Minor inconsistency in javac prediction of branch

Question

Just curious why javac can predict branches when possible to determine if local variable is initialized but cannot do the same to determine if unreachable code exists:
public void foo(){
     int x;
     if(true){
          x = 7;
     int p = x;
}no problem here, javac can detect that the local variable x will be initialized every time and does not complain that x is not initialized when it is assigned to p. very good, javac.
public void foo(){
     if(true){
          return;
     int x = 7;
}in this case, javac fails to notice that the branch with the same condition will always execute, which leaves the int x=7 as unreachable code.
So in the first code example, javac confidently believes the code will execute to remove the possibility of an uninialized variable being used; however, in the second code example, it believes there is a possibility that this same if branch will not be taken so the code that follows may be executed. This seems inconsistent.
I'm not disappointed in this behavior, just surprised and wondering if there is a reason for it.

Answer 1

in this case, javac fails to notice that the branch
with the same condition will always execute, which
leaves the int x=7 as unreachable code. It's probably not malicious or deliberate - just a condition that the compiler implementor forgot to check. And it's not a required check according to the language semantics either - you just lucked out in one case, and didn't in the other.
Send in a bug report/enhancement request for consideration in a future release..