MarcoFalke 28bdaa3f76
Merge bitcoin/bitcoin#24080: policy: Remove unused locktime flags
fa8d4d9128c35de0fe715f2e2b99269d23c09cc1 scripted-diff: Clarify CheckFinalTxAtTip name (MarcoFalke)
fa4e30b0f36f2e7a09db7d30dca9008ed9dbcb35 policy: Remove unused locktime flags (MarcoFalke)

Pull request description:

  The locktime flags have many issues:
  * They are passed in by a default argument, which is fragile. It has already lead to bugs like the one fixed in commit e30b6ea194fee3bb95a45e7b732a99566b88f1f5.
  * They are negative (signed), which doesn't make sense for flags (unsigned in general). According to the review comments when the code was added: "The max on the flags is a fairly weird operation." (https://github.com/bitcoin/bitcoin/pull/6566#issuecomment-150310861)
  * No call site relies on the default argument and they all pass in a single compile-time constant, rendering most of the code dead and untested.
  * The dead code calls `GetAdjustedTime` (network adjusted time), which has its own issues. See https://github.com/bitcoin/bitcoin/issues/4521

  Fix all issues by removing them

ACKs for top commit:
  ajtowns:
    ACK  fa8d4d9128c35de0fe715f2e2b99269d23c09cc1
  theStack:
    Code-review ACK fa8d4d9128c35de0fe715f2e2b99269d23c09cc1
  glozow:
    ACK fa8d4d9128c35de0fe715f2e2b99269d23c09cc1, agree the default arg `flags` is a massive footgun and just setting max flags is weird. Adding `AtTip` to the names makes sense to me, since they're both testing for *next* block and only ever used for {,re}addition to mempool.

Tree-SHA512: 79f4a52f34909eb598d88bbae7afe8abe5f85f45c128483d16aa83dacd0e5579e561b725d01b1e9a931d1821012a51ad2bc6fb2867f8d09ee541f9d234d696f8
2022-03-14 16:32:23 +01:00
..
2021-11-01 14:20:56 +01:00

Unit tests

The sources in this directory are unit test cases. Boost includes a unit testing framework, and since Bitcoin Core already uses Boost, it makes sense to simply use this framework rather than require developers to configure some other framework (we want as few impediments to creating unit tests as possible).

The build system is set up to compile an executable called test_bitcoin that runs all of the unit tests. The main source file for the test library is found in util/setup_common.cpp.

Compiling/running unit tests

Unit tests will be automatically compiled if dependencies were met in ./configure and tests weren't explicitly disabled.

After configuring, they can be run with make check.

To run the unit tests manually, launch src/test/test_bitcoin. To recompile after a test file was modified, run make and then run the test again. If you modify a non-test file, use make -C src/test to recompile only what's needed to run the unit tests.

To add more unit tests, add BOOST_AUTO_TEST_CASE functions to the existing .cpp files in the test/ directory or add new .cpp files that implement new BOOST_AUTO_TEST_SUITE sections.

To run the GUI unit tests manually, launch src/qt/test/test_bitcoin-qt

To add more GUI unit tests, add them to the src/qt/test/ directory and the src/qt/test/test_main.cpp file.

Running individual tests

test_bitcoin accepts the command line arguments from the boost framework. For example, to run just the getarg_tests suite of tests:

test_bitcoin --log_level=all --run_test=getarg_tests

log_level controls the verbosity of the test framework, which logs when a test case is entered, for example. test_bitcoin also accepts the command line arguments accepted by bitcoind. Use -- to separate both types of arguments:

test_bitcoin --log_level=all --run_test=getarg_tests -- -printtoconsole=1

The -printtoconsole=1 after the two dashes redirects the debug log, which would normally go to a file in the test datadir (BasicTestingSetup::m_path_root), to the standard terminal output.

... or to run just the doubledash test:

test_bitcoin --run_test=getarg_tests/doubledash

Run test_bitcoin --help for the full list.

Adding test cases

To add a new unit test file to our test suite you need to add the file to src/Makefile.test.include. The pattern is to create one test file for each class or source file for which you want to create unit tests. The file naming convention is <source_filename>_tests.cpp and such files should wrap their tests in a test suite called <source_filename>_tests. For an example of this pattern, see uint256_tests.cpp.

Logging and debugging in unit tests

make check will write to a log file foo_tests.cpp.log and display this file on failure. For running individual tests verbosely, refer to the section above.

To write to logs from unit tests you need to use specific message methods provided by Boost. The simplest is BOOST_TEST_MESSAGE.

For debugging you can launch the test_bitcoin executable with gdb or lldb and start debugging, just like you would with any other program:

gdb src/test/test_bitcoin

Segmentation faults

If you hit a segmentation fault during a test run, you can diagnose where the fault is happening by running gdb ./src/test/test_bitcoin and then using the bt command within gdb.

Another tool that can be used to resolve segmentation faults is valgrind.

If for whatever reason you want to produce a core dump file for this fault, you can do that as well. By default, the boost test runner will intercept system errors and not produce a core file. To bypass this, add --catch_system_errors=no to the test_bitcoin arguments and ensure that your ulimits are set properly (e.g. ulimit -c unlimited).

Running the tests and hitting a segmentation fault should now produce a file called core (on Linux platforms, the file name will likely depend on the contents of /proc/sys/kernel/core_pattern).

You can then explore the core dump using

gdb src/test/test_bitcoin core

(gbd) bt  # produce a backtrace for where a segfault occurred