checker: fix missing check for invalid argument for builtin

vlib/v/checker/str.v

@@ -47,12 +47,15 @@ fn (mut c Checker) string_inter_lit(mut node ast.StringInterLiteral) ast.Type {
 		mut ftyp := c.expr(mut expr)
 		ftyp = c.type_resolver.get_type_or_default(expr, c.check_expr_option_or_result_call(expr,
 			ftyp))
-		if ftyp == ast.void_type {
+		if ftyp == ast.void_type || ftyp == 0 {
 			c.error('expression does not return a value', expr.pos())
 		} else if ftyp == ast.char_type && ftyp.nr_muls() == 0 {
 			c.error('expression returning type `char` cannot be used in string interpolation directly, print its address or cast it to an integer instead',
 				expr.pos())
 		}
+		if ftyp == 0 {
+			return ast.void_type
+		}
 		c.markused_string_inter_lit(mut node, ftyp)
 		c.fail_if_unreadable(expr, ftyp, 'interpolation object')
 		node.expr_types << ftyp

vlib/v/checker/tests/invalid_generic_field_err.out

@@ -0,0 +1,49 @@
+vlib/v/checker/tests/invalid_generic_field_err.vv:4:15: error: type `User` has no field named `typo`
+    2 | 
+    3 | fn (u &User) debug_1() {
+    4 |     println('${u.typo}')
+      |                  ~~~~
+    5 | }
+    6 |
+vlib/v/checker/tests/invalid_generic_field_err.vv:4:15: error: expression does not return a value
+    2 | 
+    3 | fn (u &User) debug_1() {
+    4 |     println('${u.typo}')
+      |                  ~~~~
+    5 | }
+    6 |
+vlib/v/checker/tests/invalid_generic_field_err.vv:8:9: error: `User` has no property `typo`
+    6 | 
+    7 | fn debug_2[T](t T) {
+    8 |     _ := t.typo
+      |            ~~~~
+    9 | }
+   10 |
+vlib/v/checker/tests/invalid_generic_field_err.vv:8:4: error: assignment mismatch: 1 variable 0 values
+    6 | 
+    7 | fn debug_2[T](t T) {
+    8 |     _ := t.typo
+      |       ~~
+    9 | }
+   10 |
+vlib/v/checker/tests/invalid_generic_field_err.vv:12:15: error: `User` has no property `typo`
+   10 | 
+   11 | fn debug_3[T](t T) {
+   12 |     println('${t.typo}')
+      |                  ~~~~
+   13 | }
+   14 |
+vlib/v/checker/tests/invalid_generic_field_err.vv:12:15: error: expression does not return a value
+   10 | 
+   11 | fn debug_3[T](t T) {
+   12 |     println('${t.typo}')
+      |                  ~~~~
+   13 | }
+   14 |
+vlib/v/checker/tests/invalid_generic_field_err.vv:12:2: error: `println` can not print void expressions
+   10 | 
+   11 | fn debug_3[T](t T) {
+   12 |     println('${t.typo}')
+      |     ~~~~~~~~~~~~~~~~~~~~
+   13 | }
+   14 |

vlib/v/checker/tests/invalid_generic_field_err.vv

@@ -0,0 +1,20 @@
+struct User {}
+
+fn (u &User) debug_1() {
+	println('${u.typo}')
+}
+
+fn debug_2[T](t T) {
+	_ := t.typo
+}
+
+fn debug_3[T](t T) {
+	println('${t.typo}')
+}
+
+fn main() {
+	u := &User{}
+	u.debug_1()
+	debug_2(u)
+	debug_3(u)
+}