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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 
      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:
     82   ~ClassWithDtor() {}
     83 };
     84 
     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 
    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