question about understand interp generate transform code

[srxqds]

mono interp transfer il code to opcode in generate function:

runtime/src/mono/mono/mini/interp/transform.c

Line 9424 in 1e5bae2

generate (MonoMethod *method, MonoMethodHeader *header, InterpMethod *rtm, MonoGenericContext *generic_context, MonoError *error)

theTransformData allocate stack at below：

runtime/src/mono/mono/mini/interp/transform.c

Lines 9501 to 9508 in 1e5bae2

	td->stack = (StackInfo*)g_malloc0 ((header->max_stack + 1) * sizeof (td->stack [0]));
	td->stack_capacity = header->max_stack + 1;
	td->sp = td->stack;
	td->max_stack_height = 0;
	td->line_numbers = g_array_new (FALSE, TRUE, sizeof (MonoDebugLineNumberEntry));
	td->current_il_offset = -1;
	if (!generate_code (td, method, header, generic_context, error))

and will store the custom data in data_items:

runtime/src/mono/mono/mini/interp/transform.c

Line 9476 in 1e5bae2

rtm->data_items = td->data_items;

at end of the function generate, I found the opcode or data_items will copy to InterpMethod in below code:

runtime/src/mono/mono/mini/interp/transform.c

Lines 9584 to 9614 in 1e5bae2

	rtm->clauses = (MonoExceptionClause*)imethod_alloc0 (td, header->num_clauses * sizeof (MonoExceptionClause));
	memcpy (rtm->clauses, header->clauses, header->num_clauses * sizeof(MonoExceptionClause));
	rtm->code = (gushort*)td->new_code;
	rtm->init_locals = header->init_locals;
	rtm->num_clauses = header->num_clauses;
	for (guint i = 0; i < header->num_clauses; i++) {
	MonoExceptionClause *c = rtm->clauses + i;
	int end_off = c->try_offset + c->try_len;
	c->try_offset = get_native_offset (td, c->try_offset);
	c->try_len = get_native_offset (td, end_off) - c->try_offset;
	g_assert ((c->try_offset + c->try_len) <= code_len_u16);
	end_off = c->handler_offset + c->handler_len;
	c->handler_offset = get_native_offset (td, c->handler_offset);
	c->handler_len = get_native_offset (td, end_off) - c->handler_offset;
	g_assert (c->handler_len >= 0 && (c->handler_offset + c->handler_len) <= code_len_u16);
	if (c->flags & MONO_EXCEPTION_CLAUSE_FILTER)
	c->data.filter_offset = get_native_offset (td, c->data.filter_offset);
	}
	// When optimized (using the var offset allocator), total_locals_size contains also the param area.
	// When unoptimized, the param area is stored in the same order, within the IL execution stack.
	g_assert (!td->optimized || !td->max_stack_size);
	rtm->alloca_size = td->total_locals_size + td->max_stack_size;
	g_assert ((rtm->alloca_size % MINT_STACK_ALIGNMENT) == 0);
	rtm->locals_size = td->param_area_offset;
	// FIXME: Can't allocate this using imethod_alloc0 as its registered with mono_interp_register_imethod_data_items ()
	//rtm->data_items = (gpointer*)imethod_alloc0 (td, td->n_data_items * sizeof (td->data_items [0]));
	rtm->data_items = (gpointer*)mono_mem_manager_alloc0 (td->mem_manager, td->n_data_items * sizeof (td->data_items [0]));
	memcpy (rtm->data_items, td->data_items, td->n_data_items * sizeof (td->data_items [0]));
	mono_interp_register_imethod_data_items (rtm->data_items, td->imethod_items);
	rtm->patchpoint_data = td->patchpoint_data;

and copy InterpInst(allocated in interp_add_ins) at generate_compacted_code:

runtime/src/mono/mono/mini/interp/transform.c

Lines 9286 to 9289 in 1e5bae2

	size = interp_compute_native_offset_estimates (td, TRUE);
	// Generate the compacted stream of instructions
	td->new_code = ip = (guint16*)imethod_alloc0 (td, size * sizeof (guint16));

but I could not found the td->stack been copy before being freed at :

runtime/src/mono/mono/mini/interp/transform.c

Lines 9675 to 9688 in 1e5bae2

	g_free (td->stack);
	g_free (td->vars);
	g_free (td->renamable_vars);
	g_free (td->renamed_fixed_vars);
	g_free (td->local_ref_count);
	dn_simdhash_free (td->data_hash);
	#ifdef ENABLE_EXPERIMENT_TIERED
	dn_simdhash_free (td->patchsite_hash);
	#endif
	g_ptr_array_free (td->seq_points, TRUE);
	if (td->line_numbers)
	g_array_free (td->line_numbers, TRUE);
	g_slist_free (td->imethod_items);
	mono_mempool_destroy (td->mempool);

why not these data not restore to InterpMethod or maybe other place restore it?

could you help me? @BrzVlad

[BrzVlad]

td->stack and InterpInst* is information that is used only during compilation time. The list of InterpInst is iterated as the last step of compilation and in generate_compacted_code this list is compacted into an array of guint16 that represents the final generated code.