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  • kForth bug detected

    From Krishna Myneni@krishna.myneni@ccreweb.org to comp.lang.forth on Sat Oct 4 21:53:47 2025
    From Newsgroup: comp.lang.forth

    In another thread discussing object-oriented Forth, I used my program epr-sim.4th as an example of using the compact OO system, mini-oof.4th. Running epr-sim.4th under the latest development versions of both
    kForth-64 and kForth-32 results in a seg fault.

    To reproduce the bug,

    1. start kforth64 (v0.6.0) / kforth32 (v2.6.0)
    2. "include epr-sim.4th"
    3. Press menu option 'C' (continuous emitter).

    This happens with the latest versions, above, but works in earlier
    versions kForth-64 v0.5.1 / kForth-32 v2.5.0.

    For kForth-64, a bug was introduced at git commit e3f3b8e in which
    substantial revisions were made to the virtual machine. The latest
    development versions passed all of the Forth system tests I use to
    validate the system. These tests are provided in the git repo (under forth-src/system-test) but they failed to catch the current bug.

    Interestingly, the fast versions of the latest kForth-64 and kForth-32 (kforthxx-fast) run epr-sim.4th properly. The VMs are substantially
    different between the regular and fast versions.

    --
    Krishna Myneni




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  • From Krishna Myneni@krishna.myneni@ccreweb.org to comp.lang.forth on Mon Oct 6 09:08:49 2025
    From Newsgroup: comp.lang.forth

    On 10/4/25 9:53 PM, Krishna Myneni wrote:
    In another thread discussing object-oriented Forth, I used my program epr-sim.4th as an example of using the compact OO system, mini-oof.4th. Running epr-sim.4th under the latest development versions of both
    kForth-64 and kForth-32 results in a seg fault.

    To reproduce the bug,

    1. start kforth64 (v0.6.0) / kforth32 (v2.6.0)
    2. "include epr-sim.4th"
    3. Press menu option 'C' (continuous emitter).

    This happens with the latest versions, above, but works in earlier
    versions kForth-64 v0.5.1 / kForth-32 v2.5.0.
    ...

    Found and fixed the problem. It was a bug within the non-standard word
    USLEEP. Updates pushed to kForth-64/32 repos on GitHub. epr-sim.4th runs properly under the new versions of kForth-64 (0.6.1) and kForth-32 (2.6.1).

    --
    Krishna Myneni

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