web2c 7.3.2 (TeX and Metafont) bounds violations
Nelson H. F. Beebe
beebe@math.utah.edu
Mon, 11 Sep 2000 12:37:24 -0600 (MDT)
There has been recent work on extended the gcc compiler to support
bounded pointers: each OBJECT* pointer points to a 3-element structure
containing the object's current address, and lower and upper bounds on
the storage allocated for the object. You can read about it in
http://gcc.gnu.org/projects/bp
The reason for this post is to inform you that as part of the project,
a number of open-source programs were built and tested with the
extended gcc compiler, among them web2c 7.3.2, for which the above Web
page notes
>> ...
>> Bounds violations exposed:
>>
>> * fixwrites: main read past the beginning of a string buffer when
>> presented with an empty line.
>>
>> 100% of the test suite passes after fixing the bug listed above,
>> and compiling with ``gcc ... -fno-strict-aliasing''. A
>> strict-aliasing bug for i586 and i686 caused two assertion
>> failures in kpathsea.
>> ...
Since TeXlive CDs are in production these past few months, it would be
beneficial to incorporate fixes in new editions. I suspect that one
or more commercial implementations of TeX also involve Web-to-C
translations, so the fixes may be more widely applicable.
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