nitg & lib: intro `Finalizable` to be called when an object is freed

[nit.git] / src / abstract_compiler.nit

diff --git a/src/abstract_compiler.nit b/src/abstract_compiler.nit
index 0ff1e22..d83d574 100644 (file)
--- a/src/abstract_compiler.nit
+++ b/src/abstract_compiler.nit
@@ -613,6 +613,25 @@ extern void nitni_global_ref_decr( struct nitni_ref *ref );
 """
        end
 
+       fun compile_finalizer_function
+       do
+               var finalizable_type = mainmodule.finalizable_type
+               if finalizable_type == null then return
+
+               var finalize_meth = mainmodule.try_get_primitive_method("finalize", finalizable_type.mclass)
+
+               if finalize_meth == null then
+                       modelbuilder.toolcontext.error(null, "The `Finalizable` class doesn't declare the `finalize` method.")
+                       return
+               end
+
+               var v = self.new_visitor
+               v.add_decl "void gc_finalize (void *obj, void *client_data) \{"
+               var recv = v.new_expr("obj", finalizable_type)
+               v.send(finalize_meth, [recv])
+               v.add "\}"
+       end
+
        # Generate the main C function.
        # This function:
        #       * allocate the Sys object if it exists
@@ -1259,6 +1278,17 @@ abstract class AbstractCompilerVisitor
        # Generate a alloc-instance + init-attributes
        fun init_instance(mtype: MClassType): RuntimeVariable is abstract
 
+       # Set a GC finalizer on `recv`, only if `recv` isa Finalizable
+       fun set_finalizer(recv: RuntimeVariable)
+       do
+               var mtype = recv.mtype
+               var finalizable_type = compiler.mainmodule.finalizable_type
+               if finalizable_type != null and not mtype.need_anchor and
+                  mtype.is_subtype(compiler.mainmodule, null, finalizable_type) then
+                       add "gc_register_finalizer({recv});"
+               end
+       end
+
        # Generate an integer value
        fun int_instance(value: Int): RuntimeVariable
        do