Vx

E5001

Error · Safety

E5001 — Unsafe function call outside unsafe block

What the compiler reports

E5001{{.*}}'reads'

The fragments the test suite holds the compiler to. An ellipsis marks text the test does not constrain; the emitted message also carries a source location.

A program that triggers it

//
// An `unsafe fn` states a contract its caller must discharge, so a call needs an unsafe
// context. Calling one from a safe function is the error the declaration exists to produce.

unsafe fn reads(ptr : *mut i32) -> i32 {
  let mut v = 0;
  unsafe { v = *ptr; }
  return v;
}

fn calls(ptr : *mut i32) -> i32 {
  return reads(ptr);
}

fn main() -> i32 {
  return 0;
}

From tests/frontend/fail/unsafe_fn_called_outside_unsafe.vx, which asserts this diagnostic on every commit.

Related

Unsafe and FFIThe chapter covering the rule this code enforces. All diagnosticsEvery code the compiler can emit, grouped by stage. E5002Unsafe memory operation outside unsafe block