/**
* Returns in the then and else blocks must be consistent with each other. If there is no else
* block, then the return statement can fall through.
*
* @return logical OR of END_* flags
*/
private int endCheckIf() {
Node th, el;
int rv = END_UNREACHED;
th = next;
el = ((Jump) this).target;
rv = th.endCheck();
if (el != null) rv |= el.endCheck();
else rv |= END_DROPS_OFF;
return rv;
}
/**
* A general block of code is examined statement by statement. If any statement (even compound
* ones) returns in all branches, then subsequent statements are not examined.
*
* @return logical OR of END_* flags
*/
private int endCheckBlock() {
Node n;
int rv = END_DROPS_OFF;
// check each statment and if the statement can continue onto the next
// one, then check the next statement
for (n = first; ((rv & END_DROPS_OFF) != 0) && n != null; n = n.next) {
rv &= ~END_DROPS_OFF;
rv |= n.endCheck();
}
return rv;
}
/**
* Consistency of return statements is checked between the case statements. If there is no
* default, then the switch can fall through. If there is a default,we check to see if all code
* paths in the default return or if there is a code path that can fall through.
*
* @return logical OR of END_* flags
*/
private int endCheckSwitch() {
Node n;
int rv = END_UNREACHED;
// examine the cases
for (n = first.next; n != null; n = n.next) {
if (n.type == Token.CASE) {
rv |= ((Jump) n).target.endCheck();
} else break;
}
// we don't care how the cases drop into each other
rv &= ~END_DROPS_OFF;
// examine the default
n = ((Jump) this).getDefault();
if (n != null) rv |= n.endCheck();
else rv |= END_DROPS_OFF;
// remove the switch block
rv |= getIntProp(CONTROL_BLOCK_PROP, END_UNREACHED);
return rv;
}
