[Bug c/65891] New: -Wlogical-op now warns about logical ‘and’ of equal expressions even when different types/sizeofs are involved

["gerald at pfeifer dot com" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65891

            Bug ID: 65891
           Summary: -Wlogical-op now warns about logical ‘and’ of equal
                    expressions even when different types/sizeofs are
                    involved
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gerald at pfeifer dot com
                CC: polacek at redhat dot com
  Target Milestone: ---

Since 2015-04-21  Marek Polacek  <polacek@redhat.com>

    PR c/63357
    * c-common.c (warn_logical_operator): Warn if the operands have the
    same expressions.

we also diagnose code the following

  typedef int r_fun_t (int);

  r_fun_t * text_funcs[] = {0,0,0};

  int report (unsigned t)
  {
    typedef int s_fun_t (long, char);

    static s_fun_t * GUI_funcs[3];

    return (t < sizeof text_funcs / sizeof text_funcs[0] &&
            t < sizeof GUI_funcs / sizeof GUI_funcs[0]);
  }

with

  input: In function ‘report’:
  input:8:58: warning: logical ‘and’ of equal expressions [-Wlogical-op]
     return (t < sizeof text_funcs / sizeof text_funcs[0] &&
                                                          ^

when these two conditions are about two different types, defined in two
different locations, and the sizes are set differently.
>From gcc-bugs-return-484650-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org Sat Apr 25 20:23:03 2015
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From: "mpolacek at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c/65891]=?UTF-8?Q? -Wlogical-op now warns about logical ‘and’ of equal expressions even when different types?=/sizeofs are involved
Date: Sat, 25 Apr 2015 20:23:00 -0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?ide891

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2015-04-25
                 CC|                            |mpolacek at gcc dot gnu.org
           Assignee|unassigned at gcc dot gnu.org      |mpolacek at gcc dot gnu.org
   Target Milestone|---                         |6.0
     Ever confirmed|0                           |1

--- Comment #1 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Sorry.  I'll look into that.