coverage.rs

use std::ptr;
/*
 Experiments in recovering coverage from the sanitizer runtime. Build with cargo, adding:
 RUSTFLAGS="-C passes=sancov -C llvm-args=-sanitizer-coverage-level=3 -Z sanitizer=address -C opt-level=3 -C debug-assertions=on -C debuginfo=2"
*/
extern "C" {
    pub fn __sanitizer_cov_init();
    pub fn __sanitizer_cov_dump();
    pub fn __sanitizer_dump_coverage(pcs: *const usize, len: usize);
    pub fn __sanitizer_maybe_open_cov_file(name:
                                               *const ::std::os::raw::c_char)
     -> isize;
    pub fn __sanitizer_get_total_unique_coverage() -> usize;
    pub fn __sanitizer_get_total_unique_caller_callee_pairs() -> usize;
    pub fn __sanitizer_reset_coverage();
    pub fn __sanitizer_get_coverage_guards(data: *mut *mut usize) -> usize;
    pub fn __sanitizer_get_number_of_counters() -> usize;
    pub fn __sanitizer_update_counter_bitset_and_clear_counters(bitset: *mut u8) -> usize;
}

#[inline(never)]
fn hi() {
    println!("Hi!")
}

fn dump() {
    let unique = unsafe { __sanitizer_get_total_unique_coverage() };
    let pairs = unsafe { __sanitizer_get_total_unique_caller_callee_pairs() };
    println!("Coverage: unique:{}; indirect pairs: {}", unique, pairs);

    // let mut guards : *mut usize = ptr::null_mut();
    // let n_guards = unsafe { __sanitizer_get_coverage_guards(&mut guards) };

    // let guards_vec = (0..n_guards).map(|i| -unsafe { *guards.offset(i as isize) } ).collect::<Vec<_>>();
    // println!("{:?}",guards_vec);
    unsafe { __sanitizer_reset_coverage() }
}

fn main() {
    dump();
    use std::env::args;
    for _ in args() {
        hi()
    }

    dump()
}