[Bug analyzer/95188] analyzer-unsafe-call-within-signal-handler shows wrong statement for signal registration event

cvs-commit at gcc dot gnu.org gcc-bugzilla@gcc.gnu.org
Wed Sep 16 23:02:58 GMT 2020


--- Comment #1 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by David Malcolm <dmalcolm@gcc.gnu.org>:


commit r11-3245-gb28491dc2d79763ecbff4f0b9f1f3e48a443be1d
Author: David Malcolm <dmalcolm@redhat.com>
Date:   Tue Aug 18 18:52:17 2020 -0400

    analyzer: bulk merger/processing of runs of nodes at CFG join points

    Prior to this patch the analyzer worklist considered only one node or
    two nodes at a time, processing and/or merging state individually or

    This could lead to explosions of merger nodes at CFG join points,
    especially after switch statements, which could have large numbers
    of in-edges, and thus large numbers of merger exploded_nodes could
    be created, exceeding the per-point limit and thus stopping analysis
    with -Wanalyzer-too-complex.

    This patch special-cases the handling for runs of consecutive
    nodes in the worklist at a CFG join point, processing and merging
    them all together.

    The patch fixes a state explosion seen in bzip2.c seen when attempting
    to reproduce PR analyzer/95188, in a switch statement in a loop for
    argument parsing.  With this patch, the analyzer successfully
    consolidates the state after the argument parsing to a single exploded

    In gcc.dg/analyzer/pr96653.c there is a switch statement with over 300
    cases which leads to hitting the per-point limit.  With this patch
    the consolidation code doesn't manage to merge all of them due to other
    worklist-ordering bugs, and it still hits the per-point limits, but it
    does manage some very long consolidations:
      merged 2 in-enodes into 2 out-enode(s) at SN: 403
      merged 2 in-enodes into 2 out-enode(s) at SN: 403
      merged 2 in-enodes into 1 out-enode(s) at SN: 11
      merged 29 in-enodes into 1 out-enode(s) at SN: 35
      merged 6 in-enodes into 1 out-enode(s) at SN: 41
      merged 31 in-enodes into 1 out-enode(s) at SN: 35
    and with a followup patch to fix an SCC issue it manages:
      merged 358 in-enodes into 2 out-enode(s) at SN: 402

    The patch appears to fix the failure on non-x86_64 of:
      gcc.dg/analyzer/pr93032-mztools.c (test for excess errors)
    which is PR analyzer/96616.

    Unfortunately, the patch introduces a memory leak false positive in
    gcc.dg/analyzer/pr94851-1.c, but this appears to be a pre-existing bug
    that was hidden by state-merging failures.

            * engine.cc (exploded_node::dump_dot): Show STATUS_BULK_MERGED.
            (exploded_graph::process_worklist): Call
            (exploded_graph_annotator::print_enode): Show STATUS_BULK_MERGED.
            * exploded-graph.h (enum exploded_node::status): Add

            * gcc.dg/analyzer/bzip2-arg-parse-1.c: New test.
            * gcc.dg/analyzer/loop-n-down-to-1-by-1.c: Remove xfail.
            * gcc.dg/analyzer/pr94851-1.c: Add xfail.

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