[Bug analyzer/96894] State explosion on gdb's fibheap.c

["dmalcolm at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96894

David Malcolm <dmalcolm at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|Analyzer assumes pointer is |State explosion on gdb's
                   |NULL, even if pointer was   |fibheap.c
                   |tested to be non-null       |
                   |before                      |

--- Comment #3 from David Malcolm <dmalcolm at gcc dot gnu.org> ---
I'm not seeing the false positive any more with trunk.

Enabling -Wanalyzer-too-complex shows that the analyzer is still safety limits
and stopping (both per-program-point limits and the overall node limit).

If I bump up the limits, it fully explores the egraph, without showing any
diagnostics:

./xgcc -B. -S -fanalyzer ../../src/pr96894.c \
  -Wanalyzer-too-complex \
  --param analyzer-max-enodes-per-program-point=200 \
  --param analyzer-bb-explosion-factor=50

So it appears that the false positive from -Wanalyzer-null-dereference is
fixed, but there's some kind of state explosion bug going on; we ought to be
able to explore this file without hitting the safety limits.

Retitling this bug accordingly