Bug 1605 – break in switch with goto breaks in ctfe

I stumbled upon a case where a break statement in a switch causes the outer while loop to exit. This happens only when the function is evaluated at compile time and a goto statement is involved. Forgive me the bad example: int Break() { int i = 0; while (true) { switch(i) { case 0: goto LABEL; // comment out this line and all is fine LABEL: // at compile time, this breaks out of the while loop: break; default: return i; } i = 1; } return 0; // unreachable } void main() { assert (Break() == 1); // ok static assert(Break() == 1); // not ok }

Actually this has nothing to do with switch or break. It only requires 'goto' inside a while loop. Reduced test case: int Break() { int i = 0; while (true) { goto LABEL; LABEL: if (i!=0) return i; i = 27; } assert(i==27); // this passes, it did actually execute the loop. return 88; // unreachable } static assert(Break() == 27); ----------- It's failing because the test for continuing to execute is wrong. ---- PATCH: interpret.c, Expression *WhileStatement::interpret(InterState *istate) if (e == EXP_BREAK_INTERPRET) return NULL; - if (e != EXP_CONTINUE_INTERPRET) + if (e && e != EXP_CONTINUE_INTERPRET) return e; } while (1) { e = condition->interpret(istate);

Fixed dmd 1.047 and 2.032