[Bug analyzer/104576] False positive from -Wanalyzer-use-of-uninitialized-value from PR 63311

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104576

--- Comment #2 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:5fbcbcaff7248604e04b39464f4fbd64fbf6e43b

commit r12-7270-g5fbcbcaff7248604e04b39464f4fbd64fbf6e43b
Author: David Malcolm <dmalcolm@redhat.com>
Date:   Wed Feb 16 18:21:58 2022 -0500

    analyzer: const functions have no side effects [PR104576]

    PR analyzer/104576 tracks that we issue a false positive from
    -Wanalyzer-use-of-uninitialized-value for the reproducers of PR 63311
    when optimization is disabled.

    The root cause is that the analyzer was considering that a call to
    __builtin_sinf could have side-effects.

    This patch fixes things by generalizing the handling for "pure"
    functions to also consider "const" functions.

    gcc/analyzer/ChangeLog:
            PR analyzer/104576
            * region-model.cc: Include "calls.h".
            (region_model::on_call_pre): Use flags_from_decl_or_type to
            generalize check for DECL_PURE_P to also check for ECF_CONST.

    gcc/testsuite/ChangeLog:
            PR analyzer/104576
            * gcc.dg/analyzer/torture/uninit-pr63311.c: New test.
            * gcc.dg/analyzer/uninit-pr104576.c: New test.
            * gfortran.dg/analyzer/uninit-pr63311.f90: New test.

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