cgen: fix autogen free method for struct with shared field (#13469)

vlib/v/gen/c/auto_free_methods.v

@@ -5,7 +5,8 @@ module c
 import v.ast
 import strings
 
-fn (mut g Gen) gen_free_method_for_type(typ ast.Type) string {
+fn (mut g Gen) get_free_method(typ ast.Type) string {
+	g.autofree_methods[typ] = true
 	styp := g.typ(typ).replace('*', '')
 	mut sym := g.table.sym(g.unwrap_generic(typ))
 	mut fn_name := styp_to_free_fn_name(styp)
@@ -15,6 +16,32 @@ fn (mut g Gen) gen_free_method_for_type(typ ast.Type) string {
 		}
 	}
 
+	if sym.has_method_with_generic_parent('free') {
+		return fn_name
+	}
+	return fn_name
+}
+
+fn (mut g Gen) gen_free_methods() {
+	for typ, _ in g.autofree_methods {
+		g.gen_free_method(typ)
+	}
+}
+
+fn (mut g Gen) gen_free_method(typ ast.Type) string {
+	styp := g.typ(typ).replace('*', '')
+	mut sym := g.table.sym(g.unwrap_generic(typ))
+	mut fn_name := styp_to_free_fn_name(styp)
+	if typ in g.generated_free_methods {
+		return fn_name
+	}
+	g.generated_free_methods[typ] = true
+	if mut sym.info is ast.Alias {
+		if sym.info.is_import {
+			sym = g.table.sym(sym.info.parent_type)
+		}
+	}
+
 	if sym.has_method_with_generic_parent('free') {
 		return fn_name
 	}
@@ -50,13 +77,21 @@ fn (mut g Gen) gen_free_for_struct(info ast.Struct, styp string, fn_name string)
 			continue
 		}
 		mut field_styp := g.typ(field.typ).replace('*', '')
+		is_shared := field_styp.starts_with('__shared')
+		if is_shared {
+			field_styp = field_styp.all_after('__shared__')
+		}
 		field_styp_fn_name := if sym.has_method('free') {
 			'${field_styp}_free'
 		} else {
-			g.gen_free_method_for_type(field.typ)
+			g.gen_free_method(field.typ)
 		}
+		if is_shared {
+			fn_builder.writeln('\t${field_styp_fn_name}(&(it->$field.name->val));')
+		} else {
 			fn_builder.writeln('\t${field_styp_fn_name}(&(it->$field.name));')
 		}
+	}
 	fn_builder.writeln('}')
 }
 
@@ -76,7 +111,7 @@ fn (mut g Gen) gen_free_for_array(info ast.Array, styp string, fn_name string) {
 		elem_styp_fn_name := if sym.has_method('free') {
 			'${elem_styp}_free'
 		} else {
-			g.gen_free_method_for_type(info.elem_type)
+			g.gen_free_method(info.elem_type)
 		}
 		fn_builder.writeln('\t\t${elem_styp_fn_name}(&((($elem_styp*)it->data)[i]));')
 		fn_builder.writeln('\t}')

vlib/v/gen/c/cgen.v

@@ -200,6 +200,8 @@ mut:
 	cur_concrete_types     []ast.Type  // do not use table.cur_concrete_types because table is global, so should not be accessed by different threads
 	cur_fn                 &ast.FnDecl = 0 // same here
 	cur_lock               ast.LockExpr
+	autofree_methods       map[int]bool
+	generated_free_methods map[int]bool
 }
 
 pub fn gen(files []&ast.File, table &ast.Table, pref &pref.Preferences) string {
@@ -346,6 +348,9 @@ pub fn gen(files []&ast.File, table &ast.Table, pref &pref.Preferences) string {
 			global_g.json_types << g.json_types
 			global_g.hotcode_fn_names << g.hotcode_fn_names
 			unsafe { g.free_builders() }
+			for k, v in g.autofree_methods {
+				global_g.autofree_methods[k] = v
+			}
 		}
 	} else {
 		for file in files {
@@ -374,6 +379,7 @@ pub fn gen(files []&ast.File, table &ast.Table, pref &pref.Preferences) string {
 	global_g.gen_array_contains_methods()
 	global_g.gen_array_index_methods()
 	global_g.gen_equality_fns()
+	global_g.gen_free_methods()
 	global_g.timers.show('cgen unification')
 
 	mut g := global_g

vlib/v/gen/c/fn.v

@@ -911,7 +911,7 @@ fn (mut g Gen) method_call(node ast.CallExpr) {
 		if rec_type.has_flag(.shared_f) {
 			rec_type = rec_type.clear_flag(.shared_f).set_nr_muls(0)
 		}
-		g.gen_free_method_for_type(rec_type)
+		g.get_free_method(rec_type)
 	}
 	mut has_cast := false
 	if left_sym.kind == .map && node.name in ['clone', 'move'] {

vlib/v/tests/autogen_free_test.v

@@ -1,6 +1,6 @@
 struct Info {
 	name  string
-	notes []string
+	notes shared []string
 	maps  map[int]int
 	info  []SubInfo
 }
@@ -15,3 +15,9 @@ fn test_autogen_free() {
 	info.free()
 	assert true
 }
+
+fn test_multiple_autogen_free() {
+	info := &Info{}
+	info.free()
+	assert true
+}