Function tactic_T2

src/e9patch/e9tactics.cpp:522–552

* Tactic T2: evict the successor instruction. */

 * Tactic T2: evict the successor instruction.
 */
static Patch *tactic_T2(Binary &B, Instr *I, const Trampoline *T)
{
    if (I->size >= JMP_SIZE || !option_tactic_T2 || !canPatch(I))
        return nullptr;

    // Step (1): Evict the successor instruction:
    Instr *J = I->succ();
    if (J == nullptr || !canPatch(J))
        return nullptr;
    const Trampoline *U = evicteeTrampoline;
    Patch *Q = nullptr;
    Q = (Q == nullptr? tactic_B2(B, J, U, TACTIC_T2): Q);
    Q = (Q == nullptr? tactic_T1(B, J, U, TACTIC_T2): Q);
    if (Q == nullptr)
        return nullptr;

    // Step (2): Patch the instruction:
    Patch *P = nullptr;
    P = (P == nullptr? tactic_B2(B, I, T, TACTIC_T2): P);
    P = (P == nullptr? tactic_T1(B, I, T, TACTIC_T2): P);

    if (P == nullptr)
    {
        undo(B, Q);
        return nullptr;
    }
    P->tactic = TACTIC_T2;
    P->next   = Q;

    return P;
}

/*
 * Tactic T3 (single-byte instruction): evict a neighbour instruction.