Gap analysis — c4 in decision #845

scry-mcdc · malloc.c:4897 · branch 5943

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 2592 (where c4 = F).

Required condition vector:

  c0 = *
  c1 = *
  c2 = *
  c3 = *
  c4 = T
  c5 = *
  c6 = *
  c7 = *
  c8 = *
  c9 = *
  c10 = *
  c11 = *
  c12 = F
  c13 = F
  c14 = F
  c15 = T
  c16 = *
  c17 = T

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_d845_c4() {
    // Verdict: scry-mcdc
    // Source: malloc.c:4897
    // Branch:  5943
    //
    // 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#845/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 #845