Merge rust-bitcoin/rust-bitcoin#3096: Add validation extension to script

298b96c579 Add an extension trait for script validation (Tobin C. Harding)
c1aa33ed89 Use impl syntax instead of generic (Tobin C. Harding)

Pull request description:

  Add an extension trait for the validation logic in preparation for moving the `Script` type to `primitives`.

ACKs for top commit:
  Kixunil:
    ACK 298b96c579
  apoelstra:
    ACK 298b96c579

Tree-SHA512: 6282bf7bd5657f0ec68e1369150969daf51f97dc6ff72a419fe823d60ab8a993f1e6d56b1cffa114580d388b36fe2bcbf7b9865776f98c46d68b7368168a07ee

bitcoin/src/blockdata/script/tests.rs

@@ -682,6 +682,8 @@ fn script_ord() {
 #[test]
 #[cfg(feature = "bitcoinconsensus")]
 fn test_bitcoinconsensus() {
+    use crate::consensus_validation::ScriptExt as _;
+
     // a random segwit transaction from the blockchain using native segwit
     let spent_bytes = hex!("0020701a8d401c84fb13e6baf169d59684e17abd9fa216c8cc5b9fc63d622ff8c58d");
     let spent = Script::from_bytes(&spent_bytes);

bitcoin/src/consensus_validation.rs

@@ -12,6 +12,7 @@ use crate::amount::Amount;
 use crate::consensus::encode;
 #[cfg(doc)]
 use crate::consensus_validation;
+use crate::internal_macros::define_extension_trait;
 use crate::script::Script;
 use crate::transaction::{OutPoint, Transaction, TxOut};
 
@@ -115,7 +116,9 @@ where
     Ok(())
 }
 
-impl Script {
+define_extension_trait! {
+    /// Extension functionality to add validation support to the [`Script`] type.
+    pub trait ScriptExt impl for Script {
         /// Verifies spend of an input script.
         ///
         /// Shorthand for [`Self::verify_with_flags`] with flag [`bitcoinconsensus::VERIFY_ALL_PRE_TAPROOT`].
@@ -127,7 +130,7 @@ impl Script {
         ///  * `spending_tx` - The transaction that attempts to spend the output holding this script.
         ///
         /// [`bitcoinconsensus::VERIFY_ALL_PRE_TAPROOT`]: https://docs.rs/bitcoinconsensus/0.106.0+26.0/bitcoinconsensus/constant.VERIFY_ALL_PRE_TAPROOT.html
-    pub fn verify(
+        fn verify(
             &self,
             index: usize,
             amount: crate::Amount,
@@ -146,16 +149,17 @@ impl Script {
         ///  * `flags` - Verification flags, see [`bitcoinconsensus::VERIFY_ALL_PRE_TAPROOT`] and similar.
         ///
         /// [`bitcoinconsensus::VERIFY_ALL_PRE_TAPROOT`]: https://docs.rs/bitcoinconsensus/0.106.0+26.0/bitcoinconsensus/constant.VERIFY_ALL_PRE_TAPROOT.html
-    pub fn verify_with_flags<F: Into<u32>>(
+        fn verify_with_flags(
             &self,
             index: usize,
             amount: crate::Amount,
             spending_tx: &[u8],
-        flags: F,
+            flags: impl Into<u32>,
         ) -> Result<(), BitcoinconsensusError> {
             verify_script_with_flags(self, index, amount, spending_tx, flags)
         }
     }
+}
 
 impl Transaction {
     /// Verifies that this transaction is able to spend its inputs.