1 // RUN: %clang_cc1 -std=c++1z -verify %s
2
f(int n)3 void f(int n) {
4 switch (n) {
5 case 0:
6 n += 1;
7 [[fallthrough]]; // ok
8 case 1:
9 if (n) {
10 [[fallthrough]]; // ok
11 } else {
12 return;
13 }
14 case 2:
15 for (int n = 0; n != 10; ++n)
16 [[fallthrough]]; // expected-error {{does not directly precede switch label}}
17 case 3:
18 while (true)
19 [[fallthrough]]; // expected-error {{does not directly precede switch label}}
20 case 4:
21 while (false)
22 [[fallthrough]]; // expected-error {{does not directly precede switch label}}
23 case 5:
24 do [[fallthrough]]; while (true); // expected-error {{does not directly precede switch label}}
25 case 6:
26 do [[fallthrough]]; while (false); // expected-error {{does not directly precede switch label}}
27 case 7:
28 switch (n) {
29 case 0:
30 // FIXME: This should be an error, even though the next thing we do is to
31 // fall through in an outer switch statement.
32 [[fallthrough]];
33 }
34 case 8:
35 [[fallthrough]]; // expected-error {{does not directly precede switch label}}
36 goto label;
37 label:
38 case 9:
39 n += 1;
40 case 10: // no warning, -Wimplicit-fallthrough is not enabled in this test, and does not need to
41 // be enabled for these diagnostics to be produced.
42 break;
43 }
44 }
45
46 [[fallthrough]] typedef int n; // expected-error {{'fallthrough' attribute cannot be applied to a declaration}}
47 typedef int [[fallthrough]] n; // expected-error {{'fallthrough' attribute cannot be applied to types}}
48 typedef int n [[fallthrough]]; // expected-error {{'fallthrough' attribute cannot be applied to a declaration}}
49
50 enum [[fallthrough]] E {}; // expected-error {{'fallthrough' attribute cannot be applied to a declaration}}
51 class [[fallthrough]] C {}; // expected-error {{'fallthrough' attribute cannot be applied to a declaration}}
52
53 [[fallthrough]] // expected-error {{'fallthrough' attribute cannot be applied to a declaration}}
g()54 void g() {
55 [[fallthrough]] int n; // expected-error {{'fallthrough' attribute cannot be applied to a declaration}}
56 [[fallthrough]] ++n; // expected-error-re {{{{^}}fallthrough attribute is only allowed on empty statements}}
57
58 switch (n) {
59 // FIXME: This should be an error.
60 [[fallthrough]];
61 return;
62
63 case 0:
64 [[fallthrough, fallthrough]]; // expected-error {{multiple times}}
65 case 1:
66 [[fallthrough(0)]]; // expected-error {{argument list}}
67 case 2:
68 break;
69 }
70 }
71