Commit Graph

480 Commits

Author SHA1 Message Date
ouz-a
a1672ad5b8 Remove bounds check with enum cast 2022-10-31 14:10:37 +03:00
Michael Howell
7e62406e01
Rollup merge of #101428 - JakobDegen:build-tests, r=oli-obk
Add mir building test directory

The first commit renames `mir-map.0` mir dumps to `built.after` dumps. I am happy to drop this commit if someone can explain the origin of the name.

The second commit moves a bunch of mir building tests into their own directory. I did my best to make sure that all of these tests are actually testing mir building, and not just incidentally using `built.after`

r? ``@oli-obk``
2022-10-30 19:31:37 -07:00
Maybe Waffle
a17ccfa621 Accept TyCtxt instead of TyCtxtAt in Ty::is_* functions
Functions in answer:

- `Ty::is_freeze`
- `Ty::is_sized`
- `Ty::is_unpin`
- `Ty::is_copy_modulo_regions`
2022-10-27 15:06:08 +04:00
Jakob Degen
c4c4c566d0 Replace mir_map.0 dump with built phase change dump 2022-10-27 00:21:57 -07:00
Jakob Degen
be2401b8bf Split phase change from MirPass 2022-10-23 14:18:09 -07:00
Patrick Walton
da630ac79d Introduce deduced parameter attributes, and use them for deducing readonly on
indirect immutable freeze by-value function parameters.

Right now, `rustc` only examines function signatures and the platform ABI when
determining the LLVM attributes to apply to parameters. This results in missed
optimizations, because there are some attributes that can be determined via
analysis of the MIR making up the function body. In particular, `readonly`
could be applied to most indirectly-passed by-value function arguments
(specifically, those that are freeze and are observed not to be mutated), but
it currently is not.

This patch introduces the machinery that allows `rustc` to determine those
attributes. It consists of a query, `deduced_param_attrs`, that, when
evaluated, analyzes the MIR of the function to determine supplementary
attributes. The results of this query for each function are written into the
crate metadata so that the deduced parameter attributes can be applied to
cross-crate functions. In this patch, we simply check the parameter for
mutations to determine whether the `readonly` attribute should be applied to
parameters that are indirect immutable freeze by-value.  More attributes could
conceivably be deduced in the future: `nocapture` and `noalias` come to mind.

Adding `readonly` to indirect function parameters where applicable enables some
potential optimizations in LLVM that are discussed in [issue 103103] and [PR
103070] around avoiding stack-to-stack memory copies that appear in functions
like `core::fmt::Write::write_fmt` and `core::panicking::assert_failed`. These
functions pass a large structure unchanged by value to a subfunction that also
doesn't mutate it. Since the structure in this case is passed as an indirect
parameter, it's a pointer from LLVM's perspective. As a result, the
intermediate copy of the structure that our codegen emits could be optimized
away by LLVM's MemCpyOptimizer if it knew that the pointer is `readonly
nocapture noalias` in both the caller and callee. We already pass `nocapture
noalias`, but we're missing `readonly`, as we can't determine whether a
by-value parameter is mutated by examining the signature in Rust. I didn't have
much success with having LLVM infer the `readonly` attribute, even with fat
LTO; it seems that deducing it at the MIR level is necessary.

No large benefits should be expected from this optimization *now*; LLVM needs
some changes (discussed in [PR 103070]) to more aggressively use the `noalias
nocapture readonly` combination in its alias analysis. I have some LLVM patches
for these optimizations and have had them looked over. With all the patches
applied locally, I enabled LLVM to remove all the `memcpy`s from the following
code:

```rust
fn main() {
    println!("Hello {}", 3);
}
```

which is a significant codegen improvement over the status quo. I expect that
if this optimization kicks in in multiple places even for such a simple
program, then it will apply to Rust code all over the place.

[issue 103103]: https://github.com/rust-lang/rust/issues/103103

[PR 103070]: https://github.com/rust-lang/rust/pull/103070
2022-10-21 02:33:15 -07:00
Matthias Krüger
2f2664923b
Rollup merge of #102778 - nbdd0121:mir, r=tmiasko
Fix MIR inlining of asm_unwind

The MIR inlining currently doesn't handle inline asm's unwind edge correctly.

This code will cause ICE:
```rust
struct D;

impl Drop for D {
    fn drop(&mut self) {}
}

#[inline(always)]
fn foo() {
    let _d = D;
    unsafe { std::arch::asm!("", options(may_unwind)) };
}

pub fn main() {
    foo();
}
```

This PR fixes this issue. I also take the opportunity to extract common code into a method.
2022-10-08 14:38:19 +02:00
Ralf Jung
fd59d44f58 make const_err a hard error 2022-10-07 18:08:49 +02:00
Gary Guo
242348343b Fix MIR inlining of asm_unwind 2022-10-07 12:59:38 +01:00
bors
0152393048 Auto merge of #99324 - reez12g:issue-99144, r=jyn514
Enable doctests in compiler/ crates

Helps with https://github.com/rust-lang/rust/issues/99144
2022-10-06 03:01:57 +00:00
Maybe Waffle
a8f7e244b7 Refactor rustc lint API 2022-10-01 10:03:06 +00:00
reez12g
9a4c5abe45 Remove from compiler/ crates 2022-09-29 16:49:04 +09:00
Pietro Albini
3975d55d98
remove cfg(bootstrap) 2022-09-26 10:14:45 +02:00
b-naber
a705e65605 rename Unevaluated to UnevaluatedConst 2022-09-23 14:27:34 +02:00
b-naber
9f3784df89 introduce mir::Unevaluated 2022-09-22 12:35:28 +02:00
Dylan DPC
7d7f55599a
Rollup merge of #102045 - RalfJung:const-prop-regression-fix, r=oli-obk
fix ConstProp handling of written_only_inside_own_block_locals

Fixes a regression introduced by https://github.com/rust-lang/rust/pull/100239, which adds an early return and thus skips some code in `visit_terminator` that must be run for soundness.

Fixes https://github.com/rust-lang/rust/issues/101973
2022-09-21 19:01:08 +05:30
Michael Howell
b149c48186
Rollup merge of #102021 - lcnr:tyConst-fun, r=b-naber,BoxyUwU
some post-valtree cleanup

r? project-const-generics cc ```@b-naber```
2022-09-20 10:13:01 -07:00
Ralf Jung
7373788c37 fix ConstProp handling of written_only_inside_own_block_locals 2022-09-20 12:49:32 +02:00
lcnr
526856768d ctfe, const_to_op only for mir constants 2022-09-19 16:17:33 +02:00
lcnr
647052fc04 remove the Subst trait, always use EarlyBinder 2022-09-19 11:37:27 +02:00
Dylan DPC
3ad81e0dd8
Rollup merge of #93628 - est31:stabilize_let_else, r=joshtriplett
Stabilize `let else`

🎉  **Stabilizes the `let else` feature, added by [RFC 3137](https://github.com/rust-lang/rfcs/pull/3137).** 🎉

Reference PR: https://github.com/rust-lang/reference/pull/1156

closes #87335 (`let else` tracking issue)

FCP: https://github.com/rust-lang/rust/pull/93628#issuecomment-1029383585

----------

## Stabilization report

### Summary

The feature allows refutable patterns in `let` statements if the expression is
followed by a diverging `else`:

```Rust
fn get_count_item(s: &str) -> (u64, &str) {
    let mut it = s.split(' ');
    let (Some(count_str), Some(item)) = (it.next(), it.next()) else {
        panic!("Can't segment count item pair: '{s}'");
    };
    let Ok(count) = u64::from_str(count_str) else {
        panic!("Can't parse integer: '{count_str}'");
    };
    (count, item)
}
assert_eq!(get_count_item("3 chairs"), (3, "chairs"));
```

### Differences from the RFC / Desugaring

Outside of desugaring I'm not aware of any differences between the implementation and the RFC. The chosen desugaring has been changed from the RFC's [original](https://rust-lang.github.io/rfcs/3137-let-else.html#reference-level-explanations). You can read a detailed discussion of the implementation history of it in `@cormacrelf` 's [summary](https://github.com/rust-lang/rust/pull/93628#issuecomment-1041143670) in this thread, as well as the [followup](https://github.com/rust-lang/rust/pull/93628#issuecomment-1046598419). Since that followup, further changes have happened to the desugaring, in #98574, #99518, #99954. The later changes were mostly about the drop order: On match, temporaries drop in the same order as they would for a `let` declaration. On mismatch, temporaries drop before the `else` block.

### Test cases

In chronological order as they were merged.

Added by df9a2e0687 (#87688):

* [`ui/pattern/usefulness/top-level-alternation.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/pattern/usefulness/top-level-alternation.rs) to ensure the unreachable pattern lint visits patterns inside `let else`.

Added by 5b95df4bdc (#87688):

* [`ui/let-else/let-else-bool-binop-init.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-bool-binop-init.rs) to ensure that no lazy boolean expressions (using `&&` or `||`) are allowed in the expression, as the RFC mandates.
* [`ui/let-else/let-else-brace-before-else.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-brace-before-else.rs) to ensure that no `}` directly preceding the `else` is allowed in the expression, as the RFC mandates.
* [`ui/let-else/let-else-check.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-check.rs) to ensure that `#[allow(...)]` attributes added to the entire `let` statement apply for the `else` block.
* [`ui/let-else/let-else-irrefutable.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-irrefutable.rs) to ensure that the `irrefutable_let_patterns` lint fires.
* [`ui/let-else/let-else-missing-semicolon.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-missing-semicolon.rs) to ensure the presence of semicolons at the end of the `let` statement.
* [`ui/let-else/let-else-non-diverging.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-non-diverging.rs) to ensure the `else` block diverges.
* [`ui/let-else/let-else-run-pass.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-run-pass.rs) to ensure the feature works in some simple test case settings.
* [`ui/let-else/let-else-scope.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-scope.rs) to ensure the bindings created by the outer `let` expression are not available in the `else` block of it.

Added by bf7c32a447 (#89965):

* [`ui/let-else/issue-89960.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/issue-89960.rs) as a regression test for the ICE-on-error bug #89960 . Later in 102b9125e1 this got removed in favour of more comprehensive tests.

Added by 856541963c (#89974):

* [`ui/let-else/let-else-if.rs`](https://github.com/rust-lang/rust/blob/1.58.1/src/test/ui/let-else/let-else-if.rs) to test for the improved error message that points out that `let else if` is not possible.

Added by 9b45713b6c:

* [`ui/let-else/let-else-allow-unused.rs`](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-allow-unused.rs) as a regression test for #89807, to ensure that `#[allow(...)]` attributes added to the entire `let` statement apply for bindings created by the `let else` pattern.

Added by 61bcd8d307 (#89841):

* [`ui/let-else/let-else-non-copy.rs`](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-non-copy.rs) to ensure that a copy is performed out of non-copy wrapper types. This mirrors `if let` behaviour. The test case bases on rustc internal changes originally meant for #89933 but then removed from the PR due to the error prior to the improvements of #89841.
* [`ui/let-else/let-else-source-expr-nomove-pass.rs `](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-source-expr-nomove-pass.rs) to ensure that while there is a move of the binding in the successful case, the `else` case can still access the non-matching value. This mirrors `if let` behaviour.

Added by 102b9125e1 (#89841):

* [`ui/let-else/let-else-ref-bindings.rs`](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-ref-bindings.rs) and [`ui/let-else/let-else-ref-bindings-pass.rs `](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-ref-bindings-pass.rs) to check `ref` and `ref mut` keywords in the pattern work correctly and error when needed.

Added by 2715c5f984 (#89841):

* Match ergonomic tests adapted from the `rfc2005` test suite.

Added by fec8a507a2 (#89841):

* [`ui/let-else/let-else-deref-coercion-annotated.rs`](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-deref-coercion-annotated.rs) and [`ui/let-else/let-else-deref-coercion.rs`](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-deref-coercion.rs) to check deref coercions.

#### Added since this stabilization report was originally written (2022-02-09)

Added by 76ea566677 (#94211):

* [`ui/let-else/let-else-destructuring.rs`](https://github.com/rust-lang/rust/blob/1.63.0/src/test/ui/let-else/let-else-destructuring.rs) to give a nice error message if an user tries to do an assignment with a (possibly refutable) pattern and an `else` block, like asked for in #93995.

Added by e7730dcb7e (#94208):

* [`ui/let-else/let-else-allow-in-expr.rs`](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-allow-in-expr.rs) to test whether `#[allow(unused_variables)]` works in the expr, as well as its non presence, as well as putting it on the entire `let else` *affects* the expr, too. This was adding a missing test as pointed out by the stabilization report.
* Expansion of `ui/let-else/let-else-allow-unused.rs` and `ui/let-else/let-else-check.rs` to ensure that non-presence of `#[allow(unused)]` does issue the unused lint. This was adding a missing test case as pointed out by the stabilization report.

Added by 5bd71063b3 (#94208):

* [`ui/let-else/let-else-slicing-error.rs`](https://github.com/rust-lang/rust/blob/1.61.0/src/test/ui/let-else/let-else-slicing-error.rs), a regression test for #92069, which got fixed without addition of a regression test. This resolves a missing test as pointed out by the stabilization report.

Added by 5374688e1d (#98574):

* [`src/test/ui/async-await/async-await-let-else.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/async-await/async-await-let-else.rs) to test the interaction of async/await with `let else`

Added by 6c529ded86 (#98574):

* [`src/test/ui/let-else/let-else-temporary-lifetime.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/let-else/let-else-temporary-lifetime.rs) as a (partial) regression test for #98672

Added by 9b56640106 (#99518):

* [`src/test/ui/let-else/let-else-temp-borrowck.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/let-else/let-else-temporary-lifetime.rs) as a regression test for #93951
* Extension of `src/test/ui/let-else/let-else-temporary-lifetime.rs` to include a partial regression test for #98672 (especially regarding `else` drop order)

Added by baf9a7cb57 (#99518):

* Extension of `src/test/ui/let-else/let-else-temporary-lifetime.rs` to include a partial regression test for #93951, similar to `let-else-temp-borrowck.rs`

Added by 60be2de8b7 (#99518):

* Extension of `src/test/ui/let-else/let-else-temporary-lifetime.rs` to include a program that can now be compiled thanks to borrow checker implications of #99518

Added by 47a7a91c96 (#100132):

* [`src/test/ui/let-else/issue-100103.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/let-else/issue-100103.rs), as a regression test for #100103, to ensure that there is no ICE when doing `Err(...)?` inside else blocks.

Added by e3c5bd617d (#100443):

* [`src/test/ui/let-else/let-else-then-diverge.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/let-else/let-else-then-diverge.rs), to verify that there is no unreachable code error with the current desugaring.

Added by 981852677c (#100443):

* [`src/test/ui/let-else/issue-94176.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/let-else/issue-94176.rs), to make sure that a correct span is emitted for a missing trailing expression error. Regression test for #94176.

Added by e182d12a84 (#100434):

* [src/test/ui/unpretty/pretty-let-else.rs](https://github.com/rust-lang/rust/blob/master/src/test/ui/unpretty/pretty-let-else.rs), as a regression test to ensure pretty printing works for `let else` (this bug surfaced in many different ways)

Added by e26285603c (#99954):

* [`src/test/ui/let-else/let-else-temporary-lifetime.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/let-else/let-else-temporary-lifetime.rs) extended to contain & borrows as well, as this was identified as an earlier issue with the desugaring: https://github.com/rust-lang/rust/issues/98672#issuecomment-1200196921

Added by 2d8460ef43 (#99291):

* [`src/test/ui/let-else/let-else-drop-order.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/let-else/let-else-drop-order.rs) a matrix based test for various drop order behaviour of `let else`. Especially, it verifies equality of `let` and `let else` drop orders, [resolving](https://github.com/rust-lang/rust/pull/93628#issuecomment-1238498468) a [stabilization blocker](https://github.com/rust-lang/rust/pull/93628#issuecomment-1055738523).

Added by 1b87ce0d40 (#101410):

* Edit to `src/test/ui/let-else/let-else-temporary-lifetime.rs` to add the `-Zvalidate-mir` flag, as a regression test for #99228

Added by af591ebe4d (#101410):

* [`src/test/ui/let-else/issue-99975.rs`](https://github.com/rust-lang/rust/blob/master/src/test/ui/let-else/issue-99975.rs) as a regression test for the ICE #99975.

Added by this PR:

* `ui/let-else/let-else.rs`, a simple run-pass check, similar to `ui/let-else/let-else-run-pass.rs`.

### Things not currently tested

* ~~The `#[allow(...)]` tests check whether allow works, but they don't check whether the non-presence of allow causes a lint to fire.~~ → *test added by e7730dcb7eb29a10ee73f269f4dc6e9d606db0da*
* ~~There is no `#[allow(...)]` test for the expression, as there are tests for the pattern and the else block.~~ → *test added by e7730dcb7eb29a10ee73f269f4dc6e9d606db0da*
* ~~`let-else-brace-before-else.rs` forbids the `let ... = {} else {}` pattern and there is a rustfix to obtain `let ... = ({}) else {}`. I'm not sure whether the `.fixed` files are checked by the tooling that they compile. But if there is no such check, it would be neat to make sure that `let ... = ({}) else {}` compiles.~~ → *test added by e7730dcb7eb29a10ee73f269f4dc6e9d606db0da*
* ~~#92069 got closed as fixed, but no regression test was added. Not sure it's worth to add one.~~ → *test added by 5bd71063b3810d977aa376d1e6dd7cec359330cc*
* ~~consistency between `let else` and `if let` regarding lifetimes and drop order: https://github.com/rust-lang/rust/pull/93628#issuecomment-1055738523~~ → *test added by 2d8460ef43d902f34ba2133fe38f66ee8d2fdafc*

Edit: they are all tested now.

### Possible future work / Refutable destructuring assignments

[RFC 2909](https://rust-lang.github.io/rfcs/2909-destructuring-assignment.html) specifies destructuring assignment, allowing statements like `FooBar { a, b, c } = foo();`.
As it was stabilized, destructuring assignment only allows *irrefutable* patterns, which before the advent of `let else` were the only patterns that `let` supported.
So the combination of `let else` and destructuring assignments gives reason to think about extensions of the destructuring assignments feature that allow refutable patterns, discussed in #93995.

A naive mapping of `let else` to destructuring assignments in the form of `Some(v) = foo() else { ... };` might not be the ideal way. `let else` needs a diverging `else` clause as it introduces new bindings, while assignments have a default behaviour to fall back to if the pattern does not match, in the form of not performing the assignment. Thus, there is no good case to require divergence, or even an `else` clause at all, beyond the need for having *some* introducer syntax so that it is clear to readers that the assignment is not a given (enums and structs look similar). There are better candidates for introducer syntax however than an empty `else {}` clause, like `maybe` which could be added as a keyword on an edition boundary:

```Rust
let mut v = 0;
maybe Some(v) = foo(&v);
maybe Some(v) = foo(&v) else { bar() };
```

Further design discussion is left to an RFC, or the linked issue.
2022-09-17 15:31:06 +05:30
b-naber
d77248e6d2 nits 2022-09-15 22:27:41 +02:00
est31
173eb6f407 Only enable the let_else feature on bootstrap
On later stages, the feature is already stable.

Result of running:

rg -l "feature.let_else" compiler/ src/librustdoc/ library/ | xargs sed -s -i "s#\\[feature.let_else#\\[cfg_attr\\(bootstrap, feature\\(let_else\\)#"
2022-09-15 21:06:45 +02:00
b-naber
6af8fb7936 address review again 2022-09-14 17:30:25 +02:00
b-naber
bea0a6dc84 address review 2022-09-13 17:44:53 +02:00
b-naber
a4bbb8db5c use ty::Unevaluated<'tcx, ()> in type system 2022-09-13 17:40:59 +02:00
Andrew Cann
62112f4dc1 minor fixups as per PR feedback 2022-09-11 14:04:17 +08:00
Andrew Cann
543023c249 Add some comments to generator clone shim code 2022-09-11 14:04:17 +08:00
Andrew Cann
22f4bbb20f Apply formatting fixes 2022-09-11 14:04:16 +08:00
Andrew Cann
2c0bc9444e implement Copy/Clone for generators 2022-09-11 13:50:35 +08:00
Matthias Krüger
acb3d11f1b
Rollup merge of #101525 - eltociear:patch-16, r=cjgillot
Fix typo in pass_manager.rs

overriden -> overridden
2022-09-07 21:48:20 +02:00
Ikko Ashimine
9cef1ee113
Fix typo in pass_manager.rs
overriden -> overridden
2022-09-07 19:32:28 +09:00
Oli Scherer
b7413511dc Generalize the Assume intrinsic statement to a general Intrinsic statement 2022-09-06 14:18:32 +00:00
Oli Scherer
3f07645120 Lower the assume intrinsic to a MIR statement 2022-09-06 14:18:32 +00:00
Deadbeef
58c8823e31 remap mir before running optimization passes 2022-09-04 20:35:23 +08:00
Deadbeef
075084f772 Make const_eval_select a real intrinsic 2022-09-04 20:35:23 +08:00
bors
f07d6e8c0a Auto merge of #99102 - JakobDegen:reorder-generators, r=oli-obk
Rework definition of MIR phases to more closely reflect semantic concerns

Implements most of rust-lang/compiler-team#522 .

I tried my best to restrict this PR to the "core" parts of the MCP. In other words, this includes just enough changes to make the new definition of `MirPhase` make sense. That means there are a couple of FIXMEs lying around. Depending on what reviewers prefer, I can either fix them in this PR or send follow up PRs. There are also a couple other refactorings of the `rustc_mir_transform/src/lib.rs` file that I want to do in follow ups that I didn't leave explicit FIXMEs for.
2022-08-30 23:43:33 +00:00
Jakob Degen
d56751cc34 Simplify pass manager's run_passes logic 2022-08-30 01:40:16 -07:00
Jakob Degen
aad14c701e Refactor MIR phases 2022-08-30 01:40:14 -07:00
bors
a0d07093f8 Auto merge of #100812 - Nilstrieb:revert-let-chains-nightly, r=Mark-Simulacrum
Revert let_chains stabilization

This is the revert against master, the beta revert was already done in #100538.

Bumps the stage0 compiler which already has it reverted.
2022-08-30 05:48:22 +00:00
Nilstrieb
d1ef8180f9 Revert let_chains stabilization
This reverts commit 3266460749.

This is the revert against master, the beta revert was already done in #100538.
2022-08-29 19:34:11 +02:00
Dylan DPC
3ea5456366
Rollup merge of #100239 - RalfJung:const-prop-uninit, r=oli-obk
remove an ineffective check in const_prop

Based on https://github.com/rust-lang/rust/pull/100043, only the last two commits are new.

ConstProp has a special check when reading from a local that prevents reading uninit locals. However, if that local flows into `force_allocation`, then no check fires and evaluation proceeds. So this check is not really effective at preventing accesses to uninit locals.

With https://github.com/rust-lang/rust/pull/100043, `read_immediate` and friends always fail when reading uninit locals, so I don't see why ConstProp would need a separate check. Thus I propose we remove it. This is needed to be able to do https://github.com/rust-lang/rust/pull/100085.
2022-08-29 16:49:40 +05:30
Matthias Krüger
3e5be57de8
Rollup merge of #101111 - saethlin:better-fnentry-spans, r=RalfJung
Use the declaration's SourceInfo for FnEntry retags, not the outermost

This addresses a long-standing `// FIXME` in the pass that adds retags.

The changes to Miri's UI tests will look like this:
```
   --> $DIR/aliasing_mut1.rs:LL:CC
    |
 LL | pub fn safe(_x: &mut i32, _y: &mut i32) {}
<   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not granting access to tag <TAG> because incompatible item [Unique for <TAG>] is protected by call ID
>   |                           ^^ not granting access to tag <TAG> because incompatible item [Unique for <TAG>] is protected by call ID
    |
```

r? ````@RalfJung````
2022-08-29 06:34:48 +02:00
Matthias Krüger
d182081de1
Rollup merge of #99027 - tmiasko:basic-blocks, r=oli-obk
Replace `Body::basic_blocks()` with field access

Since the refactoring in #98930, it is possible to borrow the basic blocks
independently from other parts of MIR by accessing the `basic_blocks` field
directly.

Replace unnecessary `Body::basic_blocks()` method with a direct field access,
which has an additional benefit of borrowing the basic blocks only.
2022-08-29 06:34:43 +02:00
Ben Kimock
cd1a42a95d Use the declaration's SourceInfo for FnEntry retags, not the outermost 2022-08-28 11:40:10 -04:00
Ralf Jung
aff9841507 remove a now-useless machine hook 2022-08-27 08:53:04 -04:00
Ralf Jung
4173e971b8 remove an ineffective check in const_prop 2022-08-27 08:53:04 -04:00
Yuki Okushi
aa6b750854
Rollup merge of #101057 - cjgillot:one-fn-sig, r=compiler-errors
Merge implementations of HIR fn_decl and fn_sig.
2022-08-27 13:14:24 +09:00
Camille GILLOT
20012ea4eb Merge implementations of HIR fn_decl and fn_sig. 2022-08-26 21:38:20 +02:00
Ralf Jung
30fa931f92 make read_immediate error immediately on uninit, so ImmTy can carry initialized Scalar 2022-08-26 13:20:57 -04:00