[Bug analyzer/104159] ICE: in finalize, at vector-builder.h:513 with -O -fanalyzer

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104159

--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by David Malcolm <dmalcolm@gcc.gnu.org>:

https://gcc.gnu.org/g:45b999f642a531c083c982dda79fa6ad65730a7c

commit r12-6817-g45b999f642a531c083c982dda79fa6ad65730a7c
Author: David Malcolm <dmalcolm@redhat.com>
Date:   Fri Jan 21 09:56:56 2022 -0500

    analyzer: fix ICE on vector casts [PR104159]

    PR analyzer/104159 describes an ICE attempting to convert a vector_cst,
    which occurs when symbolically executing within a recursive call on:

      _4 = BIT_FIELD_REF <w_3(D), 32, 0>;
      _1 = VIEW_CONVERT_EXPR<T>(_4);

    where the BIT_FIELD_REF leads to a get_or_create_cast from
      VEC<long, 8> to VEC<unsigned 4>
    which get_code_for_cast erroneously picks NOP_EXPR for the cast, leading
    to a bogus input to the VIEW_CONVERT_EXPR.

    This patch fixes the issue by giving up on attempts to cast symbolic
    values of vector types, treating the result of such casts as unknowable.

    gcc/analyzer/ChangeLog:
            PR analyzer/104159
            * region-model-manager.cc
            (region_model_manager::get_or_create_cast): Bail out if the types
            are the same.  Don't attempt to handle casts involving vector
            types.

    gcc/testsuite/ChangeLog:
            PR analyzer/104159
            * gcc.dg/analyzer/torture/pr104159.c: New test.

    Signed-off-by: David Malcolm <dmalcolm@redhat.com>