Rust-GCC / Rust-GCC/gccrs

Enum discriminants are not checked for their repr's numeric limits.

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#3,353 2 comments 0 reactions 0 assignees View on GitHub

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bug good-first-pr
Dominant language
C++
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Description

enum Foo{
    Bar = 99999999999999999999999999999999999999999999999999999999,
    Qaz,
    Quax,
}

#[repr(u8)]
enum Bar{
    Qaz = 256,
    Quax = -1,
}

fn main(){}

This code passes without any errors in gccrs.
Link: https://godbolt.org/z/M54P3h3Y1

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Research direction

Start with the linked Godbolt reproducer and inspect gccrs's enum handling for discriminant values. Confirm that both the unannotated enum and the #[repr(u8)] enum reject values outside their numeric limits, then add regression coverage for the resulting diagnostics.

Written by the indexing model from the issue text.

Assessment

Tech stack
rust
Domain
compilers
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
45/100

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