Merge #20211: Use -Wswitch for TxoutType where possible

fa650ca7f19307a9237e64ac311488c8947fc12a Use -Wswitch for TxoutType where possible (MarcoFalke)
fa59e0b5bd2aed8380cc9b9e52791f662aecd6a6 test: Add missing script_standard_Solver_success cases (MarcoFalke)

Pull request description:

  This removes unused `default:` cases for all `switch` statements on `TxoutType` and adds the cases (`MULTISIG`, `NULL_DATA`, `NONSTANDARD`) to `ExtractDestination` for clarity.

  Also, the compiler is now able to use `-Wswitch`.

ACKs for top commit:
  practicalswift:
    cr ACK fa650ca7f19307a9237e64ac311488c8947fc12a: patch looks correct and `assert(false);` is better than UB :)
  hebasto:
    ACK fa650ca7f19307a9237e64ac311488c8947fc12a, I have reviewed the code and it looks OK, I agree it can be merged.

Tree-SHA512: 282458b6523bd8923a0c0f5c423d1db2dce2a2d1b1d1dae455415c6fc995bb41ce82c1f9b0a1c0dcc6d874d171e04c30eca585f147582f52c7048c140358630a

5 files changed, 42 insertions, 23 deletions

diff --git a/src/script/sign.cpp b/src/script/sign.cpp
index 8afbe9ebed..dba5ce621a 100644
--- a/src/script/sign.cpp
+++ b/src/script/sign.cpp
@@ -106,8 +106,7 @@ static bool SignStep(const SigningProvider& provider, const BaseSignatureCreator
     std::vector<valtype> vSolutions;
     whichTypeRet = Solver(scriptPubKey, vSolutions);
 
-    switch (whichTypeRet)
-    {
+    switch (whichTypeRet) {
     case TxoutType::NONSTANDARD:
     case TxoutType::NULL_DATA:
     case TxoutType::WITNESS_UNKNOWN:
@@ -173,10 +172,8 @@ static bool SignStep(const SigningProvider& provider, const BaseSignatureCreator
         // Could not find witnessScript, add to missing
         sigdata.missing_witness_script = uint256(vSolutions[0]);
         return false;
-
-    default:
-        return false;
-    }
+    } // no default case, so the compiler can warn about missing cases
+    assert(false);
 }
 
 static CScript PushAll(const std::vector<valtype>& values)
diff --git a/src/script/standard.cpp b/src/script/standard.cpp
index 7967c01858..4d882cd1f1 100644
--- a/src/script/standard.cpp
+++ b/src/script/standard.cpp
@@ -45,8 +45,7 @@ WitnessV0ScriptHash::WitnessV0ScriptHash(const CScript& in)
 
 std::string GetTxnOutputType(TxoutType t)
 {
-    switch (t)
-    {
+    switch (t) {
     case TxoutType::NONSTANDARD: return "nonstandard";
     case TxoutType::PUBKEY: return "pubkey";
     case TxoutType::PUBKEYHASH: return "pubkeyhash";
@@ -182,7 +181,8 @@ bool ExtractDestination(const CScript& scriptPubKey, CTxDestination& addressRet)
     std::vector<valtype> vSolutions;
     TxoutType whichType = Solver(scriptPubKey, vSolutions);
 
-    if (whichType == TxoutType::PUBKEY) {
+    switch (whichType) {
+    case TxoutType::PUBKEY: {
         CPubKey pubKey(vSolutions[0]);
         if (!pubKey.IsValid())
             return false;
@@ -190,26 +190,28 @@ bool ExtractDestination(const CScript& scriptPubKey, CTxDestination& addressRet)
         addressRet = PKHash(pubKey);
         return true;
     }
-    else if (whichType == TxoutType::PUBKEYHASH)
-    {
+    case TxoutType::PUBKEYHASH: {
         addressRet = PKHash(uint160(vSolutions[0]));
         return true;
     }
-    else if (whichType == TxoutType::SCRIPTHASH)
-    {
+    case TxoutType::SCRIPTHASH: {
         addressRet = ScriptHash(uint160(vSolutions[0]));
         return true;
-    } else if (whichType == TxoutType::WITNESS_V0_KEYHASH) {
+    }
+    case TxoutType::WITNESS_V0_KEYHASH: {
         WitnessV0KeyHash hash;
         std::copy(vSolutions[0].begin(), vSolutions[0].end(), hash.begin());
         addressRet = hash;
         return true;
-    } else if (whichType == TxoutType::WITNESS_V0_SCRIPTHASH) {
+    }
+    case TxoutType::WITNESS_V0_SCRIPTHASH: {
         WitnessV0ScriptHash hash;
         std::copy(vSolutions[0].begin(), vSolutions[0].end(), hash.begin());
         addressRet = hash;
         return true;
-    } else if (whichType == TxoutType::WITNESS_UNKNOWN || whichType == TxoutType::WITNESS_V1_TAPROOT) {
+    }
+    case TxoutType::WITNESS_UNKNOWN:
+    case TxoutType::WITNESS_V1_TAPROOT: {
         WitnessUnknown unk;
         unk.version = vSolutions[0][0];
         std::copy(vSolutions[1].begin(), vSolutions[1].end(), unk.program);
@@ -217,8 +219,13 @@ bool ExtractDestination(const CScript& scriptPubKey, CTxDestination& addressRet)
         addressRet = unk;
         return true;
     }
-    // Multisig txns have more than one address...
-    return false;
+    case TxoutType::MULTISIG:
+        // Multisig txns have more than one address...
+    case TxoutType::NULL_DATA:
+    case TxoutType::NONSTANDARD:
+        return false;
+    } // no default case, so the compiler can warn about missing cases
+    assert(false);
 }
 
 bool ExtractDestinations(const CScript& scriptPubKey, TxoutType& typeRet, std::vector<CTxDestination>& addressRet, int& nRequiredRet)
diff --git a/src/test/script_standard_tests.cpp b/src/test/script_standard_tests.cpp
index 366385b619..4dc0dd5f51 100644
--- a/src/test/script_standard_tests.cpp
+++ b/src/test/script_standard_tests.cpp
@@ -107,6 +107,22 @@ BOOST_AUTO_TEST_CASE(script_standard_Solver_success)
     BOOST_CHECK_EQUAL(solutions.size(), 1U);
     BOOST_CHECK(solutions[0] == ToByteVector(scriptHash));
 
+    // TxoutType::WITNESS_V1_TAPROOT
+    s.clear();
+    s << OP_1 << ToByteVector(uint256::ZERO);
+    BOOST_CHECK_EQUAL(Solver(s, solutions), TxoutType::WITNESS_V1_TAPROOT);
+    BOOST_CHECK_EQUAL(solutions.size(), 2U);
+    BOOST_CHECK(solutions[0] == std::vector<unsigned char>{1});
+    BOOST_CHECK(solutions[1] == ToByteVector(uint256::ZERO));
+
+    // TxoutType::WITNESS_UNKNOWN
+    s.clear();
+    s << OP_16 << ToByteVector(uint256::ONE);
+    BOOST_CHECK_EQUAL(Solver(s, solutions), TxoutType::WITNESS_UNKNOWN);
+    BOOST_CHECK_EQUAL(solutions.size(), 2U);
+    BOOST_CHECK(solutions[0] == std::vector<unsigned char>{16});
+    BOOST_CHECK(solutions[1] == ToByteVector(uint256::ONE));
+
     // TxoutType::NONSTANDARD
     s.clear();
     s << OP_9 << OP_ADD << OP_11 << OP_EQUAL;
diff --git a/src/wallet/rpcdump.cpp b/src/wallet/rpcdump.cpp
index 8505ddc309..99803a91d2 100644
--- a/src/wallet/rpcdump.cpp
+++ b/src/wallet/rpcdump.cpp
@@ -934,9 +934,9 @@ static std::string RecurseImportData(const CScript& script, ImportData& import_d
     case TxoutType::NONSTANDARD:
     case TxoutType::WITNESS_UNKNOWN:
     case TxoutType::WITNESS_V1_TAPROOT:
-    default:
         return "unrecognized script";
-    }
+    } // no default case, so the compiler can warn about missing cases
+    CHECK_NONFATAL(false);
 }
 
 static UniValue ProcessImportLegacy(ImportData& import_data, std::map<CKeyID, CPubKey>& pubkey_map, std::map<CKeyID, CKey>& privkey_map, std::set<CScript>& script_pub_keys, bool& have_solving_data, const UniValue& data, std::vector<CKeyID>& ordered_pubkeys)
diff --git a/src/wallet/scriptpubkeyman.cpp b/src/wallet/scriptpubkeyman.cpp
index 15972fe7bb..55110f30d9 100644
--- a/src/wallet/scriptpubkeyman.cpp
+++ b/src/wallet/scriptpubkeyman.cpp
@@ -94,8 +94,7 @@ IsMineResult IsMineInner(const LegacyScriptPubKeyMan& keystore, const CScript& s
     TxoutType whichType = Solver(scriptPubKey, vSolutions);
 
     CKeyID keyID;
-    switch (whichType)
-    {
+    switch (whichType) {
     case TxoutType::NONSTANDARD:
     case TxoutType::NULL_DATA:
     case TxoutType::WITNESS_UNKNOWN:
@@ -194,7 +193,7 @@ IsMineResult IsMineInner(const LegacyScriptPubKeyMan& keystore, const CScript& s
         }
         break;
     }
-    }
+    } // no default case, so the compiler can warn about missing cases
 
     if (ret == IsMineResult::NO && keystore.HaveWatchOnly(scriptPubKey)) {
         ret = std::max(ret, IsMineResult::WATCH_ONLY);