try to force inclusion with msvc and gcc as well

Author: evertlammerts

CMakeLists.txt

@@ -105,6 +105,9 @@ elseif(UNIX AND NOT APPLE)
   target_link_options(
     _duckdb PRIVATE "LINKER:--export-dynamic-symbol=duckdb_adbc_init"
     "LINKER:--export-dynamic-symbol=PyInit__duckdb")
+elseif(WIN32)
+  target_link_options(_duckdb PRIVATE "/EXPORT:duckdb_adbc_init"
+                      "/EXPORT:PyInit__duckdb")
 endif()
 
 # ────────────────────────────────────────────

src/duckdb_py/duckdb_python.cpp

@@ -20,6 +20,7 @@
 #include "duckdb_python/pybind11/conversions/python_udf_type_enum.hpp"
 #include "duckdb_python/pybind11/conversions/python_csv_line_terminator_enum.hpp"
 #include "duckdb/common/enums/statement_type.hpp"
+#include "duckdb/common/adbc/adbc-init.hpp"
 
 #include "duckdb.hpp"
 
@@ -1007,14 +1008,34 @@ static void RegisterExpectedResultType(py::handle &m) {
 	expected_return_type.export_values();
 }
 
-/**
- * Fwd declaration of duckdb_adbc_init (the entrypoint of our ADBC driver) that must be exported.
- */
-extern "C" PYBIND11_EXPORT void duckdb_adbc_init(void);
+// ######################################################################
+// Symbol exports
+//
+// We want to limit the symbols we export to only the absolute minimum.
+// This means we compile with -fvisibility=hidden to hide all symbols,
+// and then explicitly export only the symbols we want.
+//
+// Right now we export two symbols only:
+// - duckdb_adbc_init: the entrypoint for our ADBC driver
+// - PyInit__duckdb: the entrypoint for the python extension
+//
+// All symbols that need exporting must be added to both the list below
+// AND to CMakeLists.txt.
+extern "C" {
+PYBIND11_EXPORT void *_force_symbol_inclusion() {
+	static void *symbols[] = {
+	    // Add functions to export here
+	    (void *)&duckdb_adbc_init,
+	};
+	return symbols;
+}
+};
 
 PYBIND11_MODULE(DUCKDB_PYTHON_LIB_NAME, m) { // NOLINT
-	// Take address to force duckdb_adbc_init symbol inclusion
-	(void)&duckdb_adbc_init;
+	// DO NOT REMOVE: the below forces that we include all symbols we want to export
+	volatile auto *keep_alive = _force_symbol_inclusion();
+	(void)keep_alive;
+	// END
 
 	py::enum_<duckdb::ExplainType>(m, "ExplainType")
 	    .value("STANDARD", duckdb::ExplainType::EXPLAIN_STANDARD)