checker: fix missing reserved name check on global declaration (fix #22345) (#22347)

vlib/v/ast/ast.v

@@ -10,6 +10,11 @@ import v.util
 import v.pref
 import sync.stdatomic
 
+// V type names that cannot be used as global var name
+pub const global_reserved_type_names = ['byte', 'bool', 'char', 'i8', 'i16', 'int', 'i64', 'u8',
+	'u16', 'u32', 'u64', 'f32', 'f64', 'map', 'string', 'rune', 'usize', 'isize', 'voidptr', 'thread',
+	'array']
+
 pub type TypeDecl = AliasTypeDecl | FnTypeDecl | SumTypeDecl
 
 // pub const int_type_name = $if amd64 || arm64 {

vlib/v/checker/checker.v

@@ -2302,6 +2302,11 @@ fn (mut c Checker) global_decl(mut node ast.GlobalDecl) {
 	}
 	for mut field in node.fields {
 		c.check_valid_snake_case(field.name, 'global name', field.pos)
+
+		if field.name in ast.global_reserved_type_names {
+			c.error('invalid use of reserved type `${field.name}` as a global name', field.pos)
+		}
+
 		if field.name in c.global_names {
 			c.error('duplicate global `${field.name}`', field.pos)
 		}

vlib/v/parser/parser.v

@@ -4106,7 +4106,9 @@ fn (mut p Parser) global_decl() ast.GlobalDecl {
 			is_exported: is_exported
 		}
 		fields << field
-		p.table.global_scope.register(field)
+		if name !in ast.global_reserved_type_names {
+			p.table.global_scope.register(field)
+		}
 		comments = []
 		if !is_block {
 			break

vlib/v/parser/tests/global_reserved_name_err.out

@@ -0,0 +1,7 @@
+vlib/v/parser/tests/global_reserved_name_err.vv:5:2: error: invalid use of reserved type `array` as a global name
+    3 | 
+    4 | __global (
+    5 |     array [16]int
+      |     ~~~~~
+    6 | )
+    7 |

vlib/v/parser/tests/global_reserved_name_err.vv

@@ -0,0 +1,9 @@
+@[has_globals]
+module main
+
+__global (
+	array [16]int
+)
+
+fn main() {
+}