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 102b9125e1856541963c#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 9b45713b6chttps://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#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
Tomasz Miąsko
b48870b451
Replace Body::basic_blocks() with field access
2022-08-26 14:27:08 +02:00
Yuki Okushi
55562c7ddc
Rollup merge of #100034 - tmiasko:elaborate-box-derefs, r=oli-obk
...
Elaborate all box dereferences in `ElaborateBoxDerefs`
so that it is the only pass responsible for elaboration, instead of
splitting this responsibility between the `StateTransform` and
`ElaborateBoxDerefs`.
2022-08-26 09:51:42 +09:00
Tomasz Miąsko
4462b4af52
Elaborate all box dereferences in ElaborateBoxDerefs
...
so that it is the only pass responsible for elaboration, instead of
splitting this responsibility between the `StateTransform` and
`ElaborateBoxDerefs`.
2022-08-25 10:38:00 +02:00
bors
4d45b0745a
Auto merge of #100571 - cjgillot:mir-cost-visit, r=compiler-errors
...
Check projection types before inlining MIR
Fixes https://github.com/rust-lang/rust/issues/100550
I'm very unhappy with this solution, having to duplicate MIR validation code, but at least it removes the ICE.
r? `@compiler-errors`
2022-08-25 08:16:43 +00:00
bors
5462da52ba
Auto merge of #99946 - tmiasko:elide-storage-makers, r=oli-obk
...
Elide superfluous storage markers
Follow the existing strategy of omitting the storage markers for temporaries
introduced for internal usage when elaborating derefs and deref projections.
Those temporaries are simple scalars which are used immediately after being
defined and never have their address taken. There is no benefit from storage
markers from either liveness analysis or code generation perspective.
2022-08-24 23:51:06 +00:00
nils
8e6c5ad696
Fix typo in UnreachableProp
2022-08-23 08:18:18 +02:00
Tomasz Miąsko
625af2cc75
Elide storage markers for internal locals when inlining
2022-08-23 10:08:48 +02:00
Tomasz Miąsko
162bd16352
Elide storage markers when elaborating deref projections
2022-08-23 10:08:48 +02:00
Tomasz Miąsko
943a380b37
Elide storage markers when elaborating box derefs
2022-08-23 10:08:48 +02:00
Nilstrieb
bc79557311
Enable UnreachablePropagation under mir-opt-level >= 2
...
It was disabled because of pathological behaviour of LLVM in some
benchmarks. As of #77680 , this has been fixed. The problem there was
that it caused pessimizations in some cases. These have now been fixed
as well.
2022-08-21 21:15:28 +02:00
Nilstrieb
eafab66096
UnreachableProp: Preserve unreachable branches for multiple targets
...
Before, UnreachablePropagation removed all unreachable branches.
This was a pessimization, as it removed information about
reachability that was used later in the optimization pipeline.
For example, this code
```rust
pub enum Two { A, B }
pub fn identity(x: Two) -> Two {
match x {
Two::A => Two::A,
Two::B => Two::B,
}
}
```
basically has `switchInt() -> [0: 0, 1: 1, otherwise: unreachable]` for the match.
This allows it to be transformed into a simple `x`. If we remove the
unreachable branch, the transformation becomes illegal.
2022-08-21 21:15:28 +02:00
Camille GILLOT
10e71dfdb8
Also validate types before inlining.
2022-08-21 12:54:26 +02:00
