Basic Taproot signing logic in script/sign.cpp

src/script/interpreter.h

@@ -260,6 +260,9 @@ enum class MissingDataBehavior
     FAIL,         //!< Just act as if the signature was invalid
 };
 
+template<typename T>
+bool SignatureHashSchnorr(uint256& hash_out, const ScriptExecutionData& execdata, const T& tx_to, uint32_t in_pos, uint8_t hash_type, SigVersion sigversion, const PrecomputedTransactionData& cache, MissingDataBehavior mdb);
+
 template <class T>
 class GenericTransactionSignatureChecker : public BaseSignatureChecker
 {