5c0aebfcd4
e3e7446305329ce96e9cf5f5161658eb2e1ea888 Add lifetimebound to attributes for general-purpose usage (Cory Fields) 1d58cc7cb040a70f768b632f294db4e0797d3a34 span: add lifetimebound attribute (Cory Fields) 62733fee874bfe7e833e71380eb8efd6a3126fbd span: (almost) match std::span's constructor behavior (Cory Fields) Pull request description: Replaces #19382 with a different approach. See [this comment](https://github.com/bitcoin/bitcoin/pull/19382#discussion_r446332852) for the reasoning behind the switch. -- Description from #19382: See [here](http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0936r0.pdf) for more detail on lifetimebound. This is implemented using preprocesor macros rather than configure checks in order to keep span.h self-contained. The ```[[clang::lifetimebound]]``` syntax was chosen over ```__attribute__((lifetimebound))``` because the former is more flexible and works to guard ```this``` as well as function parameters, and also because at least for now, it's available only in clang. There are currently no violations in our codebase, but this can easily be tested by inserting one like this somewhere and compiling with a modern clang: ```c++ Span<const int> bad(std::vector<int>{1,2,3}); ``` The result: > warning: temporary whose address is used as value of local variable 'bad' will be destroyed at the end of the full-expression [-Wdangling] Span<const int> bad(std::vector<int>{1,2,3}); ``` ACKs for top commit: sipa: ACK e3e7446305329ce96e9cf5f5161658eb2e1ea888 ajtowns: ACK e3e7446305329ce96e9cf5f5161658eb2e1ea888 (drive by; only a quick skim of code and some basic sanity checks) MarcoFalke: review ACK e3e7446305329ce96e9cf5f5161658eb2e1ea888 🔗 jonatack: ACK e3e7446 change since last review is adding `[[clang::lifetimebound]]` as `LIFETIMEBOUND` to src/attributes.h as suggested in https://github.com/bitcoin/bitcoin/pull/19387#issuecomment-650752959. Tree-SHA512: 05a3440ee595ef0e8d693a2820b360707695c016a68e15df47c20cd8d053646cc6c8cca8addd7db40e72b3fce208879a41c8102ba7ae9223e4366e5de1175211
Bitcoin Core integration/staging tree
What is Bitcoin?
Bitcoin is an experimental digital currency that enables instant payments to anyone, anywhere in the world. Bitcoin uses peer-to-peer technology to operate with no central authority: managing transactions and issuing money are carried out collectively by the network. Bitcoin Core is the name of open source software which enables the use of this currency.
For more information, as well as an immediately usable, binary version of the Bitcoin Core software, see https://bitcoincore.org/en/download/, or read the original whitepaper.
License
Bitcoin Core is released under the terms of the MIT license. See COPYING for more information or see https://opensource.org/licenses/MIT.
Development Process
The master branch is regularly built (see doc/build-*.md for instructions) and tested, but it is not guaranteed to be
completely stable. Tags are created
regularly from release branches to indicate new official, stable release versions of Bitcoin Core.
The https://github.com/bitcoin-core/gui repository is used exclusively for the development of the GUI. Its master branch is identical in all monotree repositories. Release branches and tags do not exist, so please do not fork that repository unless it is for development reasons.
The contribution workflow is described in CONTRIBUTING.md and useful hints for developers can be found in doc/developer-notes.md.
Testing
Testing and code review is the bottleneck for development; we get more pull requests than we can review and test on short notice. Please be patient and help out by testing other people's pull requests, and remember this is a security-critical project where any mistake might cost people lots of money.
Automated Testing
Developers are strongly encouraged to write unit tests for new code, and to
submit new unit tests for old code. Unit tests can be compiled and run
(assuming they weren't disabled in configure) with: make check. Further details on running
and extending unit tests can be found in /src/test/README.md.
There are also regression and integration tests, written
in Python, that are run automatically on the build server.
These tests can be run (if the test dependencies are installed) with: test/functional/test_runner.py
The Travis CI system makes sure that every pull request is built for Windows, Linux, and macOS, and that unit/sanity tests are run automatically.
Manual Quality Assurance (QA) Testing
Changes should be tested by somebody other than the developer who wrote the code. This is especially important for large or high-risk changes. It is useful to add a test plan to the pull request description if testing the changes is not straightforward.
Translations
Changes to translations as well as new translations can be submitted to Bitcoin Core's Transifex page.
Translations are periodically pulled from Transifex and merged into the git repository. See the translation process for details on how this works.
Important: We do not accept translation changes as GitHub pull requests because the next pull from Transifex would automatically overwrite them again.
Translators should also subscribe to the mailing list.