build: Add option --enable-danger-fuzz-link-all

.fuzzbuzz.yml

@@ -7,7 +7,7 @@ setup:
   - sudo apt-get update
   - sudo apt-get install -y autoconf bsdmainutils clang git libboost-all-dev libboost-program-options-dev libc++1 libc++abi1 libc++abi-dev libc++-dev libclang1 libclang-dev libdb5.3++ libevent-dev libllvm-ocaml-dev libomp5 libomp-dev libprotobuf-dev libqt5core5a libqt5dbus5 libqt5gui5 libssl-dev libtool llvm llvm-dev llvm-runtime pkg-config protobuf-compiler qttools5-dev qttools5-dev-tools software-properties-common
   - ./autogen.sh
-  - CC=clang CXX=clang++ ./configure --enable-fuzz --with-sanitizers=address,fuzzer,undefined
+  - CC=clang CXX=clang++ ./configure --enable-fuzz --with-sanitizers=address,fuzzer,undefined --enable-danger-fuzz-link-all
   - make
   - git clone https://github.com/bitcoin-core/qa-assets
 auto_targets:

configure.ac

@@ -167,6 +167,12 @@ AC_ARG_ENABLE([fuzz],
     [enable_fuzz=$enableval],
     [enable_fuzz=no])
 
+AC_ARG_ENABLE([danger_fuzz_link_all],
+    AS_HELP_STRING([--enable-danger-fuzz-link-all],
+    [Danger! Modifies source code. Needs git and gnu sed installed. Link each fuzz target (default no).]),
+    [enable_danger_fuzz_link_all=$enableval],
+    [enable_danger_fuzz_link_all=no])
+
 AC_ARG_WITH([qrencode],
   [AS_HELP_STRING([--with-qrencode],
   [enable QR code support (default is yes if qt is enabled and libqrencode is found)])],
@@ -1612,6 +1618,7 @@ AM_CONDITIONAL([USE_SQLITE], [test "x$use_sqlite" = "xyes"])
 AM_CONDITIONAL([USE_BDB], [test "x$use_bdb" = "xyes"])
 AM_CONDITIONAL([ENABLE_TESTS],[test x$BUILD_TEST = xyes])
 AM_CONDITIONAL([ENABLE_FUZZ],[test x$enable_fuzz = xyes])
+AM_CONDITIONAL([ENABLE_FUZZ_LINK_ALL],[test x$enable_danger_fuzz_link_all = xyes])
 AM_CONDITIONAL([ENABLE_QT],[test x$bitcoin_enable_qt = xyes])
 AM_CONDITIONAL([ENABLE_QT_TESTS],[test x$BUILD_TEST_QT = xyes])
 AM_CONDITIONAL([ENABLE_BENCH],[test x$use_bench = xyes])

src/Makefile.test.include

@@ -10,6 +10,7 @@ endif
 
 TEST_SRCDIR = test
 TEST_BINARY=test/test_bitcoin$(EXEEXT)
+FUZZ_BINARY=test/fuzz/fuzz$(EXEEXT)
 
 JSON_TEST_FILES = \
   test/data/script_tests.json \
@@ -320,6 +321,11 @@ if EMBEDDED_UNIVALUE
 	$(AM_V_at)$(MAKE) $(AM_MAKEFLAGS) -C univalue check
 endif
 
+if ENABLE_FUZZ_LINK_ALL
+all-local: $(FUZZ_BINARY)
+	bash ./test/fuzz/danger_link_all.sh
+endif
+
 %.cpp.test: %.cpp
 	@echo Running tests: `cat $< | grep -E "(BOOST_FIXTURE_TEST_SUITE\\(|BOOST_AUTO_TEST_SUITE\\()" | cut -d '(' -f 2 | cut -d ',' -f 1 | cut -d ')' -f 1` from $<
 	$(AM_V_at)$(TEST_BINARY) --catch_system_errors=no -l test_suite -t "`cat $< | grep -E "(BOOST_FIXTURE_TEST_SUITE\\(|BOOST_AUTO_TEST_SUITE\\()" | cut -d '(' -f 2 | cut -d ',' -f 1 | cut -d ')' -f 1`" -- DEBUG_LOG_OUT > $<.log 2>&1 || (cat $<.log && false)

src/test/fuzz/danger_link_all.sh

@@ -0,0 +1,28 @@
+#!/usr/bin/env bash
+# Copyright (c) 2020 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
+
+set -e
+
+ROOT_DIR="$(git rev-parse --show-toplevel)"
+
+# Run only once (break make recursion)
+if [ -d "${ROOT_DIR}/lock_fuzz_link_all" ]; then
+  exit
+fi
+mkdir "${ROOT_DIR}/lock_fuzz_link_all"
+
+echo "Linking each fuzz target separately."
+for FUZZING_HARNESS in $(PRINT_ALL_FUZZ_TARGETS_AND_ABORT=1 "${ROOT_DIR}/src/test/fuzz/fuzz" | sort -u); do
+    echo "Building src/test/fuzz/${FUZZING_HARNESS} ..."
+    git checkout -- "${ROOT_DIR}/src/test/fuzz/fuzz.cpp"
+    sed -i "s/std::getenv(\"FUZZ\")/\"${FUZZING_HARNESS}\"/g" "${ROOT_DIR}/src/test/fuzz/fuzz.cpp"
+    make
+    mv "${ROOT_DIR}/src/test/fuzz/fuzz" "${ROOT_DIR}/src/test/fuzz/${FUZZING_HARNESS}"
+done
+git checkout -- "${ROOT_DIR}/src/test/fuzz/fuzz.cpp"
+rmdir "${ROOT_DIR}/lock_fuzz_link_all"
+echo "Successfully built all fuzz targets."