add `PK_NO_EXPORT_C_API`

CMakeLists.txt

@@ -43,6 +43,11 @@ if(PK_ENABLE_OS)
     add_definitions(-DPK_ENABLE_OS=1)
 endif()
 
+option(PK_NO_EXPORT_C_API "" OFF)
+if(PK_NO_EXPORT_C_API)
+    add_definitions(-DPK_NO_EXPORT_C_API)
+endif()
+
 # PK_IS_MAIN determines whether the project is being used from root
 # or if it is added as a dependency (through add_subdirectory for example).
 if ("${CMAKE_SOURCE_DIR}" STREQUAL "${CMAKE_CURRENT_SOURCE_DIR}")

src/pocketpy_c.cpp

@@ -1,3 +1,5 @@
+#ifndef PK_NO_EXPORT_C_API
+
 #include "pocketpy.h"
 #include "pocketpy_c.h"
 
@@ -574,4 +576,6 @@ bool pkpy_repl_input(void* r, const char* line){
 
 void pkpy_delete_repl(void* repl){
     delete (REPL*)repl;
-}
+}
+
+#endif // PK_NO_EXPORT_C_API