From 412c17ccda2b21bf14e4e34154c7d78f64852323 Mon Sep 17 00:00:00 2001
From: Nick Treleaven <n@trelsoft.com>
Date: Wed, 3 Mar 2021 09:12:50 +0000
Subject: [PATCH] checker: check private built-in methods are not accessible
 (#9062)

---
 vlib/v/checker/checker.v                              | 6 ++----
 vlib/v/checker/tests/import_symbol_fn_private_err.out | 9 ++++++++-
 vlib/v/checker/tests/import_symbol_fn_private_err.vv  | 4 ++++
 3 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/vlib/v/checker/checker.v b/vlib/v/checker/checker.v
index 4cddda3091..67949eb25c 100644
--- a/vlib/v/checker/checker.v
+++ b/vlib/v/checker/checker.v
@@ -1470,8 +1470,7 @@ pub fn (mut c Checker) call_method(mut call_expr ast.CallExpr) table.Type {
 		}
 	}
 	if has_method {
-		if !method.is_pub && !c.is_builtin_mod && !c.pref.is_test && left_type_sym.mod != c.mod
-			&& left_type_sym.mod != '' { // method.mod != c.mod {
+		if !method.is_pub && !c.pref.is_test && method.mod != c.mod {
 			// If a private method is called outside of the module
 			// its receiver type is defined in, show an error.
 			// println('warn $method_name lef.mod=$left_type_sym.mod c.mod=$c.mod')
@@ -1823,8 +1822,7 @@ pub fn (mut c Checker) call_fn(mut call_expr ast.CallExpr) table.Type {
 		}
 	}
 	if !f.is_pub && f.language == .v && f.name.len > 0 && f.mod.len > 0 && f.mod != c.mod {
-		c.error('function `$f.name` is private, so you can not import it in module `$c.mod`',
-			call_expr.pos)
+		c.error('function `$f.name` is private', call_expr.pos)
 	}
 	if !c.cur_fn.is_deprecated && f.is_deprecated {
 		mut deprecation_message := 'function `$f.name` has been deprecated'
diff --git a/vlib/v/checker/tests/import_symbol_fn_private_err.out b/vlib/v/checker/tests/import_symbol_fn_private_err.out
index c12f27ee2c..b034706220 100644
--- a/vlib/v/checker/tests/import_symbol_fn_private_err.out
+++ b/vlib/v/checker/tests/import_symbol_fn_private_err.out
@@ -3,9 +3,16 @@ vlib/v/checker/tests/import_symbol_fn_private_err.vv:1:20: error: module `time`
       |                    ~~~~~
     2 | fn main() {
     3 |   since(now())
-vlib/v/checker/tests/import_symbol_fn_private_err.vv:3:3: error: function `time.since` is private, so you can not import it in module `main`
+vlib/v/checker/tests/import_symbol_fn_private_err.vv:3:3: error: function `time.since` is private
     1 | import time { now, since }
     2 | fn main() {
     3 |   since(now())
       |   ~~~~~~~~~~~~
     4 | }
+    5 |
+vlib/v/checker/tests/import_symbol_fn_private_err.vv:7:20: error: method `map[string]int.exists_1` is private
+    5 | 
+    6 | fn method() {
+    7 |     _ = map{'h':2}.exists_1('h')
+      |                    ~~~~~~~~~~~~~
+    8 | }
diff --git a/vlib/v/checker/tests/import_symbol_fn_private_err.vv b/vlib/v/checker/tests/import_symbol_fn_private_err.vv
index 9c959e89b2..f1425b8ce0 100644
--- a/vlib/v/checker/tests/import_symbol_fn_private_err.vv
+++ b/vlib/v/checker/tests/import_symbol_fn_private_err.vv
@@ -2,3 +2,7 @@ import time { now, since }
 fn main() {
   since(now())
 }
+
+fn method() {
+    _ = map{'h':2}.exists_1('h')
+}