Function ConsumeNodeSmart

src/test/fuzz/miniscript.cpp:771–843

* Consume a Miniscript node from the fuzzer's output. * * This is similar to ConsumeNodeStable, but uses a precomputed table with permitted * fragments/subnode type for each required type. It is intended to more quickly explore * interesting miniscripts, at the cost of higher implementation complexity (which could * cause it miss things if incorrect), and with less regard for stability of the

 * everything).
 */
std::optional<NodeInfo> ConsumeNodeSmart(MsCtx script_ctx, FuzzedDataProvider& provider, Type type_needed) {
    /** Table entry for the requested type. */
    const auto& table{IsTapscript(script_ctx) ? SMARTINFO.tap_table : SMARTINFO.wsh_table};
    auto recipes_it = table.find(type_needed);
    assert(recipes_it != table.end());
    /** Pick one recipe from the available ones for that type. */
    const auto& [frag, subt] = PickValue(provider, recipes_it->second);

    // Based on the fragment the recipe uses, fill in other data (k, keys, data).
    switch (frag) {
        case Fragment::PK_K:
        case Fragment::PK_H:
            return {{frag, ConsumePubKey(provider)}};
        case Fragment::MULTI: {
            const auto n_keys = provider.ConsumeIntegralInRange<uint8_t>(1, 20);
            const auto k = provider.ConsumeIntegralInRange<uint8_t>(1, n_keys);
            std::vector<CPubKey> keys{n_keys};
            for (auto& key: keys) key = ConsumePubKey(provider);
            return {{frag, k, std::move(keys)}};
        }
        case Fragment::MULTI_A: {
            const auto n_keys = provider.ConsumeIntegralInRange<uint16_t>(1, 999);
            const auto k = provider.ConsumeIntegralInRange<uint16_t>(1, n_keys);
            std::vector<CPubKey> keys{n_keys};
            for (auto& key: keys) key = ConsumePubKey(provider);
            return {{frag, k, std::move(keys)}};
        }
        case Fragment::OLDER:
        case Fragment::AFTER:
            return {{frag, provider.ConsumeIntegralInRange<uint32_t>(1, 0x7FFFFFF)}};
        case Fragment::SHA256:
            return {{frag, PickValue(provider, TEST_DATA.sha256)}};
        case Fragment::HASH256:
            return {{frag, PickValue(provider, TEST_DATA.hash256)}};
        case Fragment::RIPEMD160:
            return {{frag, PickValue(provider, TEST_DATA.ripemd160)}};
        case Fragment::HASH160:
            return {{frag, PickValue(provider, TEST_DATA.hash160)}};
        case Fragment::JUST_0:
        case Fragment::JUST_1:
        case Fragment::WRAP_A:
        case Fragment::WRAP_S:
        case Fragment::WRAP_C:
        case Fragment::WRAP_D:
        case Fragment::WRAP_V:
        case Fragment::WRAP_J:
        case Fragment::WRAP_N:
        case Fragment::AND_V:
        case Fragment::AND_B:
        case Fragment::OR_B:
        case Fragment::OR_C:
        case Fragment::OR_D:
        case Fragment::OR_I:
        case Fragment::ANDOR:
            return {{subt, frag}};
        case Fragment::THRESH: {
            uint32_t children;
            if (subt.size() < 2) {