checker: disallow module name duplicates in local names (#18118)

Author: ttytm

examples/sokol/06_obj_viewer/modules/obj/obj.v

@@ -138,7 +138,7 @@ fn (mut m ObjPart) parse_floats(row string, start_index int) m4.Vec4 {
 }
 
 // read and manage all the faes from an .obj file data
-fn (mut p Part) parse_faces(row string, start_index int, obj ObjPart) {
+fn (mut p Part) parse_faces(row string, start_index int, obj_part ObjPart) {
 	mut i := start_index + 1
 	mut res := [][3]int{}
 	mut v := 0
@@ -171,15 +171,15 @@ fn (mut p Part) parse_faces(row string, start_index int, obj ObjPart) {
 		// manage negative indexes
 		// NOTE: not well suporeted now
 		if v < 0 {
-			// println("${obj.v.len} ${obj.v.len-c}")
-			v = obj.v.len - v + 1
+			// println("${obj_part.v.len} ${obj_part.v.len-c}")
+			v = obj_part.v.len - v + 1
 			// exit(0)
 		}
 		if n < 0 {
-			n = obj.vn.len - n + 1
+			n = obj_part.vn.len - n + 1
 		}
 		if t < 0 {
-			t = obj.vt.len - t + 1
+			t = obj_part.vt.len - t + 1
 		}
 		res << [v - 1, n - 1, t - 1]!
 	}

vlib/arrays/arrays.v

@@ -128,23 +128,23 @@ pub fn append[T](a []T, b []T) []T {
 //
 // NOTE: An error will be generated if the type annotation is omitted.
 // Example: arrays.group[int]([1, 2, 3], [4, 5, 6]) // => [[1, 4], [2, 5], [3, 6]]
-pub fn group[T](arrays ...[]T) [][]T {
-	mut length := if arrays.len > 0 { arrays[0].len } else { 0 }
+pub fn group[T](arrs ...[]T) [][]T {
+	mut length := if arrs.len > 0 { arrs[0].len } else { 0 }
 	// calculate length of output by finding shortest input array
-	for ndx in 1 .. arrays.len {
-		if arrays[ndx].len < length {
-			length = arrays[ndx].len
+	for ndx in 1 .. arrs.len {
+		if arrs[ndx].len < length {
+			length = arrs[ndx].len
 		}
 	}
 
 	if length > 0 {
 		mut arr := [][]T{cap: length}
 		// append all combined arrays into the resultant array
 		for ndx in 0 .. length {
-			mut grouped := []T{cap: arrays.len}
+			mut grouped := []T{cap: arrs.len}
 			// combine each list item for the ndx position into one array
-			for arr_ndx in 0 .. arrays.len {
-				grouped << arrays[arr_ndx][ndx]
+			for arr_ndx in 0 .. arrs.len {
+				grouped << arrs[arr_ndx][ndx]
 			}
 			arr << grouped
 		}

vlib/json/json_primitives.v

@@ -252,15 +252,15 @@ fn json_parse(s string) &C.cJSON {
 
 // json_string := json_print(encode_User(user))
 [markused]
-fn json_print(json &C.cJSON) string {
-	s := C.cJSON_PrintUnformatted(json)
+fn json_print(data &C.cJSON) string {
+	s := C.cJSON_PrintUnformatted(data)
 	r := unsafe { tos_clone(&u8(s)) }
 	C.cJSON_free(s)
 	return r
 }
 
-fn json_print_pretty(json &C.cJSON) string {
-	s := C.cJSON_Print(json)
+fn json_print_pretty(data &C.cJSON) string {
+	s := C.cJSON_Print(data)
 	r := unsafe { tos_clone(&u8(s)) }
 	C.cJSON_free(s)
 	return r

vlib/orm/orm.v

@@ -350,25 +350,25 @@ pub fn orm_stmt_gen(sql_dialect SQLDialect, table string, q string, kind StmtKin
 // orm - See SelectConfig
 // q, num, qm, start_pos - see orm_stmt_gen
 // where - See QueryData
-pub fn orm_select_gen(orm SelectConfig, q string, num bool, qm string, start_pos int, where QueryData) string {
+pub fn orm_select_gen(cfg SelectConfig, q string, num bool, qm string, start_pos int, where QueryData) string {
 	mut str := 'SELECT '
 
-	if orm.is_count {
+	if cfg.is_count {
 		str += 'COUNT(*)'
 	} else {
-		for i, field in orm.fields {
+		for i, field in cfg.fields {
 			str += '${q}${field}${q}'
-			if i < orm.fields.len - 1 {
+			if i < cfg.fields.len - 1 {
 				str += ', '
 			}
 		}
 	}
 
-	str += ' FROM ${q}${orm.table}${q}'
+	str += ' FROM ${q}${cfg.table}${q}'
 
 	mut c := start_pos
 
-	if orm.has_where {
+	if cfg.has_where {
 		str += ' WHERE '
 		for i, field in where.fields {
 			mut pre_par := false
@@ -402,21 +402,21 @@ pub fn orm_select_gen(orm SelectConfig, q string, num bool, qm string, start_pos
 
 	// Note: do not order, if the user did not want it explicitly,
 	// ordering is *slow*, especially if there are no indexes!
-	if orm.has_order {
+	if cfg.has_order {
 		str += ' ORDER BY '
-		str += '${q}${orm.order}${q} '
-		str += orm.order_type.to_str()
+		str += '${q}${cfg.order}${q} '
+		str += cfg.order_type.to_str()
 	}
 
-	if orm.has_limit {
+	if cfg.has_limit {
 		str += ' LIMIT ${qm}'
 		if num {
 			str += '${c}'
 			c++
 		}
 	}
 
-	if orm.has_offset {
+	if cfg.has_offset {
 		str += ' OFFSET ${qm}'
 		if num {
 			str += '${c}'

vlib/v/checker/assign.v

@@ -374,6 +374,10 @@ fn (mut c Checker) assign_stmt(mut node ast.AssignStmt) {
 								c.warn('duplicate of a const name `${full_name}`', left.pos)
 							}
 						}
+						if left.name == left.mod && left.name != 'main' {
+							c.add_error_detail('Module name duplicates will become errors after 2023/10/31.')
+							c.note('duplicate of a module name `${left.name}`', left.pos)
+						}
 						// Check if variable name is already registered as imported module symbol
 						if c.check_import_sym_conflict(left.name) {
 							c.error('duplicate of an import symbol `${left.name}`', left.pos)

vlib/v/checker/checker.v

@@ -1652,6 +1652,15 @@ fn (mut c Checker) const_decl(mut node ast.ConstDecl) {
 					field.expr.pos())
 			}
 		}
+		const_name := field.name.all_after_last('.')
+		if const_name == c.mod && const_name != 'main' {
+			name_pos := token.Pos{
+				...field.pos
+				len: util.no_cur_mod(field.name, c.mod).len
+			}
+			c.add_error_detail('Module name duplicates will become errors after 2023/10/31.')
+			c.note('duplicate of a module name `${field.name}`', name_pos)
+		}
 		c.const_names << field.name
 	}
 	for i, mut field in node.fields {

vlib/v/checker/fn.v

@@ -262,6 +262,10 @@ fn (mut c Checker) fn_decl(mut node ast.FnDecl) {
 					}
 				}
 			}
+			if param.name == node.mod && param.name != 'main' {
+				c.add_error_detail('Module name duplicates will become errors after 2023/10/31.')
+				c.note('duplicate of a module name `${param.name}`', param.pos)
+			}
 			// Check if parameter name is already registered as imported module symbol
 			if c.check_import_sym_conflict(param.name) {
 				c.error('duplicate of an import symbol `${param.name}`', param.pos)

vlib/v/checker/tests/mod_name_duplicate_const_err.out

@@ -0,0 +1,11 @@
+vlib/v/checker/tests/mod_name_duplicate_const_err.vv:3:7: notice: duplicate of a module name `foo.foo`
+    1 | module foo
+    2 | 
+    3 | const foo = 'bar'
+      |       ~~~
+Details: Module name duplicates will become errors after 2023/10/31.
+vlib/v/checker/tests/mod_name_duplicate_const_err.vv:1:1: error: project must include a `main` module or be a shared library (compile with `v -shared`)
+    1 | module foo
+      | ^
+    2 | 
+    3 | const foo = 'bar'

vlib/v/checker/tests/mod_name_duplicate_const_err.vv

@@ -0,0 +1,3 @@
+module foo
+
+const foo = 'bar'

vlib/v/checker/tests/mod_name_duplicate_param_err.out

@@ -0,0 +1,13 @@
+vlib/v/checker/tests/mod_name_duplicate_param_err.vv:3:8: notice: duplicate of a module name `foo`
+    1 | module foo
+    2 | 
+    3 | fn bar(foo string) {
+      |        ~~~
+    4 |     println(foo)
+    5 | }
+Details: Module name duplicates will become errors after 2023/10/31.
+vlib/v/checker/tests/mod_name_duplicate_param_err.vv:1:1: error: project must include a `main` module or be a shared library (compile with `v -shared`)
+    1 | module foo
+      | ^
+    2 | 
+    3 | fn bar(foo string) {