[Bug c++/80744] Detect Divide By Zero and give a warning in C/C++

[egallager at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80744

Eric Gallager <egallager at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2017-08-01
                 CC|                            |egallager at gcc dot gnu.org
          Component|c                           |c++
     Ever confirmed|0                           |1

--- Comment #1 from Eric Gallager <egallager at gcc dot gnu.org> ---
Testcase needs some modification to compile properly; after adding the proper
includes and namespace, the results are:

$ /usr/local/bin/g++ -c -Wdiv-by-zero 80744.cc
80744.cc: In function ‘void test_func(size_t, const string&)’:
80744.cc:14:25: warning: division by zero [-Wdiv-by-zero]
     printf("B %zu\n", 10/i);
                       ~~^~
$

Confirmed that warnings are still missing for (A) and (C), although maybe there
should be a separate option: -Wmaybe-div-by-zero, analogous to how there's both
-Wmaybe-uninitialized and -Wuninitialized, depending on how certain gcc is.

(Changing component from 'c' to 'c++' while I'm at it since testcase uses
c++-specific things)