Gap analysis — c4 in decision #1212

scry-mcdc · malloc.c:4398 · branch 8306

Status: GAP

What you need

To prove condition c4 independently affects the decision, you need a row where c4 = T and the outcome differs from row 3201 (where c4 = F).

Required condition vector:

  c0 = *
  c1 = *
  c2 = *
  c3 = F
  c4 = T
  c5 = T
  c6 = *
  c7 = *
  c8 = *
  c9 = *
  c10 = *
  c11 = *
  c12 = *
  c13 = *

Conditions marked * were short-circuited in the baseline row; the new test must drive inputs so they get evaluated to either T or F.

Suggested test stub

#[test]
fn closes_gap_d1212_c4() {
    // Verdict: scry-mcdc
    // Source: malloc.c:4398
    // Branch:  8306
    //
    // TODO: drive the function so condition c4 evaluates to the
    // value above and the resulting decision outcome differs from
    // the existing pair row.
    todo!("witness viz: gap drill-down for d#1212/c4");
}

After adding the test, re-run: witness instrument && witness run --invoke run_row_NEW && witness report. The condition should flip from gap to proved.

← back to decision #1212