rust-analyzer/crates/ide_diagnostics/src/missing_unsafe.rs

use crate::{Diagnostic, DiagnosticsContext};

// Diagnostic: missing-unsafe
//
// This diagnostic is triggered if an operation marked as `unsafe` is used outside of an `unsafe` function or block.
pub(super) fn missing_unsafe(ctx: &DiagnosticsContext<'_>, d: &hir::MissingUnsafe) -> Diagnostic {
    Diagnostic::new(
        "missing-unsafe",
        "this operation is unsafe and requires an unsafe function or block",
        ctx.sema.diagnostics_display_range(d.expr.clone().map(|it| it.into())).range,
    )
}

#[cfg(test)]
mod tests {
    use crate::tests::check_diagnostics;

    #[test]
    fn missing_unsafe_diagnostic_with_raw_ptr() {
        check_diagnostics(
            r#"
fn main() {
    let x = &5 as *const usize;
    unsafe { let y = *x; }
    let z = *x;
}         //^^ this operation is unsafe and requires an unsafe function or block
"#,
        )
    }

    #[test]
    fn missing_unsafe_diagnostic_with_unsafe_call() {
        check_diagnostics(
            r#"
struct HasUnsafe;

impl HasUnsafe {
    unsafe fn unsafe_fn(&self) {
        let x = &5 as *const usize;
        let y = *x;
    }
}

unsafe fn unsafe_fn() {
    let x = &5 as *const usize;
    let y = *x;
}

fn main() {
    unsafe_fn();
  //^^^^^^^^^^^ this operation is unsafe and requires an unsafe function or block
    HasUnsafe.unsafe_fn();
  //^^^^^^^^^^^^^^^^^^^^^ this operation is unsafe and requires an unsafe function or block
    unsafe {
        unsafe_fn();
        HasUnsafe.unsafe_fn();
    }
}
"#,
        );
    }

    #[test]
    fn missing_unsafe_diagnostic_with_static_mut() {
        check_diagnostics(
            r#"
struct Ty {
    a: u8,
}

static mut STATIC_MUT: Ty = Ty { a: 0 };

fn main() {
    let x = STATIC_MUT.a;
          //^^^^^^^^^^ this operation is unsafe and requires an unsafe function or block
    unsafe {
        let x = STATIC_MUT.a;
    }
}
"#,
        );
    }

    #[test]
    fn no_missing_unsafe_diagnostic_with_safe_intrinsic() {
        check_diagnostics(
            r#"
extern "rust-intrinsic" {
    pub fn bitreverse(x: u32) -> u32; // Safe intrinsic
    pub fn floorf32(x: f32) -> f32; // Unsafe intrinsic
}

fn main() {
    let _ = bitreverse(12);
    let _ = floorf32(12.0);
          //^^^^^^^^^^^^^^ this operation is unsafe and requires an unsafe function or block
}
"#,
        );
    }
}