Assertions in static blocks ?

Ulf Zibis Ulf.Zibis at gmx.de
Fri Mar 5 15:08:16 PST 2010


Neal, Keith, thanks for your answer.

... but shouldn't javac claim, that there the code in the static block 
will be *never reached*, if there is no trigger to run it?

-Ulf


Am 05.03.2010 22:59, schrieb Neal Gafter:
> On Fri, Mar 5, 2010 at 1:47 PM, Ulf Zibis <Ulf.Zibis at gmx.de 
> <mailto:Ulf.Zibis at gmx.de>> wrote:
>
>     No response ??  :-(
>
>
> Keith's response is correct.  An assertion in a method only occurs 
> when the method is executed.  An assertion in a constructor only 
> occurs when the constructor is called.  An assertion in a static 
> initializer only occurs when the class is statically initialized.  
> Accessing a constant of the class does not initialize the class.  So 
> there is no bug.
>
> Cheers,
> Neal
>
>
>     I've filed a bug:
>
>      internal review ID of 1730072
>
>
>     -Ulf
>
>
>
>     Am 12.02.2010 15:44, schrieb Ulf Zibis:
>
>         Am 12.02.2010 15:06, schrieb Ulf Zibis:
>
>             Hi,
>
>             in the following example, I have an assert statement in a
>             static block of my class.
>
>             If accessing the static final constants from another
>             class, the static block is not executed.
>             This causes the assertions to remain un-proofed, even if
>             -ea -esa is set.
>
>             Is that correct ?
>
>
>         If yes, javac should claim the code as never reached.
>
>
>             IMO, assertions should always run, if -ea -esa is set.
>
>             -Ulf
>
>
>         -Ulf
>
>
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>         Date: Fri, 12 Feb 2010 10:12:58 -0500
>         From: Keith McGuigan <Keith.McGuigan at Sun.COM>
>         Subject: Re: Assertions in static blocks ?
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>         To: Ulf Zibis <Ulf.Zibis at gmx.de <mailto:Ulf.Zibis at gmx.de>>
>         Cc: compiler-dev at openjdk.java.net
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>
>
>         Hi Ulf -
>
>         Accessing a constant static field in a class does not trigger
>         class initialization, so your initializer is probably just not
>         being run.
>
>         See
>         http://java.sun.com/docs/books/jvms/second_edition/html/Concepts.doc.html#19075
>
>
>         -- 
>         - Keith
>
>         Ulf Zibis wrote:
>
>             Hi,
>
>             in the following example, I have an assert statement in a
>             static block of my class.
>
>             If accessing the static final constants from another
>             class, the static block is not executed.
>             This causes the assertions to remain un-proofed, even if
>             -ea -esa is set.
>
>             Is that correct ?
>
>             IMO, assertions should always run, if -ea -esa is set.
>
>             -Ulf
>
>
>
>             package sun.nio.cs.ext;
>
>             import static sun.nio.cs.CharsetMapping.*;
>
>             /**
>              *
>              * @author Ulf Zibis, Cologne CoSoCo.de
>              */
>             class EUC_TWMapping3 extends EUC_TWMapping {
>                static final short PL0_5_B2C_RANGE = 0x2300; // plane
>             0, 5 b2c range
>                static final short PLANE_B2C_RANGE = 0x1f00; // plane
>             2..4, 6..15 b2c range
>
>             // TODO: file bug: static block should run, if assertions
>             are enabled.
>                static {
>                    // assert plane offsets and content
>                    for (int p=0, range, offset=0; p<b2c.length; p++) {
>                        range = p % 4 == 0 ? PL0_5_B2C_RANGE :
>             PLANE_B2C_RANGE;
>                        for (int i=range; i<b2c[p].length(); i++)
>                            assert b2c[p].charAt(i) == UNMAPPABLE_DECODING;
>             // static block should run, if assertions are enabled. For
>             test uncomment following line
>             //            System.out.printf("offset: %d, range: %d,
>             b2c[p].length(): %d%n", offset, range, b2c[p].length());
>                        assert (offset += range) <= Character.MAX_VALUE
>             + 1;
>                    }
>                }
>
>             // WORKAROUND:
>             //    static int offset = 0; // assert from calling
>             context to force static block to process
>             //    static {
>             //        // assert plane offsets and content
>             //        for (int p=0, range; p<b2c.length; p++) {
>             //            range = p % 4 == 0 ? PL0_5_B2C_RANGE :
>             PLANE_B2C_RANGE;
>             //            for (int i=range; i<b2c[p].length(); i++)
>             //                assert b2c[p].charAt(i) ==
>             UNMAPPABLE_DECODING;
>             //// static block should run, if assertions are enabled.
>             For test uncomment following line
>             ////            System.out.printf("offset: %d, range: %d,
>             b2c[p].length(): %d%n", offset, range, b2c[p].length());
>             //            assert (offset += range) <=
>             Character.MAX_VALUE + 1;
>             //        }
>             //// static block should run, if assertions are enabled.
>             For test uncomment following line
>             ////        assert false;
>             //    }
>             }
>
>
>             package sun.nio.cs.ext;
>
>             /**
>              *
>              * @author Ulf Zibis, Cologne CoSoCo.de
>              */
>             public class AssertTest {
>
>                public static void main(String... args) {
>             // static block in EUC_TWMapping3 should run, if
>             assertions are enabled.
>                    System.out.println(EUC_TWMapping3.PLANE_B2C_RANGE);
>             // WORKAROUND: For test uncomment following line
>             //        assert EUC_TWMapping3.offset > 0; // force
>             assertion, TODO: JDK bug ?
>                }
>             }
>
>
>
>
>
>
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