ekzyis

Build

# clone Bitcoin Core
$ git clone git@github.com:bitcoin/bitcoin
# clone nix flake for Bitcoin Core dev environment
$ git clone git@github.com:bitcoin-dev-tools/bix
# enter dev environment
$ nix develop bix/
# build
$ cd bitcoin
$ cmake -DCMAKE_EXPORT_COMPILE_COMMANDS=1 -B build
$ cmake --build build -j$(nproc)

_{With CMAKE_EXPORT_COMPILE_COMMANDS, cmake will create
compile_commands.json in build/. It is needed to enable code navigation with
clangd. It will look for this file in build/ by default.}

Clean rebuild in one command:

$ rm -rf build && cmake -DCMAKE_EXPORT_COMPILE_COMMANDS=1 -B build && cmake --build build -j$(nproc)

_{Usually, only recompiling changed files with cmake --build is enough,
though.}

Test

Functional tests:

# all functional tests
$ python build/test/functional/test_runner.py
# specific functional test
$ python build/test/functional/test_runner.py feature_signet.py

Unit tests:

# all unit tests
$ build/bin/test_bitcoin
# specific unit test
$ build/bin/test_bitcoin --run_test=txospenderindex_tests

Fuzz

_{doc/fuzzing.md}

Build for fuzzing:

$ cmake --preset libfuzzer
$ cmake --build build_fuzz -j$(nproc)

Fuzz specific target:

# smoke test of target: fuzz until first crash, discarding any progress
$ FUZZ_TARGET=process_message
$ FUZZ=$FUZZ_TARGET build_fuzz/bin/fuzz
# fuzz target for 1 minute and generate corpus
$ mkdir -p fuzz_corpora/$FUZZ_TARGET
$ FUZZ=$FUZZ_TARGET build_fuzz/bin/fuzz -max_total_time=60 fuzz_corpora/$FUZZ_TARGET

Fuzz with fuzz corpora:

# fuzz target with existing corpus
$ git clone git@github.com:bitcoin-core/qa-assets ../qa-assets
$ FUZZ=$FUZZ_TARGET build_fuzz/bin/fuzz -runs=0 ../qa-assets/fuzz_corpora/$FUZZ_TARGET
# minimize corpus
$ tmp=$(mktemp -d)
$ FUZZ=$FUZZ_TARGET build_fuzz/bin/fuzz -merge=1 $tmp ../qa-assets/fuzz_corpora/$FUZZ_TARGET
# check if existing corpus was minimized by comparing input count
$ diff -u \
    <(ls -l ../qa-assets/fuzz_corpora/$FUZZ_TARGET | wc -l) \
    <(ls -l $tmp | wc -l)

Build for fuzz coverage:

$ cmake --preset libfuzzer -B build_cov \
    -DCMAKE_C_FLAGS="-fprofile-instr-generate -fcoverage-mapping" \
    -DCMAKE_CXX_FLAGS="-fprofile-instr-generate -fcoverage-mapping"
$ cmake --build build_cov -j$(nproc)

Fuzz for coverage data:

$ FUZZ=$FUZZ_TARGET build_cov/bin/fuzz -max_total_time=5 fuzz_corpora/$FUZZ_TARGET
$ llvm-profdata merge build_cov/raw_profile_data/*.profraw -o build_cov/coverage.profdata

Generate HTML coverage report:

$ llvm-cov show \
    --object=build_cov/bin/fuzz \
    -Xdemangler=llvm-cxxfilt \
    --instr-profile=build_cov/coverage.profdata \
    --ignore-filename-regex="src/crc32c/|src/leveldb/|src/minisketch/|src/secp256k1/|src/test/" \
    --format=html \
    --show-instantiation-summary \
    --show-line-counts-or-regions \
    --show-expansions \
    --output-dir=build_cov/coverage_report \
    --project-title="Bitcoin Core Fuzz Coverage Report"