checker: handle alias container str uses

Author: medvednikov

vlib/v/checker/used_features.v

@@ -472,6 +472,15 @@ fn (c &Checker) alias_parent_concrete_types(info ast.Alias) []ast.Type {
 		ast.GenericInst {
 			return parent_sym.info.concrete_types.clone()
 		}
+		ast.Array {
+			return [parent_sym.info.elem_type]
+		}
+		ast.ArrayFixed {
+			return [parent_sym.info.elem_type]
+		}
+		ast.Map {
+			return [parent_sym.info.key_type, parent_sym.info.value_type]
+		}
 		ast.Alias {
 			return c.alias_parent_concrete_types(parent_sym.info)
 		}

vlib/v/gen/c/auto_str_methods.v

@@ -718,6 +718,15 @@ fn (mut g Gen) alias_parent_concrete_types(info ast.Alias) []ast.Type {
 		ast.GenericInst {
 			return parent_sym.info.concrete_types.clone()
 		}
+		ast.Array {
+			return [parent_sym.info.elem_type]
+		}
+		ast.ArrayFixed {
+			return [parent_sym.info.elem_type]
+		}
+		ast.Map {
+			return [parent_sym.info.key_type, parent_sym.info.value_type]
+		}
 		ast.Alias {
 			return g.alias_parent_concrete_types(parent_sym.info)
 		}

vlib/v/markused/walker.v

@@ -962,13 +962,15 @@ fn (mut w Walker) expr(node_ ast.Expr) {
 					w.mark_by_type(w.table.find_or_register_array(sym.info.key_type))
 				}
 			} else if !node.is_method && node.args.len == 1
-				&& node.name in ['println', 'print', 'eprint', 'eprintln'] {
+				&& node.name in ['println', 'print', 'eprint', 'eprintln', 'panic'] {
 				if f := w.table.find_fn(node.name) {
 					if f.mod == 'builtin' {
 						if node.args[0].typ != ast.string_type {
 							w.uses_str[node.args[0].typ] = true
+							w.mark_generic_str_method_for_type(node.args[0].typ)
 						}
-						if w.pref.gc_mode == .boehm_leak && (node.args[0].typ != ast.string_type
+						if node.name != 'panic' && w.pref.gc_mode == .boehm_leak
+							&& (node.args[0].typ != ast.string_type
 							|| node.args[0].expr !in [ast.Ident, ast.StringLiteral, ast.SelectorExpr, ast.ComptimeSelector]) {
 							w.uses_free[ast.string_type] = true
 						}

vlib/v/tests/generics/generic_auto_str_nested_generic_field_test.v

@@ -18,10 +18,16 @@ struct InterpBox[T] {
 
 type InterpIntBox = InterpBox[int]
 
+type Ints = []int
+
 struct StructuredContainer[T] {
 	box Box[[]T]
 }
 
+struct IntsContainer {
+	values Ints
+}
+
 struct AssertNode[T] {
 	val T
 }
@@ -50,6 +56,10 @@ fn (box InterpIntBox) str[T]() string {
 	return 'interp alias ${box.val}'
 }
 
+fn (values Ints) str[T]() string {
+	return 'ints ${values[0]}'
+}
+
 fn (list AssertList[T]) str() string {
 	return 'assert list'
 }
@@ -58,6 +68,12 @@ fn (bad SkippedBad[[]T]) str() string {
 	return bad.val[0].len.str()
 }
 
+fn maybe_panic_auto_str_container(should_panic bool) {
+	if should_panic {
+		panic(MyContainer[string]{})
+	}
+}
+
 fn test_auto_str_registers_nested_generic_field_str_method() {
 	c := MyContainer[string]{}
 	assert '${c}' == 'MyContainer[string]{
@@ -81,6 +97,18 @@ fn test_interpolation_registers_exact_generic_alias_str_method() {
 	assert '${box}' == 'interp alias 987'
 }
 
+fn test_auto_str_registers_container_alias_parent_str_method() {
+	c := IntsContainer{
+		values: Ints([654])
+	}
+	assert '${c}'.contains('values: ints 654')
+}
+
+fn test_interpolation_registers_container_alias_parent_str_method() {
+	values := Ints([321])
+	assert '${values}' == 'ints 321'
+}
+
 fn test_dump_registers_exact_generic_alias_str_method() {
 	box := InterpIntBox{
 		val: 654
@@ -89,6 +117,11 @@ fn test_dump_registers_exact_generic_alias_str_method() {
 	assert dumped.val == 654
 }
 
+fn test_panic_marks_auto_str_dependencies_under_skip_unused() {
+	maybe_panic_auto_str_container(false)
+	assert true
+}
+
 fn test_assert_auto_str_registers_nested_generic_field_str_method() {
 	left := AssertContainer[string]{
 		list: AssertList[AssertNode[string]]{