issue-55492-borrowck-migrate-scans-parents.rs

// rust-lang/rust#55492: errors detected during MIR-borrowck's
// analysis of a closure body may only be caught when AST-borrowck
// looks at some parent.

// transcribed from borrowck-closures-unique.rs
mod borrowck_closures_unique {
    pub fn e(x: &'static mut isize) {
        static mut Y: isize = 3;
        let mut c1 = |y: &'static mut isize| x = y;
        //~^ ERROR is not declared as mutable
        unsafe {
            c1(&mut Y);
            //~^ WARN mutable reference to mutable static is discouraged [static_mut_refs]
        }
    }
}

mod borrowck_closures_unique_grandparent {
    pub fn ee(x: &'static mut isize) {
        static mut Z: isize = 3;
        let mut c1 = |z: &'static mut isize| {
            let mut c2 = |y: &'static mut isize| x = y;
            //~^ ERROR is not declared as mutable
            c2(z);
        };
        unsafe {
            c1(&mut Z);
            //~^ WARN mutable reference to mutable static is discouraged [static_mut_refs]
        }
    }
}

// adapted from mutability_errors.rs
mod mutability_errors {
    pub fn capture_assign_whole(x: (i32,)) {
        || {
            x = (1,);
            //~^ ERROR is not declared as mutable
        };
    }
    pub fn capture_assign_part(x: (i32,)) {
        || {
            x.0 = 1;
            //~^ ERROR is not declared as mutable
        };
    }
    pub fn capture_reborrow_whole(x: (i32,)) {
        || {
            &mut x;
            //~^ ERROR is not declared as mutable
        };
    }
    pub fn capture_reborrow_part(x: (i32,)) {
        || {
            &mut x.0;
            //~^ ERROR is not declared as mutable
        };
    }
}

fn main() {
    static mut X: isize = 2;
    unsafe {
        borrowck_closures_unique::e(&mut X);
        //~^ WARN mutable reference to mutable static is discouraged [static_mut_refs]
    }

    mutability_errors::capture_assign_whole((1000,));
    mutability_errors::capture_assign_part((2000,));
    mutability_errors::capture_reborrow_whole((3000,));
    mutability_errors::capture_reborrow_part((4000,));
}