/*
* In a switch statement that has (expr & constant) as the controlling
* expression, complain if a case branch is unreachable because the case
* label can never match the controlling expression.
*
* GCC 10 does not complain about the unreachable branch. It knows that the
* branch is unreachable though, since it doesn't generate any code for it.
* GCC once had the option -Wunreachable-code, but that option was made a
* no-op in 2011.
*
* Clang 10 does not complain about this either, and just like GCC it doesn't
* generate any code for this branch. The code for tracking an expression's
* possible values may be related to RangeConstraintManager, just guessing.
*/
/* lint1-extra-flags: -chap -X 351 */
void println(const char *);
void
example(unsigned x)
{
switch (x & 6) {
case 0:
println("0 is reachable");
break;
case 1:
/* expect-1: warning: 'case' statement not reached [193] */
println("1 is not reachable");
break;
case 2:
println("2 is reachable");
break;
case 6:
println("6 is reachable");
break;
case 7:
/* expect-1: warning: 'case' statement not reached [193] */
println("7 is not reachable");
break;
}
}
