[Bug c++/107593] New: ice with -Wduplicated-cond

[Bug c++/107593] New: ice with -Wduplicated-cond

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107593

            Bug ID: 107593
           Summary: ice with -Wduplicated-cond
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dcb314 at hotmail dot com
  Target Milestone: ---

This C++ code:

template <typename T> void SaturatingCast() {
  if (T() && T() && int())
    ;
  else if (T() && T() && int())
    ;
}

when compiled with recent gcc trunk and flag -Wduplicated-cond:

$ ~/gcc/results/bin/g++ -c -Wduplicated-cond bug860.cc 
bug860.cc: In function ‘void SaturatingCast()’:
bug860.cc:4:31: internal compiler error: Segmentation fault
    4 |   else if (T() && T() && int())
      |                               ^
0x106b5d9 crash_signal(int)
        ../../trunk.d1/gcc/toplev.cc:314
0x6f9f54 location_wrapper_p(tree_node const*)
        ../../trunk.d1/gcc/tree.h:4235
0x6f9f54 tree_strip_any_location_wrapper(tree_node*)
        ../../trunk.d1/gcc/tree.h:4247

I don't have a git hash range for this bug. It seems to have existed for at
least a few weeks.

[Bug c++/107593] [12/13 Regression] ice with -Wduplicated-cond

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107593

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |12.3
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2022-11-09
     Ever confirmed|0                           |1
                 CC|                            |mpolacek at gcc dot gnu.org
            Summary|ice with -Wduplicated-cond  |[12/13 Regression] ice with
                   |                            |-Wduplicated-cond
           Priority|P3                          |P2
           Assignee|unassigned at gcc dot gnu.org      |mpolacek at gcc dot gnu.org

--- Comment #1 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Started with r12-6022-gbb2a7f80a98de3:

commit bb2a7f80a98de3febefbb32b1e4898062bdb6af8
Author: Patrick Palka <ppalka@redhat.com>
Date:   Thu Dec 16 13:40:42 2021 -0500

    c++: two-stage name lookup for overloaded operators [PR51577]

but it's -Wduplicated-cond so probably mine.

[Bug c++/107593] [12/13 Regression] ice with -Wduplicated-cond

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107593

--- Comment #2 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The trunk branch has been updated by Marek Polacek <mpolacek@gcc.gnu.org>:

https://gcc.gnu.org/g:623730d954a051941ae6a098f851bef308916ca0

commit r13-5582-g623730d954a051941ae6a098f851bef308916ca0
Author: Marek Polacek <polacek@redhat.com>
Date:   Thu Jan 26 09:34:28 2023 -0500

    c++: fix ICE with -Wduplicated-cond [PR107593]

    Here we crash because a CAST_EXPR, representing T(), doesn't have
    its operand, and operand_equal_p's STRIP_ANY_LOCATION_WRAPPER doesn't
    expect that.  (o_e_p is called from warn_duplicated_cond_add_or_warn.)

    In the past we've adjusted o_e_p to better cope with template codes,
    but in this case I think we just want to avoid attempting to warn
    about inst-dependent expressions; I don't think I've ever envisioned
    -Wduplicated-cond to warn about them.  Also destroy the chain when
    an inst-dependent expression is encountered to not warn in
    Wduplicated-cond4.C.

    The ICE started with r12-6022, two-stage name lookup for overloaded
    operators, which gave dependent operators a TREE_TYPE (in particular,
    DEPENDENT_OPERATOR_TYPE), so we no longer bail out here in o_e_p:

      /* Similar, if either does not have a type (like a template id),
         they aren't equal.  */
      if (!TREE_TYPE (arg0) || !TREE_TYPE (arg1))
        return false;

            PR c++/107593
            PR c++/108597

    gcc/c-family/ChangeLog:

            * c-common.h (instantiation_dependent_expression_p): Declare.
            * c-warn.cc (warn_duplicated_cond_add_or_warn): If the condition
            is dependent, invalidate the chain.

    gcc/c/ChangeLog:

            * c-objc-common.cc (instantiation_dependent_expression_p): New.

    gcc/cp/ChangeLog:

            * cp-tree.h (instantiation_dependent_expression_p): Don't
            declare here.

    gcc/testsuite/ChangeLog:

            * g++.dg/warn/Wduplicated-cond3.C: New test.
            * g++.dg/warn/Wduplicated-cond4.C: New test.
            * g++.dg/warn/Wduplicated-cond5.C: New test.

[Bug c++/107593] [12/13 Regression] ice with -Wduplicated-cond

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107593

--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-12 branch has been updated by Marek Polacek
<mpolacek@gcc.gnu.org>:

https://gcc.gnu.org/g:07ef737cf1ab08f5c36786c7ab1ffc596fe52138

commit r12-9093-g07ef737cf1ab08f5c36786c7ab1ffc596fe52138
Author: Marek Polacek <polacek@redhat.com>
Date:   Tue Jan 31 11:54:03 2023 -0500

    c++: fix ICE with -Wduplicated-cond [PR107593]

    Here we crash because a CAST_EXPR, representing T(), doesn't have
    its operand, and operand_equal_p's STRIP_ANY_LOCATION_WRAPPER doesn't
    expect that.  (o_e_p is called from warn_duplicated_cond_add_or_warn.)

    In the past we've adjusted o_e_p to better cope with template codes,
    but in this case I think we just want to avoid attempting to warn
    about inst-dependent expressions; I don't think I've ever envisioned
    -Wduplicated-cond to warn about them.  Also destroy the chain when
    an inst-dependent expression is encountered to not warn in
    Wduplicated-cond4.C.

    The ICE started with r12-6022, two-stage name lookup for overloaded
    operators, which gave dependent operators a TREE_TYPE (in particular,
    DEPENDENT_OPERATOR_TYPE), so we no longer bail out here in o_e_p:

      /* Similar, if either does not have a type (like a template id),
         they aren't equal.  */
      if (!TREE_TYPE (arg0) || !TREE_TYPE (arg1))
        return false;

            PR c++/107593
            PR c++/108597

    gcc/c-family/ChangeLog:

            * c-common.h (instantiation_dependent_expression_p): Declare.
            * c-warn.cc (warn_duplicated_cond_add_or_warn): If the condition
            is dependent, invalidate the chain.

    gcc/c/ChangeLog:

            * c-objc-common.cc (instantiation_dependent_expression_p): New.

    gcc/cp/ChangeLog:

            * cp-tree.h (instantiation_dependent_expression_p): Don't
            declare here.

    gcc/testsuite/ChangeLog:

            * g++.dg/warn/Wduplicated-cond3.C: New test.
            * g++.dg/warn/Wduplicated-cond4.C: New test.
            * g++.dg/warn/Wduplicated-cond5.C: New test.

[Bug c++/107593] [12/13 Regression] ice with -Wduplicated-cond

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107593

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
             Status|ASSIGNED                    |RESOLVED

--- Comment #4 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Fixed.