[Bug analyzer/98969] [11 Regression] ICE: Segmentation fault (in print_mem_ref)

[cvs-commit at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98969

--- Comment #12 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by David Malcolm <dmalc...@gcc.gnu.org>:

https://gcc.gnu.org/g:e0139b2a912585496f23c352f0e2c56895f78fbf

commit r11-7270-ge0139b2a912585496f23c352f0e2c56895f78fbf
Author: David Malcolm <dmalc...@redhat.com>
Date:   Wed Feb 17 10:37:16 2021 -0500

    analyzer: fix false leak involving params [PR98969]

    This patch updates the svalue liveness code so that the initial value
    of parameters at top-level functions to the analysis are treated as
    live (since the values are presumably still live within the
    outside-of-the-analysis calling code).

    This fixes the false leak in PR analyzer/98969 seen on:

    void
    test (long int i)
    {
      struct foo *f = (struct foo *)i;
      f->expr = __builtin_malloc (1024);
    }

    since the calling code can presumably still access the allocated
    buffer via:
      ((struct foo *)i)->expr

    The patch also removes the expected leak warnings from
    g++.dg/analyzer/pr99064.C and gcc.dg/analyzer/pr96841.c, which now
    appear to me to be false positives.

    gcc/analyzer/ChangeLog:
            PR analyzer/98969
            * constraint-manager.cc (dead_svalue_purger::should_purge_p):
            Update for change to svalue::live_p.
            * program-state.cc (sm_state_map::on_liveness_change): Likewise.
            (program_state::detect_leaks): Likewise.
            * region-model-reachability.cc (reachable_regions::init_cluster):
            When dealing with a symbolic region, if the underlying pointer is
            implicitly live, add the region to the reachable regions.
            * region-model.cc (region_model::compare_initial_and_pointer):
            Move logic for detecting initial values of params to
            initial_svalue::initial_value_of_param_p.
            * svalue.cc (svalue::live_p): Convert "live_svalues" from a
            reference to a pointer; support it being NULL.
            (svalue::implicitly_live_p): Convert first param from a
            refererence to a pointer.
            (region_svalue::implicitly_live_p): Likewise.
            (constant_svalue::implicitly_live_p): Likewise.
            (initial_svalue::implicitly_live_p): Likewise.  Treat the initial
            values of params for the top level frame as still live.
            (initial_svalue::initial_value_of_param_p): New function, taken
            from a test in region_model::compare_initial_and_pointer.
            (unaryop_svalue::implicitly_live_p): Convert first param from a
            refererence to a pointer.
            (binop_svalue::implicitly_live_p): Likewise.
            (sub_svalue::implicitly_live_p): Likewise.
            (unmergeable_svalue::implicitly_live_p): Likewise.
            * svalue.h (svalue::live_p): Likewise.
            (svalue::implicitly_live_p): Likewise.
            (region_svalue::implicitly_live_p): Likewise.
            (constant_svalue::implicitly_live_p): Likewise.
            (initial_svalue::implicitly_live_p): Likewise.
            (initial_svalue::initial_value_of_param_p): New decl.
            (unaryop_svalue::implicitly_live_p): Convert first param from a
            refererence to a pointer.
            (binop_svalue::implicitly_live_p): Likewise.
            (sub_svalue::implicitly_live_p): Likewise.
            (unmergeable_svalue::implicitly_live_p): Likewise.

    gcc/testsuite/ChangeLog:
            PR analyzer/98969
            * g++.dg/analyzer/pr99064.C: Convert dg-bogus to dg-warning.
            * gcc.dg/analyzer/pr96841.c: Add -Wno-analyzer-too-complex to
            options.  Remove false leak directive.
            * gcc.dg/analyzer/pr98969.c (test_1): Remove xfail from leak
            false positive.
            (test_3): New.