The counter is an optimization over calling `ret.empty()`. It was
suggested that the compiler would realize `cnt` is only `0` on the first
iteration, and not actually emit the check and conditional.
This optimization was actually not triggered at all, since we
incremented `cnt` at the beginning of the first iteration. Fix it by
incrementing at the end instead.
This was reported by Github user "Janus".
Some prep work for Miniscript. BuildScript is an efficient way to build
Scripts in a generic manner (by concatenating OPs, data, and other
Scripts).
Co-Authored-By: Pieter Wuille <pieter@wuille.net>
4828d53ecc Add (sorted)multi_a descriptors to doc/descriptors.md (Pieter Wuille)
b5f33ac1f8 Simplify wallet_taproot.py functional test (Pieter Wuille)
eb0667ea96 Add tests for (sorted)multi_a derivation/signing (Pieter Wuille)
c17c6aa08d Add signing support for (sorted)multi_a scripts (Pieter Wuille)
3eed6fca57 Add multi_a descriptor inference (Pieter Wuille)
79728c4a3d Add (sorted)multi_a descriptor and script derivation (Pieter Wuille)
25e95f9ff8 Merge/generalize IsValidMultisigKeyCount/GetMultisigKeyCount (Pieter Wuille)
Pull request description:
This adds a new `multi_a(k,key_1,key_2,...,key_n)` (and corresponding `sortedmulti_a`) descriptor for k-of-n policies inside `tr()`. Semantically it is very similar to the existing `multi()` descriptor, but with the following changes:
* The corresponding script is `<key1> OP_CHECKSIG <key2> OP_CHECKSIGADD <key3> OP_CHECKSIGADD ... <key_n> OP_CHECKSIGADD <k> OP_NUMEQUAL`, rather than the traditional `OP_CHECKMULTISIG`-based script, making it usable inside the `tr()` descriptor.
* The keys can optionally be specified in x-only notation.
* Both the number of keys and the threshold can be as high as 999; this is the limit due to the consensus stacksize=1000 limit
I expect that this functionality will later be replaced with a miniscript-based implementation, but I don't think it's necessary to wait for that.
Limitations:
* The wallet code will for not estimate witness size incorrectly for script path spends, which may result in a (dramatic) fee underpayment with large multi_a scripts.
* The multi_a script construction is (slightly) suboptimal for n-of-n (where a `<key1> OP_CHECKSIGVERIFY ... <key_n-1> OP_CHECKSIGVERIFY <key_n> OP_CHECKSIG` would be better). Such a construction is not included here.
ACKs for top commit:
achow101:
ACK 4828d53ecc
gruve-p:
ACK 4828d53ecc
sanket1729:
code review ACK 4828d53ecc
darosior:
Code review ACK 4828d53ecc
Tree-SHA512: 5dcd434b79585f0ff830f7d501d27df5e346f5749f47a3109ec309ebf2cbbad0e1da541eec654026d911ab67fd7cf7793fab0f765628d68d81b96ef2a4d234ce
This adds a new `SigVersion::TAPSCRIPT`, makes the necessary interpreter
changes to make it implement BIP342, and uses them for leaf version 0xc0
in Taproot script path spends.
This implements the new sighashing scheme from BIP341, with all relevant
whole-transaction values precomputed once and cached.
Includes changes to PrecomputedTransactionData by Pieter Wuille.
c57f03ce17 refactor: Replace const char* to std::string (Calvin Kim)
Pull request description:
Rationale: Addresses #19000
Some functions should be returning std::string instead of const char*.
This commit changes that.
Main benefits/reasoning:
1. The functions never return nullptr, so returning a string makes code at call sites easier to review (reviewers don't have to read the source code to verify that a nullptr is never returned)
2. All call sites convert to string anyway
ACKs for top commit:
MarcoFalke:
re-ACK c57f03ce17 (no changes since previous review) 🚃
Empact:
Fair enough, Code Review ACK c57f03ce17
practicalswift:
ACK c57f03ce17 -- patch looks correct
hebasto:
re-ACK c57f03ce17
Tree-SHA512: 9ce99bb38fe399b54844315048204cafce0f27fd8f24cae357fa7ac6f5d8094d57bbf5f5c1f5878a65f2d35e4a3f95d527eb17f49250b690c591c0df86ca84fd
f9ee0f37c2 Add comments to CustomUintFormatter (Pieter Wuille)
4eb5643e35 Convert everything except wallet/qt to new serialization (Pieter Wuille)
2b1f85e8c5 Convert blockencodings_tests to new serialization (Pieter Wuille)
73747afbbe Convert merkleblock to new serialization (Pieter Wuille)
d06fedd1bc Add SER_READ and SER_WRITE for read/write-dependent statements (Russell Yanofsky)
6f9a1e5ad0 Extend CustomUintFormatter to support enums (Russell Yanofsky)
769ee5fa00 Merge BigEndian functionality into CustomUintFormatter (Pieter Wuille)
Pull request description:
The next step of changes from #10785.
This:
* Adds support for enum serialization to `CustomUintFormatter`, used in `CAddress` for service flags.
* Merges `BigEndian` into `CustomUintFormatter`, used in `CNetAddr` for port numbers.
* Converts everything (except wallet and gui) to use the new serialization framework.
ACKs for top commit:
MarcoFalke:
re-ACK f9ee0f37c2, only change is new documentation commit for CustomUintFormatter 📂
ryanofsky:
Code review ACK f9ee0f37c2. Just new commit adding comment since last review
jonatack:
Code review re-ACK f9ee0f37c2 only change since last review is an additional commit adding Doxygen documentation for `CustomUintFormatter`.
Tree-SHA512: e7a0a36afae592d5a4ff8c81ae04d858ac409388e361f2bc197d9a78abca45134218497ab2dfd6d031e0cce0ca586cf857077b7c6ce17fccf67e2d367c1b6cd4
ccccd51908 script: Remove undocumented and unused operator+ (MarcoFalke)
Pull request description:
This operator has no documented use case and is also unused outside of test code. The test code and all other (imaginary) code that might use this operator is written more clear and concise by the existing CScript push operators for opcodes and data.
Removing the operator is also going to protect against accidentally reintroducing bugs like this 6ff5f718b6 (diff-8458adcedc17d046942185cb709ff5c3L1135) (last time it was used).
ACKs for top commit:
laanwj:
ACK ccccd51908
Tree-SHA512: 43898ac77e4d9643d9f8ac6f8f65497a4f0bbb1fb5dcaecc839c3719aa36181ba77befb213e59a9f33a20a29e0173a0e9c4763b1930940b32c3d1598b3e39af9
Switches to named constants, because numeric_limits calls can be harder to read
and less portable.
Change was suggested by James O'Beirne <james.obeirne@gmail.com> in
https://github.com/bitcoin/bitcoin/pull/10973#discussion_r213473620
There are no changes in behavior except on some platforms we don't support
(ILP64, IP16L32, I16LP32), where SignalsOptInRBF() and MutateTxAddInput()
functions would now work correctly.
The current code contains a rather complex script template matching engine,
which is only used for 3 particular script types (P2PK, P2PKH, multisig).
The first two of these are trivial to match for otherwise, and a specialized
matcher for multisig is both more compact and more efficient than a generic
one.
The goal is being more flexible, so that for example larger standard multisigs
inside SegWit outputs are more easy to implement.
As a side-effect, it also gets rid of the pseudo opcodes hack.
This adds a READWRITEAS(type, obj) macro which serializes obj as if it
were casted to (const type&) when const, and to (type&) when non-const.
This makes it usable in serialization code that uses a single
implementation for both serialization and deserializing, which doesn't
know the constness of the object involved.
9ad6746ccd Use static_cast instead of C-style casts for non-fundamental types (practicalswift)
Pull request description:
A C-style cast is equivalent to try casting in the following order:
1. `const_cast(...)`
2. `static_cast(...)`
3. `const_cast(static_cast(...))`
4. `reinterpret_cast(...)`
5. `const_cast(reinterpret_cast(...))`
By using `static_cast<T>(...)` explicitly we avoid the possibility of an unintentional and dangerous `reinterpret_cast`. Furthermore `static_cast<T>(...)` allows for easier grepping of casts.
For a more thorough discussion, see ["ES.49: If you must use a cast, use a named cast"](https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#es49-if-you-must-use-a-cast-use-a-named-cast) in the C++ Core Guidelines (Stroustrup & Sutter).
Tree-SHA512: bd6349b7ea157da93a47b8cf238932af5dff84731374ccfd69b9f732fabdad1f9b1cdfca67497040f14eaa85346391404f4c0495e22c467f26ca883cd2de4d3c
A C-style cast is equivalent to try casting in the following order:
1. const_cast(...)
2. static_cast(...)
3. const_cast(static_cast(...))
4. reinterpret_cast(...)
5. const_cast(reinterpret_cast(...))
By using static_cast<T>(...) explicitly we avoid the possibility
of an unintentional and dangerous reinterpret_cast. Furthermore
static_cast<T>(...) allows for easier grepping of casts.
08f71c29e [Trivial] Add a comment on the use of prevector in script. (Gregory Maxwell)
Pull request description:
Tree-SHA512: 020981516e67e576685eb9a8532178fb97d1780af409fc86d869cd05c293c0c823c26e838cf544d18610f5a3f479ce3e47d2ccb95fb1c4e55fe9e7ceb354f20b
ad1ae7a Check and enable -Wshadow by default. (Pavel Janík)
9de90bb Do not shadow variables (gcc set) (Pavel Janík)
Tree-SHA512: 9517feb423dc8ddd63896016b25324673bfbe0bffa97f22996f59d7a3fcbdc2ebf2e43ac02bc067546f54e293e9b2f2514be145f867321e9031f895c063d9fb8
