Akim Demaille bbf37f2534 lalr: fix segmentation violation ...

The "includes" relation [DeRemer 1982] is between gotos, so of course,
for a given goto, there cannot be more that ngotos (number of gotos)
images.  But we manipulate the set of images of a goto as a list,
without checking that an image was not already introduced.  So we can
"register" way more images than ngotos, leading to a crash (heap
buffer overflow).

Reported by wcventure.
http://lists.gnu.org/archive/html/bug-bison/2019-03/msg00007.html

For the records, this bug is present in the first committed version of
Bison.

* src/lalr.c (build_relations): Don't insert the same goto several
times.
* tests/sets.at (Build Relations): New.

2019-03-30 10:10:39 +01:00

8.1 KiB

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