build: Attempt #1

configure.ac

@@ -1779,6 +1779,20 @@ if test x$build_bitcoin_wallet$build_bitcoin_cli$build_bitcoin_tx$build_bitcoin_
   AC_MSG_ERROR([No targets! Please specify at least one of: --with-utils --with-libs --with-daemon --with-gui --enable-bench or --enable-tests])
 fi
 
+if test x$enable_fuzz_binary = xyes; then
+  AC_LINK_IFELSE(
+    [AC_LANG_PROGRAM([[
+    #include <stdbool.h>
+    #include <stdint.h>
+    #if defined(__has_builtin) && __has_builtin(__builtin_mul_overflow)
+    bool test(int x, int y, int* prod) { return __builtin_mul_overflow(x, y, prod); }
+    #endif
+    ]])],
+    [FUZZ_BINARY_LDFLAGS="empty"],
+    [FUZZ_BINARY_LDFLAGS="--rtlib=compiler-rt -lgcc_s"]
+  )
+fi
+
 AM_CONDITIONAL([TARGET_DARWIN], [test x$TARGET_OS = xdarwin])
 AM_CONDITIONAL([BUILD_DARWIN], [test x$BUILD_OS = xdarwin])
 AM_CONDITIONAL([TARGET_LINUX], [test x$TARGET_OS = xlinux])
@@ -1977,3 +1991,5 @@ echo "  CXXFLAGS        = $DEBUG_CXXFLAGS $HARDENED_CXXFLAGS $WARN_CXXFLAGS $NOW
 echo "  LDFLAGS         = $PTHREAD_LIBS $HARDENED_LDFLAGS $GPROF_LDFLAGS $LDFLAGS"
 echo "  ARFLAGS         = $ARFLAGS"
 echo
+echo "  FUZZ_BINARY_LDFLAGS = $FUZZ_BINARY_LDFLAGS"
+echo