checker, cgen: fix the static from_string method of Enum across mods(fix #20050) (#20068)

vlib/v/checker/fn.v

@@ -883,14 +883,42 @@ fn (mut c Checker) fn_call(mut node ast.CallExpr, mut continue_check &bool) ast.
 				}
 			}
 		}
-		if fn_name.ends_with('from_string') {
+	}
+	// Enum.from_string, `mod.Enum.from_string('item')`, `Enum.from_string('item')`
+	if !found && fn_name.ends_with('__static__from_string') {
 		enum_name := fn_name.all_before('__static__')
-			full_enum_name := if !enum_name.contains('.') {
+		mut full_enum_name := if !enum_name.contains('.') {
 			c.mod + '.' + enum_name
 		} else {
 			enum_name
 		}
-			idx := c.table.type_idxs[full_enum_name]
+		mut idx := c.table.type_idxs[full_enum_name]
+		if idx > 0 {
+			// is from another mod.
+			if enum_name.contains('.') {
+				if !c.check_type_and_visibility(full_enum_name, idx, .enum_, node.pos) {
+					return ast.void_type
+				}
+			}
+		} else if !enum_name.contains('.') {
+			// find from another mods.
+			for import_sym in c.file.imports {
+				full_enum_name = '${import_sym.mod}.${enum_name}'
+				idx = c.table.type_idxs[full_enum_name]
+				if idx < 1 {
+					continue
+				}
+				if !c.check_type_and_visibility(full_enum_name, idx, .enum_, node.pos) {
+					return ast.void_type
+				}
+				break
+			}
+		}
+		if idx == 0 {
+			c.error('unknown enum `${enum_name}`', node.pos)
+			return ast.void_type
+		}
+
 		ret_typ := ast.Type(idx).set_flag(.option)
 		if node.args.len != 1 {
 			c.error('expected 1 argument, but got ${node.args.len}', node.pos)
@@ -904,7 +932,6 @@ fn (mut c Checker) fn_call(mut node ast.CallExpr, mut continue_check &bool) ast.
 		node.return_type = ret_typ
 		return ret_typ
 	}
-	}
 	mut is_native_builtin := false
 	if !found && c.pref.backend == .native {
 		if fn_name in ast.native_builtins {
@@ -1622,6 +1649,24 @@ fn (mut c Checker) cast_to_fixed_array_ret(typ ast.Type, sym ast.TypeSymbol) ast
 	return typ
 }
 
+// checks if a type from another module is is expected and visible(`is_pub`)
+fn (mut c Checker) check_type_and_visibility(name string, type_idx int, expected_kind &ast.Kind, pos &token.Pos) bool {
+	mut sym := c.table.sym_by_idx(type_idx)
+	if sym.kind == .alias {
+		parent_type := (sym.info as ast.Alias).parent_type
+		sym = c.table.sym(parent_type)
+	}
+	if sym.kind != expected_kind {
+		c.error('expected ${expected_kind}, but `${name}` is ${sym.kind}', pos)
+		return false
+	}
+	if !sym.is_pub {
+		c.error('module `${sym.mod}` type `${sym.name}` is private', pos)
+		return false
+	}
+	return true
+}
+
 fn (mut c Checker) method_call(mut node ast.CallExpr) ast.Type {
 	left_type := c.expr(mut node.left)
 	if left_type == ast.void_type {

vlib/v/checker/tests/modules/enum_from_string_in_different_mods.out

@@ -0,0 +1,40 @@
+vlib/v/checker/tests/modules/enum_from_string_in_different_mods/src/main.v:3:8: warning: module 'mod' is imported but never used
+    1 | module main
+    2 |
+    3 | import mod { MyEnum, MyStruct }
+      |        ~~~
+    4 |
+    5 | fn main() {
+vlib/v/checker/tests/modules/enum_from_string_in_different_mods/src/main.v:3:14: error: module `mod` type `MyEnum` is private
+    1 | module main
+    2 |
+    3 | import mod { MyEnum, MyStruct }
+      |              ~~~~~~
+    4 |
+    5 | fn main() {
+vlib/v/checker/tests/modules/enum_from_string_in_different_mods/src/main.v:6:7: error: module `mod` type `mod.MyEnum` is private
+    4 |
+    5 | fn main() {
+    6 |     _ := MyEnum.from_string('item1')
+      |          ~~~~~~~~~~~~~~~~~~~~~~~~~~~
+    7 |     _ := MyStruct.from_string('item1')
+    8 | }
+vlib/v/checker/tests/modules/enum_from_string_in_different_mods/src/main.v:6:4: error: assignment mismatch: 1 variable(s) but `MyEnum.from_string()` returns 0 value(s)
+    4 |
+    5 | fn main() {
+    6 |     _ := MyEnum.from_string('item1')
+      |       ~~
+    7 |     _ := MyStruct.from_string('item1')
+    8 | }
+vlib/v/checker/tests/modules/enum_from_string_in_different_mods/src/main.v:7:7: error: expected enum, but `mod.MyStruct` is struct
+    5 | fn main() {
+    6 |     _ := MyEnum.from_string('item1')
+    7 |     _ := MyStruct.from_string('item1')
+      |          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+    8 | }
+vlib/v/checker/tests/modules/enum_from_string_in_different_mods/src/main.v:7:4: error: assignment mismatch: 1 variable(s) but `MyStruct.from_string()` returns 0 value(s)
+    5 | fn main() {
+    6 |     _ := MyEnum.from_string('item1')
+    7 |     _ := MyStruct.from_string('item1')
+      |       ~~
+    8 | }

vlib/v/checker/tests/modules/enum_from_string_in_different_mods/src/main.v

@@ -0,0 +1,8 @@
+module main
+
+import mod { MyEnum, MyStruct }
+
+fn main() {
+	_ := MyEnum.from_string('item1')
+	_ := MyStruct.from_string('item1')
+}

vlib/v/checker/tests/modules/enum_from_string_in_different_mods/src/mod.v

@@ -0,0 +1,8 @@
+module mod
+
+enum MyEnum {
+	item1
+	item2
+}
+
+pub struct MyStruct {}

vlib/v/checker/tests/modules/enum_from_string_in_different_mods/v.mod

@@ -0,0 +1 @@
+1

vlib/v/gen/c/auto_str_methods.v

@@ -1150,12 +1150,22 @@ fn should_use_indent_func(kind ast.Kind) bool {
 
 fn (mut g Gen) gen_enum_static_from_string(fn_name string) {
 	enum_name := fn_name.all_before('__static__')
-	mod_enum_name := if !enum_name.contains('.') {
+	mut mod_enum_name := if !enum_name.contains('.') {
 		g.cur_mod.name + '.' + enum_name
 	} else {
 		enum_name
 	}
-	idx := g.table.type_idxs[mod_enum_name]
+	mut idx := g.table.type_idxs[mod_enum_name]
+	if idx == 0 && (enum_name.contains('.') || enum_name[0].is_capital()) {
+		// no cur mod, find from another mods.
+		for import_sym in g.file.imports {
+			mod_enum_name = '${import_sym.mod}.${enum_name}'
+			idx = g.table.type_idxs[mod_enum_name]
+			if idx > 0 {
+				break
+			}
+		}
+	}
 	enum_typ := ast.Type(idx)
 	enum_styp := g.typ(enum_typ)
 	option_enum_typ := ast.Type(idx).set_flag(.option)
@@ -1164,9 +1174,10 @@ fn (mut g Gen) gen_enum_static_from_string(fn_name string) {
 	enum_field_vals := g.table.get_enum_field_vals(mod_enum_name)
 
 	mut fn_builder := strings.new_builder(512)
-	g.definitions.writeln('static ${option_enum_styp} ${fn_name}(string name); // auto')
+	fn_name_no_dots := util.no_dots(fn_name)
+	g.definitions.writeln('static ${option_enum_styp} ${fn_name_no_dots}(string name); // auto')
 
-	fn_builder.writeln('static ${option_enum_styp} ${fn_name}(string name) {')
+	fn_builder.writeln('static ${option_enum_styp} ${fn_name_no_dots}(string name) {')
 	fn_builder.writeln('\t${option_enum_styp} t1;')
 	fn_builder.writeln('\tbool exists = false;')
 	fn_builder.writeln('\tint inx = 0;')

vlib/v/gen/c/fn.v

@@ -1803,7 +1803,7 @@ fn (mut g Gen) fn_call(node ast.CallExpr) {
 				g.gen_enum_static_from_string(node.name)
 				g.str_fn_names << node.name
 			}
-			g.write('${node.name}(')
+			g.write('${util.no_dots(node.name)}(')
 			g.call_args(node)
 			g.write(')')
 		} else {

vlib/v/tests/modules/enum_from_string_in_different_mods/src/main_test.v

@@ -0,0 +1,10 @@
+module main
+
+import mod { MyEnum }
+
+fn test_main() {
+	item1 := MyEnum.from_string('item1')?
+	assert item1 == MyEnum.item1
+	item2 := mod.MyEnum.from_string('item2')?
+	assert item2 == MyEnum.item2
+}

vlib/v/tests/modules/enum_from_string_in_different_mods/src/mod/mod.v

@@ -0,0 +1,6 @@
+module mod
+
+pub enum MyEnum {
+	item1
+	item2
+}

vlib/v/tests/modules/enum_from_string_in_different_mods/v.mod

@@ -0,0 +1 @@
+1