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

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."