checker: add check for using a private const in another module (#8501)

vlib/gx/text.v

@@ -7,7 +7,7 @@ const (
 )
 
 // TODO: remove these and uae the enum everywhere
-const (
+pub const (
 	align_left  = HorizontalAlign.left
 	align_right = HorizontalAlign.right
 )

vlib/net/common.v

@@ -111,12 +111,12 @@ const (
 
 // no_timeout should be given to functions when no timeout is wanted (i.e. all functions
 // return instantly)
-const (
+pub const (
 	no_timeout = time.Duration(0)
 )
 
 // infinite_timeout should be given to functions when an infinite_timeout is wanted (i.e. functions
 // only ever return with data)
-const (
+pub const (
 	infinite_timeout = time.Duration(-1)
 )

vlib/net/errors.v

@@ -1,8 +1,11 @@
 module net
 
-// Well defined errors that are returned from socket functions
 const (
 	errors_base = 0
+)
+
+// Well defined errors that are returned from socket functions
+pub const (
 	err_new_socket_failed = error_with_code('net: new_socket failed to create socket', errors_base+1)
 	err_option_not_settable = error_with_code('net: set_option_xxx option not settable', errors_base+2)
 	err_option_wrong_type = error_with_code('net: set_option_xxx option wrong type', errors_base+3)

vlib/time/time.v

@@ -5,7 +5,7 @@ module time
 
 #include <time.h>
 
-const (
+pub const (
 	days_string        = 'MonTueWedThuFriSatSun'
 	month_days         = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
 	months_string      = 'JanFebMarAprMayJunJulAugSepOctNovDec'

vlib/v/checker/checker.v

@@ -4037,6 +4037,9 @@ pub fn (mut c Checker) ident(mut ident ast.Ident) table.Type {
 		if obj := c.file.global_scope.find(name) {
 			match mut obj {
 				ast.ConstField {
+					if !(obj.is_pub || obj.mod == c.mod || c.pref.is_test) {
+						c.error('constant `$obj.name` is private', ident.pos)
+					}
 					mut typ := obj.typ
 					if typ == 0 {
 						c.inside_const = true

vlib/v/checker/tests/import_symbol_const_private_err.out

@@ -0,0 +1,6 @@
+vlib/v/checker/tests/import_symbol_const_private_err.vv:4:19: error: constant `v.scanner.single_quote` is private
+    2 | 
+    3 | fn main() {
+    4 |   println(scanner.single_quote)
+      |                   ~~~~~~~~~~~~
+    5 | }

vlib/v/checker/tests/import_symbol_const_private_err.vv

@@ -0,0 +1,5 @@
+import v.scanner
+
+fn main() {
+  println(scanner.single_quote)
+}

vlib/v/parser/parser.v

@@ -2002,6 +2002,7 @@ fn (mut p Parser) const_decl() ast.ConstDecl {
 		field := ast.ConstField{
 			name: full_name
 			mod: p.mod
+			is_pub: is_pub
 			expr: expr
 			pos: pos
 			comments: comments

vlib/v/token/token.v

@@ -126,9 +126,12 @@ pub enum Kind {
 	_end_
 }
 
-const (
+pub const (
 	assign_tokens = [Kind.assign, .plus_assign, .minus_assign, .mult_assign, .div_assign, .xor_assign,
 		.mod_assign, .or_assign, .and_assign, .right_shift_assign, .left_shift_assign]
+)
+
+const (
 	nr_tokens     = int(Kind._end_)
 )
 
@@ -160,7 +163,7 @@ pub enum AtKind {
 	vmod_file
 }
 
-const (
+pub const (
 	valid_at_tokens = ['@FN', '@MOD', '@STRUCT', '@VEXE', '@FILE', '@LINE', '@COLUMN', '@VHASH',
 		'@VMOD_FILE',
 	]
@@ -291,6 +294,9 @@ fn build_token_str() []string {
 
 const (
 	token_str = build_token_str()
+)
+
+pub const (
 	keywords  = build_keys()
 )