constant expression is not executed during compilation

Name: ngC57085 Date: 04/18/97



Java compiler (JDK1.1.2) does not execute constant expressions
while compile condition expression.

JLS (14.19) says:

"
A while statement can complete normally iff at least one of the following
is true:
     The while statement is reachable and the condition expression is not
     a constant expression with value true.
     
     There is a reachable break statement that exits the while statement.
"

A while statement cannot complete normally if the condition expression
is a constant expression with value true.

Test stmt14104, where condition expression is a constant expression with
value true, is compiled successfully by JDK1.1.2 instead of error message.

> javac112 stmt14104.java
>

------------------------stmt14104--------------
import java.io.PrintStream;

public class stmt14104 {
  public static void main(String argv[]) {
     System.exit(run(argv, System.out) + 95/*STATUS_TEMP*/);
  }
  public static int run(String argv[],PrintStream out) {
     int a1 = 1;
     int a2 = 1;
     int a3 = 1;
     final boolean b = true;
     a1 = 2;
     while (b) {
        a2++;
     }
     a3 = 2;
     return 2/*STATUS_FAILED*/;
  }
}
--------------------------------------

And test stmt14104a, where condition expression is literal true,
is not compiled by JDK1.1.2.

> javac112 stmt14104a.java
stmt14104a.java:15: Statement not reached.
     a3 = 2;
     ^
1 error
>
------------------------stmt14104a--------------
import java.io.PrintStream;

public class stmt14104a {
  public static void main(String argv[]) {
     System.exit(run(argv, System.out) + 95/*STATUS_TEMP*/);
  }
  public static int run(String argv[],PrintStream out) {
     int a1 = 1;
     int a2 = 1;
     int a3 = 1;
     a1 = 2;
     while (true) {
        a2++;
     }
     a3 = 2;
     return 2/*STATUS_FAILED*/;
  }
}
--------------------------------------


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