From 97f21d6102c2a8b136ec48bcb0f3b23bd068b017 Mon Sep 17 00:00:00 2001
From: dergoegge <n.goeggi@gmail.com>
Date: Tue, 15 Oct 2024 12:10:36 +0100
Subject: [PATCH] Introduce `g_fuzzing` global for fuzzing checks

---
 CMakeLists.txt         | 5 -----
 src/pow.cpp            | 6 ++----
 src/test/fuzz/fuzz.cpp | 2 ++
 src/util/check.cpp     | 2 ++
 src/util/check.h       | 4 +++-
 5 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8b687641f263b..ade57726695de 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -240,11 +240,6 @@ if(BUILD_FOR_FUZZING)
   set(BUILD_GUI_TESTS OFF)
   set(BUILD_BENCH OFF)
   set(BUILD_FUZZ_BINARY ON)
-
-  target_compile_definitions(core_interface INTERFACE
-    ABORT_ON_FAILED_ASSUME
-    FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
-  )
 endif()
 
 include(ProcessConfigurations)
diff --git a/src/pow.cpp b/src/pow.cpp
index 6c8e7e5d98a6b..012841a86911a 100644
--- a/src/pow.cpp
+++ b/src/pow.cpp
@@ -9,6 +9,7 @@
 #include <chain.h>
 #include <primitives/block.h>
 #include <uint256.h>
+#include <util/check.h>
 
 unsigned int GetNextWorkRequired(const CBlockIndex* pindexLast, const CBlockHeader *pblock, const Consensus::Params& params)
 {
@@ -138,11 +139,8 @@ bool PermittedDifficultyTransition(const Consensus::Params& params, int64_t heig
 // the most signficant bit of the last byte of the hash is set.
 bool CheckProofOfWork(uint256 hash, unsigned int nBits, const Consensus::Params& params)
 {
-#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
-    return (hash.data()[31] & 0x80) == 0;
-#else
+    if(g_fuzzing) return (hash.data()[31] & 0x80) == 0;
     return CheckProofOfWorkImpl(hash, nBits, params);
-#endif
 }
 
 bool CheckProofOfWorkImpl(uint256 hash, unsigned int nBits, const Consensus::Params& params)
diff --git a/src/test/fuzz/fuzz.cpp b/src/test/fuzz/fuzz.cpp
index bba2dd8e3a393..654e1f8be2470 100644
--- a/src/test/fuzz/fuzz.cpp
+++ b/src/test/fuzz/fuzz.cpp
@@ -102,6 +102,8 @@ void ResetCoverageCounters() {}
 
 void initialize()
 {
+    g_fuzzing = true;
+
     // By default, make the RNG deterministic with a fixed seed. This will affect all
     // randomness during the fuzz test, except:
     // - GetStrongRandBytes(), which is used for the creation of private key material.
diff --git a/src/util/check.cpp b/src/util/check.cpp
index e1956042c300e..57ff78f7a089a 100644
--- a/src/util/check.cpp
+++ b/src/util/check.cpp
@@ -14,6 +14,8 @@
 #include <string>
 #include <string_view>
 
+bool g_fuzzing = false;
+
 std::string StrFormatInternalBug(std::string_view msg, std::string_view file, int line, std::string_view func)
 {
     return strprintf("Internal bug detected: %s\n%s:%d (%s)\n"
diff --git a/src/util/check.h b/src/util/check.h
index 8f28f5dc94127..86e26b2be0026 100644
--- a/src/util/check.h
+++ b/src/util/check.h
@@ -13,6 +13,8 @@
 #include <string_view>
 #include <utility>
 
+extern bool g_fuzzing;
+
 std::string StrFormatInternalBug(std::string_view msg, std::string_view file, int line, std::string_view func);
 
 class NonFatalCheckError : public std::runtime_error
@@ -50,7 +52,7 @@ constexpr T&& inline_assertion_check(LIFETIMEBOUND T&& val, [[maybe_unused]] con
         if (!val) {
             assertion_fail(file, line, func, assertion);
         }
-    }
+    } else if (g_fuzzing && !val) abort();
     return std::forward<T>(val);
 }