CDRIVER-5789 Workaround missing __cdecl in mongoc_log_func_t

Author: eramongodb

src/mongocxx/lib/mongocxx/v_noabi/mongocxx/private/libmongoc.cpp

@@ -33,6 +33,9 @@ namespace libmongoc {
 #include "libmongoc_symbols.hh"
 #undef MONGOCXX_LIBMONGOC_SYMBOL
 
+mongocxx::test_util::mock<log_set_handler_cdecl_t>& log_set_handler =
+    *new test_util::mock<log_set_handler_cdecl_t>(mongoc_log_set_handler);
+
 #if defined(__GNUC__) && (__GNUC__ >= 6) && !defined(__clang__)
 #pragma GCC diagnostic pop
 #endif

src/mongocxx/lib/mongocxx/v_noabi/mongocxx/private/libmongoc.hh

@@ -59,6 +59,17 @@ namespace libmongoc {
 #include "libmongoc_symbols.hh"
 #undef MONGOCXX_LIBMONGOC_SYMBOL
 
+// CDRIVER-5678
+using log_func_cdecl_t = void(MONGOCXX_ABI_CDECL*)(mongoc_log_level_t log_level,
+                                                   const char* log_domain,
+                                                   const char* message,
+                                                   void* user_data);
+using log_set_handler_cdecl_t = void(MONGOCXX_ABI_CDECL*)(log_func_cdecl_t log_func,
+                                                          void* user_data);
+
+extern MONGOCXX_ABI_EXPORT_TESTING mongocxx::test_util::mock<log_set_handler_cdecl_t>&
+    log_set_handler;
+
 #if defined(__GNUC__) && (__GNUC__ >= 6) && !defined(__clang__)
 #pragma GCC diagnostic pop
 #endif
@@ -69,6 +80,9 @@ namespace libmongoc {
 #include "libmongoc_symbols.hh"
 #undef MONGOCXX_LIBMONGOC_SYMBOL
 
+// CDRIVER-5678
+constexpr auto log_set_handler = mongoc_log_set_handler;
+
 #endif
 
 }  // namespace libmongoc

src/mongocxx/lib/mongocxx/v_noabi/mongocxx/private/libmongoc_symbols.hh

@@ -278,7 +278,7 @@ MONGOCXX_LIBMONGOC_SYMBOL(index_opt_geo_init)
 MONGOCXX_LIBMONGOC_SYMBOL(index_opt_init)
 MONGOCXX_LIBMONGOC_SYMBOL(index_opt_wt_init)
 MONGOCXX_LIBMONGOC_SYMBOL(init)
-MONGOCXX_LIBMONGOC_SYMBOL(log_set_handler)
+// MONGOCXX_LIBMONGOC_SYMBOL(log_set_handler)  // CDRIVER-5678: not __cdecl.
 MONGOCXX_LIBMONGOC_SYMBOL(read_concern_copy)
 MONGOCXX_LIBMONGOC_SYMBOL(read_concern_destroy)
 MONGOCXX_LIBMONGOC_SYMBOL(read_concern_get_level)