clang/test/SemaCXX/switch-implicit-fallthrough-cxx98.cpp

   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 }