Merge bitcoin/bitcoin#29648: Remove libbitcoinconsensus

80f8b92f4f2311b9e9a25361c9dd973244e6f95c remove libbitcoinconsensus (fanquake)

Pull request description:

  This was deprecated in `v27.0`, for removal in `v28.0`. See discussion in PR #29189.

ACKs for top commit:
  theuni:
    Concept ACK and light review ACK 80f8b92f4f2311b9e9a25361c9dd973244e6f95c. My only hesitation here is that (afaics?) there's now nothing keeping undesired features like threading or globals from working their way into the interpreter in future commits.
  m3dwards:
    Concept ACK https://github.com/bitcoin/bitcoin/pull/29648/commits/80f8b92f4f2311b9e9a25361c9dd973244e6f95c
  TheCharlatan:
    ACK 80f8b92f4f2311b9e9a25361c9dd973244e6f95c
  hebasto:
    ACK 80f8b92f4f2311b9e9a25361c9dd973244e6f95c, I have reviewed the code and it looks OK.

Tree-SHA512: 17a62118aeb088f2695c892bb32794dfea3061e3cb7d9e8e9f1c06c3ff6f63a7587fa532e37edbb91fbc5a19b12c9a0f8e05fa9e8864aa07f92665375d847e80

3 files changed, 4 insertions, 84 deletions

diff --git a/doc/README.md b/doc/README.md
index 446684b482..7b6dacaf4f 100644
--- a/doc/README.md
+++ b/doc/README.md
@@ -59,7 +59,6 @@ The Bitcoin repo's [root README](/README.md) contains relevant information on th
 - [Translation Strings Policy](translation_strings_policy.md)
 - [JSON-RPC Interface](JSON-RPC-interface.md)
 - [Unauthenticated REST Interface](REST-interface.md)
-- [Shared Libraries](shared-libraries.md)
 - [BIPS](bips.md)
 - [Dnsseed Policy](dnsseed-policy.md)
 - [Benchmarking](benchmarking.md)
diff --git a/doc/design/libraries.md b/doc/design/libraries.md
index 7cda64e713..3346c8e81b 100644
--- a/doc/design/libraries.md
+++ b/doc/design/libraries.md
@@ -4,10 +4,9 @@
 |--------------------------|-------------|
 | *libbitcoin_cli*         | RPC client functionality used by *bitcoin-cli* executable |
 | *libbitcoin_common*      | Home for common functionality shared by different executables and libraries. Similar to *libbitcoin_util*, but higher-level (see [Dependencies](#dependencies)). |
-| *libbitcoin_consensus*   | Stable, backwards-compatible consensus functionality used by *libbitcoin_node* and *libbitcoin_wallet* and also exposed as a [shared library](../shared-libraries.md). |
-| *libbitcoinconsensus*    | Shared library build of static *libbitcoin_consensus* library |
-| *libbitcoin_kernel*      | Consensus engine and support library used for validation by *libbitcoin_node* and also exposed as a [shared library](../shared-libraries.md). |
-| *libbitcoinqt*           | GUI functionality used by *bitcoin-qt* and *bitcoin-gui* executables |
+| *libbitcoin_consensus*   | Stable, backwards-compatible consensus functionality used by *libbitcoin_node* and *libbitcoin_wallet*. |
+| *libbitcoin_kernel*      | Consensus engine and support library used for validation by *libbitcoin_node*. |
+| *libbitcoinqt*           | GUI functionality used by *bitcoin-qt* and *bitcoin-gui* executables. |
 | *libbitcoin_ipc*         | IPC functionality used by *bitcoin-node*, *bitcoin-wallet*, *bitcoin-gui* executables to communicate when [`--enable-multiprocess`](multiprocess.md) is used. |
 | *libbitcoin_node*        | P2P and RPC server functionality used by *bitcoind* and *bitcoin-qt* executables. |
 | *libbitcoin_util*        | Home for common functionality shared by different executables and libraries. Similar to *libbitcoin_common*, but lower-level (see [Dependencies](#dependencies)). |
@@ -17,7 +16,7 @@
 
 ## Conventions
 
-- Most libraries are internal libraries and have APIs which are completely unstable! There are few or no restrictions on backwards compatibility or rules about external dependencies. Exceptions are *libbitcoin_consensus* and *libbitcoin_kernel* which have external interfaces documented at [../shared-libraries.md](../shared-libraries.md).
+- Most libraries are internal libraries and have APIs which are completely unstable! There are few or no restrictions on backwards compatibility or rules about external dependencies. An exception is *libbitcoin_kernel*, which, at some future point, will have a documented external interface.
 
 - Generally each library should have a corresponding source directory and namespace. Source code organization is a work in progress, so it is true that some namespaces are applied inconsistently, and if you look at [`libbitcoin_*_SOURCES`](../../src/Makefile.am) lists you can see that many libraries pull in files from outside their source directory. But when working with libraries, it is good to follow a consistent pattern like:
 
diff --git a/doc/shared-libraries.md b/doc/shared-libraries.md
deleted file mode 100644
index 3a448c6556..0000000000
--- a/doc/shared-libraries.md
+++ /dev/null
@@ -1,78 +0,0 @@
-Shared Libraries
-================
-
-## bitcoinconsensus
-***This library is deprecated and will be removed in v28***
-
-The purpose of this library is to make the verification functionality that is critical to Bitcoin's consensus available to other applications, e.g. to language bindings.
-
-### API
-
-The interface is defined in the C header `bitcoinconsensus.h` located in `src/script/bitcoinconsensus.h`.
-
-#### Version
-
-`bitcoinconsensus_version` returns an `unsigned int` with the API version *(currently `2`)*.
-
-#### Script Validation
-
-`bitcoinconsensus_verify_script`, `bitcoinconsensus_verify_script_with_amount` and `bitcoinconsensus_verify_script_with_spent_outputs` return an `int` with the status of the verification. It will be `1` if the input script correctly spends the previous output `scriptPubKey`.
-
-##### Parameters
-###### bitcoinconsensus_verify_script
-- `const unsigned char *scriptPubKey` - The previous output script that encumbers spending.
-- `unsigned int scriptPubKeyLen` - The number of bytes for the `scriptPubKey`.
-- `const unsigned char *txTo` - The transaction with the input that is spending the previous output.
-- `unsigned int txToLen` - The number of bytes for the `txTo`.
-- `unsigned int nIn` - The index of the input in `txTo` that spends the `scriptPubKey`.
-- `unsigned int flags` - The script validation flags *(see below)*.
-- `bitcoinconsensus_error* err` - Will have the error/success code for the operation *(see below)*.
-
-###### bitcoinconsensus_verify_script_with_amount
-- `const unsigned char *scriptPubKey` - The previous output script that encumbers spending.
-- `unsigned int scriptPubKeyLen` - The number of bytes for the `scriptPubKey`.
-- `int64_t amount` - The amount spent in the input
-- `const unsigned char *txTo` - The transaction with the input that is spending the previous output.
-- `unsigned int txToLen` - The number of bytes for the `txTo`.
-- `unsigned int nIn` - The index of the input in `txTo` that spends the `scriptPubKey`.
-- `unsigned int flags` - The script validation flags *(see below)*.
-- `bitcoinconsensus_error* err` - Will have the error/success code for the operation *(see below)*.
-
-###### bitcoinconsensus_verify_script_with_spent_outputs
-- `const unsigned char *scriptPubKey` - The previous output script that encumbers spending.
-- `unsigned int scriptPubKeyLen` - The number of bytes for the `scriptPubKey`.
-- `int64_t amount` - The amount spent in the input
-- `const unsigned char *txTo` - The transaction with the input that is spending the previous output.
-- `unsigned int txToLen` - The number of bytes for the `txTo`.
-- `UTXO *spentOutputs` - Previous outputs spent in the transaction. `UTXO` is a struct composed by `const unsigned char *scriptPubKey`, `unsigned int scriptPubKeySize` (the number of bytes for the `scriptPubKey`) and `unsigned int value`.
-- `unsigned int spentOutputsLen` - The number of bytes for the `spentOutputs`.
-- `unsigned int nIn` - The index of the input in `txTo` that spends the `scriptPubKey`.
-- `unsigned int flags` - The script validation flags *(see below)*.
-- `bitcoinconsensus_error* err` - Will have the error/success code for the operation *(see below)*.
-
-##### Script Flags
-- `bitcoinconsensus_SCRIPT_FLAGS_VERIFY_NONE`
-- `bitcoinconsensus_SCRIPT_FLAGS_VERIFY_P2SH` - Evaluate P2SH ([BIP16](https://github.com/bitcoin/bips/blob/master/bip-0016.mediawiki)) subscripts
-- `bitcoinconsensus_SCRIPT_FLAGS_VERIFY_DERSIG` - Enforce strict DER ([BIP66](https://github.com/bitcoin/bips/blob/master/bip-0066.mediawiki)) compliance
-- `bitcoinconsensus_SCRIPT_FLAGS_VERIFY_NULLDUMMY` - Enforce NULLDUMMY ([BIP147](https://github.com/bitcoin/bips/blob/master/bip-0147.mediawiki))
-- `bitcoinconsensus_SCRIPT_FLAGS_VERIFY_CHECKLOCKTIMEVERIFY` - Enable CHECKLOCKTIMEVERIFY ([BIP65](https://github.com/bitcoin/bips/blob/master/bip-0065.mediawiki))
-- `bitcoinconsensus_SCRIPT_FLAGS_VERIFY_CHECKSEQUENCEVERIFY` - Enable CHECKSEQUENCEVERIFY ([BIP112](https://github.com/bitcoin/bips/blob/master/bip-0112.mediawiki))
-- `bitcoinconsensus_SCRIPT_FLAGS_VERIFY_WITNESS` - Enable WITNESS ([BIP141](https://github.com/bitcoin/bips/blob/master/bip-0141.mediawiki))
-- `bitcoinconsensus_SCRIPT_FLAGS_VERIFY_TAPROOT` - Enable TAPROOT ([BIP340](https://github.com/bitcoin/bips/blob/master/bip-0340.mediawiki), [BIP341](https://github.com/bitcoin/bips/blob/master/bip-0341.mediawiki), [BIP342](https://github.com/bitcoin/bips/blob/master/bip-0342.mediawiki))
-
-##### Errors
-- `bitcoinconsensus_ERR_OK` - No errors with input parameters *(see the return value of `bitcoinconsensus_verify_script` for the verification status)*
-- `bitcoinconsensus_ERR_TX_INDEX` - An invalid index for `txTo`
-- `bitcoinconsensus_ERR_TX_SIZE_MISMATCH` - `txToLen` did not match with the size of `txTo`
-- `bitcoinconsensus_ERR_DESERIALIZE` - An error deserializing `txTo`
-- `bitcoinconsensus_ERR_AMOUNT_REQUIRED` - Input amount is required if WITNESS is used
-- `bitcoinconsensus_ERR_INVALID_FLAGS` - Script verification `flags` are invalid (i.e. not part of the libconsensus interface)
-- `bitcoinconsensus_ERR_SPENT_OUTPUTS_REQUIRED` - Spent outputs are required if TAPROOT is used
-- `bitcoinconsensus_ERR_SPENT_OUTPUTS_MISMATCH` - Spent outputs size doesn't match tx inputs size
-
-### Example Implementations
-- [NBitcoin](https://github.com/MetacoSA/NBitcoin/blob/5e1055cd7c4186dee4227c344af8892aea54faec/NBitcoin/Script.cs#L979-#L1031) (.NET Bindings)
-- [node-libbitcoinconsensus](https://github.com/bitpay/node-libbitcoinconsensus) (Node.js Bindings)
-- [java-libbitcoinconsensus](https://github.com/dexX7/java-libbitcoinconsensus) (Java Bindings)
-- [bitcoinconsensus-php](https://github.com/Bit-Wasp/bitcoinconsensus-php) (PHP Bindings)
-- [rust-bitcoinconsensus](https://github.com/rust-bitcoin/rust-bitcoinconsensus) (Rust Bindings)
\ No newline at end of file