```console
#![feature(prelude_import)]
#[prelude_import]
use std::prelude::rust_2021::*;
#[macro_use]
extern crate std;
fn main() {
(loop {}).to_string() + "";
match () { _ => (loop {}).to_string() + "", };
}
```
After:
```console
#![feature(prelude_import)]
#[prelude_import]
use std::prelude::rust_2021::*;
#[macro_use]
extern crate std;
fn main() {
loop {}.to_string() + "";
match () { _ => loop {}.to_string() + "", };
}
```
Make `ty::Error` implement all auto traits
I have no idea what's up with the crashes test I fixed--I really don't want to look into it since it has to do something with borrowck and multiple layers of opaques. I think the underlying idea of allowing error types to implement all auto traits is justified though.
Fixes#134796Fixes#131050
r? lcnr
Add a compiler intrinsic to back `bigint_helper_methods`
cc https://github.com/rust-lang/rust/issues/85532
This adds a new `carrying_mul_add` intrinsic, to implement `wide_mul` and `carrying_mul`.
It has fallback MIR for all types -- including `u128`, which isn't currently supported on nightly -- so that it'll continue to work on all backends, including CTFE.
Then it's overridden in `cg_llvm` to use wider intermediate types, including `i256` for `u128::carrying_mul`.
Spruce up the docs of several queries related to the type/trait system and const eval
- Editorial
- Proper rustdoc summary/synopsis line by making use of extra paragraphs: Leads to better rendered output on module pages, in search result lists and overall, too
- Use rustdoc warning blocks for admonitions of the form "do not call / avoid calling this query directly"
- Use intra-doc links of the form ``[`Self::$query`]`` to cross-link queries. Indeed, such links are generally a bit brittle due to the existence of `TyCtxtFeed` which only contains a subset of queries. Therefore the docs of `feedable` queries cannot cross-link to non-`feedable` ones. I'd say it's fine to use intra-doc links despite the potential/unlikely occasional future breakage (if a query with the aforementioned characteristics becomes `feedable`). `Self::` is nicer than `TyCtxt::` (which would be more stable) since it accounts for other contexts like `TyCtxt{Feed,At,Ensure{,WithValue}}`
- Informative
- Generally add, flesh out and correct some doc comments
- Add *Panic* sections (to a few selected queries only). The lists of panics aren't necessarily exhaustive and focus on the more "obvious" or "important" panics.
- Where applicable add a paragraph calling attention to the relevant [`#[rustc_*]` TEST attribute](https://rustc-dev-guide.rust-lang.org/compiler-debugging.html#rustc_-test-attributes)
The one non-doc change (it's internal and not observable):
Be even more defensive in `query constness`'s impl (spiritual follow-up to #134122) (see self review comment).
Fixes#133494.
r\? **any**(compiler-errors, oli-obk)
ptr::copy: fix docs for the overlapping case
Fixes https://github.com/rust-lang/unsafe-code-guidelines/issues/549
As discussed in that issue, it doesn't make any sense for `copy` to read a byte via `src` after it was already written via `dst`. The entire point of this method is that is copies correctly even if they overlap, and that requires always reading any given location before writing it.
Cc `@rust-lang/opsem`
[macro_metavar_expr_concat] Fix#128346Fix#128346Fix#131393
The syntax is invalid in both issues so I guess that theoretically the compiler should have aborted early.
This PR tries to fix a local problem but let me know if there are better options.
cc `@petrochenkov` if you are interested
fix default-backtrace-ice test
when running `tests/ui/panics/default-backtrace-ice.rs locally it gave this error:
```
failures:
---- [ui] tests/ui/panics/default-backtrace-ice.rs stdout ----
Saved the actual stderr to "/home/jyn/src/rust3/build/x86_64-unknown-linux-gnu/test/ui/panics/default-backtrace-ice/default-backtrace-ice.stderr"
diff of stderr:
7
8 aborting due to `-Z treat-err-as-bug=1`
9 stack backtrace:
- (end_short_backtrace)
- (begin_short_backtrace)
- (end_short_backtrace)
- (begin_short_backtrace)
+ [... omitted 22 frames ...]
+
```
(note that you must *not* use --bless; we previously did not have an error annotation to verify it was a full backtrace instead of a short backtrace.)
this is a regression from setting RUST_BACKTRACE=1 by default in https://github.com/rust-lang/rust/pull/134743. we need to turn off the new behavior when running UI tests so that they reflect our dist compiler. normally that's done by checking `sess.unstable_opts.ui_testing`, but this happens extremely early in the compiler before we've expanded arg files. do an extremely simple hack that doesn't work in all cases - we don't need it to work in all cases, only when running UI tests.
cc https://github.com/rust-lang/rust/pull/129658#issuecomment-2561988081
r? `@jieyouxu`
when running `tests/ui/panics/default-backtrace-ice.rs locally it gave this error:
```
failures:
---- [ui] tests/ui/panics/default-backtrace-ice.rs stdout ----
Saved the actual stderr to "/home/jyn/src/rust3/build/x86_64-unknown-linux-gnu/test/ui/panics/default-backtrace-ice/default-backtrace-ice.stderr"
diff of stderr:
7
8 aborting due to `-Z treat-err-as-bug=1`
9 stack backtrace:
- (end_short_backtrace)
- (begin_short_backtrace)
- (end_short_backtrace)
- (begin_short_backtrace)
+ [... omitted 22 frames ...]
+
```
this is a regression from setting RUST_BACKTRACE=1 by default. we need to turn off the new behavior when running UI tests so that they reflect our dist compiler. normally that's done by checking `sess.unstable_opts.ui_testing`, but this happens extremely early in the compiler before we've expanded arg files. do an extremely simple hack that doesn't work in all cases - we don't need it to work in all cases, only when running UI tests.
