Merge #16975: test: Show debug log on unit test failure

fa37e0a68bea65979f9f8f2e5258fe608acf2bdf test: Show debug log on unit test failure (MarcoFalke)

Pull request description:

  Often, it is hard to debug unit test failures without the debug log. Especially when the failure happens remotely (e.g. on a ci system).

  Fix that by printing the log on failure.

ACKs for top commit:
  jamesob:
    ACK fa37e0a68bea65979f9f8f2e5258fe608acf2bdf ([`jamesob/ackr/16975.1.MarcoFalke.test_show_debug_log_on_u`](https://github.com/jamesob/bitcoin/tree/ackr/16975.1.MarcoFalke.test_show_debug_log_on_u))

Tree-SHA512: 2ca4150c4ae3d4ad47e03b5e5e70da2baffec928ddef1fdf53a3ebc061f14aee249205387cb1b12ef6d4eb55711ef0080c0b41d9d18000b5da124ca80299793b

7 files changed, 34 insertions, 0 deletions

diff --git a/src/bench/bench.cpp b/src/bench/bench.cpp
index 745fd0966d..d1b2b938ff 100644
--- a/src/bench/bench.cpp
+++ b/src/bench/bench.cpp
@@ -16,6 +16,7 @@
 #include <regex>
 
 const RegTestingSetup* g_testing_setup = nullptr;
+const std::function<void(const std::string&)> G_TEST_LOG_FUN{};
 
 void benchmark::ConsolePrinter::header()
 {
diff --git a/src/qt/test/test_main.cpp b/src/qt/test/test_main.cpp
index f8c0379ea8..aefdcd2716 100644
--- a/src/qt/test/test_main.cpp
+++ b/src/qt/test/test_main.cpp
@@ -37,6 +37,8 @@ Q_IMPORT_PLUGIN(QCocoaIntegrationPlugin);
 #endif
 #endif
 
+const std::function<void(const std::string&)> G_TEST_LOG_FUN{};
+
 // This is all you need to run all the tests
 int main(int argc, char *argv[])
 {
diff --git a/src/test/fuzz/fuzz.cpp b/src/test/fuzz/fuzz.cpp
index da4e623e98..a6ab620e21 100644
--- a/src/test/fuzz/fuzz.cpp
+++ b/src/test/fuzz/fuzz.cpp
@@ -4,10 +4,14 @@
 
 #include <test/fuzz/fuzz.h>
 
+#include <test/util/setup_common.h>
+
 #include <cstdint>
 #include <unistd.h>
 #include <vector>
 
+const std::function<void(const std::string&)> G_TEST_LOG_FUN{};
+
 static bool read_stdin(std::vector<uint8_t>& data)
 {
     uint8_t buffer[1024];
diff --git a/src/test/main.cpp b/src/test/main.cpp
index ff3f36b561..e6529949e2 100644
--- a/src/test/main.cpp
+++ b/src/test/main.cpp
@@ -2,6 +2,21 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+/**
+ * See https://www.boost.org/doc/libs/1_71_0/libs/test/doc/html/boost_test/utf_reference/link_references/link_boost_test_module_macro.html
+ */
 #define BOOST_TEST_MODULE Bitcoin Core Test Suite
 
 #include <boost/test/unit_test.hpp>
+
+#include <test/util/setup_common.h>
+
+/** Redirect debug log to boost log */
+const std::function<void(const std::string&)> G_TEST_LOG_FUN = [](const std::string& s) {
+    if (s.back() == '\n') {
+        // boost will insert the new line
+        BOOST_TEST_MESSAGE(s.substr(0, s.size() - 1));
+    } else {
+        BOOST_TEST_MESSAGE(s);
+    }
+};
diff --git a/src/test/util/setup_common.cpp b/src/test/util/setup_common.cpp
index 3bdf3485fa..ccb3064d59 100644
--- a/src/test/util/setup_common.cpp
+++ b/src/test/util/setup_common.cpp
@@ -71,6 +71,7 @@ BasicTestingSetup::BasicTestingSetup(const std::string& chainName)
     SelectParams(chainName);
     SeedInsecureRand();
     gArgs.ForceSetArg("-printtoconsole", "0");
+    if (G_TEST_LOG_FUN) LogInstance().PushBackCallback(G_TEST_LOG_FUN);
     InitLogging();
     LogInstance().StartLogging();
     SHA256AutoDetect();
diff --git a/src/test/util/setup_common.h b/src/test/util/setup_common.h
index 1e2e059a56..6741be8480 100644
--- a/src/test/util/setup_common.h
+++ b/src/test/util/setup_common.h
@@ -18,6 +18,9 @@
 
 #include <boost/thread.hpp>
 
+/** This is connected to the logger. Can be used to redirect logs to any other log */
+extern const std::function<void(const std::string&)> G_TEST_LOG_FUN;
+
 // Enable BOOST_CHECK_EQUAL for enum class types
 template <typename T>
 std::ostream& operator<<(typename std::enable_if<std::is_enum<T>::value, std::ostream>::type& stream, const T& e)
diff --git a/test/sanitizer_suppressions/tsan b/test/sanitizer_suppressions/tsan
index 70eea34363..b9c5c038d0 100644
--- a/test/sanitizer_suppressions/tsan
+++ b/test/sanitizer_suppressions/tsan
@@ -7,6 +7,14 @@ deadlock:WalletBatch
 # Intentional deadlock in tests
 deadlock:TestPotentialDeadLockDetected
 
+# Race due to unprotected calls to thread-unsafe BOOST_TEST_MESSAGE from different threads:
+# * G_TEST_LOG_FUN in the index thread
+# * boost test case invoker (entering a test case) in the main thread
+# TODO: get rid of BOOST_ macros, see also https://github.com/bitcoin/bitcoin/issues/8670
+race:blockfilter_index_initial_sync_invoker
+race:txindex_initial_sync_invoker
+race:validation_block_tests::TestSubscriber
+
 # Wildcard for all gui tests, should be replaced with non-wildcard suppressions
 race:src/qt/test/*
 deadlock:src/qt/test/*