Re: [patch] Java definite assignment

[Mo DeJong <mdejong at cygnus dot com>]

On 6 Feb 2001, Tom Tromey wrote:

> >>>>> "Per" == Per Bothner <per@bothner.com> writes:
> 
> Per> This does seem like the correct fix, but I haven't tested it
> Per> seriously.  Could someone try applying it before their next build
> Per> and testsuite-run?
> 
> Per>         * check-init.c (check_init):  Don't call done_alternative after
> Per>         processing loop code, as a LOOP_EXPR never terminates normally.
> 
> Changes like this are good candidates for before-and-after runs
> through Jacks, to see if they cause regressions and/or improvements.
> IMHO.
> 
> Tom

I applied this patch and ran Jacks over it again. I did not
see any regressions, but I also did not see any FAILED -> PASSED
conversions. It looks like there are no tests for the
specific bug that this patch should be fixing, so I created
the following test cases:

tcltest::test true-1 { for loop + if + break } {
    empty_main T1 {
        int i;
        for (;;) {
            if (true) {
                i = 0;
                break;
            }
        }
        i++;
    }
} PASS

tcltest::test true-2 { for while + if + break } {
    empty_main T2 {
        int i;
        while (true) {
            if (true) {
                i = 0;
                break;
            }
        }
        i++;
    }
} PASS

tcltest::test false-1 { for loop + if + break } {
    empty_main F1 {
        int i;
        for (;;) {
            if (false) {
                i = 0;
                break;
            }
        }
        i++;
    }
} FAIL

tcltest::test none-1 { for while + break } {
    empty_main N1 {
        int i;
        while (true) {
            i = 0;
            break;
        }
        i++;
    }
} PASS

tcltest::test non-const-1 { for + if with nonconst variable,
        this should fail since we can't know at compile time
        that b is true } {
    empty_main NC1 {
        int i;
        boolean b = true;
        for (;;) {
            if (b) {
                i = 0;
                break;
            }
        }
        i++;
    }

} FAIL

tcltest::test non-const-2 { for + if with nonconst variable,
        this should fail since we can't know at compile time
        that b is true } {
    empty_main NC2 {
        int i;
        boolean b = false;
        for (;;) {
            if (b) {
                i = 0;
                break;
            }
        }
        i++;
    }

} FAIL



These tests all pass before the patch is added:

gcj:    Total   6       Passed  6       Skipped 0       Failed  0

After adding the patch, 3 of these tests fail:

gcj:    Total   6       Passed  3       Skipped 0       Failed  3


The ones that failed are:

==== false-1  for loop + if + break  FAILED
==== Contents of test case:

    empty_main F1 {
        int i;
        for (;;) {
            if (false) {
                i = 0;
                break;
            }
        }
        i++;
    }

---- Result was:
PASS
---- Result should have been:
FAIL
==== false-1 FAILED


==== non-const-1  for + if with nonconst variable,
        this should fail since we can't know at compile time
        that b is true  FAILED
==== Contents of test case:

    empty_main NC1 {
        int i;
        boolean b = true;
        for (;;) {
            if (b) {
                i = 0;
                break;
            }
        }
        i++;
    }


---- Result was:
PASS
---- Result should have been:
FAIL
==== non-const-1 FAILED

==== non-const-2  for + if with nonconst variable,
        this should fail since we can't know at compile time
        that b is true  FAILED
==== Contents of test case:

    empty_main NC2 {
        int i;
        boolean b = false;
        for (;;) {
            if (b) {
                i = 0;
                break;
            }
        }
        i++;
    }


---- Result was:
PASS
---- Result should have been:
FAIL
==== non-const-2 FAILED


At this point, I would advise against adding
that patch.

Mo DeJong
Red Hat Inc