clang/test/SemaCXX/switch-implicit-fallthrough-off-by-default.cpp

   1 // RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 -DUNREACHABLE=1 %s
   2 // RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 -DUNREACHABLE=0 -Wimplicit-fallthrough %s
   3
   4 void fallthrough(int n) {
   5   switch (n) {
   6   case 1:
   7     if (UNREACHABLE)
   8       return;
   9     [[fallthrough]]; // expected-no-diagnostics, only checked when UNREACHABLE=0
  10   case 2:
  11     break;
  12   }
  13 }