Fixed ICEs with pattern matching in const expression #41055
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…ixes rust-lang#31577, fixes rust-lang#29093, and fixes rust-lang#40012.
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ryan-scott-dev
changed the title
| if self.mode != Mode::Fn { | ||
| bug!("implement discriminant const qualify"); | ||
| } | ||
| // Discriminants in consts will error elsewhere as an unimplemented expression type |
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You are not calling .not_const() because we report an error for the SwitchInt terminator too? I don't think there is any way of it getting split from its Discriminant now before qualify_consts, but it sounds like we want some other way to avoid duplicate errors.
Maybe have not_const keep a (per-function) HashSet of spans?
Or maybe just not set NOT_CONST and implement Discriminant in trans::mir::consts?
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r+ if you make |
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Awesome fixes for old ices @Archytaus! |
@arielb1 To clarify, do you mean making it valid by removing I wouldn't mind trying to implement it in trans, but I would be taking my time learning how that part of the compiler works. So I would want to do that in another PR if possible. |
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@Archytaus Yup. Remove the |
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@bors r+ |
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📌 Commit c9932b3 has been approved by |
…, r=arielb1
Fixed ICEs with pattern matching in const expression
Fixed 2 ICEs with when pattern matching inside a constant expression.
Both of these ICEs now resolve to an appropriate compiler error.
1. ICE was caused by a compiler bug to implement discriminant const qualify.
I removed this intentionally thrown bug and changed it to a FIXME as the unimplemented expression type is handled as a compiler error elsewhere.
2. ICE was caused during a drop check when checking if a variable lifetime outlives the current scope if there was no parent scope .
I've changed it to stop checking if there is no parent scope for the current scope. It is valid syntax for a const variable to be assigned a match expression with no enclosing scope.
The ICE seemed to mainly be used as a defensive check for bugs elsewhere.
Fixes #38199.
Fixes #31577.
Fixes #29093.
Fixes #40012.
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☀️ Test successful - status-appveyor, status-travis |
Fixed 2 ICEs with when pattern matching inside a constant expression.
Both of these ICEs now resolve to an appropriate compiler error.
ICE was caused by a compiler bug to implement discriminant const qualify.
I removed this intentionally thrown bug and changed it to a FIXME as the unimplemented expression type is handled as a compiler error elsewhere.
ICE was caused during a drop check when checking if a variable lifetime outlives the current scope if there was no parent scope .
I've changed it to stop checking if there is no parent scope for the current scope. It is valid syntax for a const variable to be assigned a match expression with no enclosing scope.
The ICE seemed to mainly be used as a defensive check for bugs elsewhere.
Fixes #38199.
Fixes #31577.
Fixes #29093.
Fixes #40012.