25 lines
691 B
Plaintext
25 lines
691 B
Plaintext
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== Why is this an issue?
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Creating a null function pointer using `transmute` results in undefined behavior, as null function pointers are not valid in Rust. Instead, use `Option<fn()>` to safely represent a nullable function pointer.
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=== Code examples
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==== Noncompliant code example
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[source,rust,diff-id=1,diff-type=noncompliant]
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----
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let null_fn: fn() = unsafe { std::mem::transmute(std::ptr::null::<()>()) }; // Noncompliant
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----
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==== Compliant solution
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[source,rust,diff-id=1,diff-type=compliant]
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----
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let null_fn: Option<fn()> = None; // Compliant
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----
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== Resources
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=== Documentation
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* Clippy Lints - https://rust-lang.github.io/rust-clippy/master/index.html#transmute_null_to_fn
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