checker: check fn return void fn call (no value) (fix #22389) (#22404)

vlib/v/checker/checker.v

@@ -2177,7 +2177,9 @@ fn (mut c Checker) stmt(mut node ast.Stmt) {
 					}
 				}
 			}
-			c.check_expr_option_or_result_call(node.expr, or_typ)
+			if !c.inside_return {
+				c.check_expr_option_or_result_call(node.expr, or_typ)
+			}
 			// TODO: This should work, even if it's prolly useless .-.
 			// node.typ = c.check_expr_option_or_result_call(node.expr, ast.void_type)
 		}

vlib/v/checker/match.v

@@ -275,6 +275,9 @@ fn (mut c Checker) check_match_branch_last_stmt(last_stmt ast.ExprStmt, ret_type
 			}
 			c.error('return type mismatch, it should be `${ret_sym.name}`', last_stmt.pos)
 		}
+	} else if expr_type == ast.void_type && ret_type.idx() == ast.void_type_idx
+		&& ret_type.has_option_or_result() {
+		c.error('`${last_stmt.expr}` used as value', last_stmt.pos)
 	}
 }
 

vlib/v/checker/tests/fn_return_void_fn_call_err.out

@@ -0,0 +1,7 @@
+vlib/v/checker/tests/fn_return_void_fn_call_err.vv:20:4: error: `install_from_github(unit, verbosity)!` used as value
+   18 |     return match source {
+   19 |         'github' {
+   20 |             install_from_github(unit, verbosity)!
+      |             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+   21 |         }
+   22 |         else {

vlib/v/checker/tests/fn_return_void_fn_call_err.vv

@@ -0,0 +1,30 @@
+fn main() {
+	install_command(['github:some/thing'], 1) or { panic(err) }
+}
+
+pub fn install_command(args []string, verbosity int) ! {
+	if args.len == 0 {
+		return error('${@FN} requires an argument')
+	}
+	component := args[0]
+	if component.count(':') == 0 {
+		return install_command(['github:${component}'], verbosity)
+	}
+	source := component.all_before(':')
+	if source != 'github' {
+		return error('${@FN} unknown source `${source}`')
+	}
+	unit := component.all_after(':')
+	return match source {
+		'github' {
+			install_from_github(unit, verbosity)!
+		}
+		else {
+			error('${@FN} unknown source `${source}`')
+		}
+	}
+}
+
+fn install_from_github(unit string, verbosity int) ! {
+	dump(unit)
+}

vlib/v/tests/fns/fn_return_match_expr_with_result_test.v

@@ -0,0 +1,31 @@
+fn test_fn_return_match_expr_with_result() {
+	install_command(['github:some/thing'], 1) or { panic(err) }
+	assert true
+}
+
+pub fn install_command(args []string, verbosity int) ! {
+	if args.len == 0 {
+		return error('${@FN} requires an argument')
+	}
+	component := args[0]
+	if component.count(':') == 0 {
+		return install_command(['github:${component}'], verbosity)
+	}
+	source := component.all_before(':')
+	if source != 'github' {
+		return error('${@FN} unknown source `${source}`')
+	}
+	unit := component.all_after(':')
+	return match source {
+		'github' {
+			install_from_github(unit, verbosity)
+		}
+		else {
+			error('${@FN} unknown source `${source}`')
+		}
+	}
+}
+
+fn install_from_github(unit string, verbosity int) ! {
+	dump(unit)
+}