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1 // RUN: %clang_cc1 -fsyntax-only -verify -std=c++98 -Wimplicit-fallthrough %s
2 // XFAIL: *
3 
4 // NOTE: This test is marked XFAIL until we come up with a good language design
5 // for a worfklow to use this warning outside of C++11.
6 
fallthrough(int n)7 int fallthrough(int n) {
8   switch (n / 10) {
9       if (n - 1) {
10         n = 100;
11       } else if (n - 2) {
12         n = 101;
13       } else if (n - 3) {
14         n = 102;
15       }
16     case -1: // expected-warning{{unannotated fall-through between switch labels}} expected-note{{insert 'break;' to avoid fall-through}}
17       ;
18     case 0: {// expected-warning{{unannotated fall-through between switch labels}} expected-note{{insert 'break;' to avoid fall-through}}
19     }
20     case 1:  // expected-warning{{unannotated fall-through between switch labels}} expected-note{{insert 'break;' to avoid fall-through}}
21       n += 100         ;
22     case 3:  // expected-warning{{unannotated fall-through between switch labels}} expected-note{{insert 'break;' to avoid fall-through}}
23       if (n > 0)
24         n += 200;
25     case 4:  // expected-warning{{unannotated fall-through between switch labels}} expected-note{{insert 'break;' to avoid fall-through}}
26       if (n < 0)
27         ;
28     case 5:  // expected-warning{{unannotated fall-through between switch labels}} expected-note{{insert 'break;' to avoid fall-through}}
29       switch (n) {
30       case 111:
31         break;
32       case 112:
33         break;
34       case 113:
35         break    ;
36       }
37     case 6:  // expected-warning{{unannotated fall-through between switch labels}} expected-note{{insert 'break;' to avoid fall-through}}
38       n += 300;
39   }
40   switch (n / 30) {
41     case 11:
42     case 12:  // no warning here, intended fall-through, no statement between labels
43       n += 1600;
44   }
45   switch (n / 40) {
46     case 13:
47       if (n % 2 == 0) {
48         return 1;
49       } else {
50         return 2;
51       }
52     case 15:  // no warning here, there's no fall-through
53       n += 3200;
54   }
55   switch (n / 50) {
56     case 17: {
57       if (n % 2 == 0) {
58         return 1;
59       } else {
60         return 2;
61       }
62     }
63     case 19: { // no warning here, there's no fall-through
64       n += 6400;
65       return 3;
66     }
67     case 21: { // no warning here, there's no fall-through
68       break;
69     }
70     case 23: // no warning here, there's no fall-through
71       n += 128000;
72       break;
73     case 25: // no warning here, there's no fall-through
74       break;
75   }
76 
77   return n;
78 }
79 
80 class ClassWithDtor {
81 public:
~ClassWithDtor()82   ~ClassWithDtor() {}
83 };
84 
fallthrough2(int n)85 void fallthrough2(int n) {
86   switch (n) {
87     case 0:
88     {
89       ClassWithDtor temp;
90       break;
91     }
92     default: // no warning here, there's no fall-through
93       break;
94   }
95 }
96 
97 #define MY_SWITCH(X, Y, Z, U, V) switch (X) { case Y: Z; case U: V; }
98 #define MY_SWITCH2(X, Y, Z) switch (X) { Y; Z; }
99 #define MY_CASE(X, Y) case X: Y
100 #define MY_CASE2(X, Y, U, V) case X: Y; case U: V
101 
fallthrough_macro1(int n)102 int fallthrough_macro1(int n) {
103   MY_SWITCH(n, 13, n *= 2, 14, break)  // expected-warning{{unannotated fall-through between switch labels}}
104 
105   switch (n + 1) {
106     MY_CASE(33, n += 2);
107     MY_CASE(44, break);  // expected-warning{{unannotated fall-through between switch labels}}
108     MY_CASE(55, n += 3);
109   }
110 
111   switch (n + 3) {
112     MY_CASE(333, return 333);
113     MY_CASE2(444, n += 44, 4444, break);  // expected-warning{{unannotated fall-through between switch labels}}
114     MY_CASE(555, n += 33);
115   }
116 
117   MY_SWITCH2(n + 4, MY_CASE(17, n *= 3), MY_CASE(19, break))  // expected-warning{{unannotated fall-through between switch labels}}
118 
119   MY_SWITCH2(n + 5, MY_CASE(21, break), MY_CASE2(23, n *= 7, 25, break))  // expected-warning{{unannotated fall-through between switch labels}}
120 
121   return n;
122 }
123