1 // PR c/7652 2 // { dg-do compile { target c++11 } } 3 // { dg-options "-Wextra -Wall -Wpedantic" } 4 5 extern void bar (int); 6 void fn(int i)7fn (int i) 8 { 9 [[gnu::fallthrough]] int j = 0; // { dg-warning "attribute ignored" } 10 11 if (j) 12 [[gnu::fallthrough]]; // { dg-error "invalid use" } 13 14 [[gnu::fallthrough]]; // { dg-error "invalid use" } 15 switch (i) 16 { 17 [[gnu::fallthrough]]; // { dg-warning "statement will never" } 18 case 1: 19 i++; 20 [[gnu::fallthrough]]; 21 case 2: 22 if (i) // { dg-warning "statement may fall through" } 23 bar (2); 24 else 25 [[gnu::fallthrough]]; 26 case 3: 27 if (i > 1) 28 [[gnu::fallthrough]]; 29 else 30 return; 31 case 4: 32 if (i) 33 [[gnu::fallthrough]]; // { dg-warning "not preceding" } 34 [[gnu::fallthrough]]; 35 case 5: 36 ; 37 [[gnu::fallthrough]]; 38 case 6: 39 if (i) // { dg-warning "statement may fall through" } 40 bar (6); 41 else 42 { 43 [[gnu::fallthrough]]; 44 } 45 case 7: 46 if (i > 1) 47 { 48 [[gnu::fallthrough]]; 49 } 50 else 51 bar (7); // { dg-warning "statement may fall through" } 52 default: 53 --j; 54 } 55 56 [[gnu::fallthrough]]; // { dg-error "invalid use" } 57 } 58