GNU bug report logs - #7825
Cannot return from the debugger

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Package: emacs;

Reported by: Stefan Monnier <monnier <at> IRO.UMontreal.CA>

Date: Tue, 11 Jan 2011 21:25:02 UTC

Severity: normal

Found in version 24.0.50

Done: Stefan Monnier <monnier <at> iro.umontreal.ca>

Bug is archived. No further changes may be made.

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From: Richard Stallman <rms <at> gnu.org>
To: Stefan Monnier <monnier <at> IRO.UMontreal.CA>
Cc: 7825 <at> debbugs.gnu.org
Subject: bug#7825: Cannot return from the debugger
Date: Wed, 12 Jan 2011 00:17:41 -0500
    The limitation that we "Cannot return from the debugger in an error",
    is a bug: we should be able to continue (i.e. run the code of the
    corresponding error handler), just as if the debugger had not been invoked.

That is fine in theory, but it would imply that any place that can get
an error can also GC.

If we make GCPRO a no-op on all platforms, allowing those places to GC
may not require massive changes.  But lots of places in the C code
would still have to be checked for possible bugs.

I don't remember how string relocation works nowadays.  It used to be
the case that many places in the C code had char * pointers into Lisp
strings, which could be invalidated by a GC.  If this is still an
issue, then keeping such a pointer across something that reports an
error would be a bug.


-- 
Richard Stallman
President, Free Software Foundation
51 Franklin St
Boston MA 02110
USA
www.fsf.org, www.gnu.org




This bug report was last modified 14 years and 78 days ago.

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