test: recently merged fuzzers don't compile on macOS #19557

The fuzzing harnesses from #19143 don't compile on macOS. i.e building at 476436b2dec254bb988f8c7a6cbec1d7bb7cecfd:

In file included from test/fuzz/addition_overflow.cpp:7:
./test/fuzz/util.h:335:13: error: no matching function for call to 'AdditionOverflow'
        if (AdditionOverflow((uint64_t)fuzzed_file->m_offset, random_bytes.size())) {
            ^~~~~~~~~~~~~~~~
./test/fuzz/util.h:201:16: note: candidate template ignored: deduced conflicting types for parameter 'T' ('unsigned long long' vs. 'unsigned long')
NODISCARD bool AdditionOverflow(const T i, const T j) noexcept
               ^
./test/fuzz/util.h:346:13: error: no matching function for call to 'AdditionOverflow'
        if (AdditionOverflow(fuzzed_file->m_offset, n)) {
            ^~~~~~~~~~~~~~~~
./test/fuzz/util.h:201:16: note: candidate template ignored: deduced conflicting types for parameter 'T' ('long long' vs. 'long')
NODISCARD bool AdditionOverflow(const T i, const T j) noexcept
               ^
2 errors generated.

In file included from test/fuzz/buffered_file.cpp:9:
./test/fuzz/util.h:335:13: error: no matching function for call to 'AdditionOverflow'
        if (AdditionOverflow((uint64_t)fuzzed_file->m_offset, random_bytes.size())) {
            ^~~~~~~~~~~~~~~~
./test/fuzz/util.h:201:16: note: candidate template ignored: deduced conflicting types for parameter 'T' ('unsigned long long' vs. 'unsigned long')
NODISCARD bool AdditionOverflow(const T i, const T j) noexcept
               ^
./test/fuzz/util.h:346:13: error: no matching function for call to 'AdditionOverflow'
        if (AdditionOverflow(fuzzed_file->m_offset, n)) {
            ^~~~~~~~~~~~~~~~
./test/fuzz/util.h:201:16: note: candidate template ignored: deduced conflicting types for parameter 'T' ('long long' vs. 'long')
NODISCARD bool AdditionOverflow(const T i, const T j) noexcept
               ^
2 errors generated.

@fanquake Thanks for reporting and thanks for the ping! Unfortunately I don't have any Mac around to test with but the following patch should make it compile? :) Feel free to submit as PR if it looks good.

diff --git a/src/test/fuzz/util.h b/src/test/fuzz/util.h
index 148610c04..e47ad47f2 100644
--- a/src/test/fuzz/util.h
+++ b/src/test/fuzz/util.h
@@ -332,7 +332,7 @@ public:
             return 0;
         }
         std::memcpy(buf, random_bytes.data(), random_bytes.size());
-        if (AdditionOverflow((uint64_t)fuzzed_file->m_offset, random_bytes.size())) {
+        if (AdditionOverflow(fuzzed_file->m_offset, (int64_t)random_bytes.size())) {
             return fuzzed_file->m_fuzzed_data_provider.ConsumeBool() ? 0 : -1;
         }
         fuzzed_file->m_offset += random_bytes.size();
@@ -343,7 +343,7 @@ public:
     {
         FuzzedFileProvider* fuzzed_file = (FuzzedFileProvider*)cookie;
         const ssize_t n = fuzzed_file->m_fuzzed_data_provider.ConsumeIntegralInRange<ssize_t>(0, size);
-        if (AdditionOverflow(fuzzed_file->m_offset, n)) {
+        if (AdditionOverflow(fuzzed_file->m_offset, (int64_t)n)) {
             return fuzzed_file->m_fuzzed_data_provider.ConsumeBool() ? 0 : -1;
         }
         fuzzed_file->m_offset += n;

@practicalswift Thanks. I'll throw a good first issue tag on here, and if someone wants to test and pick this up as their first change they can. Otherwise I'll test and PR it shortly.

Hi, @fanquake , I would like to give it a shot and see if I could get it fixed.

How do I reproduce this issue please? Is it simply a make check on macOS? Thanks!

@freenancial you can test by doing a fuzz build for macOS at commit 476436b2dec254bb988f8c7a6cbec1d7bb7cecfd versus with your proposed fix. See https://github.com/bitcoin/bitcoin/blob/master/doc/fuzzing.md for more information on building for fuzzing. Personally, I build for fuzzing with ./autogen.sh ; ./configure --enable-c++17 --enable-fuzz --with-sanitizers=address,fuzzer,undefined CC=clang CXX=clang++ && make clean ; make -j5. If you find the build docs here confusing, you can also try following this build tutorial I wrote: https://jonatack.github.io/articles/how-to-compile-bitcoin-core-and-run-the-tests