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

   1 // RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 -Wimplicit-fallthrough -DCLANG_PREFIX -DCOMMAND_LINE_FALLTHROUGH=[[clang::fallthrough]] -DUNCHOSEN=[[fallthrough]] %s
   2 // RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 -Wimplicit-fallthrough -DCOMMAND_LINE_FALLTHROUGH=[[fallthrough]] %s
   3 // RUN: %clang_cc1 -fsyntax-only -verify -std=c++1z -Wimplicit-fallthrough -DCLANG_PREFIX -DCOMMAND_LINE_FALLTHROUGH=[[clang::fallthrough]] %s
   4 // RUN: %clang_cc1 -fsyntax-only -verify -std=c++1z -Wimplicit-fallthrough -DCOMMAND_LINE_FALLTHROUGH=[[clang::fallthrough]] %s
   5 // RUN: %clang_cc1 -fsyntax-only -verify -std=c++1z -Wimplicit-fallthrough -DCOMMAND_LINE_FALLTHROUGH=[[fallthrough]] -DUNCHOSEN=[[clang::fallthrough]] %s
   6
   7 int fallthrough_compatibility_macro_from_command_line(int n) {
   8   switch (n) {
   9     case 0:
  10       n = n * 10;
  11     case 1: // expected-warning{{unannotated fall-through between switch labels}} expected-note{{insert 'COMMAND_LINE_FALLTHROUGH;' to silence this warning}} expected-note{{insert 'break;' to avoid fall-through}}
  12       ;
  13   }
  14   return n;
  15 }
  16
  17 #ifdef CLANG_PREFIX
  18 #define COMPATIBILITY_FALLTHROUGH   [ [ /* test */  clang /* test */ \
  19     ::  fallthrough  ]  ]    // testing whitespace and comments in macro definition
  20 #else
  21 #define COMPATIBILITY_FALLTHROUGH   [ [ /* test */  /* test */ \
  22     fallthrough  ]  ]    // testing whitespace and comments in macro definition
  23 #endif
  24
  25 int fallthrough_compatibility_macro_from_source(int n) {
  26   switch (n) {
  27     case 0:
  28       n = n * 20;
  29     case 1: // expected-warning{{unannotated fall-through between switch labels}} expected-note{{insert 'COMPATIBILITY_FALLTHROUGH;' to silence this warning}} expected-note{{insert 'break;' to avoid fall-through}}
  30       ;
  31   }
  32   return n;
  33 }
  34
  35 // Deeper macro substitution
  36 #ifdef CLANG_PREFIX
  37 #define M1 [[clang::fallthrough]]
  38 #else
  39 #define M1 [[fallthrough]]
  40 #endif
  41 #ifdef __clang__
  42 #define M2 M1
  43 #else
  44 #define M2
  45 #endif
  46
  47 #define WRONG_MACRO1 clang::fallthrough
  48 #define WRONG_MACRO2 [[clang::fallthrough]
  49 #define WRONG_MACRO3 [[clang::fall through]]
  50 #define WRONG_MACRO4 [[clang::fallthrough]]]
  51
  52 int fallthrough_compatibility_macro_in_macro(int n) {
  53   switch (n) {
  54     case 0:
  55       n = n * 20;
  56     case 1: // expected-warning{{unannotated fall-through between switch labels}} expected-note{{insert 'M1;' to silence this warning}} expected-note{{insert 'break;' to avoid fall-through}}
  57                                                                           // there was an idea that this ^ should be M2
  58       ;
  59   }
  60   return n;
  61 }
  62
  63 #undef M1
  64 #undef M2
  65 #undef COMPATIBILITY_FALLTHROUGH
  66 #undef COMMAND_LINE_FALLTHROUGH
  67 #undef UNCHOSEN
  68
  69 int fallthrough_compatibility_macro_undefined(int n) {
  70   switch (n) {
  71     case 0:
  72       n = n * 20;
  73 #if __cplusplus <= 201402L
  74     case 1: // expected-warning{{unannotated fall-through between switch labels}} expected-note{{insert '[[clang::fallthrough]];' to silence this warning}} expected-note{{insert 'break;' to avoid fall-through}}
  75 #else
  76     case 1: // expected-warning{{unannotated fall-through between switch labels}} expected-note{{insert '[[fallthrough]];' to silence this warning}} expected-note{{insert 'break;' to avoid fall-through}}
  77 #endif
  78       ;
  79   }
  80 #define TOO_LATE [[clang::fallthrough]]
  81   return n;
  82 }
  83 #undef TOO_LATE
  84
  85 #define MACRO_WITH_HISTORY 11111111
  86 #undef MACRO_WITH_HISTORY
  87 #define MACRO_WITH_HISTORY [[clang::fallthrough]]
  88 #undef MACRO_WITH_HISTORY
  89 #define MACRO_WITH_HISTORY 2222222
  90
  91 int fallthrough_compatibility_macro_history(int n) {
  92   switch (n) {
  93     case 0:
  94       n = n * 20;
  95 #undef MACRO_WITH_HISTORY
  96 #if __cplusplus <= 201402L
  97     case 1: // expected-warning{{unannotated fall-through between switch labels}} expected-note{{insert '[[clang::fallthrough]];' to silence this warning}} expected-note{{insert 'break;' to avoid fall-through}}
  98 #else
  99     case 1: // expected-warning{{unannotated fall-through between switch labels}} expected-note{{insert '[[fallthrough]];' to silence this warning}} expected-note{{insert 'break;' to avoid fall-through}}
 100 #endif
 101       ;
 102 #define MACRO_WITH_HISTORY [[clang::fallthrough]]
 103   }
 104   return n;
 105 }
 106
 107 #undef MACRO_WITH_HISTORY
 108 #define MACRO_WITH_HISTORY 11111111
 109 #undef MACRO_WITH_HISTORY
 110 #define MACRO_WITH_HISTORY [[clang::fallthrough]]
 111 #undef MACRO_WITH_HISTORY
 112 #define MACRO_WITH_HISTORY 2222222
 113 #undef MACRO_WITH_HISTORY
 114
 115 int fallthrough_compatibility_macro_history2(int n) {
 116   switch (n) {
 117     case 0:
 118       n = n * 20;
 119 #define MACRO_WITH_HISTORY [[clang::fallthrough]]
 120     case 1: // expected-warning{{unannotated fall-through between switch labels}} expected-note{{insert 'MACRO_WITH_HISTORY;' to silence this warning}} expected-note{{insert 'break;' to avoid fall-through}}
 121       ;
 122 #undef MACRO_WITH_HISTORY
 123 #define MACRO_WITH_HISTORY 3333333
 124 #undef MACRO_WITH_HISTORY
 125 #define MACRO_WITH_HISTORY 4444444
 126 #undef MACRO_WITH_HISTORY
 127 #define MACRO_WITH_HISTORY 5555555
 128   }
 129   return n;
 130 }
 131
 132 template<const int N>
 133 int fallthrough_compatibility_macro_history_template(int n) {
 134   switch (N * n) {
 135     case 0:
 136       n = n * 20;
 137 #define MACRO_WITH_HISTORY2 [[clang::fallthrough]]
 138     case 1: // expected-warning{{unannotated fall-through between switch labels}} expected-note{{insert 'MACRO_WITH_HISTORY2;' to silence this warning}} expected-note{{insert 'break;' to avoid fall-through}}
 139       ;
 140 #undef MACRO_WITH_HISTORY2
 141 #define MACRO_WITH_HISTORY2 3333333
 142   }
 143   return n;
 144 }
 145
 146 #undef MACRO_WITH_HISTORY2
 147 #define MACRO_WITH_HISTORY2 4444444
 148 #undef MACRO_WITH_HISTORY2
 149 #define MACRO_WITH_HISTORY2 5555555
 150
 151 void f() {
 152   fallthrough_compatibility_macro_history_template<1>(0); // expected-note{{in instantiation of function template specialization 'fallthrough_compatibility_macro_history_template<1>' requested here}}
 153 }