Repository: bitcoin/bitcoin
File: ci/test/00_setup_env_native_fuzz_with_msan.sh (Shell)

Code before:
#!/usr/bin/env bash
#
# Copyright (c) 2020-present The Bitcoin Core developers
# Distributed under the MIT software license, see the accompanying
# file COPYING or http://www.opensource.org/licenses/mit-license.php.

export LC_ALL=C.UTF-8

export CI_IMAGE_NAME_TAG="docker.io/ubuntu:24.04"
LIBCXX_DIR="/msan/cxx_build/"
export MSAN_FLAGS="-fsanitize=memory -fsanitize-memory-track-origins=2 -fno-omit-frame-pointer -g -O1 -fno-optimize-sibling-calls"
LIBCXX_FLAGS="-nostdinc++ -nostdlib++ -isystem ${LIBCXX_DIR}include/c++/v1 -L${LIBCXX_DIR}lib -Wl,-rpath,${LIBCXX_DIR}lib -lc++ -lc++abi -lpthread -Wno-unused-command-line-argument"
export MSAN_AND_LIBCXX_FLAGS="${MSAN_FLAGS} ${LIBCXX_FLAGS}"

export CONTAINER_NAME="ci_native_fuzz_msan"
export PACKAGES="ninja-build"
# BDB generates false-positives and will be removed in future
export DEP_OPTS="DEBUG=1 NO_BDB=1 NO_QT=1 CC=clang CXX=clang++ CFLAGS='${MSAN_FLAGS}' CXXFLAGS='${MSAN_AND_LIBCXX_FLAGS}'"
export GOAL="install"
# _FORTIFY_SOURCE is not compatible with MSAN.
export BITCOIN_CONFIG="\
 -DBUILD_FOR_FUZZING=ON \
 -DSANITIZERS=fuzzer,memory \
 -DAPPEND_CPPFLAGS='-DBOOST_MULTI_INDEX_ENABLE_SAFE_MODE -U_FORTIFY_SOURCE' \
"
export USE_MEMORY_SANITIZER="true"
export RUN_UNIT_TESTS="false"
export RUN_FUNCTIONAL_TESTS="false"
export RUN_FUZZ_TESTS=true
export CCACHE_MAXSIZE=250M


Review comment (bug):
I think I understand why this needs to pass BUILD_TYPE=Debug so the debug flags from the depends system will be applied. But I don't understand why FLAGS_DEBUG variables need to be set to empty stings. How does setting those to empty strings cause MSAN_FLAGS to remain unaltered? What code is altering MSAN_FLAGS if FLAGS_DEBUG variables are unset?

Code after:
#!/usr/bin/env bash
#
# Copyright (c) 2020-present The Bitcoin Core developers
# Distributed under the MIT software license, see the accompanying
# file COPYING or http://www.opensource.org/licenses/mit-license.php.

export LC_ALL=C.UTF-8

export CI_IMAGE_NAME_TAG="docker.io/ubuntu:24.04"
LIBCXX_DIR="/msan/cxx_build/"
export MSAN_FLAGS="-fsanitize=memory -fsanitize-memory-track-origins=2 -fno-omit-frame-pointer -g -O1 -fno-optimize-sibling-calls"
LIBCXX_FLAGS="-nostdinc++ -nostdlib++ -isystem ${LIBCXX_DIR}include/c++/v1 -L${LIBCXX_DIR}lib -Wl,-rpath,${LIBCXX_DIR}lib -lc++ -lc++abi -lpthread -Wno-unused-command-line-argument"
export MSAN_AND_LIBCXX_FLAGS="${MSAN_FLAGS} ${LIBCXX_FLAGS}"

export CONTAINER_NAME="ci_native_fuzz_msan"
export PACKAGES="ninja-build"
# BDB generates false-positives and will be removed in future
export DEP_OPTS="DEBUG=1 NO_BDB=1 NO_QT=1 CC=clang CXX=clang++ CFLAGS='${MSAN_FLAGS}' CXXFLAGS='${MSAN_AND_LIBCXX_FLAGS}'"
export GOAL="install"
# Setting CMAKE_{C,CXX}_FLAGS_DEBUG flags to an empty string ensures that the flags set in MSAN_FLAGS remain unaltered.
# _FORTIFY_SOURCE is not compatible with MSAN.
export BITCOIN_CONFIG="\
 -DCMAKE_BUILD_TYPE=Debug \
 -DCMAKE_C_FLAGS_DEBUG='' \
 -DCMAKE_CXX_FLAGS_DEBUG='' \
 -DBUILD_FOR_FUZZING=ON \
 -DSANITIZERS=fuzzer,memory \
 -DAPPEND_CPPFLAGS='-DBOOST_MULTI_INDEX_ENABLE_SAFE_MODE -U_FORTIFY_SOURCE' \
"
export USE_MEMORY_SANITIZER="true"
export RUN_UNIT_TESTS="false"
export RUN_FUNCTIONAL_TESTS="false"
export RUN_FUZZ_TESTS=true
export CCACHE_MAXSIZE=250M